E FA - 600/R-9 5-159
November 1995
DEMONSTRATION OF RADON RESISTANT
CONSTRUCTION TECHNIQUES
PHASE II
FINAL REPORT
By
James L. Tyson and
Charles R. Withers
Florida Solar Energy Center
300 State Road 401
Cape Canaveral, Florida 32920
EPA Interagency Agreement RWFL 9337 83
DCA Agreement 92RD-66-13-00-22-004
EPA Project Officer: David C. Sanchez
Air and Energy Engineering Research Laboratory
Research Triangle Park, North Carolina 27711
DCA Project Officer: Mohammad Madani
Department of Community Affairs
2740 Centerview Drive
Tallahassee, Florida 32399
Prepared for:
State of Florida
Department of Community Affairs
27 4 0 Centerview Drive
Tallahassee, Florida 32399
and
U.S.Environmental Protection Agency
Office of Research and Development
Washington, D.C. 20460
-------
NOTICE
This document has been reviewed in accordance with
U.S. Environmental Protection Agency policy and
approved for publication. Mention of trade names
or commercial products does not constitute endorse-
ment or recommendation for use.
ii
-------
ABSTRACT
Sub-slab mitigation systems were installed in 15 new Florida homes
in 1992, and these homes have undergone extensive testing to
validate techniques used to prevent radon intrusion into the home.
Soil radon levels ranged from just under 500 to over 8,000 pCi/L.
Mitigation systems were installed according to the Draft Standard,
and all systems have been determined to extend negative pressure to
practically all areas under the slab.
Slabs tended to crack less than expected. Four houses had no
cracks at the time the floors were covered, only one of which used
post-tensioning techniques on the slab. Post-tensioned slabs
performed best at preventing cracks. A substantial amount of radon
was detected during crack tests on only one house, and this test is
done at much higher depressurization levels than is normally found
in homes. Intact vapor barriers under new homes prevent radon
intrusion through slab cracks in most instances. Slab pipe
penetrations not sealed in accordance with the Draft Standard
contribute relatively higher amounts of radon into the home, and
methods of sealing these penetrations should be further
investigated to determine which are most effective.
Eleven mitigation systems were installed using ventilation matting,
and four systems used wellpoint suction pipe. Both systems perform
well as long as installation is carefully done. Pressure fields
rapidly go to zero just inside or just beyond the slab edge,
regardless of slab edge type.
The highest indoor radon level with the mitigation system capped
off was 5.6 pCi/L for a 48 hour period. Ten houses (671 of the
total number) were under 2.9 pCi/L, the action level for a 48 hour
measurement by continuous radon monitor, and did not require
activation of their mitigation systems. Five houses (33%) required
activation of their mitigation systems after the uncapped system
test. All houses are currently under the action level.
Houses requiring mitigation in the project on average were smaller,
tighter and have a higher air flow through the slab as measured by
tracer gas techniques.
iii
-------
TABLE OF CONTENTS
Page
ABSTRACT ii
LIST OF FIGURES ..... v
LIST OF TABLES ix
LIST OF PHOTOS X
METRIC CONVERSIONS .... xii
INTRODUCTION ...... 1
I. PROJECT OVERVIEW 2
A.Draft Standard Compliance . 2
II. SCOPE OF WORK 4
A. Soil . 4
B. Slab 4
1. Cracks 4
2. Pressure Field Extension .... 5
C. House 8
1. Blower Door Test 8
2. Pressure Differential Test 9
3. Infiltration Test 10
4. Radon Stress Test 13
5. Indoor Radon Levels 16
III. RESULTS ...... 17
A. Soil 17
B. Slab 19
1. Cracks 19
2. Pressure field extension ...... 31
3. Slab leakage 47
C. House 47
1. HVAC 47
2. Blower door test 49
3. Pressure test 53
4. Infiltration test 58
5. Radon stress test 59
6. Indoor radon levels . 63
IV. ANALYSIS 65
A.Soi l . 65
1. Soil radium levels . 65
2. Soil radon variability 68
B. Slab 72
1. Pressure field extension 7 2
2. Cracks ............ 75
3. Slab leakage............ 82
C. House ' * 84
1. Blower door 84
2. Differential pressure 85
3. Infiltration . 87
4. HVAC 88
v
-------
Contents (Cont.)
5. Eaclon stress test 91
6. Indoor radon 92
7. Model validation ........ 93
8. Mitigation system costs 95
V. HOUSE 7 REPORT * 96
VI. CONCLUSIONS 100
A. SOIL 100
B. SLAB 100
C. HOUSE 101
VII. RECOMMENDATIONS 102
REFERENCES . 105
GLOSSARY 106
APPENDIX A (House Narrative) ' A-l
APPENDIX B (Long Term Monitoring) . B-l
APPENDIX C (Testing Data) C-l
APPENDIX D (Proposed Radon Code) . D-l
vi
-------
LIST OP FIGURES
Figure II.1. Top and side views of measurement
point installation » . . . 6
Figure II.2. Variations of tube installation for
monolithic and stem wall slabs 6
Figure III. 1. House 14 crack map 23
Figure III.2. House 15 crack map 23
Figure III. 3. House 16 crack map 24
Figure III.4. House 17 crack map 24
Figure III.5. House 18 crack map 25
Figure III.6. House 19 crack map 25
Figure III.7. House 20 crack map ..... 26
Figure 111.8. House 21 crack map 26
Figure III.9. House 22 crack map 27
Figure III.10. House 23 crack map 27
Figure III.11. House 24 crack map ..... 28
Figure III.12. House 25 crack map ............ 28
Figure III.13. House 26 crack map ..... 29
Figure III.14. House 27 crack map ....... 29
Figure III.15. House 28 crack map ....... 30
Figure III.16. House 14 layout ........ 32
Figure III.17. House 14 pressure field ......... 32
Figure III.18. House 15 layout 33
Figure III.19. House 15 pressure field . 3 3
Figure III.20. House 16 layout 34
Figure III.21. House 16 pressure field . . 34
Figure III.22. House 17 layout 35
Figure III.23. House 17 pressure field 35
Figure III.24. House 18 layout 36
Figure III.25. House 18 pressure field 36
Figure III.26. House 19 layout ...... 37
Figure III.27. House 19 pressure field 37
Figure III.28. House 20 layout 38
Figure III.29. House 20 pressure field 38
Figure III.30. House 21 layout 39
Figure III.31. House 21 pressure field ......... 39
Figure III.32. House 22 layout . 40
Figure III.33. House 22 pressure field 40
Figure III. 34. House 23 layout . 41
Figure III.35. House 23 pressure field . 41
Figure III.36. House 24 layout 42
Figure III.37. House 24 pressure field ......... 42
Figure III.38. House 25 layout 43
Figure III.39. House 25 pressure field . 43
Figure III.40. House 26 layout ..... 44
Figure III.41. House 26 pressure field• ......... 44
Figure III.42. House 27 layout 45
Figure III.43. House 27 pressure field 45
Figure III. 44. House 28 layout . 46
Figure III.45. House 28 pressure field ... 46
Figure III.46. House and Duct ACH50 49
vi i
-------
Figures (Cont.)
Figure III. 47. House and Duct CFM50 ..." 50
Figure III. 48. House and Duct ELA50 . 50
Figure III.49. Comparison of ACH50 in 1991 and 1992 ... 51
Figure III.50. Comparison of CFM50 in 1991 and 1992 ... 51
Figure III.Si. Comparison of ELA50 in 1991 and 1992 ... 52
Figure III.52. Comparison of Duct ELA50 and House
Envelope ELA50 in 1991 and 1992 52
Figure III.53. Sub-slab to main body pressure measurements
with the AH off and doors open 54
Figure III.54. Sub-slab to main body pressure measurements
with the AH on and doors open 54
Figure III.55. Sub-slab to main body pressure measurements
with AH and exhausts on and doors open . . 55
Figure III.56. Sub-slab to main body pressure measurements
with AH on, exhausts off, and doors closed 55
Figure III.57. Sub-slab to main body pressure measurements
with AH and exhausts on and doors closed . 56
Figure III.58. Main sub-slab pressure measurements with
different test configurations 56
Figure III.59. Room sub-slab pressure measurements with
different test configurations 57
Figure III.60. Sub-slab pressure measurements on the edge
of the slab with different test
configurations ........ 57
Figure III.61. Changes in house ach for three test
conf igurations . . . . - 58
Figure III.62. Radon levels during infiltration testing . 59
Figure III.63. Blower door CFM during stress test
depressurization. (1-11) 60
Figure III.64. Blower door CFM during stress test
depressurization. (12-22) ........ 61
Figure III.65. Indoor radon during stress test, (l-ll) . 61
Figure III.66. Indoor radon during stress test. (12-22) . 62
Figure III.67. Radon entry rate during stress test, (l-ll) 62
Figure III.68. Radon entry rate during stress test.(12-22) 63
Figure III.69. Indoor radon levels during capped, passive
and active testing periods . 64
Figure IV.1. Native and fill soil radium levels .... 65
Figure IV.2. Figure IV.1 data minus house 28 native
reading ............ 65
Figure IV. 3. 1991 soil radium data . 66
Figure IV.4. Native radium and native radon (R2 =0.19) . 66
Figure IV.5. Native radium and passive sub-slab radon
levels. (R; = 0.37) 67
Figure IV.6. Native radium and indoor radon levels.
(R 2 = 0.03) 68
Figure IV.7 Native soil radon and indoor radon levels . 68
Figure IV.8 Seasonal soil radon variability ..... 69
Figure IV.9. Sub-slab radon, taken on the same day at
different slab locations ......... 70
Figure IV.10. Additional SS radon data, taken on the same
day at different locations 70
v i i i
-------
Figures (Cont.)
Figure IV.11
Figure IV.12
Figure IV.13
Figure IV.14
Figure IV.15
Figure IV.16
Figure IV.17
Figure IV.18
Figure IV.19
Figure IV.20
Figure IV.21
Figure IV.22
Figure IV.2 3
Figure IV.24
Figure IV.2 5
Figure IV.26
Figure IV.27
Figure IV.28
Figure IV.29
Figure IV.30
Figure IV.31
Figure IV.32
Figure IV.33
Figure IV.34
Figure IV.3 5
Figure IV.3 6
Figure IV.37
Figure IV.38
Figure IV.39,
Figure IV.40.
Figure IV.41.
SS radon at the same point on different days 71.
Additional SS radon at the same point on
different days ....... 71
Criteria for choosing mat end to slab edge
measurement points . 73
Distance for P=0 for monolithic slabs ... 74
Distance for P=0 for stem-wall slabs .... 74
19 91 monolothic slab distances from the mat
end for the pressure field to equal zero . . 75
1991 stem-wall slab distances from the mat end
for the pressure field to equal zero ... 75
Total crack length per house by slab type . 7 6
Total crack length per house by
plasticizer use . 76
Total crack length vs.corner reinforcement 77
Total crack length vs.slump for slabs with
and without plasticizer 77
Indoor radon versus concrete slump .... 78
Indoor radon versus total crack length . . 78
Indoor radon levels separated by the use
of tar on pipe penetrations 79
Radon through pipe penetrations in House 7. 80
Radon intrusion preceding a rainstorm in
House 7 80
Slab equivalent area and indoor radon . . 81
Slab figure of merit and indoor radon , . 81
Indoor radon versus air changes per hour
through the slab 83
Slab ach for activated and unactivated
houses 83
House CFM50 and system activation .... 85
House ELA50 and system activation .... 85
Average depressurization with the air
handler on and doors closed ........ 86
Indoor radon versus sub-slab to main body
pressure differential with AH on and
doors closed 86
Natural ach and indoor radon . 87
RLF versus indoor radon for activated and
unactivated houses .... 87
HVAC system compliance and total duct leak! 88
Supply and return dominant systems versus
dP between the sub-slab and main body with
AH on and doors open 89
Supply and return dominant systems versus dP
a 4» i ) v«, Wt f-K <•-» i W _ e« 1 "< w H n m Vs i»s 11 i t I !¦*•. +• V* <•,
DGtween trie Sud^siqD anu inain Doay wiin ine
AH on and doors closed 90
Supply and return dominant systems versus dP
between a closed room and the main body with
the AH on and doors closed 90
Indoor radon versus 4 Pa entry rate ... 91
IX
-------
Figures (Cent.)
Figure IV-42. Indoor radon versus the radon potential
calculated from radon stress test results
Figure IV.43. Sub-slab radon and achA versus indoor radon
Figure IV.44. Slab achA times dp versus indoor radon . . .
Figure IV.45. Selected entities versus indoor radon . . .
Figure IV.46. R&E model correlation with average indoor
radon
Figure IV.47. Modified and adjusted RAE model correlation
with average indoor radon .........
Figure V.1. Ambient, bath wall, and family room radon
levels in House 7 .
Figure V.2. Family room and vent stack wall radon levels
in House 7 with the mitigation fan on . « .
Figure V.3. House 7 radon levels with the mitigation
fan on . . .
Figure V.4. House 7 ambient and family room radon
levels . . .
Figure V.5. Ambient radon levels at 4 and 20 feet
above ground .
Figure V.6. House 7 ambient and attic rdon levels . . .
Figure V.7. House 7 family room and attic radon levels .
91
92
92
93
94
94
96
97
97
98
98
99
99
X
-------
LIST OF TABLES
Table I.1. Compliance with Draft Standard,Chapter
3, Practices . 3
Table III.1. Initial Soil Testing Results ....... 17
Table III.2. Additional Soil Testing Results ..... 18
Table III.3. Crack Measurement Summary ........ 19
Table III.4. Cracks and Radon 20
Table III.5. Equivalent Area and Figure of Merit ... 21
Table III. 6. Slab Leakage 47
Table III.7. House Description ...... 48
Table III.8. HVAC Description ............. 48
Table III.9. Blower Door Results ........... 49
Table III.10. High Pressure Differentials (Pa) ..... 53
Table III.11. Infiltration Test Results ........ 58
Table III.12. Radon Stress Testing 60
Table III. 13. Stress Test Radon Entry Rate 60
Table III.14. Radon Levels (pCi/L) . . 64
Table IV.1. Radium-Radon Correlations (R2 values) . . 67
Table IV. 2. Slab Leakage (R2 Values) 82
Table IV.3. Blower Door Averages and % Differences . . 84
Table IV.4. Mitigation System Costs 95
xi
-------
LIST OF PHOTOS
Photo
A. 1.
House 14 layout showing excavated garage
A-i
Photo
A.2.
Wellpoint section in garage of House 14 . .
A-2
Photo
A. 3.
Wellpoint section under main floor of
House 14
A-2
Photo
A. 4.
Finished floor with sawcut pattern ....
A-3
Photo
A.5.
Duct connections in House 14
A-4
Photo
A.6.
Pit and mat combination in House 16 . . . .
A-5
Photo
A.7.
Finished surface of suction point
A-6
Photo
A.8.
Overall view of SSDS system in House 16 . .
A-6
Photo
A.9.
Duct connections in House 16
A-7
Photo
A.10.
Duct connection with mastic in House 17 . .
A-8
Photo
A.11.
Flex duct to box connection in House 18 . .
A-9
Photo
A.12.
Top portion of wellpoint system
A-10
Photo
A.13.
Flex duct to box connection in House 19 . .
A-11
Photo
A.14.
Position of vent stack relative to eave . .
A-11
Photo
A. 15.
Stack as installed by the builder
A-12
Photo
A.16.
Final mitigation fan installation
A-12
Photo
A.17.
Flex duct to box connection in House 20 . .
A-13
Photo
A.18.
Tub Clean out located on outer wall ....
A-14
Photo
A.19.
House 21 flex duct connection
A-15
Photo
A. 20.
Vent stack with leaky lead shield
A-16
Photo
A.21.
Radon re-entrainment pathway
A-16
Photo
A.22.
Repaired vent stack in House 21
A-17
Photo
A.23.
Duct connections in House 22 .......
A-18
Photo
A.24.
Pipe penetrations in House 23
A-19
Photo
A.25.
Vapor barrier at edge of slab in House 23 .
A-19
Photo
A.26.
Well placed concrete at slab edge in
House 23
A-20
Photo
A.27.
Air gaps left at slab edge in House 23 . .
A-20
Photo
A.28.
Placing reinforcement in corners of
House 23 ..........
A-21
Photo
A.29.
Reinforcement bars in place in House 23 . .
A—21
Photo
A.30.
Duct closures in House 23
A-22
Photo
A.31.
Pipe penetrations in House 24 ...... .
A-2 3
Photo
A.32.
Four-inch slump being poured in footers . .
A-2 3
Photo
A.33.
Long rebar reinforcement around
inside corner
A-24
Photo
A. 34 .
Duct connection in House 24
A-2 5
Photo
A.35.
Top section of wall plenum left unsealed
A-2 5
Photo
A.36.
Section seen in Photo A.35 after repair . .
A-2 6
Photo
A.37.
Other end of plenum showing gap between
insulation and stud .
A-2 6
Photo
A.38.
Section seen in Photo A.37 after repair . .
A-27
Photo
A.39.
Low slump pour around footers in
House 25 slab
A-2 8
Photo
A.40.
Corner reinforcement used in House 25 slab .
A-2 9
Photo
A.41.
Duct connection in House 25 .......
A-2 9
Photo
A.42.
Corner reinforcement in House 26 slab . .
A-30
Photo
A.43.
Duct connections in House 26
A-31
Photo
A. 4 4 .
Pipe penetrations in House 27 slab ....
A-3 2
xii
-------
Photos (Cont.)
Photo A, 45. Wellpoint SSDS system layout under
House 27 . A-32
Photo A.46. Crawlspace air barrier installed under
House 27 . A-33
Photo A.47. Pipe penetrations in House 28 slab .... A-34
Photo A.48. Low-slump concrete being dumped into place A-34
Photo A.49. Dragging concrete over a long distance
requires a higher slump concrete ..... A-35
Photo A.50. Installing corner reinforcement in
House 28 slab A-35
Photo A.51. Mastic applied to ductwork by FSEC .... A-36
xi ii
-------
METRIC CONVERSION FACTORS
Nonmetric Times Yields Metric
°F 5/9 (°F—32) oc
ft 0.3 ra
ft2 0.0929 m2
ft3 0.02831 m3
ft/min 0.0005 m/s
ftJ/min 0.00047 m3/s
gal 0.0038 in3
in 0.025 m
in2 0.00065 n2
in W.C. 0.249 kPa
lb 0.45 kg
micron 0.001 ran
mil 0.0254 mm
mph 1.61 km/h
psi 6.89 kPa
pCi/L 37.0 Bq/m3
yd3 0.7645 m3
xiv
-------
INTRODUCTION
The data presented here are taken from the work performed by the
Florida Solar Energy Center for the Florida Department of Community
Affairs (DCA) under contract #92RD-66-13-00-22-004, and are
designed to demonstrate radon resistant construction techniques in
new Florida homes. A study of 15 houses began in January of 1992
and ended April 30, 1993. This report also includes data
generated by a study of 13 houses performed under DCA Contract
91RD-41-13-00-22-002 which concluded in November 1991.
In addition to information concerning construction performance and
adherence to the Draft Florida Standard for Radon-Resistant
Building Construction, hereinafter referred to as HThe Draft
Standard," data collected can be divided into three areas:
1} Soils were tested to determine type, permeability, radon and
radium content, radium emanation coefficient, and moisture.
2) The house slab was examined to characterize the crack size
and number, and the pressure field extension under the slab
created by the sub-slab dcpressurization system was measured.
3) The house itself underwent extensive testing, including
blower door, tracer gas, and duct leak measurements.
The report begins with a discussion and a compliance checklist
table of the adherence of the subject houses to the Draft Standard,
followed by the Scope of Work section, which explains the
objectives, methods used, results expected, and problems
encountered in each part of the project. Testing results are then
presented, followed by an analysis of the data for correlations to
radon intrusion into the home.
Finally, conclusions are drawn, both from the results of testing
and from administration of the project. Recommendations are also
made with respect to the testing and concerning the continuation of
the project.
1
-------
I. PROJECT OVERVIEW
During this study building contractor co-operation was much better
than it was during the 13-house study conducted in 1991. This may
be due in part to the fact that builders were allowed $2000 per
house as an incentive to conform to the Draft Standard, and to" the
relationship previously established. Sites were chosen based on a
native soil gas radon level close to 1000 pCi/L, with the exception
of one house which was 418 pCi/L. This house was accepted because
we expected the sub-slab measurement to be above 1000 pCi/L after
the addition of hot fill to the site. We were assured to have
compliance on the HVAC codes as well for this house.
Houses were monitored throughout construction to see if Draft
Standard practices were implemented. Due to a lack of training or
understanding, some practices were not implemented correctly.
A. DRAFT STANDARD COMPLIANCE
Table 1.1 presents the extent of Draft Standard compliance, with
"x" representing compliance, "o" non-compliance, "p" partial
compliance, and representing a situation where the particular
requirement does not apply. Appendix A contains house by house
reports on observations and difficulties encountered. Some
photographs are included, but the photographic record is incomplete
due to the late inclusion of photographs as monitoring requirements
in the project. A complete listing of the proposed Draft Standard
is included in Appendix D.
Partial compliance in the design slump and workability of the
concrete sometimes occurred when .some of the concrete trucks
arrived with the correct slump, and others did not, or when water
was added to a truck to make the concrete easier to reach a remote
corner of the slab.
Partial compliance in slab reinforcement occurs when the contractor
installs reinforcement in the corners of the slab, but not exactly
as specified in the Draft Standard.
No builder complied with the curing requirements, presumably
because a week delay in construction could easily cost the builder
more in lost interest on his construction loan than was being
offered as an incentive in the project.
-------
Table 1.1. Compliance with Draft Standard, Chapter 3, Practices
Section HOUSE NUMBER
14
IS
16
17
18
19
20
21
22
23
24
25
26
27
28
302
SS and Soil Cover
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
303
.2.1 Design Slump
X
X
o
X
X
X
0
X
X
X
p
X
p
X
X
,2.2 Workability
X
p
0
X
X
X
0
p
p
X
X
X
p
X
P
.3.1 Post-Tension
.
X
-
.
X
.
.
-
.
.
-
-
.
.
-
.3.2 Reinforcement
p
p
p
p
p
p
p
p
p
X
p
X
X
X
X
.3.3 Edge Detail
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
.4.1 Backfill
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
.4.2 Curing
0
0
0
o
0
0
0
o
0
o
0
o
0
0
0
.4.3 Loading
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
.5,1 Cont. Joints
X
o
-
.
-
-
-
-
-
-
-
-
-
-
.5.2.1 Stakes
X
X
0
X
0
0
0
X
X
o
o
o
o
X
X
.5.2,2 Work Spaces
-
X
p
X
X
X
X
X
X
p
X
p
X
X
X
.5.2.3 Pipes
X
X
o
o
X
X
X
o
o
X
X
X
X
X
X
.5.2.4 Vert Joints
-
-
.53 Cracks
X
X
X
X
-
X
X
X
X
X
X
X
X
X
X
.6 - Sealing Walls
X
X
X
X
X
X
o
X
X
X
X
X
X
X
X
.7.1 Waterstops
-
-
-
-
-
-
•
-
-
-
•
-
-
-
-
.7.2 Sealants
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
308
.1.1 Garage Vent.
-
-
.1.2 Garage Floor
-
.
-
-
-
-
-
-
-
-
-
-
-
-
-
.1.4 Cond. Drains,
Pipe Chases
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
.1,5 AH Clearance
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
,2.1 Sealing
p
o
o
X
o
o
o
0
X
p
p
X
X
X
X
.2.2 Return Ducts
X
o
0
X
X
X
0
X
X
X
p
p
X
X
X
.2.3 Return Grills
X
p
o
X
X
X
X
X
X
X
p
p
X
¦X
X
.2.4 Ret. Location
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
.2.5 Cross Zones
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
.2.6 Supply Box
o
0
o
X
o
o
o
X
X
X
X
X
X
X
X
.3 - Supply Ducts
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
.4.1 Bath Fans
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
.4.2 Kitchen Fans
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
.4,3 Attic Fans
X
-
-
-
-
-
-
Percent Compliance
88
75
60
so
80
82
66
84
88
88
76
82
88
96
92
NOTE; x= compliance, p = partial compliance, o = non-compliance, = not applicable
Compliance percentage is figured by awarding 2 points for an "x"
1 point for a "p", and no points for a "o". Two points are
tallied for each category for each house, and divided into the
house total. Multiplying by 100 gives the percent compliance. A
section must be most implemented to have a "p" designation, and
no attempt is made to weight the various parts of the Draft
Standard for relative importance.
The compliance percentage reported here should only be used to
compare between the houses as to their individual compliance, and
should not be used to infer the ability of a particular house to
resist radon intrusion. Average compliance for the 15 houses
studied was 82.3%.
3
-------
II. SCOPE OF WORK
A, SOIL
The objective of the soil measurements is to characterize the site for
inclusion in the project. An initial soil radon level of over 1000 pCi/L
was considered the minimum reading for inclusion. Exceptions were made
to this minimum radon figure if it was anticipated that high radium
content fill soil was to be used on the site. A prediction of high-radon
fill soil was based on a particular builder's previous fill soil use
pattern.
Permeability and soil radon measurements and soil and fill sampling was
done according to the procedures outlined in Section 1.1 of the FRRP
"Standard Measurement Protocols" (Wil 91). Permeability measurements were
taken at two locations 90-120 cm apart at depths of 30, 60, and 90 cm
with the soil radon sample taken at 90 or 120 cm depending on soil
density and moisture content. Soil samples were collected at the time of
initial soil-gas radon testing, and fill soil samples were collected just
before the slab was poured. Soil characterization for soil density,
emanation coefficient, radon diffusion, etc. was done by the University
of Florida Soil Sciences Department.
Some sites had high water tables, and were wet at the 90 and 120 cm
depths during successive tests. In this instance, the soil radon sample
was taken at the deepest dry depth, usually 60 cm. Fill soil radon
readings were also taken at the start of the project, but were
discontinued. It was decided to rely only on laboratory analysis of the
radium content of the fill soils because of the difficulty of isolating
the fill soil for a radon sample on the building site. When the fill is
first delivered to the site, the naturally accumulated radon in the soil
gas has been vented to the atmosphere due to the digging, transporting
and dumping of the soil. After the soil has been spread onto the site,
soil gas from the native soil starts to permeate the fill soil, and an
accurate measurement of the radon level in the fill soil is unobtainable.
B. SLAB
1. Cracks
Slab cracks were characterized at least one month after the pour in the
new homes to allow sufficient time for most of the shrinkage cracking to
have occurred. Cracks were counted in four different size categories, as
listed below.
size category
visible hairline
< 1/32 inch fine
>1/32 inch & < 1/16 inch medium
> 1/16 inch wide
4
-------
Total length of cracks in each category are recorded on a copy of the
floor plan. A representative crack in each category had an air flow
resistance test conducted in accordance with Guidance for Research House
Studies of the Florida Radon Research Program (GRHS), Volume I, Appendix
C (Red 92). This allows the integrity of the vapor barrier to be
assessed. A radon grab sample was also taken during the air flow
resistance test, to determine radon levels under the homes. This sample
was taken from the sub-slab measurement tube nearest to the crack in
question.
Problems with crack assessment include the fact that shrinkage cracking
can OGCur up to one year after the slab has been poured. Sufficient time
is allowed for most of the cracking to have occurred, but some additional
cracking is expected to occur for some of the project houses. Also, the
air flow resistance test and the radon grab sample taken at that time are
wholly dependent on the integrity of the vapor barrier in the local area
of the test. This may or may not represent the average condition of the
vapor barrier under the slab. Additionally, no data is available on
older homes to determine the longevity- of plastic vapor barriers. The
degradation of the vapor barrier over time could cause radon intrusion
problems for older homes.
2. Pressure Field Extension
Pressure field extension measurements were made to determine how well the
active sub-slab depressurization systems work in practice. Pressure
differential measurements between the house interior and the sub-slab
region have been made for other projects, but always entailed drilling
into an existing slab at some remote location, and repairing the hole at
the end of the test. This method naturally limits both the number and
location of the measurements, and also affects the slab boundary by
puncturing the vapor barrier.
As it was necessary for us to measure in many locations to determine the
overall pressure field extension, and to keep the slab system as intact
as possible, it was decided to use small diameter (3/16 inch) plastic
tubing laid under the slab to take the measurements.
a. Installation
The tubing is run to each measurement spot, inserted into a small square
of ventilation mat cut for the purpose, and anchored to the fill soil.
This is done using an S hook from a garden supply store, commonly used
to hang plants. These hooks are cut in half, leaving two strong pins
with one end turned over, and are easily pushed through the backing of
the ventilation mat. A good kick with the heel of the installer's shoe
pins the end of the tubing and the square of ventilation matting in the
desired location. This is done to insure the pressure reading is being
taken where the investigator thinks it is, and to insure that h igh winds
or careless workers do not alter the tube locations. The pins are also
used to secure the ventilation mat in place% The installation procedure
is illustrated in Figures II.1 and 2.
5
-------
small piece of
ventilation aal
Figure 11,1, Top and side views of measurement
point installation.
Figure II.2. Variations of tube installation for
monolithic and stem wall slabs.
-6
-------
The plastic tubes are brought together at two or three convenient
locations at the slab perimeter, and either trenched under the footer or
punched through the stem wall. A two to three foot section of PVC sewer
pipe is used as an upright to keep the tubes off the ground and prevent
damage from the construction process. The tubes are run up through the
upright, with enough length to ensure easy measurement later. The
upright is then capped off to prevent it from filling up with rainwater,
and flagged to keep it from being run over by machinery. The ends of the
tubes are filled with a bead of caulking to keep insects and rainwater
out, and to ensure that no short-circuiting occurs through the tubing
when the sub-slab depressurization fan is turned on. When measurements
are taken, the end of each tube is snipped off for the measurement, and
then recaulked immediately afterward. After the house is completed and
all measurements are taken, the PVC uprights are simply lifted out of the
ground, the tubes either bundled up or snipped off, buried and landscaped
over.
Measurement locations are limited to the mat and the perimeter of the
slab. This pattern was only altered when there were unusual patterns or
corners in the ventilation mat that needed investigating, or when
interior footers in the slab called for measurements to be taken on both
sides of the trench to quantify the amount of pressure extending under
it.
b. Measurement
Measurements can be made at any time after the slab has cured
sufficiently for construction to continue. We use 4 or 6 inch in-line
fans to depressurize the system attaching the fan to the rough stub of
the suction riser or to the end of the stack on the roof if construction
has progressed that far. Fans are only installed permanently on these
systems if after final testing the indoor radon level is above 4 pCi/L
(2.9 for a 48 hour measurement).
Measurements are taken with a Shortridge ADM-860 hand-held electronic
micromanorneter at each tube end, first snipping off the caulked end, and
then recaulking the end after the measurement is taken. There are
typically 20 to 30 measurement tubes on a house, and this process can be
completed in less than one hour. We then have a map of the house
footprint with pressure measurements in the ventilation mat, at different
points between the mat and the slab edge, and around the slab perimeter.
c. Evaluation
The pressure contours are obtained using the program FSECPLT, written by
Muthusamy Swami of FSEC. FSECPLT is an output processor for the program
FSEC 3.0 (Swa 92). FSEC 3.0 uses the principle of the Finite Element
Method (FEM) to solve coupled partial differential equations. The basic
idea of the finite element method is to divide the region of interest
into a large number of finite elements. These elements contain nodes
where the field variable is obtained after solution. In our case the
elements are triangles and the nodes are the measurement points.
The space and pressure distributions are defined through shape and
7
-------
parameter functions. In our case, the functions describing the geometry
and distribution within an element are the same, known as isoparametric
elements. In finite elements, nodes are placed at the corners of the
element. The elements in FEM link the nodes it contains and this
connectivity allows the specification of the influence of one node on the
other. This is a distinct advantage of FEM that allows one to obtain
contours using relatively fewer measurement points and also specify the
influence of one measurement point on another.
There is some limitation to the amount of detail obtained in the pressure
map due to the limited number of measurement points, but since other
methods depend on much fewer measurements, we feel this method generally
gives a very good evaluation of sub-slab pressure field extension.
Mitigation system layouts and pressure field extension maps are presented
in the Data Analysis section. Measurement point coordinates and pressure
measurements are included in Appendix C.
C. HOUSE
1. Blower Door Test
The objective of this test is to assess the tightness of the house
envelope, determine the location of major leaks, and locate and quantify
leaks in the air distribution system. This work was done by Natural
Florida Retrofit under subcontract to FSEC. House tightness is
determined by blowing known quantities of air through the house envelope
at specified house pressures.
Tests were conducted with all exterior doors and windows closed. The
tests were then repeated with all of the supply and return registers in
the house sealed off by paper and tape. By subtraction, the airtightness
of the duct system was also obtained. Airtightness of the house or duct
system can be expressed in ACH50 (air changes per hour of the house
volume at 50 Pa depressurization), CFM50 (air flow in cubic feet per
minute into the house or duct system from outside the house at 50 Pa
depressurization), or ELA50 (equivalent leak area of the house or duct
system at 50 Pa depressurization). Since this testing was done it has
been reported that significant errors can occur if the ducts are
installed in an area that is not at ambient pressure, such as between the
floors of a two-story house. It is assumed that attic spaces will be at
ambient pressure. Current protocol at FSEC includes measurement of
pressure differences in duct spaces.
In addition to quantifying the airtightness of the house and duct system,
a visual inspection was made of the duct system. First the house was
pressurized to about 15 Pa by the blower door with the air handler turned
off,' and smoke (t it aniumtetr a chloride) from a smoke stick was placed in
front of each supply and return register to observe the speed with which
it entered each register. If the smoke entered slowly or not at all,
then little or no duct leak existed in the ducts nearby. If, on the
other hand, smoke entered the register rapidly, then a large duct leak
was located nearby.
8
-------
Blower door testing was carried out in accordance with the "Test
Method for Determining HVAC Duct System Leakage" (Mil 91} except
for the following:
1. Testing is done with wind speeds up to 10 miles per hour. We
will not report ELM and ELMO for tests done with wind speed
in excess of 4 MPH, as is recommended in section 9.4,2 of ASTM
E779-87.
2. Data is plotted per section 9.3 of ASTM E779-87 for
depressurization only. We feel air leakage through dryer and
fan exhaust dampers distorts the data in the pressurization
mode. However, a least square fit for Q = C(dP)n and a
correlation coefficient, r2, is calculated as required in
Section 9.4 of ASTM E779-87.
3. The blower door tests are done in the depressurization mode
only. Pressurization tests push open dampers in exhaust fans
and dryers, resulting in an exaggerated leak area for the
house. Because we feel that the depressurization test most
accurately reflects the true leak area of the house, we limit
our test to depressurization only.
2. Pressure Differential Test
Air pressure in homes is a function of house airtightness and the
air flow rate into or out of the house. The greater the house
airtightness, the greater the pressure difference for a given flow
rate. The greater the air flow rate into or out of the house, the
greater the pressure difference.
The relations between the three variables of pressure difference,
hole size, and air flow rate through a round orifice in a duct can
be expressed in the form (SMACNA 81);
Q = 21,8 K D2 h-5
where
Q = air flow (CFM)
K = coefficient of air flow
D = diameter of orifice (inches)
h = pressure drop across orifice (in. water)
The flow from or into a house, however, rarely passes through a
single round ori fice. ASTM E779 provides a means for
characterizing the size and shape of the leaks in a house envelope
by computing an air flow coefficient (C), and a flow exponent (n)
based on a blower door test:
Q = C(h)n
Then an effective leak area (ELA) of the house may be defined as:
ELA = C (density/2) -5(h)n"-5
9
-------
ELA is not a fixed number for each house at all pressure
differences, but varies with the reference pressure. Pressures of
4 and 10 Pa have been used to assess building leak area, but we
feel these pressures allow wind effects to introduce errors into
the blower door results, and so we are presenting ELA at 50 Pa
(ELA50) since there is less error in the blower door tests at this
pressure. This is especially important because the leak area of
the duct system is calculated from two separate house blower door
tests, and the relative error from each test is propagated into the
final result.
In order to fully characterize the pressure differentials occurring
in the subject houses due to both natural and mechanical effects,
pressure differential measurements were made between the indoors
(in the main body of the house) and the outdoors, subslab, and
various sections of the house. These measurements were made by
running plastic tubing to the various locations from the main body
of the house. For the sub-slab measurements, the same tubing was
used that was installed for the pressure field extension
measurements. Various combinations of mechanical systems and house
configurations were tested;
1. with no mechanical systems operating, doors open
2. with the air handler (AH) on
3. with the air handler and all exhaust fans on
4. with the air handler on and all doors closed
5. with the AH and all fans on, and all doors closed
These measurements are all made with respect to the main body of
the house. A positive measurement represents pressurization with
respect to the main body of the house, and a negative measurement
represents depressurization with respect to the main body of the
house.
3. Infiltration Test
Infiltration testing is used to determine what the air exchange
rate is for the houses. The infiltration rates are established for
a base case, average operating mode, and a worst case situation.
This testing will also help us analyze the quality of HVAC
installation and equipment. Duct leakage is a primary
consideration since the house may be depressurized with leaks of
this nature (Cum 89).
Tracer gas testing was done using a modification of "Standard Test
Methods for Determining the External Air Leakage of Air
Distribution Systems by Fan Pressurization" (ASTM 94). A tracer
gas is used in diagnosing air exchange rates in buildings. The gas
is injected into a building at some concentration. Since buildings
are not sealed 100% from air leaks, the gas is diluted over time.
The principle of this method involves the dilution of a given
concentration is the air exchange rate.
10
-------
The tracer gas used is sodium hexafluoride (SF6) . It is rare,
nontoxic, and a very stable gas which makes it suitable for testing
houses. Its concentration is measured by infrared means. The
Foxboro Miran 101 is the specific vapor analyzer used. It measures
two ranges of concentration. The first is from 0 to 50 parts per
million (ppm), and the second from 0 to 5 ppm. An internal air
pump moves air at 0.5 L/sec from a sample point to the internal
chamber. In the chamber a high temperature emitter gives off a
10.1/im wave length that is absorbed by the SF6. A change in
temperature can change the zero drift of this device. This
requires an initial warm-up period of about twenty minutes and zero
calibrations throughout testing. Four infiltration tests are
performed. The last test considers slab leakage and is discussed
in detail.
The first test measures natural infiltration. Upon arrival at the
house, the air conditioner is put on with the fan on continuously
to stabilize air temperature. Then a preliminary check is made to
assure that all supplies and returns are open, ventilation
equipment off, and windows shut. The SF6 is injected at the return
and the concentration is stabilized at about 35 ppm, using small
fans if necessary. One half inch vinyl tubing is used to sample
the rate of decay of this concentration at four locations in the
house. All mechanical equipment is then turned off. In all
infiltration tests measurements are made every ten minutes for an
hour. The analyzer is zeroed every twenty minutes. Average drift
is about 0.2 ppm. During tests, the indoor and outdoor ambient
conditions are recorded as well as radon concentrations.
The second test is conducted with the air conditioner on and the
fan operating continuously. This test gives an idea of the air
exchange rate and duct leakage under average Florida summer
conditions when homes are often closed. Tracer gas concentrations
are monitored at four well-distributed locations and at the return
and supply grills. The supply and return levels are used to
calculate the fraction of air that leaks into the return side of
the HVAC system. Leaks in air handlers or return ducting located
near radon entry pathways can contribute to radon intrusion by
depressurizing the local area. Leaks in air handlers and return
ducting located in an unconditioned space not near a radon entry
pathway can dilute radon levels and pressurize the house. The
following formula calculates return leak fraction.
RLF = {A-B}/(A-C)
where A = return concentration
B = supply concentration
C = buffer concentration
11
-------
The buffer accounts for any unconditioned air that leaks into the system,
and is measured with a separate tube attached to the air handler at a
point where a significant return leak is present. The air changes per
hour are calculated by :
ACH = In a/b
where a = average concentration at start
b = average concentration at end
The third test is intended to give an example of the worst case scenario
in depressurizing the main space. The air conditioner is run with the
fa n on continuously and all doors closed. The return pulls air from the
main space and it depressurizes provided the doors seal and other returns
are not present in the closed off space. Concentrations are monitored
at three closed locations and in the main space of the house.
In test 4 a method is being studied that could quantify the slab leakage,
and identify any impacts on occupant comfort from an activated sub-slab
depressurization system (SSDj. The slab leakage is quantized as an
airflow through the slab by using tracer gas while the SSDS is activated.
The fan creates a negative pressure under the slab, and if any slab
leakage exists, the tracer gas is pulled through the slab and exits at
the stack. By monitoring house and stack concentrations, a leakage rate
can be calculated (Cla91).
The procedure developed for this test was one that could accommodate the
materials and practices of pre-existing tests in the project. Sub-slab
leakage infiltration testing is performed following three previous
infiltration tests. The transition into this test is easy since tracer
gas concentrations are already being monitored within the house, as are
indoor and outdoor ambient conditions. Some tracer gas will already be
in the sub-slab area due to differences in pressure between the house and
the sub-slab, but these levels will be small compared to the amount of
tracer gas drawn through the slab by the activation of the mitigation
system fan.
Ten to twenty minutes is allowed for the sub-slab stack concentration to
stabilize following activation of the system. This test uses one Miran
101 SF6 I R spectrometer, the vinyl tubing locations in the house from
previous infiltration testing, and the sample tube placed under the slab
at the stack prior to slab pour. The tracer gas is monitored every ten
minutes for an hour. The airflow through the stack is measured using a
Solomat hotwire anemometer.
-------
One proposed method of calculating the slab leakage is as a slab
leak ratio to the stack airflow. The house and sub-slab
concentrations are averaged separately, then used in the following
equation.
C/D = B/A
where A = House Gas Concentration
B = Stack Gas Concentration
C = Slab Leak Airflow
D = Stack Airflow
The slab can now be characterized using the leakage rate in cubic
feet per minute and the differential pressure field below the slab.
Additional information from this data will be the percentage of
exhaust stack air that is conditioned, and the change in
temperature, relative humidity, and dew point after the system is
activated. One drawback to this method is that it does not account
for the locations of the cracks and penetrations in the slab.
A second method of calculating the slab leakage was considered,
using the natural air exchange rate of each house. With the system
activated, house air would be pulled through leaks, and make-up air
would come from outside the house. This causes a greater air
exchange. The difference between the natural infiltration rate and
the SSDS infiltration rate would equal the slab leakage rate. This
method involves no more additional measurement than the first and
can serve as a comparative measurement. The potential problem of
this method is that it can be influenced by wind effects and large
leaks in the ductwork.
4. Radon Stress Test
This test is designed to evaluate the radon resistance of houses.
An evaluation based on standard short-term measurement protocols
may not be completely satisfactory. The wide variability of radon
concentrations in a single house may require measurement periods
too long, or threshold values too low, for public acceptance of a
standard enforced by such measurement. The stress test protocol,
though artificial, may provide an unambiguous alternative test
which may be completed in less than a day with reduced possibility
of tampering. For such an approach to be feasible, the
measurements must be demonstrated to be reproducible and at a
minimum highly correlated with long-term average radon
concentrations. The protocol should also be consistent with sound
building practice, in that it should not discriminate in favor of
poorly-sealed houses or leaky ductwork.
13
-------
The test procedure consists of mechanically depressurizing a
structure to levels greater than the mean environmental
depressurization, measuring the resulting air flow rates at given
indoor-outdoor static pressure differences, measuring the indoor
radon concentrations after a delay to reach a steady state, and
then repeating the sequence at two higher levels of
depressurization. From the air flow rates and radon
concentrations, the radon entry rate for each pressure difference
can be determined. From the relationship between the radon entry
rates and pressure differences, the radon entry rates and expected
mean radon potential of the structure can be evaluated.
This method relies on several assumptions, not the least of which
is that the ef f ects of central HVAC systems, such as extreme
unbalance in pressures or infiltration rate caused by air handler
operation will not dominate the effects measured by this technique.
It is also anticipated that the radon entry rate will vary linearly
with the applied pressure, and that the system will reach a steady
state within a few hours after a change in applied pressure. We
used pressures of 10, 15, and 40 pascals during our tests.
This measurement protocol has been submitted to the Florida Radon
Research Project (FRRP) by the Southern Research Institute (SRI).
Its inclusion in this project is part 'of the review and testing
process.
Procedure
a. All interconnecting doors (except for closets, which should
be closed) in the space being tested should be opened such
that a uniform pressure will be maintained within a range of
less than 10% of the measured inside/outside pressure
difference.
b. HVAC balancing dampers and registers should not be
adjusted. Fireplace and other operable dampers should be
closed.
c. Establish baseline conditions for the structure for at
least one hour before proceeding.
d. Measure and record the wind speed and direction, indoor and
outdoor temperatures, and the time of day at the beginning and
the end of the test.
e. Perform fan depressurization test per ASTM E779-87. Plot
exhaust flow rate against applied depressurization. Calculate
exhaust flow rate and air changes per hour at 10, 20, and 40
Pa from the best fit to the curve.
14
-------
f. Using the air-moving equipment, depressurize the structure
to 10 Pa for 1 hour or the time sufficient to exhaust 3 air
changes if longer than 1 hour.
g. Fill duplicate Lucas alpha-scintillation cells with house
air in line with the intake of the depressurization flow.
Note time and exhaust flow rate. Set aside for at least four
hours. Repeat procedure for 20 and 40 Pa.
h. Using the calibrated scintillation cell counting station or
radon monitor, count each cell for three 30 minute periods and
average these counts to determine radon concentrations in
pCi/L, using pre-determined calibration factors. Average each
pair of calculated radon concentrations to obtain a single
concentration at each depressurization. (A counting period of
to 1 hour was used where possible to increase accuracy.)
Analysis
a. Using the measured exhaust flow rate Q and the calculated
radon concentration C for each depressurization dP, calculate
the approximate radon entry rate R for each dP as follows:
R (pCi/sec) = 0.47 (l-min/ft3-sec)C (pCi/L) Q (cfm)
or
R (pCi/sec) = 1000 (1/rrt3) C (pCi/L) Q (m3/sec)
b. Plot R versus dP and extrapolate to dP=0. estimate the
value for R where dP is about 2.4 Pa, the estimated mean
structure depressurization. Call this value Rcyp, the expected
radon entry rate.
c. Using the fan depressurization response curve, extrapolate
to obtain the estimated air exhaust rate at 2.4 Pa. This will
be assumed to represent a typical infiltration rate for the
house Qtyp.
d. Define Ctyp, the expected mean radon potential of the
structure, by
CtyP
-------
Precision and Bias
The precision and bias of this test procedure is largely dependent on the
instrumentation and apparatus used and on the ambient conditions under
which the data are taken. It is more precise to take pressure and flow
data at a higher pressure difference than at lower differences. The
typical infiltration rate for the structures used in the calculations is
approximated from a low pressure difference, usually between 1 and 4 Pa.
There'is inherently poor precision in measurements made in this range,
so the extrapolated values may have low precision as well.
5. Indoor Radon Levels
Indoor radon levels were tested by placing a PYLON monitor in continuous
operation in the main body of the house for a period of at least 48
hours. Monitors were used in the passive mode when possible, and in
pumped mode when passive cells were not available. The tests are
conducted with all exterior doors and windows closed, and hopefully with
a minimum of traffic in and out of the house. Three testing periods are
possible. The first is with the stack of the mitigation system capped
off, to determine the ability of the slab to act as a radon barrier. The
system is then uncapped, and tested again. If the uncapped test is above
2.9 pCi/L, then the system is activated by installing an in-line fan in
the mitigation stack. The third test is then conducted to determine
final indoor radon levels. If levels still persist above 2.9 pCi/L,
further study is done on the house to locate the source of the radon
intrusion.
The value of 2.9 pCi/L was chosen to assure with 80% confidence that the
annual average radon concentration does not exceed four picocuries per
liter. The four picocuries per liter level is accepted as meeting the
"not to exceed" 0.02 working level standard established by the Florida
Department of Health and Rehabilitative Services (Fla 89).
16
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III. RESULTS
A. SOIL
The data on the fifteen houses are presented below in Tables III.1
and 2. These data are incomplete due to the down time of our soil
permeameter. The second native radon readings for houses 17, 22 and
24 were taken beneath the slab after start of construction.
Table III.1. Initial Soil Testing Results
House Native Fill Native Avg. Native
Number Ra-226 Ra-226 Radon Permeability
(pCi/g)
(pCi/g)
(pCi/L)
(cm2)
14
8.83
_
2330
2
.72
X
10"7
15
5.44
12.15
3440
2
09
X
10~8
16
3.4
10.0
4080
8
26
X
10-8
17
5.9
5.25
947/1660*
8
80
X
10"9
18
2.6
13.0
7263
8
78
X
10~e
19
1.5
13.4/5.2
1650*
2
71
X
10"7
20
-
10.6
3000
4
59
X
1Q-8
21
11.5
2.3
6860
7
98
X
10"8
22
0.5
2.5/.5
853/2684*
1
83
X
10"7
23
0.7
7.4
1600
2
98
X
10'7
24
0.4
6,4
418/2822*
1
60
X
10~7
25
13.4
6.4
4512*
3
42
X
10"7
26
3.4
5.6
2210
4
83
X
10"8
27
8.6
4.4
8450
3
58
X
10-7
28
68.6
5,0
6285
2
74
X
10"7
* Measurements taken under the slab after pour.
The permeability is the average value taken at 30, 60, and 90 cm
in two different locations on site. Radon is sampled at the
deepest location possible, but some sites were too wet at times
to sample at 90 cm depth. The sites with native radon over 6000
pCi/L are all in the same development. Houses 15, 16, and 25
were noted as wet sxtes at the txme of soil testing.
Measurements on these sites were then taken at shallower depths.
Retests have shown that the water level in the soil on these
sites does not change over time. Saturated soil at a depth of
one meter under the house would tend to lower radon levels in the
soil unless high-radon fill is used, in which case radon is still
available for intrusion into the house. Permeability varied as a
function of depth. This may be from the non-heterogeneity in
soils of mined or worked sites, and moisture effects. Houses 17
and 18 had a clay layer while house 20 had smaller particles of
clay throughout a zone of the soil. Low permeability at the site
17
-------
of House 17 is due in part to high soil moisture content. All
houses but 14, 22, and 26 are on reclaimed mine sites. The
permeability of soils on reclaimed mine sites varies
unpredictably with depth. The lower permeability for houses 15
and 16 is attributed to wet soil. Results for soil moisture may
not coincide with on-site reports of soil wetness, since soil
samples were taken at a shallower depth where moisture content
was lower.
Tsblc XXX•2. Addition&l Soil Testing Kssults
House
Radon
Emanating
S 0 x 1
Number
Emanation
Radium *
Moisture
(%)
(pCi/g)
(%)
14N
15
CO
•
1—1
6
F
-
-
-
15N
12
0.65
6
F
3
0.37
5
16N
18
0.61
13
F
8
0.8
10
17N
1
0.07
11
F
6
0.3
4
18N1
26
0.7
5
N2
21
0.4
5
F
14
1.8
5
19N
41
0.6
1
Fl
12
1.6
7
F2
16
0.8
5
2 ON
-
11
F
8
0.8
6
2 IN
26
3.0
7
F
10
0.2
4
22N
22
0.1
5
Fl
30
0.7
1
F2 •
17
0.1
1
23N
33
0.2
3
F
1
0.1
5
24N
28
0.1
7
F
9
0.6
5
25N
8
1.1
11
p
9
0.6
4
26N
35
1.2
9
F
19
1
5
27N
32
2.8
8
F
10
0.5
7
28N
32
21.8
19
F
9
0.4
11
* Emanating Radium = radium-226(pCi/g) X %emanation/100.
N - Native soil.
F - Fill soil.
18
-------
B. SLAB
Two of the fifteen houses are post-tensioned, and the others are
conventional slabs. Post-tensioning involves placement of steel cables
in the slab about every ten feet in both directions, and tightening the
tension on these cables two or three times after the slab is poured.
This makes it more difficult for the concrete to crack and draws together
any cracks that might occur. Five slabs are of monolithic construction,
and eight are stem-wall slabs. At least 30 days elapsed before crack
measurements were done to allow sufficient time for cracks to develop,
and each slab is monitored for additional cracks until the floor
coverings are put down.
1. Cracks
Table III.3 below contains a summary of the crack measurements taken,
with crack sizes divided into the following four categories:
size category
< 1/64 inch hairline
>1/64 inch & < 1/32 inch fine
>1/32 inch & < 1/16 inch medium
> 1/16 inch wide
Table III.3.
Crack Measurement
Summary-
House
Hairline
Fine
Medium
Wide
Total Crack
Number
Length
Length
Length
Length
Length
ft.
ft.
ft.
ft.
ft.
14
8
0
*276
0
284
15
5
5
0
0
10
16
0
0
0
0
0
17
0
18
0
0
18
18
0
0
0
0
0
19
7.5
30
0
0
37.5
20
10.3
15
0
0
25.3
21
14
20.5
0
0
34.5
22
0
0
0
0
0
23
0
16.7
16.5
0
33.2
24
97.6
193.7
0
0
291.3
25
36
0
0
0
36
26
4
0
14
0
18
27
0
0
0
0
0
28
118.2
0
36.5
0
154.7
* All sawcut control joints.
All but ten feet of the cracks in house 14 are sawcut control joints. The
slab contained control joints spaced approximately six feet apart in both
directions covering the whole slab. This was due to the use of the
poured slab as a finished floor.
19
-------
Control joints where used are counted in the medium category. The cut
itself is wider than this, but the actual crack through the slab was
measured to fall in the medium category. All of the houses, with the
exception of house 24, exhibited less cracking than would have appeared
had control joints been included to the extent required by the code. Fo
this reason we are recommending that the provision for specific spacing
of the control joints be dropped from the code. Designs with a recessed
entry in the front and a recessed porch or lanai in the back of the
house, such as houses 23 and 25, tend to crack along the axis connecting
these structures, and control joints are recommended for these locations
Table III.4 presents the results from crack tests performed as per
Protocol for: Crack, Joint, and Opening Characterization for Radon
Entry (Act 90). Radon levels coming through the cracks are determined
using a PVC chamber sealed to the crack. A Rogers and Associates
permeameter is used to test crack axr flow versus pressure at three
intervals, then a scintillation cell is placed in line with the air flow
to collect a representative sample of the air. This air sample is then
analyzed to determine the radon level in the air being drawn through the
crack.
Substantial amounts of radon were detected in house 26 during crack
testing, which is evidence that the vapor barrier in that area did not
provide an intact seal. It should be pointed out, however, that much
larger depressurization levels are used in the crack testing than is
found in normal house conditions. The low levels found in all other
houses are evidence that the vapor barriers are intact, at least in the
local area of the test.
Table III.4. Cracks and Radon
House
Number
Representative
Crack Width
{inches)
Radon Level
Through Crack
(pCi/L)
Sub-slab
Radon
(pCi/L)
Total Crack
Length/house
(ft.)
14
0.031
* +
284
15
0.013
4r -k
10
16
0
_
0
17
0.016
2.5
1440
18
18
0
_
0
19
0.015
-
1650*
38
20
0.019
13. 6
2730
25
21
0.013
* -k
35
22
0
0
0
23
0.027
**
33
24
0.024
24.4
2822*
291
25
0.010
12.3
4512*
36
'2 6
0.027
666.4
3794
18
27
0
-
0
28
0.017
20.4
1716*
155
* - Sub-slab radon level not taken on date of crack test.
** - Not tested.
20
-------
Equivalent area and Figure of Merit calculations appear in Table III.5.
Data from ten houses are all that is available due to various problems
with scheduling and equipment. House 14 had its control joints sealed
before we were informed, and house 15 had very small hairline cracks too
small to test. The permeameter malfunctioned on houses 21 and 23, and
house 19 had cracks that developed too late to test.
Each crack category is characterized separately. The "equivalent area",
normally reported on an area per test chamber length basis, is expanded
to a "slab equivalent area" by multiplying the equivalent area for each
size crack by the number of test chamber lengths contained in the total
crack length for that size. The equivalent areas for each size crack are
then added to obtain the slab equivalent area. The Figure of Merit for
each crack category is the actual crack area multiplied by the radon
level found to be coming through each category. Therefore, the smaller
the Figure of Merit the better. The Figure of Merit for the slab is then
the sum of the individual categories' Figures of Merit. The Figure of
Merit was intended to provide a comparative measure between houses and to
possibly correlate well with indoor radon levels, but the uncertainty
involved in the measurements and the lack of comprehensive data on each
slab prevents the obtainment of meaningful results.
Table III.5. Equivalent Area and Figure of Merit
(Units: Equivalent area - in.2; Figure of merit - in.2 X pCi/L)
House Hairline Fine Medium Wide Slab Figure of
Number Eq. Area Eq. Area Eq. Area Eq. Area Eq. Area Merit
16
0
0
0
0
0
0
17
0
0.01
0
0
0. 01
8. 64
18
0
0
0
0
0
0
20
-
0.0062
0
0
0.0062
63.32
22
0
0
0
0
0
0
24
0.0024
0.014
0
0
0.0164
1655.87
25
0.0008
-
0
0
0.0008
53.28
26
_
0
0.
0008
0
0.0008
3022.79
27
0
0
0
0
0
0
28
-
0
0.
0044
0
0.0044
151.90
Houses 15 and 18 were post-tensioned slabs. House 18 had no cracks appear
by the time the floors were covered, and house 15 had minor surface
cracks totalling 10 feet in length none of which were long enough to
test. Houses 16, 22 and 27 also had no cracks at the time the floors
were covered.
21
-------
Houses 14, 19, and 21 had late developing cracks at a time when our
permeameter was inoperative, and finish flooring was to be installed.
House 14 also had construction joints at regular intervals in both
directions, as the poured concrete was to be the finish floor in that
house. One crack developed across a thin section of the slab in house
14.
House 16 had no cracks at the time of finish flooring; however, a floor
electric outlet was added after the slab was poured. Concrete was
chiseled two-inches deep, eight-inches wide and eight feet long to run
conduit to the added outlet. Concrete was then added up to the floor
level after the conduit was in place. During finished house testing, a
sniff test was taken at this location. No mechanical systems were on at
the time and a grab sample produced 17.1 pCi/L. Another grab at a spa
tile and floor tile seam produced 5,7 pCi/L. Ultimately this house was
actively mitigated. Crack maps are presented in Figures III.l through
15.
22
-------
GROUND FLOOR GARAGE
Figure III.1. House 14 crack map.
Garage
Figure III.2. House 15 crack map.
-23-
-------
Lanai
NO CRACKS
i
i Garage
S
i
t
Figure III,3. House 16 crack map.
Garage
Figure III.4. House 17 crack map.
-24-
-------
NO CRACKS
Garage
Figure III.5. House 18 crack map,
NO CRACKS
TOP FLOOR
BOTTOM FLOOR
Figure III.6. House 19 crack map.
-25-
-------
Garage
Figure III.7. House 20 crack map.
I * ,
1 I
i t
1 !
i l
Garage
Figure III.8. House 21 crack map.
-------
NO CRACKS
Figure III.9. House 22 crack map.
Figure III.10. House 23 crack map.
-27-
-------
Figure III.11. House 24 crack map.
i
i
i Garage
Figure III.12. House 25 crack map.
-28-
-------
V
V\
Entry
Garage
Figure III;13. House 26 crack map
CRAWL SPACE
NO CRACKS
r
i
Garage
I
FiQure XIX.14, House 27 crack map,
-29-
-------
-30-
-------
2. Pressure Field Extension
Analysis of pressure field extension in the 15 contract houses is
presented here in Figures III.16 through III.45. The first figure for
each house will be the footprint, showing the placement of the
ventilation mat and the measurement points. The second figure will
contain the pressure field contour lines.
The test was conducted by placing a fan temporarily on the system and
measuring the pressure at each of the measurement points by means of
plastic tubes that were laid down under the slab between the soil and the
vapor barrier at the time of system installation and run under the edge
of the slab.
The length of ventilation matting used on each house was under 100 feet
leading to the installation of one suction point per house. As a general
rule the matting was run down the center of the long axis of the house,
and kept more than six feet from any edge to guard against short-
circuiting to the outside. Priority was given to areas with multiple
slab penetrations such as bathrooms and areas prone to negative indoor
pressures, such as living, dining, and family rooms, and utility rooms.
Special consideration was given to slabs with interior footers.
Ventilation matting was run down into these trenches and up the other
sides into areas that might not have felt the pressure field otherwise.
Suction pit designs were used on Houses 16 and 19, and were installed
according to FRRP protocols. A length of ventilation mat was run through
the pit in House 16 to extend to the pressure field {see photo in
Appendix A) . Wellpoint suction pipe designs were installed on Houses 14,
19, 21, and 21, with two suction pipe sections in House 19, and three
sections in the rest of the houses. The wellpoint suction pipe sections
were spaced according to the minimum requirements for pit designs, and
were connected by 2 inch piping. Each suction pipe section was
approximately three feet in length, and surrounded by 3-5 inches of
washed gravel to keep fine particles of sand in the fill soil from
clogging the pipes.
Measurements were made with a 4 or 6 inch in-line fan attached
temporarily to either the rough stub of the suction riser or to the end
of the stack on the roof, if construction had progressed that far. The
pressure contours were obtained using the program FSECPLT, written by
Muthusamy Swami of FSEC. FSECPLT is an output processor for the program
FSEC 3.0 (Swa 92), and uses the principle of the Finite Element Method
(FEM) to solve coupled partial differential equations. This method has
been of great use in that it eliminates the grind-it-out manual analysis
that would otherwise be necessary in producing the pressure field
contours.
House 14 is a two-story structure with an underground garage. An attempt
was made to characterize not only the sub-slab pressure field, but also
the extension along the vertical walls of the garage on two sides. The
bottom measurement points were installed on top of the footer and outside
the block wall after the initial pour.
31
-------
~z
#18
#17
*16
#19
#23 «25
HIS
»
«21!
«13
*12«
»
¦
• 6
#1
#5
#2
•
•
Garcia 9
; S2Q
»E2
. #4
H3_
«B2
814
Figure III.16. House 14 layout.
Figure III.17. House 14 pressure field.
The high pressure point in the first floor drawing should
correspond to the suction pipe location shown in Figure III.16.
-32-
-------
Figure III.18. House 15 layout.
House 15 has a standard layout along the lateral axis of the house
footprint with one section extending into the family room area,
which is likely to be de-pressurized. Dashed lines indicate
interior footers in the slab.
Figure III.19. House 15 pressure field.
-33
-------
»H
-s—
Gorcge
Figure III.20. House 16 layout.
Figure III.21. House 16 pressure field
-34-
-------
Figure III.22. .House 17 layout.
-35-
-------
Figure III.24. House 18 layout.
The layout in House 18 is' axialiy offset to allow maximum coverage
of the house footprint without resorting to multiple corners in the
mat. One corner is necessary to extend che mat into the "main
living•area.
Figure 111,25. House 18 pressure field.
-------
Top Floor
Figure III.26. House 19 layout.
House 19 used a combination of a suction pit and wellpoint suction
pipe in its system. The bottom floor has a suction pit filled with
2 inch diameter stones centrally located in the footprint, and the
upper floor has two sections of well point suction pipe located to
give the greatest pressure field extension coverage. This type of
system was chosen to make it easier to connect the two floors
together.
Bottom Floor
Top Floor
Figure 3X1.27. House 19 pressure field.
The field shows a lower pressure in one arm of the wellpoint
system. This could be due to short-circuiting to the front entry
slab' recess.
-37-
-------
Figure III.28. House 20 layout.
The House 2 0 layout is axially rotated to favor areas of the house
likely to be depressurized.
Figure III.29. House 20 pressure field.
-38-
-------
( ¦ !
Figure III.30. House 21 layout.
This system consists of three we11point sections with the riser
located in the garage wall.
-39-
-------
Figure III.32. House 22 layout.
Figure III.33. House 22 pressure field.
-40-
-------
Figure III.35. House 23 pressure field.
-41-
-------
l[
14
Lonci
i7
*8
*»J2
12
* is «? @
no.
ait •
if
*13
*
*6
j- I
*3
*
¦:
| Garage
i
i
i_
Figure III.36. House 24 layout.
FXQ""U.X*6 IXI , *3"7 • HOUSS 4 J3X*0SSUXS £X0Xcl*
-42-
-------
Lonoi
II
* iO
• 4
3
Garage
i
Figure 111,38. House 25 layout.
Figure III.39. House 25 pressure field.
-43-
-------
Figure III.40. House 26 layout, - -
Dashed lines indicate an extensive interior footer network,
Figure III.41. House 26 pressure field.
-44-
-------
Crawl
Space
. i
n *aj
au
**\
*8
*18
ti '
*5
i Ga::age .
«M3 IS* jj
Figure XII.42. House 27 layout.
-------
Figure III.44. House 28 layout.
Figure III.45. House 28 pressure field.
-46-
-------
3. Slab Leakage
The results of testing for slab leakage are shown in Table III.6. This
data was collected by using a 6" Fantech model f-150 suction fan. The
test was conducted for an hour. The leakage is assessed in three ways.
The first is through the comparison between subslab tracer gas levels
measured in the mitigation stack to indoor tracer gas levels. This is
called the slab leak fraction (SLF). The second method of comparison
uses the cfm of conditioned air measured in the stack, calculates an ach
based on the house volume, and is reported as slab achA. The third
method subtracts the natural infiltration rate from the "mitigation fan
on" rate. This is noted by slab achB. Negative numbers in this column
indicate that the natural infiltration rate is sometimes higher than the
mitigation fan on rate, and that this measure is not a good one for
determining the air change rate through the slab. The last column
normalizes the slab achA. measurement to arrive at a comparison of ach per
square foot of slab.
Table III.6 Slab Leakage
House Stack Cond. Air Slab Slab Slab
Number SLF Airflow Thru Slab achA achB achA/ft2
{%) (cfm) (cfm) (lO"5) (10"B)
14
4.3
39.8
1.7
7.0
-0
.52
5.7
15
13.3
47.9
6.4
23.6
0
048
8.7
16
22.0
58.1
12.8
68.2
0
16
36.4
17
34.8
45.0
15.7
73.8
0
15
32.1
18
10.0
11.0
1.1
5.0
0
060
1.9
19
17.4
46.4
8.1
36.6
-0
058
23.6
20
18.7
-
-
_
-0
066
-
21
(Not tested) -
-
-
-
22
9.2
13.0
1.2
6.4
0
093
2.8
23
6.6
24.4
1.6
3.0
-0
129
0.9
24
30.2
14.4
4.4
16.3
-0
106
6.6
25
6.9
43. 9
3.0
16.0
-0
033
8.5
26
14.7
22.1
3.2
6.5
-0
071
1.9
27
(Stack not
taken
through roof)
-
-
28
(House not
finished) -
-
-
C. HOUSE
1. HVAC
HVAC installation techniques remain an area of non-compliance with the
Draft Standard, mainly due to sub-contractor reluctance to change
existing practices. Compliance in this area is greater than in the 1991
project, but could still be better. House description data is presented
in Table III.7, and HVAC data in Table III.8. A complete description of
each house and its mechanical systems is presented in Appendix A.
47
-------
Table III.7. House Description
House
Floor
Average
Max. Ceil.
Volume
Number
Number
Area
Ceil Ht.
Height
(ft3)
of
(ft2)
(ft)
(ft)
Stories
14
1218
12
20
24,360
2
15
2715
10
10
27,150
1
16
1876
10
12
18,760
1
17
2300
9.3
10
21,275
1
18
2600
8.5
11
22,100
1
19
2356
9.4
20
22,140
2
20 '
17 64
10
10
17,640
1
21
2673
9.8
10
26,062
1
22
2270
8.3
10
18,728
1
23
3380
16
22
54,080
1
24
2456
11
12
27,016
1
25
1876
10
12
18,760
1
26
52 94
9.3
24
49,184
2
27
2992
10
24
29,920
2
28*
-
-
-
-
2
* - Not tested.
Table III.8. HVAC Description
House
Supply
Return
Exhaust
# of
Sup.,
Ret.
Location
Number
CFM
CFM
CFM
Sup.,
Ret.
Leak %
of AH
14
1125
583
14,
1
5,
5
attic
15
2127
1568
309
18,
3
5,
20
attic
16
1400
942
263
12,
2
3,
15
attic
17
1405
914
415
20,
2
2,
3
attic
18a
1349
980
273
8,
1
3,
3
attic
18b
1392
100S
-
9,
1
3,
3
attic
19
1685
1446
221
13,
1
5,
5
attic
20
1653
872
123
10,
2
5,
15
attic
21a
1980
1539
168
12,
1
5,
5
attic
21b
805
676
-
5,
1
5,
5
attic
22
1450
1055
183
14,
1
10,
7
attic
23a
1560
1301
317
9,
2
2,
4
attic
23b
1400
1136
-
7,
1
3,
3
attic
24
1301
1005
409
12,
2 .
3,
5
attic
25*
-
—
_
—
—
—
—
—
26a
1688
1128
413
13,
1
3,
3
attic
2 6b
1034
827
-
6,
2
3,
3
attic
26c
1396
991
-
10,
1
3,
3
attic
27a
1608
1210
448
13,
1
3,
3
attic
27b
862
650
_
5,
2
3,
3
attic
28*
-
-
_
_
-
_
-
* - Not tested.
48
-------
2. Blower Door Test
Table III.9 presents blower door data, and Figures III.46 through 48
present the data in graphical format. Comparisons are made with the
houses in the 1991 study (numbers 1 through 13) in Figures III.49
through 52.
Table III.9. Blower Boor Results
House
House
House
House
Duct
Duct
Duct
Number
ACH50
CFM50
ELA50
ACH50
CFM50
ELA50
14
5.1
2086
271.2
0
.3
120
15.6
15
6.5
2923
380.0
0
. 5
238
30.9
16
7.1
2229
289.8
0
9
293
38.1
17
3.9
1378
179.1
0
5
169
22.0
18
6.7
2470
321.1
0
6
232
30.2
19
5.2
1934
251.4
0
4
128
16.6
20
5.6
1648
214.2
0
7
216
28.0
21
4.8
2099
272 .9
0
6
276
35.9
22
4.6
1447
188.1
0
5
160
20.8
23
3.8
3405
442 .7
0
2
147
19.1
24
5.3
2365
307.5
0
5
201
26.1
25*
-
-
-
-
-
26
7.8
6373
828.5
0
5
373
48.5
27
5.4
2680
348.4
0
3
158
20.5
28*
-
-
-
-
-
Avg.
5.5
2541
330.4
0
.5
199
27 .1
* - Not Tested.
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
HOUSE NUMBER
Figure III.46. House and Duct ACH50.
-49-
-------
7OO0-
6000-
5000-
g 4000-
° 3000-
2000-
1000-
£>
HOUSE CFM50 IBB0 DUCT CFMS)
aL
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
HOUSE NUMBER
Figure 111,47. House and Duct CFM50.
House 26 has three HVAC systems and the- largest footprint in the group,
which could account in part for its large CFM50 and ELA50 values.
900-
SOO-
700-
HOUSE ELASO
DUCT ELASO
600- -
500- -
400-
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
HOUSE NUMBER
Figure III.48. House and Duct ELASO.
-50-
-------
1 3 5 7 9 11 13 15 17 19 21 23 25 27
2 4 6 8 lO 12 14 16 18 20 22 24 26 28
HOUSE NUMBER
Figure III.49. Comparison of ACH50 in 1991 and 1992,
7000-
6000
SOOO-
c 4000-
3QOO-
HOUSE CFMSO IKI DUCT CFMSO
Lt I
ill
l.fi.fc Jfl .Ba-fe JE Ja
1 3 5 7 9 11 13 15 17 19 21 23 25 27
2 4 6 8 lO 12 14 16 18 20 22 24 26 28
HOUSE NUMBER
Figure III.50. Comparison of CFMSO in 1991 and 1992
-51-
-------
QOO
1 3 5 7 9 11 13 15 17 19 21 23 25 27
2 4 6 8 10 12 14 16 18 20 22 24 26 20
HOUSE NUMBER
Figure III.51. Comparison of ELA50 in 1991 ana 1992
Envelope ELA50 is found by subtracting duct ELA50 from house ELA50.
Figure III.52 compares the relative contributions of the ducts and the
house envelope to the whole house ELA50 for both years of the study.
9 11 13 15 17 19 21 23 25 27
8 10 12 14 16 18 20 22 24 26 28
HOUSE NUMBER
Figure III.52, Comparison of Duct ELA50 and House Envelope
ELA50 in 1991 ana 1992.
-52-
-------
3. Pressure Test
Results from the pressure testing is presented in Table III.10. These
data are the high readings for one-time measurements in each test
configuration. In this case "high" means the most positive of the
measurements. Sub-slab measurements were taken in three locations, and
room measurements were taken in each room of the house. The reference
point is the main body of the house, so that a positive measurement of
sub-slab to interior represents a depressurization of the main body of
the house with respect to the sub-slab region. A negative result means
that all other measurements in that particular group were even more
negative than the reported value. A negative value corresponds to a
pressurization of the main body of the house with respect to the
measurement point. A complete listing of test results is found in
Appendix C.
fable III.10. High pressure Differentials (Fa)
High SS
High SS
High SS
High SS
High Rm
High Rm
#
To Int.
To Int.
To Int.
To Int.
To Int.
To Int.
(No AH)
(With AH)
(AH,Drs
(AH, Exh,
(AH, Drs
(AH, Exh,
Clsd)
Drs CI)
Clsd)
Drs CI)
14
-0.3
-0.2
0.0
4.4
2.5
5.2
15
-0.3
-0.7
2.0
5.3
11.2
12.4
16
0.6
-0.2
1.2
2.9
5.8
7.1
17
* 10.6
13.6
7.3
20.6
7.9
6.5
18
-0.4
-0.9
4.0
5.6
9.0
9.9
19
0.0
-0.2
2.8
8.1
17 .2
18.1
20
-0.3
-0.5
1.6
1.9
4.7
3.9
21
0.4
0.0
7.8
10.9
21.3
22.2
22
-0.2
-0.3
7.3
6.1
12.2
12.0
23
0.5
0.5
1.9
4.1
10.1
9.7
24
0.0
-0.2
2.5
4.3
3.9
5.2
25'
* —
-
-
-
-
-
26
0.6
1.2
2.4
5.2
11.5
12.0
27
0.2
0.0
1.2
6.3
9.9
10.5
28'
k * * „
-
_
-
-
-
* - Contains variable speed AH. Configuration of AH unclear.
** - Not tested due to homeowner refusal.
*** _ House not completed.
Sub-slab measurements were taken at three locations in the slab; one in
the main part of the house, one in a remote room, and one at the edge.
Figures III.53 through 57 show each of these measurements for each house
as the test configurations change. The configuration in Figure III.53
is with the air handler (AH) off and-the doors open. The AH is then
turned on with the doors open, and finally the exhausts are also turned
on with the doors open. The exhausts are then turned back off, and the
doors closed, and the last configuration is with the air handler and all
exhausts on with the doors closed. (Data in Figures III.53-60 is taken
from Appendix C.)
-53-
-------
g
%
Figure 111,53. Sub-slab to main body pressure measurements with
the All off and doors open.
» "I i" 1 •"» * i i ¦ 'I » i i i > i i
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
HOUSE NUMBER
House 17 has a variable speed air handler, and it may not have been
turned completely off during this test. The variable speed AH also
makes it difficult to compare the pressures recorded for different house
configurations during this series of tests.
pa MAIN SLAB 111 ROOM SLAB Ml SLAB EDGE
- - - — -
J - ¦
""1 t| I| " " ¦»
%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
HOUSE NUMBER
Figure III.54. Sub-slab to main body pressure measurements with
the AH on and doors open.
k.
-54-
-------
10
MAIN SLAB
ROOM SLAB
SLAB EDGE
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
HOUSE NUMBER
Figure ill.55. Sub-slab to main body pressure measurements with
AH and exhausts on and doors open.
Adding exhausts to the AH is enough to change most of the houses from a
neutral or slightly pressurized state to one of significant
depressurization in most cases. (A positive measurement of sub-slab
pressure with respect to the main body of the house corresponds to a
depressurization of the main body of the house with respect to the sub-
slab region.) Closing doors with the AH on also causes large
depressurization in some of the main bodies of the homes due to the lack
of a return air pathway. This is illustrated in Figure III.56.
14 15 16 17 IB 19 20 21 22 23 24 25 26 27 28
HOUSE NUMBER
Figure III. 56. Sub-slab to main body pressure measurements with
AH on, exhausts off, and doors closed.
-55-
-------
Figure III.57 illustrates the worst-case condition for main body
depressurization in the home, when the doors are closed and the AH and
all exhaust fans are running. All the homes are now depressurized, and
in some cases large driving forces exist for the intrusion of radon into
the home in the absence of an intact vapor barrier and/or sub-slab
mitigation system.
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
HOUSE NUMBER
Figure III.57. Sub-slab to main body pressure measurements with
AH and exhausts on and doors closed.
Figures III.58 through 60 present the results for each measurement point
for three of the test configurations; AH on with doors open, AH on with
doors closed, and AH and exhausts on with doors closed.
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
HOUSE NUMBER
Figure III.58. Main sub-slab pressure measurements
different test configurations.
with
-56-
-------
In every house except number 17, going from the initial configuration to
the final one in Figure III.58 involves a higher depressurization of the
house with respect to the subslab. The behavior in house 17 is unusual,
and may be due to the effects of the variable speed air handler. The
same behavior exists in the room slab measurements (Figure III.59), and
in the edge slab measurements in Figure III.60 all the houses exhibit a
progressive depressurization. (The behavior of the edge of the house
and slab in house 17 are less likely to be influenced by the actions of
the variable speed AH.)
14 ' 15 ' 16 ' 17 ' 18 ' 19 ' 20 ' 21 ' 22 ' 23 ' 24 ' 25 ' 26 " 27 ' 28
HOUSE NUMBER
Figure 111,59. Room sub-slab pressure measurements
different test configurations.
with
DOORS OPEN BHi DOORS CLOSED
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
HOUSE NUMBER
Figure III.60. Sub-slab pressure measurements on the edge of
the slab with different test configurations.
-57-
-------
4. Infiltration Test
Infiltration test results are presented in Table III.11 and in Figures
III.61 and 62.
Table III.11. Infiltration Vest Results
#
ach
Radon
ach
Radon
ach
Radon
ach
Radon
t IfJ**
SLF
off
1
on
2
closed
3
SSD
4
(%)
(%)
14
0.13
2.3
0.44
3.0
0.39
1.8
0.08
2.2
4.8
4.3
15
0.19
0.9
0.50
0.6
0.70
0.9
0.23
0.7
4.6
13.3
16
0.12
2.8
0.61
2.0
0.57
0.8
0.16
0.6
7.0
22.0
17
0.16
1.1
0.47
0.8
0.45
0.6
0.31
1.0
1.8
34.8
18
0.06
1.8
0.18
1.8
0.47
2.2
0.12
2.3
0.0
10.0
19
0.19
3.0
0.26
4.9
0.44
4.0
0.13
2.7
1.7
17.4
20
0.20
0.0
0.52
0.0
0.60
0.0
0.14
0.0
ii; 2
18.7
21
0.12
2.5
0.26
2.7
0.85
3.0
-
-
8.2
_
22
0.13
0.2
0.36
0.4
0.58
0.6
0.22
0.1
6.0
9.2
23
0.31
0.2
0.46
0.2
0.54
0.0
0.18
0.5
8.0
6.6
24
0.22
0.5
0.44
0.6
0.35
0.4
0.12
0.6
11.7
30.2
25
0.12
1.2
0.76
0.7
0.56
0.8
0.08
0.6
24.1
6.9
26
0.27
1.3
0.45
1.4
0.50
1.5
0.20
1.5
18.0
14.7
27
0.17
1.1
0.41
2.1
0.45
1.5
-
-
11.0
-
28
-
-
-
_
-
-
-
-
-
-
Avg.
0.17
¦« —
1.4
0.44
1.5
0.53
1.3
0.17
1.1
6.6
15.7
0.8
0.6
-6
TO
0.4-
0.2
NATURAL ach 11113 AN ON ach
14 15 16 17 18 1S 20 21 22 23 • 24 25 26 27 28
HOUSE NUMBER
Figure 111.61. Changes in house ach for three
configurations.
test
58
-------
Figure III.61 reports increases in ach for each succeeding test
configuration in each house except for 14, 16, 17, 24 and 25. All of
these except 14 have dominant return leaks, and consist of one AH with
multiple returns (2 or more), including one in the master suite.
d 6-
s
r-i 4
cc
RADON 1
Z-
RADON2I
RADON 3
dm ft
14 15 16 17 1© 19 20 21 22 23 24 25 26 27 26
HOUSE NUMBER
Pitnirp TTT fi2 Radon 1 pvp 1 s durlncr infiltration teBtijiff.
A A m v? JUJL«l»*wa*9 Vtv./A* JU W » W 4> 0 JL JL, W «ft» W JUVM.* 1*^7 5? V» dLxlAjy »
Radon levels in house 2 0 were 0.0 for all three testing periods- The
remaining data show that nine out of the 14 houses had changes in radon
levels from test 2 to test 3 that matched the changes seen in ach in
Figure III.61.
5, Radon Stress Test
Results of stress tests conducted to date are included in Table III.12.
As can be seen by the results, the test is not tailored very well to the
house environment, either due to house mechanisms specific to each
house's construction, or due to the large depressurizations used. It
could be that much longer test periods of several hours would be
necessary on large houses to approximate a steady state of radon entry
for anything close to an environmental depressurization level. For
these reasons, the stress test was discontinued in the middle of the
project. Table 111.13 presents radon entry rate data. These data are
also presented in graphical form in Figures III.63 through 68.
-59-
-------
Table III.12. Radon Stress Testing
House #
Radon Cone. @ Given ciP (pCi/L)
lQPa 20Pa 40Pa
Fan Airflow(CFM)
lOPa 20Pa 40Pa
14
15
16
17
18
19
20
1.1
0.8
2.7
1.4
1.5
4.1
1.3
0.5
0.3
2.7
1.2
1. 6
3.6
1.3
1.0
0.0
1.3
0.2
1.4
4.5
0.7
691
973
973
691
973
4 65
844
1086
1675
1371
844
1453
1087
1087
1531
2501
2156
1371
2102
1531
1605
Table III.13. Stress Test Radon Entry Rate
House
Radon
Entry Rate
(pCi/s)
4 Pa Entry
Radon (pCi/1
#
lOPa
20?a
40 Pa
(pCi/s)
Potential
14
361
258
727
130
0.7
15
367
236
0
16000
73.3
16
1247
1758
1331
1410
2.3
17
459
481
130
1780
9.6
18
693
1104
1397
465
1.7
19
905
1858
3271
400
3.8
20
521
671
533
530
2.0
Twenty two stress tests were done over a two year period. The data are
divided into two graphs to better illustrate the test results. All
houses follow the expected pattern of increased CFM with increased
depressurization.
4 5 6 7 8
HOUSE NUMBER
Figure III.63. Blower door CFM during stress test
depressurization. (1-11)
-60-
-------
4500-
4000-
3S00- -
3000-
2500-
2000-
1500-
100O" •
500- -
to Pa CFM ]
20 Pa CFM I
40 Pa CFM
12 13 14 15 16 ' 17 18 19 20 21 22
HOUSE NUMBER
Figure III.64. Blower door CFM during
depressurization. {12-22}
stress
£6S t-
*1
5-.
10 Pa RADON
20 Pa RADON
40 Pa RADON
4-
2-
1-
JJU
_ffl_
Jtt
12345678© 10 11
HOUSE NUMBER
Figure III.65. Indoor radon during stress test. (1-11)
-61-
-------
As can be seen from Figures III.67 and 68, the radon entry rates do not
follow the pattern of increased radon entry with increased CFM. We feel
that the time period for the test (1 hour) is too short for system
equilibrium to be reached.
12 13 14 15 16 17 1B 19 20 21 22
HOUSE NUMBER
Figure III.66. Indoor radon during stress test. (12-22)
4000
35 OO
3O0O'
S
til 2500
s
2000-
1500'
1000
BOO-
10 Pa RATE HH 20 Pa RATE ¦¦ AO Pa RATE
1 I -
..jJl
12 3 4 5 6 7 8 9 10 ' 11
HOUSE NUMBER
Figure III.67. Radon entry rate during stress test. (1-11)
-62-
-------
4O0O
12 13 14 15 16 17 18 1© SO 21 22
HOUSE NUMBER
Figure III.68. Radon entry rate during stress test. (12-22)
6, Indoor Radon Levels
Indoor radon levels were obtained by placing a PYLON monitor in continuous
operation for a minimum period of 48 hours. Capped results are with the
mitigation system capped off, passive results with the system uncapped but no
fan attached/ and active results are with a fan attached to the system and
running. Sub-slab measurements are grab samples taken during the time of each
test. Results appear in Table III. 14 and Figure III.69.
Five systems were activated, although one was due to an initial misreading of
test results (house 27) . Nine of the houses (64%) were below the cutoff point
of 2,9 pCi/L for a 48 hour measurement on the initial capped indoor radon test,
although one of these had a higher level during the passive test and was
eventually activated. An additional house fell below 2.9 pCi/L during the
passive test.
€3
-------
Table III.14. Radon Levels (pCi/L)
#
Native
Capped
Passive
Active
Soil/SS
Indoor/SS
Indoor/SS
Indoor/SS
14
2, 330
1.4
/
5,584
1.5
/
4,530
15*
3,440
1.0
/
2,690
1.9
/
2,840
16
4,080
5.2:
1
3,639
4.3
I
3,683
1.8 / 1,510
17
947/1,660
3.4
t
7,182
3.7
i
3,647
2.8
18*
7,263
2.1
/
3,460
3.4
/
X
2.0 / x
19
1,650
3.0
/
1,158
4.4
/
988
1.7
20
3,000
2.3
I
2,673
2.-1
/
3,040
21
6,860
5.6
/
4,780
4.8
/
4,760
2.88
22
853/2,684
1.1
/
1,240
1.4
/
1,700
23
1,600
0.9
/
2,414
2.8
/
1,090
24
418/2,822
2.5
/
739
1.0
/
2, 664
25
/4512
1.1
/
3,552
0.9
/
4,512
26
2,210
2.5
/
1,940
2.8
/
2,230
27
8,450
3.5
/
3,200
2.2
/
3,700
1.1 / 298
28
6,285
0.9
/
1,660
1.0
/
1,320
* - post-terisioned slab
x - tubes removed at homeowner's request
14 15 15 17 18 19 20 21 22 23 24 25 2G 27 28
HOUSE NUMBER
Figure III.69. Indoor radon levels during capped, passive, and
active testing periods.
64
-------
IV. ANALYSIS
A. SOIL
Soil analysis was done by the Soil Sciences Department of the University
of Florida, and complete results are listed in Appendix C.
1. Soil Radium Levels
An interesting feature of the results is the prevalence of high-radium
content fill soil used in the project houses. Figures IV. 1 and 2 detail
the radium levels for the native and fill soil sanples for each house.
The House 28 native soil value is left off of the second figure to
illustrate the remaining relationships more clearly.
70-|
60-
50-
40-
30* —
20
NATIVE RADIUM
FILL RADIUM
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
HOUSE NUMBER
Figure IV.1. Native and fill soil radium levels.
14 15 1€ 17 1S 19 20 21 22 23 24 25 26
HOUSE NUMBER
27 28
Figure IV.2. Figure IV.1 data minus house 28 native reading,
65
-------
House 28 is built on a lake made from an old phosphate mining operation,
and the sample could contain some localized material from that operation
that is much higher in radium content than the surrounding soil.
St 5^ *4*
Figure IV.3
5 6 7 8 9 10 11 12 13
house number
1991 soil radium data.
Soil radium content might seem to be a good indicator for soil radon
levels, but Figure IV,4 illustrates that this is not the case. Native
radium levels are contrasted with native radon level's with an R2 value
of 0.19. This lack of correlation could be due to soil sampling
techniques not adequately characterizing the site as to average soil
radium content. Soil samples are taken in one location, and soil radon
measured under the slab is produced from a much larger local area.
CM . . .
O 2 4 6 8 10 12 14
NATIVE RADIUM (pCi/1)
Figure IV.4. Native radium and native radon. (Ra ¦ 0.19)
-66-
-------
A study of correlations between radium and radon levels revealed that
native radium readings are a better indicator than either fill soil
radium or total radium (native + fill) levels. These results are
reported in Table IV. 1. Capped and passive SS are radon readings taken
from sub-slab measurement tubes during those portions of the finished
house indoor radon tests.
Table IV. 1. Radium-Radon Correlations. (R2 values)
Native Fill Total
Radium Radium Radium
0.22 0.009 0.14
0.37 0.03 0.03
0.03 0.005 0.005
Capped SS
Passive SS
Indoor Radon
A graph of the native radium to passive sub-slab radon relationship is
shown in Figure IV.5. Figure IV.6 shows native radium with indoor radon
levels, and it is clear that no - correlation exists here (R2 = 0.03).
aooo
7000'
«?. 6000-
%
Ifsooo-
e£ 4000-H
CD
5
to 3QOD-
OQ
CO
2000-
1000-
Figure IV.5.
6 8 10
NATIVE RADIUM (pCi/g)
12
14
Native radium and passive sub-slab radon levels
(R2 « 0.37)
-67-
-------
2 4 6 8 10 12 14
NATIVE RADIUM (pCi/g)
Figure IV.6. Native radium and indoor radon levels.
(R2 - 0.03}
Native radon levels are also not a good indicator of indoor radon
levels, as is shown in Figure IV.7.
1.4-
2- ¦
o
I
15
20
10
2£
NATIVE RADON (pCi/1)
(Thousands)
Figure IV.7. Native soil radon and indoor radon levels.
2. Soil Radon Variability
Soil radon readings are usually taken by grab sample, and not measured
over long periods of time. It is instructive to look at the variability
of these measurements. This section will try to compare the seasonal
variability of soil radon measurements with those taken at different
points under one slab on one day, and at the same point on a slab on
different days. A calculation of standard deviation is made between
these groups of measurements, even though the number of measurements in
each group is too small for statistical validity. The calculations are
-68-
-------
made to show the extent of variability in the measurements. The
standard deviation (S) is derived using the following equation:
where x_i = a particular radon grab
x « average of grabs for a particular slab
N_ t\tiTfiVs^y Tnoa e I* slf an
— iiuLiiujex 01 niecio uzr^xncnus taKcn
S is calculated for each slab, and then averaged over the whole group* of
slabs to generalize.
Figure IV.8 compares measurements in-different seasons on the same slab.
These measurements may or may not be taken at the same point on a
particular slab* (WS—wmter—sprmg, SS~sprmg—suuuue.r, FW=fall—winter)
WS1 WS2 SS1 SS2 SS3 SS4 SS5 SS6 FW1 FW2 FW3
SEASONAL MEASUREMENTS
Figure XV.8. Seasonal soil radon variability.
Not enough data are available to draw definitive conclusions from
the seasonal variations, but the variations within seasons are
consistent.The soil radon levels increased with increasing
temperature (WS and SS) and decreased with decreasing temperature
(FW). This consistency is present even though the measurements
were not always taken at the same measurement point on an
individual slab. The average measurement^in this group is 2665
pCi/L, with an average standard deviation of 1409 pCi/L.
Variations between different points underneath the same slab can
also be significant, as seen in Figures IV.9 and 10. These are
all measurements taken on the same slab on the same day, but at
different sub-slab locations. Multiple listings for the same
slab are comparisons made on different days (group A on one day,
group B on another day, etc.).
-69-
-------
HOUSE NUMBER
Figure IV.9. Sub-slab radon, taken on the same day at
Figure iv.10. Additional SS radon data, taken on the same da*
at different locations.
The average sub-slab radon measurement for this group is 2283 pCi/'L, and
the average standard deviation is 822 pCi/L. Twenty-six of 68
measurements are within 1 standard deviation of the mean, 51 are within
2 S.D./ and 64 are within 3 S.D.. Thus there is a 75% assurance ±1644
pCi/L that one measurement represents the whole slab, and a 94%
assurance ±2466 pCi/L that one measurement represents the whole slab.
Source strength doesn't seem to affect the standard deviation of these
measurements much. As an example, the measurements were divided into a
high and low measurement group, with a cutoff of 2000 pCi/L. The
numbers are evenly divided, with 14 in the high group, and 13 in the
low. The high group's average sub-slab radon is 3283 pCi/L, with an
-70-
-------
aVr221 S5aSffS5-a2y12ti0n °!.!4Z pCi/L (29% of av^ ss radon)and
a range of values of S from 334 to 2135 pCi/L. The low group's
ecf/T9?«57t ff, «' w*th average standard deviation of 688
pCi/L (57% of avg. SS radon) and a range for s from 106 to 1895
taken'»++Llit variation to be analyzed is that of measurements
taken at the same point on a particular slab but on different
IV 11 and l2Same Season* These data *re presented in figures
14 15B 16B 17 10 20B 21A
15A 16A 16C 18 20A 20 C
HOUSE NUMBER
Figure IV.11. SS radon at the same point on different days,
21B 22
21C
24 25B 26 B 28A
23 25A 2SA 27 28B
HOUSE NUMBER
Figure IV. 12. Additional 6S radon at the same poisrt on
different days.
In this group, the average sub-slab radon measurement is 2751
pCi/L, and the average standard deviation is 1012 pci/L. 13 of
26 measurements are within 1 S.D., and 25 are within 2 S.D.. For
a measurement taken on any given day, there is a 50% assurance
+1012 that the value will be the same as that measured on another
-71-
-------
day, and a 96% assurance ±2024 pCi/L. Comparing these numbers
with those for the seasonal variations, it is apparent that
variations on the same slab and on different days at the same
measurement point have approximately the same level of
variability attached to them.
Moisture content of the soil and weather conditions during sampling can
affect variability, of course, but most measurements were taken under
aya 11 \r eimi 1 av "l I- *i Ania f av .e^sst r»"h na 4 r»i il fly a 1 bK fivr'D'Ah f nv hhAca
y cilcX QX J>y 5? JLIIUL JL C* X. vUIiUiXCXwIli? X UX 'CJClviii wXvUXCiX 0 JL O § ¦ CNriv> l>UX WilUdC
taken in different seasons, where temperature differences exist. Those
taken on the same slab on the same day have the most similar conditions,
especially soil moisture content, as it is assumed to be relatively
uniform beneath the slab. No measurements were taken during rainstorms,
or when the ground had been recently saturated by rainfall.
Most variability is due to the inhomogeneity of the soil radon source,
and differences in the radon diffusion through, and emanation from, the
soil. Most building sites will have a large variability in the radon
being produced m the soil from one side of a slab to another. We
recommend that soil radon measurements be used only for classification
#¦% "f" s4 f" AO ckcs #¦' #¦% 1 ATi? «nA#9
-------
Stem-wall slabs should create more of a barrier to pressure driven flow,
especially where the stem wall has been built up to accommodate sloping
terrain. It should be emphasized that this is only a value calculated
by extrapolation from the pressure field gradient for field extension
from the end of the ventilation mat, but does give an idea of how well
the mat system will work depending on the varying distances of mat end
to slab edge.
Figure IV. 13 illustrates how the measurement points were chosen for this
study. Only those points outside of a perpendicular to the slab end
were chosen to eliminate those points feeling an additive effect from
more than one portion of ventilation mat. Points in the middle of the
slab opposite a long run of mat are usually well affected by multiple
points along the mat, and variations from the code requirement that the
mat be not more than 25 feet from the edge of the slab are not usually
needed, as slabs are seldom more than 50 feet wide.
no
x
yes
no x
yes
no
no
x
yes
x
yes
yes
Figure IV.13.
Criteria for choosing mat end to
slab edge measurement points.
Figures IV.14 and 15 compare the distance from the mat end to the slab
edge with the calculated value for the distance required for the
pressure field from the mat to go to zero. Data from wellpoint suction
pipe systems are included also. These data are compared to the 1:1
line, as it is expected that the pressure will go to zero at or just
beyond the slab edge due to short-circuiting to the atmosphere.
The data are separated by type of slab, with the first showing
monolithic slab results. Measurement points for monolithic slabs are
usually 2.5 to 3 feet inside the slab perimeter, due to the perimeter
beam trench. A half dozen or so (out of more than 60) calculated
distances for P=0 greater than the actual distance were found, which is
surprising since the monolithic footer is not an effective barrier to
the pressure field. Having the field go to zero just inside the footer
for most of the calculations is not a great problem, however, since
there is no perimeter joint in the concrete and the beam itself is a
thickened and reinforced portion of concrete not given to cracking.
-------
Figure IV.14. Distance for P=0 for monolithic slabs.
The data from the stem-wall slabs shows the same behavior, again
surprising as it was expected that most calculated distances for P=0
would be greater than the actual distance from the mat end to the slab
edge. This could be due to the pressure field short-circuiting through
the block stem wall. Measurement points in this case are located about
one foot inside the actual slab perimeter, due to the lack of a
thickened beam. Most of the measurements show P=0 at or just inside the
stem wall, and this could allow soil-gas intrusion into the home if good
slab edge details were not followed during construction.
Figure IV.15. Distance for P=0 for stem-wall slabs.
These data support the provision for not allowing ventilation mat within
six feet of the slab perimeter, as short-circuiting can easily occur due
• to the lack of an effective pressure barrier provided by either the
monolithic or stem-wall slab perimeter detail.
-74-
-------
Figures IV, 16 and 17 show results for a similar study done on the houses
in the 1991 project. The 1991 monolithic slabs seem to have performed
better than in 1992, with a larger percentage of measurements above the
1:1 line. Both graphs show that the pressure fields extend to the edge
of the slab, or just inside of the edge, and then rapidly fall off to
zero.
Figure IV.16.
15 20 25 30
MAT END TO SLAB EDGE (ft)
1991 monolithic slab distances from the mat end
for the pressure field to equal zero.
Figure IV. 17. 1991 stem-wall slab distances from the mat end
for the pressure field to equal zero.
2. Cracks
Crack data from both years of the study will be included here to expand
the sample size. Average values for total crack length per house are 83
ft. for 1991 and 44 ft. for 1992. These values do not include control
joints purposely cut into the slabs. Figure IV.18 presents total crack
-75-
-------
length data separated by slab type. Average crack length per house is
100 ft. for monolithic slabs, 36 ft. for stem-wall slabs, and 13 ft. for
post-tensioned slabs.
450'
400
350"
EE 3O0'
3 250-
ac:
o
g ZOO-
o
5^ 150-
¦— 100-
50-
O-
MONOLITHIC
STEM WALL
POST TENSION
.1781,1
1
1 4 10 12 16 20 24 5 8 19 23 27 Q 18
2 7 11 13 17 21 25 6 14 22 26 28 3 15
HOUSE NUMBER
Figure IV.18. Total crack length per house by slab type.
Figure IV.19 breaks out the total crack length per house by plasticizer
use. Post-tensioned slabs are again separated, because the tightening
of steel cables laid in these slabs makes comparisons based on any other
criteria meaningless. Average crack length for houses using plasticizer
is 63 ft., and without plasticizer is 76 feet, only a marginal
difference.
4S0-
2 5 7 11
4 6 8
13 16 20 22 27
12 14 17 21 24 26
HOUSE NUMBER
1 23 28 18 3
19 25 15 ©
Figure IV.19. Total crack length per house by plasticizer use.
Figure IV.2 0 examines total crack length by corner reinforcement.
Reinforcement of inside corners is designed to help eliminate cracks
starting in these areas. In 1991, only one house contained corner
-76-
-------
reinforcement, and 7 of 13 houses had cracks originating at an inside
corner. In 1992, all but one house had some type of inside corner
reinforcement, and only 5 of the 15 houses contained a crack originating
from an inside corner. In house 23, however, it appears the
reinforcement has only forced the crack to start beyond the extent of
the reinforcement. Average total crack length for reinforced houses is
51 ft., and 98 ft. for non-reinforced.
12 16 IS 21 23 25 27 1 A 6 8 11
14 17 20 22 24 26 28 2 5 7 10 13
HOUSE NUMBER
Figure iv.20. Total crack length vs. corner reinforcement*
The relationship of total crack length to the slump of the concrete used
in the slab is examined in Figure IV.21. No direct correlation is seen
in this limited data.
500-
Q W/O PLASTICLZER
WITH PLASTICLZER
*ta*
€3
S3
3.5
4.5 & S.5 6
SLUMP (in.)
6.5
7.5
Figure IV.21. Total crack length vs. slump for slabs with and
without plasticizer.
-77-
-------
The ordered slump for a slab pour is not always an accurate indicator of
the concrete that is actually poured in place on a construction site.
The footers and thickened sections around tubs and garage step-downs
usually get concrete not mixed with much water. As the work progresses
toward the middle and back portions of a slab, especially if the truck
has no access to these areas, more and more water will be added to the
concrete to allow the workers to drag it into place. This makes for an
inhomogeneous pour as far as slump is concerned. In same houses cracks
will stop before reaching the edge of the slab, in part because of the
lower slump concrete in the'edge beam. Houses 21 and 24 are examples of
this. Figure IV.22 shows^indoor radon versus the slump of the concrete.
A higher slump concrete "might be less dense, and allow more radon to
diffuse through into the house,, but no such effect is seen here.
6- -
5-
4-
3-
2-
1-
NO PLASTICIZER o PLASTICIZER
m POST TENSION
,.w.,
"Or'
o
•t3"
.a.
4.5
(S 5
SLUMP (in.)
6.S ¦
7.5
Figure IV.22. Indoor radon versus concrete slump,
Figure IV.23 examines indoor radon with respect
length, and this also shows no correlation.
to the total crack
100
150 200 250 300
TOTAL CRACK LENGTH (ft.)
450
Figure IV.23. Indoor radon versus total crack length.
-78-
-------
During crack testing in 1991, a high of 2370 pCi/L of radon was pulled through
a crack in house 7, the house with the highest source term (>20,000 pCi/L) in
the project; the next highest value was 234 pCi/L, and all others were under
50 pCi/L. In 1992, the highest value was 666 pCi/L, and the rest of the
results were under 25 pCi/L, with four tests returning 0 pCi/L. These results
were obtained in spite of using much higher depressurizations {-30 Pa) than are
normally found in the house environment, and do not correspond to variations
in sub-slab radon.
It would seem that the vapor barriers in these homes are providing a
good shield against radon intrusion. That radon can be drawn through
cracks the size of those found in these slabs is attested to by the few
high values returned during the crack tests, but the lack of
consistently high values leads to the conclusion that most vapor
barriers are intact under new house slabs. How long they will remain
intact will determine whether these homes will find radon intrusion
through slab cracks a problem in the future.
Discounting radon entry through slab cracks as a major factor in new
homes leaves other slab penetrations for consideration. A series of
chambers designed to test pipe penetrations in new slabs has been
developed by FSEC, and penetrations on one house have been tested,
although no significant radon was measured, probably due to the fact
that the penetrations in the house were tarred, which is the preferred
method for sealing penetrations against soil gas intrusion. Pipes
protected by plastic sleeves, however, allow an avenue for soil gas
intrusion between the sleeve and the pipe, and testing this type of slab
penetration should be done to determine its effectiveness against soil
gas. Houses in the project are divided according to whether tar was
used on the pipe penetrations or not, and shown in Figure IV.24 versus
indoor radon The indoor average for houses with no tar on their pipes
is 2.94 pCi/L, and is 1.93 for houses with tar on the pipes. This
result at least suggests that more testing of pipe penetrations is in
order.
. wa no tar ON PIPES
Ill I "1 T r I J — , I » j' X T I I I ( \ -f
1 3 S 7 9 11 13 17 22 IS 19 23 25 27
2 4 6 8 10 12 16 21 14 18 20 24 26 28
HOUSE NUMBER
Figure IV.24. Indoor radon levels separated by the use of tar
on pipe penetrations.
-79-
-------
Further evidence of radon being drawn through pipe penetrations is found
in data obtained from House 7. Figure IV,25 shows data taken from the
living room wall cavity containing the mitigation stack in house 7
during a period when the mitigation system was not running. Wall cavity
radon levels were recorded by continuous sampling using pumped
recirculation of air inside the cavity, A daily cycle of elevated radon
is being drawn into the house through the pipe penetrations, which in
'this house had plastic sleeves without tar protecting the pipes. These
penetrations were not sealed according to the Standard.
Figure IV.25. Radon through pipe penetrations in Bouse 7,
Figure IV.26 contains data from a one-time event that occurred
before a heavy thunderstorm'. The bathroom wall cavity contains
water pipe and tub drain penetrations. Its scale is on the right
of the figure, and shows a high value of over 450 pCi/L during a
time when the mitigation system was not running.
Figure IV.26. Radon intrusion preceding a rainstorm
in House 7.
80
-------
Figures IV,27 and 2 8 present comparisons of indoor radon levels with the
slab equivalent area and the slab figure of merit, both based on slab
cracks. Neither of these has a correlation with indoor radon.
6-
5
O 0.01 0.02 0.03 0.04 O.05 O.OS 0.07 0.08
SLAB EQUIVALENT AREA (sq.in.)
Figure IV.27. Slab equivalent area and. indoor radon.
6-
ai
j
°0 """ 5 To 15 20 25 30
FIGURE OF MERIT (sq.in.XpCW)
(Thousands)
Figure IV.28. Slab figure of merit and indoor radon.
The lack of correlation in these last two graphs underscores the
separation of the amount of slab cracking from any effects on indoor
radon levels. This is probably due to the intact vapor barriers under
new homes. Slab penetrations, on the other hand, are only required by
the code to have the vapor barrier come to within one half inch of the
pipe. This creates a built-in avenue for radon to move from the soil
into the house through the joint between the pipe and the concrete.
81
-------
It is recommended that the same measurements be taken oil slab penetrations
that were heretofore taken on slab cracks, with equipment similar to that
already developed by FSEC, and using the same measurement protocol and
data reporting. h slab pipe penetration area can be calculated, and a
slab figure of merit based on slab penetrations can be obtained.
Measures taken to eliminate soil gas flow through cracks caused by pipe
penetrations can include sealing vapor barriers around pipes under the
slab, possibly with hot air blowers and heat shrink materials, and the use
of tar around all penetrations to provide an airtight seal.
It is our opinion that requirements for concrete slump can be relaxed from
4 to 5 inches without measurably increasing indoor radon levels.
Requiring a 4 inch slump would be unenforceable, as it would require an
inspector to be on hand for every concrete truck delivery on every slab
built in the code area. It would also be an economic hardship to builders
as 4 inch slump concrete cannot be pulled across a slab by hand and would
require a pump truck to place the concrete on any slab with access
problems.
3• Slab Leakage
Three methods of determining slab leakage were tested, slab leak fraction
(SLF), achA, and achB, listed in Table III.6. Slab achB subtracted the
natural infiltration rate from the "mitigation fan on" infiltration rate
to arrive at a slab air change per hour, anticipating that the "mitigation
fan on" rate would be larger than the natural rate by an amount that could
be attributed to the slab. This situation did not occur, however, as the
natural rate was higher than the "mitigation fan on" rate for 7 out of the
12 houses reporting. There is obviously a more complex relationship in
place here, allowing the mitigation fan to distort the natural
infiltration rate, and this method of slab leakage calculation will be
discarded.
The slab leak fraction is found by dividing the house tracer gas
concentration into the mitigation stack tracer gas concentration, and slab
achA is found using the stack tracer gas concentration to calculate the
rate of conditioned air flow through the stack, which is divided by the
house volume. Table IV.2 reports R2 values for various relationships
involving SLF, achA, achA divided by slab area, total crack length, and
indoor radon levels.
Table IV.2. Slab Leakage R2 Values
SLF achA achA/ft.2
Crack Length .005 .035 .005
Indoor Radon .19 ,36 .08
These data suggest that achA, the slab air change calculation using the
amount of conditioned air flowing through the mitigation stack, is the
-------
with indoor radon levels, which are assumed to enter the house through
the slab. Normalizing achA by dividing by the slab square footage
worsens the R2 value.
The higher R2 value for achA is due to in part to the division by the
house volume, which is the amount of space a certain amount of radon has
to expand into. The slab leak fraction does not take volume into
account, and has a smaller correlation with indoor radon. The low
correlation of SLF with total crack length also suggests that the slab
leakage is not occurring through cracks in the slab. Figure IV.29
presents achA compared with indoor radon.
6
O
0,01
0.02
0.03
0,04
achA
O.OS
0.06
0.07
0.08
Figure IV,29. Indoor radon versus air changes per hour through
the slab.
(JO
5 9 11 14 22 24 26 4
3 6 10 12 15 23 25 2
HOUSE NUMBER
16 18
8 17 19
Figure IV.30. Slab ach for activated and unactivated houses
-83 ^
-------
Comparing the average achA of activated houses with unactivated houses in
Figure IV.30 reveals that the average achA of activated houses is 160%
higher than that of the unactivated houses. The mechanism represented by
achA seems to be an important measure of the radon entry pathway through
the slab, and should be further investigated.
C. HOUSE
On the average, the houses needing activation of their mitigation systems
in this project were 11% smaller than those not needing active mitigation.
They were tighter, with a lower ACH50, but had a higher slab ach as seen
in the last section. They also had higher depre s sur i z at ion levels with
respect to the sub-slab region. Illustrations of these points will be
made in the following sections. Houses with active systems will be
referred to as "activated."
1. Blower Door
Averages and percentage differences for the results of blower door testing
are presented in Table IV.3. Activated houses having a higher average
slab ach as reported in Figure IV.29 and a lower overall ACH50 than
unactivated houses suggests that a larger percentage of the infiltration
air is coming through the slab in these houses.
Table IV.3. Blower Door Averages and % Differences.
Unactivated
Activated
% Difference
House ACH50
6.34
5.94
-6.3
House CFM5 0
3032.
2359.
-22.
House ELA5 0
394.
312.
-21.
Duct ACH50
.55
.58
+5.
Duct CFM50
257.
238 .
-7.
Duct ELA50
33.4
30.9
-8.
Duct Leak %
16.8
13.4
-20.
These results do not show us how radon is entering these homes, but may
explain in part why radon levels in these homes are somewhat higher than
in the others. It is also a reminder that making houses tighter for the
sake of energy conservation can lead to concerns over the air quality in
homes.
Figures IV.31 and 32 show house CFM50 and ELA50 respectively for
unactivated and activated houses. Activated houses have had their systems
activated. Unactivated houses have systems in passive mode.
84
-------
1 S 9 11 14 20 23 26 2 7 13 17 1©
3 6> 10 12 15 22 24- 27 4 8 16 18 21
HOUSE NUMBER
Figure IV,31, House CPM50 and system activation,
14 20 23
26 2 7 13 17
3 6 10 12 15 22 24 27 4
HOUSE NUMBER
19
16 18 21
Figure IV.32. House ELA50 and system activation.
2. Differential Pressure
Differences in activated and unactivated -houses are illustrated in
Figure IV.33. The main bodies of activated houses on average were
depressurized to -3.34 Pa with respect to the main sub-slab area, a 101%
increase in depressurization from that of unactivated houses. When
house 6, the one with the highest depressurization in the group, is
taken out, che average depressurization of the main bodies of activated
houses is 204% greater than that of the unactivated houses.
k
-85-
-------
HOUSE NUMBER
Figure IV.33. Average depressurization with the air handler on
and doors closed.
The subslab with respect to house main body pressure differential is
shown compared to indoor radon in Figure IV.34. An R2 value of .27
indicates no strong correlation, but the figure illustrates the trend of
activated houses having larger subslab to main body pressure
differentials. (A positive measurement of subslab to main body
represents a depressurization of the main body with respect to the
subslab.) Higher pressure differentials can lead to increased radon
entry, but also increases infiltration, which dilutes indoor radon if
the infiltration airstream is not connected to a radon source.
!5t *v
o 53
Q.
S£ 3'
1-
-2
-EI/
o UNACTIVATED
ACTIVATED
o
o
n f~i
o
o
.a.
,.Q..
2X68
DIFFERENTIAL PRESSURE (f^a)
t-
6
—f—
10
12
Figure IV.34
Indoor radon versus subslab to main body
pressure differential with AH on and doors
closed.
-86-
-------
4. Infiltration
Infiltration testing revealed that the activated houses were among those
with lower natural infiltration rates, as shown in Figure IV.35. The
average natural infiltration rate for activated houses is 31% lower than
the average for unactivated houses. (.139 ach vs. .201 ach)
0.1S
0.25 0.3 0.35
NATURAL ach
0.45
O.S
Figure IV.35. Natural ach and indoor radon.
Return leak fraction (RLF) vs. with indoor radon, shown in Figure IV.36,
also highlights the trend for activated houses to be tighter. Average
RLF for unactivated houses is 9.7%, and is 4.8% for activated houses.
Figure IV.36.
RETURN LEAK FRACTION <%)
RLF versus indoor radon for activated and
unactivated houses.
-87-
-------
4. PVAC
The total duct leakage of systems in compliance with the Draft
Standard were compared to those not in compliance in Figure IV.37.
Compliance with the Draft Standard requires the use of mastic on duct
closures, and airtight seals on plenums. A system for this comparison
must have had over 75% compliance to be listed in compliance with the
Draft Standard. The average total duct leakage (supply % + return %?
for non-compliance systems is 16.8%, and is 13.4% for systems in
compliance, a difference of -20% in duct leak percentage for systems
using mastic on duct closures.
1 3 5 7 11 13 15 18 20 O 17 23 25 27
2 4 6 8 12 14 16 19 21 lO 22 24 26 28
HOUSE NUMBER
S,
Figure IV.37. HVAC system compliance and total duct leak %.
Duct leakage can cause either pressurization or depressurization,
depending on whether the return side or the supply side of the system is
dominant. This effect is overcome by door closure, however, as can be
seen in the following figures. The situation with the AH on and doors
open is illustrated in Figure IV.38. The division into supply and
return dominant systems was accomplished by subtracting the supply leak
percentage from the return leak percentage. Since supply leaks are
normally associated with depressurization, they are then listed on the
negative side. The positive side contains the return dominant systems.
This division is .artificial and is for illustrative purposes only. The
pressures reported here are measured in the middle of the sub-slab
region and referenced to the main body of the house.
With the doors open, more of the return dominant systems are positively
pressurized than depressurized, and more of the supply dominant systems
are depressurized. Keep in mind that these measurements are taken with
respect to the main body, and represent the pressure on the sub-slab
side of the slab boundary, therefore a positive reading in these figures
denotes depressurization of the main body of the house with respect to
the subslab. Conversely, a negative reading denotes pressurization.
-88-
-------
14
12-
10-
SUPPLY DOMINANT
4-
2- —••••••
RETURN DOMINANT
-2-
-10
Figure IV.38.
X
10
15
O S
DOMINANT PERCENTAGE
Supply and return dominant systems versus dP
between the subslab and main body with AH on and
doors open.
This convention is confusing, but arises from the method of data
collection. The data collection station during a house test is in the
main body of the house because that is the most centrally located area,
and measurement tubes can be run in all directions with ease. The base
comparison pressure then is that of the main body of the house. This
convention is followed throughout this report, and in the data reporting
sections.
Closing the doors, as seen in Figure IV.39, causes the main body of all
but one of the return dominant houses to go negative with respect to the
subslab, the main body of all the supply dominant houses to go negative,
and all but one of the neutral systems also. (The neutral systems are on
the zero line, and contain equal percentages of supply and return
leaks.)
It seems that the average supply dominant system is still more
depressurized than that of the return dominant systems, but it is clear
that door closure overcomes the differences normally found between the
two types. This effect shows that return dominant systems are not
natural barriers to radon intrusion, as door closures can cause a
significant driving force to exist. The effect of door closures on
house to subslab pressure differentials will have to be taken into
account in figuring the amount of outside air needed to pressurize the
house.
89
-------
1S-
10-
SUPPLY DOMINANT
RETURN DOMINANT
-ID
o s
DOMINANT PERCENTAGE
IO
15
Figure IV.39.
Supply and return dominant systems versus dP
between the subs lab and main body with the AH on
and doors closed.
Figure IV,40 shows the pressure differences between a closed room and
the main body of the house. In this instance the measurements represent
the pressure in the closed room with respect to the main body. The
average supply dominant system remains more depressurized in the main
body of the house with respect to the closed room.
SUPPLY DOMINANT
RETURN DOMINANT
• — * """1
~ «
• • a
~
~ ^
1
I !
1 1*
»
¦uljljlJ
10-*
-10 -5 O 5 10 IS
DOMINANT PERCENTAGE
Figure IV.40. Supply and return dominant systems versus dP
between a closed room and the main body with the
AH on and doors closed.
-90-
-------
5. Radon Stress Test
This test was discontinued midway through the project due to a lack of
meaningful results. This is illustrated in Figures IV.41 and 42,
showing no correlation between indoor radon levels and the 4 Fa entry
rate or the radon potential, both calculated from the radon stress data.
0.
3- —
1000
2000 3000 4000
* Pa ENTRY RATE
6000
6000
Figure IV.41. Indoor radon versus 4 Pa entry rate.
Figure IV.42,
20 30 4b -^0
RADON POTENTIAL
-------
6. Indoor Radon
Relationships with indoor radon have been investigated throughout the
report, with no direct correlations found, due to the complex nature of
the house as a system. No individual aspect of the construction stands
out as being able to control radon intrusion.
Three ent 2. t les have been chosen to be investigated m combination to
determine their relationship with indoor radon. Sub-slab radon was
chosen as the most likely source term, differential pressure across the
slab was chosen as a likely driving force, and slab achA was chosen as
the best measurement characterizing the slab as a radon entry pathway.
Figure IV.43 relates indoor radon to sub-slab radon times slab achA,
with an R2 value of .31. Figure IV.44 relates achA times dP with indoor
radon levels with an R2 of .49 (without house 17) .
so
100
150 200 250
SS RADON X achA (pCi/l)
300
350
*O0
Figure IV.43. Sub-slab radon and achA versus indoor radon.
5.5
5-
4.5-¦
. A-
3.5-
3"
2.5' -**"
S 2"
1.5-
1-1-—
0.5
o.n
0.2
0,3 0.4 O.S 0.6 0.7
SLAB achA x dF (Pa)
0.8 0.9
Figure IV.44. Slab achA times dP versus indoor radon.
92
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Figure IV.45 multiplies all three of the selected entities to obtain an
R2 of .42 against indoor radon. Houses 2 and 17 have been dropped as
outIyers.
^ I.
%
x 9.5- •
2LS*
2+
1,5'
1-
o.s-
so
lOO 150 200
SS RADON XdPX mchA
2 SO
300
Figure IV.45. Selected entities versus indoor radon.
None of these results in a strong correlation with indoor radon, but may
be as close to a relationship as may be found while investigating real
world houses. Making comparisons among houses built as diverse as this
group will always be difficult at best. Testing new homes in the field
is informative and enlightening, but determining relationships among
certain building components might be done better in a laboratory
setting.
7. Model Validation
An analysis of FSEC data was done using the Rodgers and Associates (RAE)
lumped parameter model, based on the forms of the model presented by RAE
at the March 1993 Quarterly Review Meeting of the FRRP. The equations
used were those shown below.
Cnet = 0.0011 Ct Xv~l (stemwall slabs)
Cnet = 0.00059 C, Xv*: (monolithic slabs)
where Xv = house ventilation rate in ACH
Cs = subslab radon concentration
Using these two equations for natural ACH, AH on ACH, and AH on doors
closed ACH, R2 values were obtained which were quite low. R2 values
improved when average sub-slab radon values were inserted, with the
highest R2 of 0.005 for the AH on infiltration.rate.
These correlations are very poor, so ah effort has been made to improve
them by modifying the model. A measurement of slab leakiness was added,
using SLF to obtain a slab ACH. Finally, an adjustment factor was added
that seems to help the correlation.
93
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SLF is the slab leak fraction found by tracer gas methods. The slab ACH
is obtained by multiplying SLF by the stack conditioned air CFM and
dividing by the house volume. The adjustment factor merely takes the
square root of the model prediction and multiplies it by 10. The new
equations are shown below.
Cmt s= 0.0011 C, (slab ACH) (stemwall slabs)
Cn.t = 0.00059 C. (slab ACH) X*"1 (monolithic slabs)
where Xy = house AH on ventilation rate in ACH
' adjustment ¦ JU^XIO
Applying the modified model with slab ACH factor and adjustment factor
improves the R2 value from 0.005 to 0.4. Figures IV.46 and 47 illustrate
these two cases.
Figure IV.46. RAE model correlation with average indoor radon.
Figure IV.47 Modified and adjusted RAE model correlation with
average indoor radon.
k
-94-
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Many factors contribute to variability when testing the model, including
test periods of relatively short duration (48 hrs.), limited
measurements, and builder and homeowner behavior. We conclude that the
model needs some measure of the entry pathway through the slab to be
more accurate. As it now stands, the model includes the source and
dilution terms, but not an "aperture" term. How large is the opening
through which the radon can be drawn? Efforts were made to include a
driving force term using the pressure differentials between the sub-slab
and the house interior, but this did not improve the correlation.
8. Mitigation System Costs
During the course of the project, Enkavent and Terradrain brand
ventilation mat, and wellpoint PVC pipe systems were used. The Enkavent
has a half-inch thick eighteen inch wide plastic fibrous layer lined
with fabric. Terradrain consists of a solid 24 inch wide plastic strip
with small dimples formed into it and covered with a fabric layer to
create the airflow passageway. All suction stacks for the vent mat
systems were 3-inch PVC pipes. In this estimate a cost of $1.80/ft. is
used for vent material, $50 for plumbing the system from the slab
through the roof, $50 for the electrician, and $5 for plumbing fittings
at the slab.
The wellpoint systems use 2-inch pipe costing $2.48/ft., while regular
2-inch PVC costs $.80/ft. The regular PVC is run until a suction area
is desired, and then a short section of wellpoint (3-4 ft.) is inserted.
These estimates include any fittings as well as the $50 charge for the
plumber to run the stack through the roof. The labor cost of two man-
hours is not included for installation of mitigation systems. Fan costs
in houses requiring active mitigation are listed separately, and include
any fittings required. Table 12 below details system costs for the
project.
Table IV.4. Mitigation System Costs
House
#
System
Type
Cost
Fan
Size
Fan
Model
Cost
Total
Cost
14
Wellpoint
$183
$183
15
Enkavent
$219
$219
16
Enkavent
$188
4"
f-100
$ 98
$286
17
Enkavent
$208
4"
f-100
$ 98
$306
18
Terradrain
$166
4"
f-100
$ 98
$264
19
Pit/W.Pt.
$165
6"
f-150
$122
$287
20
Terradrain
$133
$133
21
Wellpoint
$162
3"
GP-501
$160
$322
22
Enkavent
$190
$190
23
Terradrain
$182
$186
24
Terradrain
$147
$147
25
Terradrain
$150
$150
26
Terradrain
$182
$182
27
Wellpoint
$169
4"
f-100
$ 98
$2 67
28
Enkavnent
$239
$239
95
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V. HOUSE 1 REPORT
House 7 was extensively monitored in the summer of 1991 to determine the
cause of high indoor radon levels despite the operation of an active
sub-slab mitigation system. The indoor radon levels rose between the
capped indoor test and the passive indoor test, and even went up during
the active mitigation system test periodJ Subsequent one day
measurements by a team of investigators from FSEC, FAMU, DCA and USEPA
could find no radon entry pathway sufficient to cause the average
indoor levels to remain above the action level of 4 pCi/L.
Continuous radon monitors (PYLOlJ AB-5) were subsequently set up to read
indoor, ambient, subslab, attic, and wall cavity radon levels for a
period of 6 weeks. Complete results for every measurement station are
not available due to breakdown and malfunction of some monitors, but
enough data was collected to explain the radon entry mechanism in the
house.
Earlier figures illustrated radon entry through slab pipe penetrations
in house 7 (Figures IV.25 and 26). Figure V.l gives further proof of
this phenomenon during a four day period in June of 1991 when the
mitigation fan was not running. Family room radon levels follow the
bath wall cavity levels, showing that radon is entering the house
through slab penetrations. This effect is likely to be overshadowed by
infiltration of radon-laden ambient air, however.
Figure v.l. Ambient, bath wall, and family room radon levels
in House 7.
Figure V.2 returns to the wall cavity containing the mitigation system
vent stack after the system's fan is turned on. It is clear from this
figure that the air flow through the slab penetration has been reversed
with the activation of the mitigation system, as expected. The wall
cavity radon level now follows the family room level, but is still
receiving elevated radon from somewhere.
-96-
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Time (hours)
Figure V.2. Family room and vent stack wall radon levels in
U ah OA *7 «.«<( 4>1% I^Va «n 4 4 #vsk f* 4 #%n 4*avi avi
IIOUo@ # WlwU w&9 2illuXpoi*XQ£L tall Ou •
In Figure V.3, ambient radon levels taken at 4 feet above ground on the
side of the house are overlaid on the previous graph. It is clear from
this figure that the source of the high indoor radon in house 7 when the
mitigation system is running is the surrounding ambient air. The house
is experiencing radon intrusion in the early hours of the morning high
enough to raise average levels above 4 pCi/L. The early morning hour
entry time explains why investigators were unable to uncover the cause
of the problem during a day-long test.
Figure V.3. House 7 radon levels with the mitigation fan on.
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Figure V.4 illustrates the cyclical nature of the early morning radon
peaks, compared with the family room levels.
Figure v.4. House 7 ambient and family room radon levels.
Once the extent of the ambient radon levels were discovered, a section
of PVC pipe was attached to the house to measure radon levels at the
height of 20 feet above the ground. Figure V.5 shows the 4 foot and 20
foot radon concentrations, illustrating that the house is completely
surrounded by radon gas for a certain period every morning.
Figure V.5. Ambient radon levels at 4 and 20 feet above ground.
Figures v,'6 and 7 show that radon is entering the house by natural
infiltration. First the attic level.is shown following the 20 radon
concentration, and then the family room is shown reacting along with the
attic level. The house radon concentration peaks at roughly the'same
time as the attic, but the attic levels fall off before the house
levels because of increased air flow through the house eaves.
k
-96-
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Figure V.6. House 7 ambient and attic radon levels.
12-
10
8
6'
A
2
0'
Family Room Attic
:jy
Tim# (hours)
Figure V.7. House 7 family room and attic radon levels.
The site on which house 7 sits is a reclaimed phosphate mine, and is
obviously not indicative of the conditions under which most houses
exist. There are enough sites of this type, however, to make further
investigation of this one desirable. Modeling the atmospheric
conditions that allow this cyclical radon emanation could be done on
this site because a container to collect the radon is not needed. Here
the natural radon levels are high enough for accurate measurement
without interference between the driving force and radon emanation.
k
-99-
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VI. CONCLUSIONS
A. SOIL
Fill soil with high radium content continues to be used in the area of
this study. Seventy percent (16 of 23) of the houses for which both
radium measurements are available had higher radium values in the fill
soil than in the native soil. Native soil radium seems to have a greater
effect on final indoor radon levels, probably due to the thin fill soil
layer on most houses. Neither native nor fill soil radium levels directly
correlate with indoor radon, however. High levels of radium in fill soils
can still import a radon problem onto a site that otherwise would not have
one based on native soil gas readings.
Sub-slab measurements of soil-gas radon taken at the same point on
different days can vary by as much as 100%, and measurements taken at
different points on a slab on the same day can also vary by 100% or more.
This variability matches that of measurements taken in different seasons
on the same slab, and leads to the conclusion that a number of
measurements taken on the same day at different locations on a site are
necessary to adequately characterize radon potential.
B. SLAB
All sub-slab mitigation systems had adequate pressure field extension,
although pressure fields for both monolithic and stem-wall slabs dropped
to zero just inside or at the slab edge. Short-circuiting of the pressure
field can occur if the ventilation mat or suction pit is located closer
than six feet from the slab edge. The six foot distance mentioned in the
Draft Standard should be taken as a minimum, as distances up to 4 0 feet
measured from the end of a ventilation mat to the slab edge have been
depressurized.
Post-tensioned slabs performed best at preventing cracks, containing an
average crack length of 13 feet in four slabs. Stem-wall systems had an
average of 3 6 feet of crack in 10 slabs, and monolithic slabs an average
of 100 feet in 14 slabs. Average crack length in slabs using plasticizer
in the concrete is 63 feet, compared with 76 feet in slabs without
plasticizer. Plasticizer use seems to have the desired effect of reducing
total crack length when all slabs are lumped together, but conflicting
results appear when slabs are separated by type. Average crack length in
two monolithic slabs with plasticizer was 35 feet, and was 114 feet in ten
monolithic slabs without plasticizer. Stem-wall slabs, however, had an
average of 7 5 feet of cracks in three slabs with plasticizer and only an
average of 16.5 feet of cracks in eight slabs without plasticizer. Also,
all three slabs in these groups with no cracks at all were among those
without plasticizer. Clearly, more data should be collected before a
definitive conclusion can be reached.
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Placement of reinforcement in the top portions of slab inside corners
helps to prevent cracks from starting in these corners. Houses with
corner reinforcement had 50% less total cracking than those without corner
reinforcement. In at least one instance, however, the corner
reinforcement merely forced the crack to start beyond the extent of the
reinforcing bars.
Total crack length does not correlate with indoor radon levels. In some
instances high levels of radon were drawn through cracks during testing,
but these tests used much higher levels of depressurization than those
found in the house environment, and most cracks are protected by the
intact vapor barriers under new homes. No data is available, however, on
how long these vapor barriers will remain intact, and it is possible that
radon levels in these homes will rise if vapor barriers deteriorate over
time.
Pipe penetrations through slabs are another avenue for radon intrusion,
and testing should be done to determine the extent to which this occurs.
Radon levels in houses without tar protecting pipes in slab penetrations
have an average indoor radon level 3 3% higher than those with tar on the
pipes. Monitoring in house 7 has also shown that slab penetrations for
plumbing pipes not built to Draft Standards can contribute to indoor radon
levels.
High ambient radon levels found on the house 7 site are not duplicated on
every reclaimed mine site, as measurements made on other reclaimed
building sites have not reproduced the levels found on the house 7 site.
This site does present the opportunity, however, to study the effects of
weather and atmospheric conditions on the emanation rate of radon from the
soil.
The best measure of slab leakiness is the amount of conditioned air being
pulled through the slab during mitigation fan operation. Dividing by the
house volume gives a slab air change per hour (ach) , which takes into
account all slab openings including cracks and pipe penetrations.
C. HOUSE
Houses needing mitigation system activation in the project were on average
smaller and tighter, with a higher value for slab ach. Activated houses
also had higher levels of depressurization than unactivated houses.
The radon stress test did not give meaningful results, and was discarded
during the course of the project. No calculated values based on its data
showed any correlation with indoor radon levels. The stress test should
be relegated to research houses, where much longer time periods for
testing are possible.
k
101
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No direct correlations with indoor radon were found in this set of houses,
due to the complex nature of the house as a system. It is usually
impossible to isolate one building component from another during testing,
and each component is likely to have an opposite effect on the results of
a test. The factors seeming to have the closest relationship with indoor
radon are the sub-slab radon level as the source term, the differential
pressure across the slab as the driving force, and the slab ach as the
medium of radon intrusion. House leakiness effects the dilution of the
radon level once it has entered the house, and may be the deciding factor
as to whether or not a house needs activation of its mitigation system.
There continue to be problems relating to energy efficiency, especially
relating to house shell design and HVAC installation procedures. The lack
of testing of these systems and the house envelope itself have led many
builders to ignore certain building components and installation procedures
that are causing energy inefficiency to be built into new homes.
VII. RECOMMENDATIONS
Recommendations for the continuation of the new house evaluation project
include shifting testing emphasis from slab cracks to slab pipe
penetrations. Testing apparatus is available to use the same protocol on
pipe penetrations as has been used on slab cracks. Number and types of
slab penetrations should be catalogued as slab cracks have been. Sealing
of sub-slab vapor barriers to the pipe penetrations, and the use of tar on
pipes where they come into contact with the concrete should be considered
as mandatory additions to the Standard.
Testing of different types of pipe penetration protection should also be
done in a laboratory setting to isolate the pipe penetration and determine
the best way to protect against radon intrusion. Obtaining direct
correlations between different types of protection for pipe penetrations
and radon intrusion through the slab will be much easier when all other
conditions can be controlled. Multiple penetrations can also be poured in
the same test bed to allow more accurate results to be achieved through
averaging.
Older homes should be investigated to determine if vapor barriers are
remaining intact over long periods of time. Ignoring the repair of slab
cracks while emphasis shifts to the testing of other slab penetrations
could create a radon problem in the future if vapor barriers are not long
lasting. Complete surveys of older homes for cracks could be done while
new carpet is being installed. Vapor barrier integrity could easily be
determined by using the same testing protocol now in place. Slab cores
could also be cut to examine first hand the condition of older vapor
barriers.
102
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We recommend that requirements for concrete slump can be relaxed from 4 to
5 inches. Requiring a 4 inch slump would be unenforcable, as it would
require an inspector to be on hand for every concrete truck delivery on
every slab built in the area covered by the Standard. It would also be an
economic hardship to builders as 4 inch slump concrete cannot be pulled
across a slab by hand and would require a pump truck to place the concrete
on any slab with access problems.
Requirements for specific spacing of slab control joints should be dropped
from the Standard. Average total crack length for the 28 houses over the
two-year project period was 71 feet, and this average drops to 42 feet
after subtraction of the three houses with the most cracks. Contrast this
with an average control joint length requirement of 442 feet based on the
average project house footprint. The control joint spacing requirement
clearly requires more work from the builder than can be justified, since
slab cracks have not been shown to be directly correlated to indoor radon
levels.
Testing of new homes should continue, to collect data on how SSDS systems
work in real houses, and how the houses themselves perform as barriers to
radon. Determining correlations between indoor radon levels and
individual parts of the Standard, however, will be difficult due to the
complex nature of real-world houses. Investigations of Standard sections
that can be isolated in a laboratory setting will yield better results due
to an enhanced ability to control the experiment.
A. SPECIFIC STANDARD RECOMMENDATIONS
What follows is a listing of specific Standard recommendations based on
project results and ease of implementation. Those Standard items not
listed here are effective and easily implemented by the industry. The
complete Standard appears in Appendix D.
303 Ploor Slab-On-Grade Buildings
303.2.1 Concrete Mix Design Slump
No direct correlation was shown between slump and crack length (Figure
IV.21) or between crack length and indoor radon (Figure IV.23). Also
enforcement is impractical, as every concrete truck to every building site
would have to be monitored. Recommend raising minimum slump from 4" to
5", as 5" slumps are in general use at present.
303.2.2 Concrete Workability
Impractical implementation. Inspectors would have to be present during
the pour on each site to monitor water added to each concrete truck. (See
enforcement discussion under section 303.4.2)
103
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303.3.1 Contraction Joints
Impractical implementation. Requiring contraction joints at the intervals
in the Standard would give an average total joint length greater than the
highest total crack length for any house in the project. As crack length
has not been directly correlated to indoor radon, we recommend that this
provision be dropped from the Standard.
303.4.2 Curing
Impractical implementation. Punitive fines levied on the builder are the
only enforcement provision available. If the fine is too high, the
builder challenges the code in the courts. If the fine is low, then the
builder just pays the fine and the code provision is bypassed. This
provision should be included as a "recommended practice."
303.4.3 Loading
Impractical implementation. Same reasoning as 303.4.2.
402 Sub-Slab Depressurization Systems
This section should be expanded to allow the installation of wellpoint
suction pipe in the SSD system. These system perform well, allow for more
flexibility in design, and are easier to install than pit systems.
Chapter 5 Testing For Mitigation Effectiveness
502.2.3 Compliance Criteria
Section 502.2.2 allows for a 48 hour measurement by continuous radon
monitor, but Table 5.1 Compliance Criteria for One Radon Measurement does
not include a 48 hour measurement period. An acceptable concentration for
the measurement period from 48 hours to 5 days should be added to Table
5.1.
k
104
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REFERENCES
Acr 90 Acres, Radon Entry Through Cracks in Slabs-on-Grade, Final
Report, Vol. V Appendices, Acres International Corp., Amherst,
NY, report P09314, October 1990.
ASTM 87 ASTM E779-87, Standard Test Method for Determining Air Leakage
Rate by Fan Pressurization, Philadelphia, PA, 1987.
ASTM 94 ASTM E1554-94, Standard Test Methods for Determining the
External Air Leakage of Air Distribution Systems by Fan
Pressurization, Philadelphia, PA, 1994.
Cla 91 Clarkin, M., Brennan, T.,and Osborne, M.,Energy Penalties
Associated with the Use of a Sub-slab Depressurization System.
In Proceedings: the 1990 International Symposium on
Radon and Radon Reduction Technology, Vol. 3, EPA-600/9-91-026c
(NTIS PB91-234443), pp. 7-1 through 7-12, July 1991.
Cum 89 Cummings, J. Tracer gas as a practical field diagnostic tool
for assessing duct system leaks. Florida Solar Energy Center,
Cape Canaveral, FL,1989.
Fla 89 Florida Administrative Code Chapter 10D-91,Part IXA, Radiation
Standards for Buildings, revised January 3, 1989.
Red 92 Gadsby, K.J., and Reddy, T.A., Guidance for Research House
Studies of the Florida Radon Research Program, Vol. I: Research
Plan. EPA—600/R-92-19la (NTIS PB93-100907), September 1992.
SMACNA 81 The Sheet Metal and Air-Conditioning Contractors' National
Association, Technical Manual for HVAC Systems Duct Design,
Chantilly, VA, 1981.
Swa 92 Swami, M., Kerestecioglu, A., Gu, L., Brahma, P., Fairey, P.,
and Chandra, S., Draft User's Manual FSEC 3.0, Florida Software
for Environment Computation: V3. Florida Solar Energy Center,
Cape Canaveral, FL, January 1992.
Wil 91 Williamson, A.D., and Finkel, J.M., Standard Measurement
Protocols, Florida Radon Research Program. EPA-600/8-91-212
(NTIS PB92-115294), November 1991.
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GLOSSARY
ach - air changes per hour; ACH 50 is ach at 50 Pascals depressurization.
activated - a house in which the mitigation system has been activated.
active - mitigation system activated and running.
AH - air handler,
Cnet - modelled indoor radon
C# - subslab radon concentration.
capped - mitigation system capped off.
cfm - cubic feet per minute; CFM50 is cfm at 50 Pa depressurization.
ela - effective leak area, a measure of the total house leakage area;
ELA50 is ela at 50 Pa depressurization.
grab - an air sampling technique whereby a specific volume of air is
captured for later analysis.
HVAC - heating, ventilating, and air conditioning, as in HVAC system,
mastic - a sealing material placed on duct closures to ensure
airtightness.
monolithic - slab construction technique where the slab and the footer
are poured at the same time.
Pa - Pascal, a measure of pressure. One inch of water column exerts 249
Pascals of pressure,
passive - mitigation system uncapped, but not activated,
plastieizer - an additive to the concrete that allows less water to be
added, increasing concrete strength,
post tension - slab construction technique where the concrete is poured
around buried steel cables and the cables are tensioned
after the pour to strengthen the concrete,
return dominant - an HVAC system in which return leaks are larger than
supply leaks.
RLF - return leak fraction, the fraction of air leaking into the return
side of the air handler.
SLF - slab leak fraction, the ratio of sub-slab tracer gas levels to
indoor tracer gas levels.
SS - sub-slab area.
BSD - sub-slab depressurization.
SSDS - sub-slab depressurization system.
stem wall - slab construction technique where the slab is poured on a
course(s) of concrete block set on a footer that was poured
earlier.
supply dominant - an HVAC system in which the supply leaks are larger
than the return leaks,
unactivated - a house in which the mitigation system has not been
activated, but is working passively.
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APPENDIX A
HOUSE NARRATIVE
DEMOl4 This house has a two-level slab poured at a four inch
slump. The bottom slab is for a one car garage below ground. The
living space above is sealed from the garage with approved urethane
caulk around wall and ceiling seams, and the garage ceiling is
finished-with gypsum board. The top and bottom slabs were sawcut
in a grid fashion. Most cuts developed cracks, and all cuts were
filled with urethane caulk. Finish floor was concrete slab painted
with a sealant. Plywood was put down to protect the slab through
all construction phases. This left little.time to crack test for
which we were not notified to do in time. A photograph of the
house layout' is shown in Photo A.l.
Photo A.l. House 14 layout showing excavated garage.
The house features unfinished solid poured concrete block walls
with no windows except on the back right corner. Here there are
doubie sliding glass doors on first and second story levels meeting
at the corner of house.
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Photo A.2, Wellpoint section in garage of House 14.
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SSDS system uses two-inch wellpoint design. The bottom slab used
a three foot section in the middle of slab situated in a shallow
suction pit of small gravel 3.5 x 2.5 x 1.5 feet as shown in Photo
A.2. The top slab wellpoint was connected to the bottom system,
and used a 2.5 foot section of wellpoint in a gravel pit design as
shown in Photo A.3. A six inch section of wellpoint was used to
depressurize a remote area of slab that jutted out from the main
slab. This small section was placed in a 0.75 cubic foot pit with
gravel.
Photo A. 4. Finished floor with sawcut pattern.
HVAC consisted of one air handler in the attic with one return
located in the second story ceiling at the stairway. Ducting
consists of flex and board duct. Connections were taped, with no
mastic used. An example of these connections is shown in Photo
A. 5 .
The house is also equipped with a whole house fan that is sealed
well when not operating.
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Photo A.5. Duct connections in House 14;
DEMO 15 The slab was ordered at a 4" slump and post-tensioned
reinforced. Center of slab likely poured at a 6" slump with the
addition of water, while footers were poured at a 4" slump. Two
hairline cracks were found but were too small to test. One was 5'
long in the kitchen area and the other was about 4' long running
through many very small surface cracks in the center of the living
room space.
SSDS system included sixty-one feet of Enkavent under the slab.
There were five interior 'footers crossing from side to side and
four from front to back. A hybrid of suction pit and Enkavent
would have been a preferred choice for this layout. Many footers
and lack of wall space to run the radon stack through made it
difficult to place the suction point.. 11. had to be located at the
corner of two footings. Even a well-anchored riser is vulnerable to
being knocked loose in this type of layout. A hybrid system would
have been used if locating and transporting such materials could
have been done that day.
HVAC consisted of one air handler with three returns. Only the
master suite had a return in closeable space. All returns were
located in the walls at floor level. Main space return was 20" x
30" duct board construction, while the master suite return was
12" x 12" wall plenum with duct board lining studs and bottom of
grill. The third return was of duct board construction 1 cubic foot
in size. No mastic or straps were used. Flex duct to supply box
connections were taped.
A-4
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DEMO 16 Site is on Fairway Oaks Drive and does not drain well
below 60 cm, Permeameter readings on this site and others at
nearby lots were very wet below 60 cm. Soil was probed in March,
May, and September of 1992. A monolithic slab was poured with a
6" slump although a 4" slump was requested and agreed upon. This
slab probably had 6" slump in footings, and a 7 - 8" slump in the
center of .the slab with the addition of water. Contractor situated
long rebar at re-entrant corners, but not to code specifications.
The reinforcing bars were longer than code and bent into a hairpin
shape. Plumbing entries were sleeved and taped at the top with duct
tape. No cracks appeared in the slab, however a section of it was
chiseled two inches deep to add an electric outlet in the floor.
We requested that this cirea be sealed to code, but the builder did
not follow up on it.
The SSDS is a gravel pit designed to code with 26' of Enkavent used
to extend the pressure field extension along the long axis of the
house. This approach was used to test the effectiveness of such a
system in houses where suction points can not be located in the
center of a house due to a lack of adequate wall space for the
stack. The radon stack was run into the garage/utility wall 10'
away from the suction pit. Three-inch PVC pipe was buried from the
pit to the wall. This house would have required a minimum of two
suction pits since its floor area is 1876 square feet, and widest
dimension 60'. Ventilation mat is much easier and quicker to
install which saved twice the labor and materials used.
Photo A.6. Pit and mat combination in House 16.
A-5
k
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Photo A. 7. Finished surface of suction point.
Photo A.8. Overall view of SSDS system in House 16.
a-6
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The front left corner of the house was the farthest point from the
suction system. It was 25' away with a pressure gradient from the
vent of -307 Pa to -2.4 Pa. All other measurements under the
living space were of -10 Pa or greater depressurization. The two
left front corners of garage were -2.2 and -0.8 Pa left to right.
HVAC consists of one air handler (AH) with two returns m wall
space at floor level. Main space hallway return is 20" x 30" duct
board construction. The 2nd return is 12" x 12* and located in the
master suite. It is a wall plenum design with duct board lining
the stud work. No mastic or strap, but flex to box connections are
secured with tape and plastic bands. Photo A.9 shows flex duct to
box connection.
Photo A.9. Duct connections in House 16.
DEMO17 Very good compliance overall. We were not able to be on
site during pour. It was understood between us and the building
contractor to be poured at a four inch slump. Only one fine sized
crack appeared up to three months after pour when final flooring
was put down.
SSDS consists of a short strip of Enkavent thirty feet long and
three feet wide centrally located under this monolithic slab.
There is approximately the same square footage of Enkavent in this
layout as there would be if a 1.5 foot wide section were put down
in a longer path for this slab.
A-7
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HVAC system has good compliance with code. House dynamics testing
showed this to be one of the tightest duct systems in this study.
The homeowner is a HVAC contractor and did the work on his home
according to standard. System has one air handler with two returns
in ceiling located in main space of house.
Photo A.10. Duct connection with mastic in House 17.
DEMO18 Site on reclaimed mine land. Monolithic, post-tensioned
slab poured with plasticizer and fibre mesh. No re-entrant corners
reinforced due to post-tensioning. No cracks. Neighborhood
children had put several 1" rocks into the stub out after the slab
was poured. Contractor removed 100% of the debris.
SSDS system used -66.6' of hard plastic "nippled" vent mat
(Terradrain)An interior footer was added after installation and
contractor dug under mat without disturbing layout. This left the
mat to bridge the footing instead of running down into it. The
vapor barrier was cut and placed over the bridged section and under
in the footing. Tests showed that there was no significant
concrete intrusion into the vent mat since the dP along the mat was
not disturbed. Suction riser was run into the attic, but not
through the roof. It was left uncapped and would have stayed that
way if we had not observed it. Builder not sure why plumber did not
finish. A radon grab measurement was taken here and was only 0.8
A-8
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pCi/L. The subslab level was 1080 pCi/L, and indoor air was 1.3
pCi/L. House was completed but had no occupants at this time.
The low attic radon may be due to good attic cross ventilation.
There are 3' diameter vents on the east and west attic walls.
HVAC system has two AH with one return each in hallway ceilings.
Duct return and supply plenum box connections used tape with no
straps. Photo A,11 shows flex duct to box connection.
Photc A.11. Flex duct to box connection in house 18.
DE!wl9 Two-story house located into a hillside. Top slab poured
one month after bottom. Piasticizer ana fibre rnesh used. Slab was
stemw&ll construction to code with exception of corner
reinforcement. Top slab had no cracks, but bottom slab had late
developing cracks four months after pour during the week finish
floor was put down. Crack through wall spaces and under sections
of floor already carpeted made testing difficult.
SSDS system is complex. The bottom slab used a suction pit design
due to its small area and lack of wall space to run radon stack
into. Two-inch PVC pipe was used. The top slab uses a two-inch
well point design which is tied into the bottom slab pipe. Photc
.-..12 shows the top portion of the wellpcint system.
A-9
k
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Photo A,12. Top portion of wellpoint system.
HVAC system has one AH with one return located in top story
ceiling. The lower story is a master suite with open stairway.
Mastic not used and duct boxes not strapped. Flex to box
connections use tape. Photo A.13 shows flex duct to box
connection.
This house eventually needed active mitigation, and upon inspection
it was determined that the vent stack was placed too close to the
eave of the roof to install the fan. Photo A.14 illustrates the
pesi tion of the vent stack relative to the outside wall of the
house. Photo A. 15 shows what was found in the attic when the
insulation was removed. This peculiar arrangement of the vent
stack piping has not been explained.
A-10
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Photo A.14. Position of vent stack relative to eave.
A-Ll
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Photo A.15. Stack as installed by the builder.
Photo A.16 shows the final installation of the mitigation fan. The
1.5 inch pipe shown running from the bottom of the fan into the
wall was left in place because the step-down from two to 1.5 inches
occurred in the wall ana was irreversible.
Photo A.15. Final mitigation fan installation.
a-12
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DEMO20 Monolithic slab ordered at 5" slump, no plasticizer. The
supervisor of this house is the same from DEM016. Although he
agreed to order a 4" slump, it was not ordered that way. Wire mesh
reinforcement used. Corners reinforced with left over re-bar, but
not to code specs. Plumbing entries were sleeved and taped at top.
After pour contractor poured roofing tar over all entries to seal.
One fine crack and one hairline crack occurred. The fine crack
developed in the first 30 days of slab and hairline after 60 days.
HVAC system included one AH and two returns. Main return is box
construction 20" x 30" and located in kitchen. The second return
is a wall plenum type with duct board lining studs and bottom of a
12" x 12" grill connection. Box supplies and plenums not strapped
down. Flex to box connections taped only. Photo A.17 shows flex
duct to box connection. Photo A.18 shows clean out for master tub
located on the outer wall of the house.
Photo A.17. Flex duct to box connection in house 20.
k
A-13
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Photo A.18. Tub clean out located on outer wall.
The- SSDS system used one strip of Terraarain vent mat.
DeraolS, 16, and 20 were built by the same builder. Their design
seems to encourage construction of wall plenums in master suites.
We could have better compliance if a ceiling mounted return could
be used.
We were troubled with the co-operation of a supervisor on houses 16
and 20. This supervisor was " released from duty" by the co-
operating builder about midway through construction of house 20.
Since then compliance has been much better with this builder.
DEMO21 This site in a mined area that does not drain well.
Homeowners have trouble with landscape plants dying from flooding.
Due to scheduled testing for another house in this study, we were
not able to be on site during pour. Slab was wire and fibre mesh
reinforced. Later developing cracks occurred around two months
after pour at a time when our permeameter was not working. Master
bedroom had one 20.5 foot long fine sized crack. All other cracks
were hairline size. Any cracks that ran to the slab edge stopped
about 2.5 feet from edge, which is the width of the footing for
this monolithic slab.
1A
-------
HVAC system locates two air handlers in the attic. Each has one
return located in the main space ceiling. Flex to duct board
connections are taped, with no mastic used, as shown in Figure
A.19.
Photo A.19. House 21 flex duct connection.
SSDS uses a two-inch wellpoint design with three well distributed
sections of well point all connected to one two inch pvc riser run
up through the wall and out the roof. Stack cover on the roof was
lead type which was not sealed tightly to the pipe allowing soil
gas to be pumped back into the attic during fan operation. A
reading of over 4000 pCi/L of radon was obtained at the roof
penetration of the vent stack. The vent stack with lead shield is
shown in Photo A.20.
Photo A.21 shows the lead shield opened up to uncover the
reentrainment pathway between the pipe and the shield. This gap
was then caulked, and the lead shield turned over, as shown in
Photo A.22. The average radon levels in the home dropped from over
5 to under 3 pCi/L after this operation.
A-15
k
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Photo A.20. Vent stack with leaky lead shield.
Photo A.21. Radon reentrainment pathway.
A-16
k
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Photo A.22. Repaired vent stack-in House 21.
DEMO22 Site located in an old grove on a hillside, Stemwall
construction was to be poured at 4 inch slump with wire
reinforcement. Due to ongoing testing we were unable to monitor
the pour. No cracks in slab by the time finish flooring went in.
HVAC has one air handler i*i attic with one return located in
ceiling. Flex duct to board connections are taped and have mastic.
Duct connections are illustrated xn Photo A.23.
SSDS consists of fifty feet of rigid vent mat (Terradrain).
A-17
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Photo A.23
Duct connection? in House 22
DEMO 23 Stemwal1 slab poured at about five inch slump with
plasticizer and fibre mesh reinforcement. An average of five
gallons of water were added to each truckload of concrete. Two
medium cracks occurred. One began between two reinforced corners
and ran across slab through section with ten gallons of water added
to the concrete truck at the time of pour. The second split about
midway from the first crack and ran near]y perpendicular to it
through a section of concrete with no water added.
A plumbing entry was tested with a special chamber to accommodate
the length of pipe that penetrates the slab. The entry was a four
pipe copper entry with tar and no plastic sleeves, similar to that
shown in Photo A.24. The radon grab sample taken during the
penetration test yielded 0.0 pCi/L, probably due to the use of tar
on the pipes.Photos A.25-A-27 show plastic placement and concrete
edge treatments, and Photos A.28 and A.29 show corner reinforcement
being placed.
The HVAC has two air handlers in attic with three returns located
in ceiling space. We observed some of the ductwork being done.
Flex duct to board duct was taped then squeegeed tight with mastic
applied, as shown in Photo A.30. Supply boxes were secured well.
SSDS system has eighty-two feet of rigid vent mat (Terradrain) used
with one three inch suction riser.
A-18
k
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Photo A,24, Pipe penetrations in House 23.
A-19
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—2 0
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Photo A.28. Placing reinforcement in corners of House
Photo A.29. Reinforcement bars in place in House 23,
A-21
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Photo A.30, Duct closures in House 23.
DEMQ24 - Native site low in radon (418 pCi/L), however past
involvement with this builder has shown high radium contents in
fill soils. Subslab measurements taken have been as high as 2664
pCi/L.
Pipe penetrations were tarred-, as shown in Photo A.31. The
concrete sub-contractor made a mistake in ordering a five inch
slump without plastici^er,. Site was monitored during pour. The
footers were poured at low slumps. Spa and master suite side
footers poured at four inch slump as well as the garage to house
footing. The pour of this section is shown in Photo A.32. The
rest of the slab averaged about fifteen gallons of water per truck.
The corners were reinforced by ten foot hairpin sections of rebar
in each corner, as illustrated in Photo A.33.
Slab cracked with 194 feet of fine sized crack and 97 feet of
hairline cracks. Cracks stop two feet from the edge where there
was a four inch slump poured into footers. Only one fine sized
crack came from a re-entrant corner that was reinforced. All other
cracks that ran to the edge of slab began on straight edged
sections between corners.
A-22
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Photo A.31. Pipe penetrations in House 24.
Photo A.32. Four-inch slump being poured in footers.
A-2 3
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Photo A. 33. Long reb&r reinforcement around inside corner.
VAC
con
scruccion had good compliance in the types
of
ma t e r
ials
sed,
s u
ch as nics11c, r.owever ent c.pp_ication wes only r
air.
The
ack
of
understanding about how return ducts
c c* n
fail
i s
era
ted in this house. Mastic was applied co
f lex
ducc
and
board duct connections but not to board ducc plenum and ceiling
connections. The problem was repaired with the application of more
mastic by FSEC personnel. The HVAC svscem was pulling twelve
percent of its axr in from ~he attic. The builder's design of this
nouSc uses waii. space returns whicn encourages tms tyoe of xeak.
FSEC personnel returned co this house and made repairs to the
return connections. The return leakage was retesced ana showed a
54% improvement to approximately a 6% leak. Eventually the
contractor sealed off the wall returns and installed returns in the
ceiling sealed with mastic. Duct connections by builder are shown
in Photo A.34. Photos A.3 5 through 3 8 show two sections of repair
done by FSEC." The first of each pair shows the original work done
by the subcontractor, wi:h the ends of the insulation board
exposed, allowing air leakage. The first picture of the second
pair shows a one-half inch gap between the insulation board and the
stud. The second photo of each pair shows the repairs made.
The SSDS system uses forty-seven feet of rigid vent mat in one
strip. A test with a four inch suction fan had an average distance
of 20.4 feet from mat end before dP would go co 0 Pa. A six inch
fan had an average distance of 21.0 feet.
A-24
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Photo A.34. Duct connection in House 24.
A-2 5
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Photo A.36. Section seen in Photo A.35 after repair.
A-2 6
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Photo A-38,
Section seen in Photo A. 37 after repair.
DEMO25 Native soil very wet below sixty crn when tested for
permeability. Site monitored during pour. This monolithic slab
had concrete ordered with plasticizer at an average of seven inch
slump and no water added in most of the slab. The fourth truck
delivered what appeared to be very watered cement. No water was
added and the ticket showed seven inch slump ordered. A concrete
company representative came to the site and said it was poorly
mixed. This area set much slower than the rest of slab.
The spa tub area was poured at a .four inch slump. An 8 x 8
concrete blbck placed in the slab was not reinforced by standard
measures. Short hairline cracks did develop here. They were two
small to test. Three hairline cracks developed about two months
after pour. One began from a well-reinforced corner with four and
a half inch slump that had fifteen gallons of water added to the
truck load. This crack ran across slab into an area with seven
inch slump and no water added. Low slump area of pour is shown in
Photo A.3 9 .
A-27
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Photo A.39. Low slump pour around footers in House 25 slab.
A second crack about ten feet long was located within the four and
a half slump area stopping four feet from the edge of slab. The
third crack was within the seven inch slump with no water added.
It ran nine feet from a straight side of slab into the slab middle.
Corner reinforcement was used, but not exactly as code specifies.
Example of corner reinforcement is shown in Photo A.40.
A-2S
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Photo A.40. Corner reinforcement used in House 25 slab.
HVAC system has one a.ir handler in the attic with two returns in
wall space. Mastic used in flex duct and board duct connections,
as shown in Photo A.41.
Photo A.41. Duct connection in House 25,
A-29
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The SSDS system consists of fifty feet of rigid vent mat used in an
"L" layout. At one end of mat one measurement tube was placed on
top and another under mat on top of soil. The top measurement was
depressurized greater by thirty-four Pa. The average distance for
dP to reach 0 Pa from the mat end with a six inch fan is 15.8 feet.
DEMO26 Site is in an old orchard. The slab pour was monitored.
A 5" slump was poured with an average of 18 gallons of water added
per truck. Code compliance was good with exception of 7 pressure
treated wood stakes through the vapor barrier. Re-entrant corners
were reinforced to code with 3 sections of rebar. This slab had
117 plumbing entries, and all were covered with tar. Photo A.42
shows corner reinforcement and tar covering on pipe penetrations.
Photo A.42. Corner reinforcement in House 26 slab.
A 10 foot medium crack developed through an area of slab that had
a total of 3 0 gallons of water added per truck. It went from the
edge to the middle of the slab. A second medium crack 4 feet long
developed in an area where no water was added at the center of the
slab. A hairline crack 4 feet long developed from the slab edge
between two reinforced corners.
k
A-30
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HVAC system included 3 units. The main first floor unit has a
return at the bottom of a wall, the 2nd unit on the first floor
serves the master suite and one other room, and each has a ceiling
return. The second floor unit has one ceiling return. Good
compliance with code HVAC system features. Duct connections are
pictured in Photo A,43.
Photo A.43. Duct connections in House 26.
The SSDS system use 82 feet of Terradrain ventilation mat. A one
foot vent tab was necessary to locate the vent stack due to an
interior footer and the interior wall alignment. The dP analysis
showed a tab this small does not adversely affect extension.
DEM027 Site is on reclaimed land. The slab footprint is
relatively small since the house is built on a hillside with a
partial crawlspace under more than 50% of the house. The builder
gave a date to observe the pour, but no crews showed up-on that
date. Testing obligations for the rest of the week kept us from
observing the pour. A 4" slump was ordered, and compliance good.
The HVAC system has .2 air handlers with one return each. Mastic
was used on ducts, and compliance good.
The SSDS system used 3 distributed wellpoint suction pipe sections
in small gravel pits. The wellpoint was cut into 2 foot sections
for the points closest to the suction stack, and one 3 foot section
A-31
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was used for a location 10 feet away from the stack. Photos A.44
and 45 show pipe penetrations and SSDS system layout, respectively.
Photo A.45. Weilpoint SSDS system layout under House 27.
A-32
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Sealing of underside of the floor in the crawl space was left off
by the builder, and added by FSEC. This installation is pictured
in Photo A.46.
Photo A.46. Crawlspace air barrier installed under House 27.
DEMO28 Site also on reclaimed land. A 5" slump was poured with
an average of 17 gallons of water added per truck. Most cracks
developed where 30 gallons of water were added to one truckload.
The HVAC system has good compliance and contains two AHs. The SSDS
system'use 80 feet if Enkavent ventilation mat. The suction point
had to be located relatively close to a re-entrant corner due to
the lack of"adequate wall space for a three-inch PVC pipe. Pipe
penetrations are pictured in Photo A.47.
The difficulty in realizing a 4 inch pour of concrete over the
whole slab in a relatively large house with poor access is
illustrated in Photos A.48 and 49. In Photo A.48 the ease of
access to the pour spot allows low slump concrete to be dumped
directly on the site. In the next photo, the lack of access to the
back of the slab (a sloping site) requires the workmen to drag the
concrete along the slab for a distance in excess of 20 feet. This
usually requires the addition of water to the mix at the site.
Corner reinforcement is shown being installed in Photo A.50. Duct
connections were originally installed without mastic, which was
added later by FSEC, as shown in Photo A.51.
A-33
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Photo A.47. Pipe penetrations in House 28 slab.
A-34
-------
.Photo A.49. Dragging concrete over a long distance
requires a higher slump concrete.
Photo A.50. Installing corner reinforcement in House 28 slab.
A-35
-------
Photo A.51. Mastic applied to ductwork by FSEC
Testing on house 28 was delayed by the builder. Construction came
to a halt in November of 1992.
A-36
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APPENDIX B
LONG-TERM MONITORING
RADON CONCENTRATION MEASUREMENTS
IN TWENTY LAKELAND AREA HOMES
By
Charles S. Fowler, Susan E. McDonough, and Ashley D. Williamson*
ABSTRACT
The Florida Radon Research Program (FRRP) has, as one of its integral components, a
new house evaluation study. Florida Solar Energy Center (FSEC) conducted research at
28 house building sites over two years in South Central Florida as part of that program.
Southern Research Institute conducted long-term (six-month) radon monitoring in twenty
homes in neighborhoods where the FSEC houses were located to be used as a set of
limited "control" houses, against which to compare the effectiveness of the application
of the Florida radon-resistant standards to normal building practices in the same area.
Alphatrack detectors (ATDS) were deployed for two quarterly time periods in the houses.
The average radon concentrations for the selected houses was 3.8 pCi/L for Fall 1 992
and 6.1 pCi/L for Winter 1 993. For the eleven neighborhoods in which there were
houses built according to the standards and control houses, the control houses had a
higher radon concentration average than the system houses in all the neighborhoods in
Fall 1 992. The control house average was also greater than the system average in all
but one neighborhood in Winter 1993.
INTRODUCTION
The Florida Radon Research Program (FRRP) has, as one of its integral components, a
new house evaluation study. Florida Solar Energy Center (FSEC) conducted research at
28 single-family house building sites in ten new developments and one older
neighborhood over two years in South Central Florida as part of that program. In the
houses built in these locations (system houses), selected components of the proposed
Florida radonresistant standards were -incorporated by the builders. Southern Research
Institute (SRI) was contracted by FSEC to monitor two quarters of radon concentrations
in twenty similar new homes in the same neighborhoods where just the normal building
practices for the area were implemented (control houses).
('Southern Research Institute, P.O.Box 55305, Birmingham, AL 35255-5305}
B-1
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The general purpose for this effort was to compare the effectiveness of the application
of the standard's features in the system houses in controlling radon entry to that of the
normal building practices for the area as found in the control houses. (Under a
separate contract, SRI has been tasked with monitoring quarterly the radon
concentrations in the system houses after completion.) Comparative analysis of the
two data sets is not part of the scope of this OPS contract to FSEC; however, since
this information is relevant and of interest to FSEC, we have incorporated some such
analyses into this report.
PROCEDURE
FSEC provided SRI the locations of the system houses as they were completed. SRI
then located twenty additional houses in the same ten new developments and
received permission to deploy quarterly alpha-track detectors (ATDs) for two quarters
in those houses. Duplicate ATDs were deployed each quarter after the house
construction was complete. Table 1 lists the codes for the neighborhoods included,
the house IDs for the homes in each neighborhood, and explanatory notes as deemed
important. The following amplifications explain the comments listed in the table. In
the GL neighborhood, the owners in house DEM17 asked not to be included after the
fall quarter. The owners of house E29 also withdrew from the program, but they threw
away both sets of ATDs deployed in their house, so their data are missing both
quarters. In the HL neighborhood, house DEM07 had the active soil depressurization
system activated, which of course was not installed in E33. In the IL neighborhood,
the owners of DEM13 were out of the state during the fall quarter; so ATD results were
available for winter only, The owners of DEM20 refused to allow their house to be
monitored at all. House DEM24 was not finished in time for the fall quarter monitoring;
so the winter results were the only ones available. The neighborhood designated BA
is an older neighborhood, and house DEM14 was the only new construction there;
therefore, a control house in that area was not found. The last neighborhoods in
which construction was taking place were CO and JG. Houses DEM23, E47, and E48
were not completed in time for fall quarter monitoring; so winter quarter data were the
B-2
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Neighborhood
Code
TABLE 1. SYSTEM AND CONTROL HOUSES BY NEIGHBORHOOD
Control
Comments House ID Comments
System
House ID
GL
LO
HV
HL
RW
SC
IL
BA
OR
CO
DEM01
DEM02
DEM03
DEM09
DEM17
DEM04
DEMOS
DEMOB
DEM22
DEM07
DEMOS
DEM10
DEM11
DEM12
DEM13
DEM16
DEM20
DEM24
DEM25
DEM14
DEM15
DEM18
DEM19
DEM21
DEM23
DEM27
DEM28
fall only
ASD
winter only
refused
winter only
old neighborhood
winter only
not finished
not finished
E29
E30
E31
E34
E36
E40
E41
E32
£37
E33
E43
E44
E35
E39
E45
withdrew
E38
E42
E47
E48
winter only
winter only
JG
DEM26
not finished
E46
B-3
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only available. Houses DEM27, DEM28, and DEM26 were not finished in time for even
winter quarter ATD placement; so no data at all are available for them.
RESULTS AND DISCUSSION
Table 2 lists the measurement results from both quarters of data collection. A few
general comments concerning the data as presented may be made. Some of the
neighborhoods, GL, HV, RW, and OR, showed uniformly low radon concentrations
{< 4 pCi/L) in both the system and control houses for both quarters. This
phenomenon could be attributable to several factors. It could be that the radon
source potential in these neighborhoods is sufficiently low so that the standard
building practices are adequate for sufficient radon resistance to keep indoor
concentrations low. It could also be the case that the builder(s) in these sub-divisions
were already trying to implement the standard features. Because the control houses
were selected from the neighborhoods after construction was complete, there was no
documentation as to what features were incorporated into the construction practices
at any of the control houses.
In another group of neighborhoods, LO, SC, and IL, the system houses had less than
4 pCi/L indoor radon concentrations for both quarters, but some of the control houses
had concentrations greater than or equal to 4 pCi/L in one or both quarters. In one
other neighborhood, HL, house DEM07 had tested high after construction; so the
active soil depressurization (ASD) system was activated. The control house (E33).
without such a system, had very elevated concentrations both quarters.
Neighborhood CO is the difficult one to explain. All three system houses had
concentrations of at least 4 pCi/L in fall quarter. Unfortunately, the control houses
were not completed in time for ATD deployment for that quarter. During the winter
quarter, one house (DEM19) had a marked reduction in indoor concentrations, but the
other two had increases. The fourth system house (DEM23) was completed in time for
monitoring during the winter, and its concentration was less than 4 pCi/L. The two
control houses that were completed for the winter measurements were both above 4
B-4
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TABLE 2. LONG-TERM MONITORING RESULTS IN THE SYSTEM AND CONTROL HOUSES
Neighborhood
House
Fall Quarter
Winter Quarter
Code
ID
Start
End
Radon
Start
End
Radon
GL
DEM01
10/02/92
01/06/93
2.3
01/06/93
03/09/93
3.7
DEM02
09/21/92
01/06/93
1.2
01/06/93
03/10/93
1.7
DEM03
09/21/92
12/29/92
1.3
12/29/92
03/10/93
1.1
DEM09
09/21/92
12/29/92
1.7
12/29/92
03/09/93
1.0
DEM17
09/21/92
01/06/93
1.7
withdrew
after fall quarter
E29
09/21/92
discarded ATDs and withdrew from study
E30
09/21/92
12/29/92
2.1
12/29/92
03/10/93
3.3
E31
09/21/92
12/29/92
1.8
12/29/92
03/10/93
2.5
E34
09/21/92
12/29/92
2.0
12/29/92
03/10/93
2.2
E36
09/21/92
12/29/92
2.1
12/29/92
03/09/93
1.6
LO
DEM04
10/08/92
01/07/93
2.9
01/07/93
03/09/93
2.5
E40
10/14/92
01/06/93
5.2
01/06/93
03/09/93
6.4
E41
10/14/92
01/07/93
4.1
01/07/93
03/11/93
5.9
HV
DEMOS
09/10/92
01/11/93
1.6
01/11/93
03/09/93
3.5
DEM06
09/15/92
01/07/93
1.5
01/07/93
03/09/93
3.2
DEM22
09/21/92
01/07/93
2.7
01/07/93
03/09/93
3.3
E32
09/21/92
01/09/93
2.3
01/09/93
03/29/93
2.3
E37
09/21/92
01/08/93
1.6
01/08/93
03/09/93
2.2
HL
DEM07
09/19/92
01 /08/93
2.6
01/08/93
03/09/93
3.3
E33
09/19/92
01/08/93
26.0
01/08/93
03/09/93
48.0
RW
DEMOS
10/15/92
12/10/92
1.7
12/10/92
03/11/93
1.9
E43
10/15/92
12/10/92
2.4
12/10/92
03/11/93
1.9
E44
10/15/92
12/10/92
2.4
12/10/92
03/11/93
1.9
SC
DEM10
09/18/92
01/09/93
0.7
01/09/93
03/10/93
2.7
E35
09/21/92
01/06/93
4.4
01/06/93
03/09/93
7.2
IL
DEM11
09/16/92
01/08/93
0.8
01/08/93
03/09/93
2.4
DEM12
10/08/92
01/07/93
1.7
01/07/93
03/09/93
3.2
DEM13
out of state fall quarter
01/07/93
03/09/93
1.7
DEM16
10/08/92
01/07/93
1.9
01/07/93
03/12/93
3.0
DEM20
refused to participate in the study
DEM24
not completed fall quarter
01/08/93
03/09/93
2.0
DEM25
10/08/92
01/26/93
1.9
01/26/93
03/11/93
2.8
E39
10/08/92
01/06/93
2.4
01/06/93
03/09/93
4.0
E45
10/15/92
01/06/93
2.8
01/06/93
03/09/93
5.2
BA
DEM14
10/01/92
01/09/93
1.7
01/09/93
03/10/93
3.4
B-5
-------
Neighborhood House Fall Quarter Winter Quarter
Code |D Start End Radon Start End Radon
OR
DEM15
09/21/92
01/06/93
1.4
01/06/93
03/09/93
2.0
E38
10/02/92
12/30/92
1.6
12/30/92
03/11/93
2.7
E42
10/14/92
12/29/92
2.9
12/29/92
03/09/93
2.7
CO
DEM18
10/01/92
01/06/93
4.2
01/06/93
03/09/93
8.5
DEM19
10/08/92
12/10/92
4.6
12/10/92
03/09/93
2.5
DEM21
10/14/92
12/10/92
4.0
12/10/92
03/09/93
5.3
DEM23
not completed fall quarter
01/11/93
03/09/93
3.3
DEM27
construction not complete in time for deployment
DEM28
construction not complete in time for deployment
E47
not completed fall quarter
01/05/93
03/10/93
6.8
E48
not completed fall quarter
01/13/93
03/29/93
4.5
JG
DEM26
construction not complete in time for deployment
E46
10/20/92
01/07/93
2.6
01/07/93
03/11/93
4.5
B-6
-------
pCi/L, in generally the same ranges as the elevated system houses. There was a
suggestion at the March quarterly meeting that the ASD system(s) may be activated in
some or all of these system houses. Such an action would account for DEM19's
decrease in indoor concentration. It is not known what action, if any, has been taken
in any of these system houses.
Finally, two neighborhoods had no comparisons to be made. In neighborhood BA, an
older neighborhood, with no other new construction available for a control house,
house DEM14 had concentrations less than 4 pCi/L both quarters. In JG, the system
house was not completed in time for ATD deployment either quarter, but the control
house E46 had concentrations below 4 pCi/L in the fall and above 4 pCi/L in the
winter. In general, the winter indoor concentrations were higher than the fail
concentrations, with 28 houses having concentrations higher in the winter than in the
fail. Eight houses showed decreases in concentrations in the winter, and one
measured the same both quarters. Figures 1 through 3 plot the cumulative
frequencies of the indoor radon concentrations for both the system and control
houses for fall quarter, winter quarter, and the six-month averages, respectively.
The radon concentrations are plotted on a log scale.
Several standard practices were followed to insure that the data reported were reliable.
First, a sampling (20) of the ATDs was exposed at EPA's National Air and Radiation
Environmental Laboratory (NAREL) in Montgomery, Alabama, at two different
concentrations. These were kept sealed, and some were mailed to the analysis
laboratory with the quarterly samples both quarters. In addition to these "blind"
samples, nine "blank" detectors that had not been exposed were opened, marked, and
returned to the analysis laboratory at the end of fall quarter, and twelve "blanks" were
returned with the winter quarter samples to insure that the measurement "background"
was not elevated. As stated earlier each measurement was replicated. One result of
the replication was the identification of three detectors fall quarter and three winter
quarter that gave unreasonable results and were classified as outliers and not used in
further analysis. All six were from a batch of ATDs that had been stored for several
months. There must have been some faulty bags that allowed radon inside. The
B-7
-------
w
CO
O
C
CD
ZD
cr
CD
u
LL
CD
>
D
E
13
o
1-
0.9-
0.8-
0.7-
0.6-
0.5-
0.4-
0.3-
0.2-
0.1-
0
0.1
Fall 92
+
+
+
+
1—i—i—i—i—1111
i i11 m
-i—i—i—i—i i M
1 10
Radon Concentration (pCi/L)
100
¦ System Houses + Control Houses
Figure 1. Cumulative frequencies of the indoor radon concentrations in the system and control houses
for fall quarter 1992.
-------
w
I
O
c
CD
13
cr
CD
CD
>
_CC
13
E
=3
o
1-
0.9-
0.8-
0.7-
0.6-
0.5-
0.4-
0.3-
0.2-
0.1-
o-
0.1
Winter 93
+
%
:
¦+
I—i—i—i—i 11
i 1—i—i—rrr
~i r
"i—r-rr
1 10
Radon Concentration (pCi/L)
100
¦ System Houses + Control Houses
Figure 2.
Cumulative frequencies of the indoor radon concentrations in the system and control houses
for winter quarter 1993.
-------
w
I
>
O
c
©
D
cr
CD
Q)
>
"¦4—1
_a3
13
E
D
o
1-
0.9-
0.8-
0.7-
0.6-
0.5-
0.4-
0.3-
0.2-
0.1-
0-
0.1
Fall & Winter
¦ +
____
+
+
t-
+
+
+
+
i—i—i—i—i m i
i—i—i—nr
1 10
Radon Concentration (pCi/L)
i 11
100
¦ System Houses + Control Houses
Figure 3. Cumulative frequencies of six-month average indoor radon concentrations in the system and
control houses.
-------
replicated samples also provided an estimate of the precision of the measurements,
calculated in terms of coefficient of variation (CV) for most of the measurements. Of
the 41 replicated measurements fall quarter, one pair of detectors was lost by the
home owners, three pairs had an outlier, nine pairs had very low concentrations within
0.5 pCi/L of one another but elevated CVs due to the low concentrations, and 28 pairs
that had CVs ranging from 0,9 to 19.6%. In winter quarter, 43 replicated
measurements were made; three contained an outlier; seven were of low
concentrations with elevated CVs; and 33 had CVs between 0.5 and 19.6%. These
precisions were considered acceptable for this study. The completion rate of the total
number of detectors deployed for these two quarters was over 95%, considered to be
quite acceptable.
CONCLUSIONS
From this small sampling of system and control houses in ten neighborhoods over two
quarters, it appears that the system houses generally perform better at providing
radon resistance. Figure 4 is a plot of the ratio of the average of the system house
indoor radon concentrations to the average of the control house concentrations in
each of nine of these neighborhoods (JG not Included because the system house was
not complete) for the two quarters. The numbers in parentheses above each
neighborhood indicates the number of system houses over the number of controls.
Only one of the ratios exceeded 1, and that was for winter quarter in HV, one of the
iow radon neighborhoods discussed earlier. The ratio for RW for winter quarter was 1,
and this was also a iow radon neighborhood. Six of the next seven highest ratios
involved these two, GL, and OR, the other two low radon neighborhoods. CO was the
only neighborhood with elevated radon and a ratio above 0.62. It would be of interest
to investigate what is happening in the system houses in that neighborhood.
B-ll
-------
td
I
ro
HL SC LO IL OR GL CO RW HV
Division
Fall 92
Winter 93
Figure 4.
The ratios of the average of the indoor radon concentrations in the system houses to the
average of the concentrations in the control houses by quarter in each neighborhood.
-------
APPENDIX C
TESTING DATA
Detail file: DEMODESC.DES Florida Solar Energy Center
HOUSE DESCRIPTION
HOUSE_ID
UTK_X
UTM_Y
FLOOR_AREA
AV_CEIL_HT
MX_CEIL_HT
HOU_VOLUME
NO_STORIES
NO_ROOMS
NO_C LOS_RM
CONS T_TY ?E
FLOOR_SURF
FIREPLACE
VOL_CRAWL
NO_VENTS
HVAC_SYSTEM
SUPPLY_CFM
RETURN_CFM
NO_SUPPLY
NONRETURN
LOC_SUPPLY
LOC_RETURN
LEK_SUPPLY
LEK_RETURN
LOC_AIRHAN
CON_CHASE
HEAT„TYPE
AC_NOM_CAP
METAL_DUCT
BOARD_DUCT
FLEX_DUCT
SUPPLY_CF2
RETURN_CF2
N0_SUPPLY2
NO_RETURN2
LOC_SUPPL2
LOC_RETUR2
LEKJ3UPPL2
LEK_RETUR2
LOC_AIRHA2
CON_CKAS2
HEAT_TYPE2
AC_NQM_CA2
METAL_DUC2
BOARD_DUC2
FLEX DUCT2
House identification number.
UTM Cordinate East.
UTM Cordinate North.
Floor area in square feet.
iirorAfro foi 1 1 T"ifr hfi-j rrht* "i tt
jf* V sOi JL CX y \IS w vl» J- JL 41 y ilCi«yilu J.ii i. CC t- «
Maximum ceiling height in feet.
House volume in cubic feet.
Number of stories.
Number of rooms.
Number of closable rooms.
Type of building material.
Percentage of carpet, linolium, etc.
Existing fireplace if any.
Volume of crawl space, if any, in cubic feet
Number of vents in crawlspace.
Total supply air flow in cubic feet/minute.
Total return air flow in cubic feet/minute.
Total number of supply registers.
Total number of return registers.
Supply duct location.
Return duct location.
Estimated supply -leaks in cubic feet/minute.
Estimated return leaks in cubic feet/minute.
Air handler location .
Physical condition of chase.
Type of heating unit.
Air conditioner nominal capacity in BTU.
Percentage of metal ducts.
Percentage of board ducts.
Percentage of flex ducts.
Total supply air flow from second system.
Total return air flow from second system.
Total number of system 2 supply registers.
Total number of system 2 return registers.
System 2 supply duct location.
System 2 return duct location.
Estimated number of supply leaks in system 2
Estimated number of return leaks in system 2
System 2 air handler location.
Physical condition of chase.
Type of secondary heating unit.
Air conditoner nominal capacity.
Percentage of metal ducts in system 2.
Percentage of board ducts in system 2.
Percentage of flex ducts in system 2.
-------
VENTILATION EQUIPMENT
KITCH_EXH
JENNAIR
MASTBTH_CF
BATH2__CFM
DRYER_CFM
LOC_DRYER
HOU_FAN
0_FAN_DESC
0_FAN_EXH
Kitchen exhaust air flow in cubic feet/min.
Jennair exhaust air flow in cubic feet/min.
Master bath exhaust- air flow in cu. ft./min.
Second bath exhaust air flow in cu. ft./min.
Dryer exhaust air flow in cu. ft./min.
Dryer location.
Whole house fan exhaust air flow in cu. ft./min.
Other fan description.
Other fan exhaust air flow in cu. ft./min.
BLOWER DOOR TESTING
TEST_DATE
STRT_TIME
END_TIME
HOUS_ACH50
HOUS_CFM50
H0US_ELA4
HOUS ELA10
HOUS_ELA50
DUCT_AC H 5 0
DUCT_CFM50
DUCT_ELA4
DUCT_ELA10
DU C T_E LA 5 0
WIND_SPEED
WIND„DIR
TEMP_OUT
DEWPT_OUT
TEMP_IN•
DEWPT_IN
P BAR
Start date of test in MM/DD/YY format.
Start time of test in military (24hr) format.
End time of test in military (24hr) format.
House air changes per hour measured at 50 pascals.
House cubic feet per minute measured at 50 pascals
House estimated leak area measured at 4 pascals.
House estimated leak area measured at 10 pascals.
House estimated leak area measured at 50 pascals.
Duct air changes per hour at 50 pascals.
Duct cubic feet per minute at 50 pascals.
Duct estimated leak area at 4 pascals.
Duct estimated leak area at 10 pascals.
Duct
estimated leak area at 50 pascals.
Wind speed in MPH.
Wind direction.
Outside temperature in degrees F.
Outside dewpoint in degrees F.
Inside temperature in degrees F.
Inside dewpoint in degrees F.
Barometric pressure.
PRESSURE MEASUREMENTS (Pa)
Outside pressure with AH off and
Underneath main slab with AH off
Underneath room slab with AH off
Underneath slab edge with AH off
Outside pressure with AH on and doors open.
Underneath main slab with AH on and doors open.
Underneath room slab with AH on and doors open.
Underneath slab edge with AH on and doors open.
P.
D
_IO
p.
D
_SM
p.
D
_SR
p.
_D_
_SE
p.
_AD_
Iio
p.
_AD_
_SM
p_
_AD_
_SR
p_
_AD_
_5E
p.
_ADE_
_IO
p_
_ADE_
_SM
p.
_ADE_
_SR
p_
_ADE_
_SE1
p_
A
10
p_
A
SM
-p.
A
SR
p_
A
SE
p_
A
BR1
p_
A
BR2
p_
.A
BR3
doors open,
and doors open,
and doors open,
and doors open.
Outside pressure with AH on,
Under main slab with AH on, all
Under room slab with AH on, all
Under slab edge with AH on, all
Outside pressure with AH on and
Underneath main slab with AH on
Underneath room slab with AH on
Underneath slab edge with AH on
all exhaust, doors open,
exhaust, doors open,
exhaust, doors open,
exhaust, doors open,
doors closed,
and doors closed,
and doors closed,
and doors closed.
In master bedroom with AH on and doors closed.
In bedroom 2 with AH on and doors closed.
In bedroom 3 with AH on and doors closed.
C~2
-------
PA B1
PA B2
PA U
PA G
P_A__E_IO
p_a_e_sm
P_A_E_SR
p_a_e_se
P_A_E_BR1
P_A_E_BR2
P_A_E_BR3
P A E B1
P_A_E_B2
P_A_E_U
p_a_e_g
TEMPE_OUT
DEWP_OUT
TEMPE_IN
DEWP_IN
WNDSPEED
WND__DIR
BAR PRESS
In master bath with AH on and doors closed.
In bath 2 with AH on and doors closed.
In utility room with AH on and doors closed.
In garage with AH on and doors closed.
Outside with AH on, all exhaust, and doors closed.
Under main slab with AH, exhaust on, and doors closed.
Under room slab with AH, exhaust on, and doors closed.
Under slab edge with AH, exhaust on, and doors closed.
In master bed with AH, exhaust on, and doors closed.
In bedroom 2 with AH, exhaust on, and doors closed.
In bedroom 3 with AH, exhaust on, and doors closed.
In master bath with AH, exhaust on, and doors closed.
In bathroom 2 with AH, exhaust on, and doors closed.
In utility room with AH, exhaust on, and doors closed.
In garage with AH on, exhaust on, and doors closed.
Outside temperature in degrees F.
Outside dewpoint in degrees F.
Inside temperature in degrees F.
Inside dewpoint in degrees F.
Windspeed in MPH.
Wind direction.
Barometric pressure.
Detail file: DEMOINFL.DES Florida Solar Energy Center
HOUSE_ID
SOIL DATA
NAT_PERM
NAT_RN_CON
NAT_RADIUM
NAT_RN_EMA
NAT_MOIST
FIL_RADIUM
FIL_RN_EMA
FIL_MOIST
FIL_DEPTH
SLAB DATA
SLAB_TYPE
SLUMP
EST_WATER
SLAB_EDGE
EX_JNT_LTH
CONT_JOINT
SEAL_TYPE
REINFORCE
INDUCE_CRK
ELAPS_TIME
HAIRLN_CRK
HAIR_EQUIV
HAIR FIGUR
House identification number.
Permeability of native soil in cm2.
Native soil radon concentration in pCi/1.
Native soil radium content in pCi/g.
Radon emanation in pCi/g.
Native moisture content in %.
Fill soil radium content in pCi/1.
Radon emanation in pCi/g.
Fill moisture content in %.
Depth of fill soil.
Type of slab poured.
Slump of concrete.
Average gal./truck of water added to concrete.
Detail of slab edge.
Length of expansion joint in feet.
Type of control joint.
Type of sealant used.
Reinforcment used in concrete.
Percentage of induced cracking in slab.
Days from pour to crack observation.
Length of hairline crack in feet.
Equivalent area of crack per protocol in in2.
Hairline figure of merit.
e-3
-------
FINE_CRACK
FINEJEQUIV
FINE_FIGUR
WIDE_CRACK
WIDE_EQUIV
WIDE_FIGUR
TOTAL_CRK
CRK_WIDTII
SLAB_EQUIV
SLAB_FIGUR
TRACER GAS
S TRT DATE
SUB_RADON
STRT__TIMF.l
END_TIME_1
TEMP_0UT_1
RH_0UT_1
DEWP_0UT_1
WINDSPD 1
WIND_DIR_1
TEMP_IN„1
RH_IN_1
DEWP_IN_1
NATRL_ACH
IND_RAD0N1
STrt_TIME2
END TIME 2
TEM P_0UT_2
RH_0UT_2
DEWP_0UT_2
WINDSPD_2'
TEMP_IN_2
RH_IN_2
DEWP_IN_2
AH_ON_ACH
IND_RAD0N2
STRT_TIME3
END_TIME_3
TEMP_0UT_3
RH_0UT-3
DEWP_0UT_3
WINDSPD_3
TEMP_IN__3
RH_IN_3 •
DEWP__IN_3
ACH_ON_CL
IND_RAD0N3
STRT_TIME4
END__TIME_4
TEMP_0UT_4
RH OUT 4
Length of fine cracks in feet.
Equivalent area of crack per protocol in in2.
Fine crack figure of merit.
Length of wide cracks in feet.
Equivalent area of crack per protocol in in2.
Wide crack figure of merxt.
Total length of all cracks in feet.
Average crack width in inches.
Equivalent area of crack per protocol in in2
Slab figure of merit.
TESTS
Start date of test in MM/DD/YY format.
Sub-slab radon level by Lucas cell grab sample.
Start time of test 1 in military (24hr} format.
End time of test 1 in military (24hr) format.
Outside temperature in degrees F at house for test
Outside relative humidity in % at house for test 1.
Outside dewpoint in degrees F at house for test 1.
Average wind speed in MPH at house during test 1.
Wind direction.
Average inside temperature in degrees F for test 1.
Inside relative humidity in % at start of test 1.
Inside dewpoint in degrees F at start of test 1.
Air changes per hour with air handler & exhausts off.
Indoor radon level for test 1 in pCi/1.
Start time of test 2 in military (24hr) format.
End time of test 2 in military (24hr) format.
Average outside temperature in degrees F for test 2.
Outside relative humidity in % at start of test 2.
Outside dewpoint in'degrees F at start of test 2.
Average wind speed in MPH during test 2.
Average inside temperature in degrees F for test 2.
Inside relative humidity in % at start of test 2.
Inside dewpoint in degrees F at start of test 2.
Air changes/hour with air handler on, exhausts off.
Indoor radon level for test 2 in pCi/1.
Start time for test 3 in military (24hr) format.
End time for test 3 in military (24hr) format.
Average outside temperature in degrees F for test 3.
Outside relative humidity in % at start of test 3.
Outside dewpoint in degrees F at start of test 3.
Average wind speed in MPH during test 3.
Average inside temperature in degrees F for test 3.
Inside relative humidity in % at start of test 3.
Inside dewpoint in degrees F at start of test 3.
Air changes/hour with air handler on and doors closed.
Indoor radon level for test 3 in pCi/1.
Start time for test 4 in military (24hr) format.
End time for test 4 in military (24hr) format.
Average outside temperature in degrees F for test 4.
Outside relative humidity in % at start of test 4.
C-4
-------
DEWP_0UT_4
WINDS PD__4
TEMP__IN__4
RH_IN_4
DEWP_IN_4
SSDS_ACH
IND RAD0N4
Outside dewpoint in degrees F at start of test 4.
Average wind speed in MPH during test 4.
Average inside temperature in degrees F for test 4.
Inside relative humidity in % at start of test 4.
Inside dewpoint in degrees F at start of test 4.
Air changes/hour, subslab fan on only.
Percent of air leakage through slab with SSDS on.
Indoor radon level for test 4 in pCi/1.
RADON STRESS TEST
TEST_PATE
STRTJTIME
END_TIME
ST_TEMP__IN
END_TEM_IN
ST_TEM_OUT
EN_TEM_OUT
TIME_10 PA
CFM_10PA
RAD0N_10 PA
ENTRY_10 PA
TIME_2 0 PA
CFM_20PA
RAD0N_2 0 PA
ENTRY_20PA
TIME_4 0 PA
CFM_4 0 PA
RAD0N_4 0 PA
ENTRY_4 0 PA
AVG_EHTRY
EXHAUS_4
RAD POTEN
Start date of radon stress test.
Start time of radon stress test.
End time of radon stress test.
Inside temperature at start of test.
Inside temperature at end of test.
Outside temperature at start of test.
Outside temperature at end of test.
End time for 10 Pascal test.
Air flow in cubic feet per minute at 10 pascals.
Indoor radon concentration in pCi/1 at 10 pascals,
Entry rate of radon in pCi/s at 10 pascals.
End time for 20 Pascal test.
Air flow in cubic feet per minute at 20 pascals.
Indoor radon concentration in pCi/1 at 20 pascals.
Entry rate of radon in pCi/s at 20 pascals.
End time for 40 Pascal test.
Air flow in cubic feet per minute at 40 pascals.
Indoor radon concentration in pCi/1 at 40 pascals.
Entry rate of radon in pCi/s at 40 pascals.
Average entry rate in pCi/s.
Estimated air exhaust rate in cfm at 4 pascals.
Mean radon potential in pCi/1.
RADON DATA
(All data reported in pCi/1.)
SS_RAD_CAP Sub-slab radon level with mitigation system capped off.
Sub-slab radon level with system in passive mode.
Sub-slab radon level with mitigation system on.
Indoor radon level with mitigation system capped off.
Indoor radon level with system in passive mode.
Indoor radon level with mitigation system on.
IN_RAD_CAP divided by SS_RAD_CAP (radon entry eff.).
SS_RAD_PAS
S S_RAD_ACT
IN_RAD_CAP
IN_RAD_PAS
IN_RAD_ACT
EFFICIENCY
C-5
-------
1991 & 1992 LAKELAND DATA FOR F.R.R.P.
HOUSE DESCRIPTION DATA THIS DATA SUPPLIED BY N.F.R.
HOUSE N UTM_X UTM_Y FIR AREA AV.CEIL.HT. MX.CEIL.HT
1
4034
30978.3
3134
11
12
2
4034
30978
2902
11
12
3
4034
30979.3
3402
10
12
4
4039,3
30913
2715
10
12
5
4100.9
30936
1802
8
10
6
4100.81
30933
1661
a
10
7
4142
30375
1425
8
10
a
3003
12
12
9
4020.7
30773,1
2583
10
18
10
4072.5
30928
2404
8
9
11
4028,5
30869
2715
10
12
12
4030.81
30892.1
2715
10
10
13
4032
30095,5
2715
10
10
14
4077.2
30988
1218
20
20
15
4047.5
3C975
2715
10
10
15
4029.9
30892.1
1876
10
12
1?
4033.B8
30978.2
2300
9.3
10
18
4048.6
30909,9
2600
8 5
11
19
4047
30909.7
2356
9.4
20
20
4032.34
30891.89
1764
10
10
21
4049.4
30911.5
2673
9,8
10
22
4102
30935.5
2270
8.3
10
23
4062 1
30913
3380
16
22
24
4029.9
30889.4
2458
11
12
25
4030.33
30S92.1
1876
10
12
26
4075.6
30992.2
5294
9.3
24
27
4048.2
30909,9
2992
10
24
STORIES ROOMS CIS ROOM CNST.TYPE FLR.SURF FIREPLC.
1 12 0 CONC.BLOCK e-B5.t-15 Y
1 9 8 CONC.BLOCKc-40.t-60 Y
1 11 7 CONC.BLOCK c50,t30,w20 Y
1 11 B BLOCK/FRAM C-B5.1-15 Y
1 9 7 CONC.BLOCK C-60J-40 N
1 B 8 CONC.BLOCK C-80,lin-20 N
1 7 5 CONC.BLOCK C-75,lin-25 Y
1 14 9 FRAME c-50,t-50 N
2 11 7 BLOCK/FRAM 0-67,t-33 Y
2 ¦ 13 10 FRAME c75,w10,l15 Y
1 11 b conc.block c-re.s-as Y
1 11 7 CONC.BLOCK c-75,t25 N
1 11 7 CONC.BLOCK c-75,t-as Y
2 8 5 CONC.BLOCK w-66,eonc-34 Y
1 11 7 CONC.BLOCK c-75,t-25 Y
1 7 5 CONC.BLOCK C-85.M5 N
1 11 6 CONC.BLOCK c-80,t-20 N
1 12 10 CONC.BLOCK c-90,t-10 N
2 8 6 BLOCK/FRAM w-68,conc-34 Y
1 7 4 CONC.BLOCK e-66,t-34 N
1 14 9 CONC.BLOCK c-60,t-40 Y
1 10 6 CONC BLOCK c-75,!-2S Y
1 14 8 FRAME/BRICK tile-99 Y
1 10 6 CONC.BLOCK c-75.1-25 Y
C-85.M5
2 22 16 FRAME c-5Q,t-50 Y
2 14 9 CONC.BLOCK W-90.C-10 N
HOUS VO
34474
31922
34020
27150
14416
13283
11400
35285
25578
19232
27150
27150
27150
24360
27150
18760
2127S
22100
22140
17640
26062
18723
54080
27018
18760
49184
29920
C-6
-------
MVAC SYSTEM MEASUREMENTS
FLXDCT
#
>
I
NO.VENT SPLY Cf
RETCFM
NO SPLY
NO RET
LOC SPLY LOG RET
SFLYLK
RETIK
LOC AH
CHASE
HEAT TYP METLDCT
BORDD
1
0
2474
1537
19
3
ATTIC
ATTIC
5
15
ATTIC
NA
HEAT PUMP
2
98
2
0
1938
1276
16
3
ATTIC
ATTIC
3
5
ATTIC
NA
HEAT PUMP
40
60
3
0
1226
855
10
1
ATTIC
ATTIC
5
2
ATTIC
MA
HEAT PUMP
34
66
4
0
1944
1516
16
3
ATTIC
ATTIC
5
7
ATTIC
NA
HEAT PUMP
5
95
s
0
81?
637
12
1
ATTIC
ATTIC
7
5
ATTIC
NA
HEAT PUMP
50
50
s
0
1422
990
14
1
ATTIC
ATTIC
5
3
ATTIC
NA
HEAT PUMP
50
50
7
0
1035
778
8
1
ATTIC
ATTIC
3
3
ATTIC
NA
HEAT PUMP
50
50
S
0
1937
1500
16
3
ATTIC
ATTIC
3
7
ATTIC
SEAL
HEAT PUMP
5
m
9
0
2265
1647
16
1
ATTIC
ATTIC
S
5
ATTIC
NA
HEAT PUMP
50
50
10
0
1413
1057
11
1
Ante
ATTIC
5
5
ATTIC
NA
HEAT PUMP
50
so
11
0
2175
1544
16
3
ATTIC
ATTIC
2
7
ATTIC
NA
HEAT PUMP
5
85
12
0
1636
1494
16
3
ATTIC
ATTIC
5
2D
ATTIC
NA
HEAT PUMP
5
95
13
0
1902
1450
17
3
ATTIC
ATTIC
5
20
ATTIC
NA
HEAT PUMP
5
95
14
0
1125
14
1
ATTIC
ATTIC
5
5
ATTIC
NA
HEAT PUMP
33
66
15
0
2127
1566
18
3
attic
ATTIC
5
20
ATTIC
NA
HEAT PUMP
5
95
16
0
1400
942
12
2
ATTIC
ATTIC
3
15
ATTIC
NA
HEAT PUMP
5
95
1?
0
1405
914
20
2
ATTIC
ATTIC
2
3
ATTIC
NA
HEAT PUMP
40
60
18
0
1349
980
6
1
ATTIC
ATTIC
3
3
ATTIC
NA
HEAT PUMP
50
50
19
0
1665
1446
13
1
ATTIC
ATTIC
5
5
ATTIC
NA
HEAT PUMP
95
5
20
0
1653
672
10
2
ATTIC
ATTIC
5
15
ATTIC
NA
HEAT PUMP
5
95
21
0
1960
1539
12
1
ATTIC
ATTIC
5
5
ATTIC
NA
HEAT PUMP
60
40
22
0
1450
1055
14
1
ATTIC
ATTIC
10
7
ATTIC
NA
HEAT PUMP
50
50
23
0
1560
1301
9
2
ATTIC
ATTIC
2
4
ATTIC
NA
HEAT PUMP
60
40
24
0
1301
1005
12
2
ATTIC
ATTIC
3
6
ATTIC
NA
HEAT PUMP
10
90
25
20
0
3064
2110
23
2
ATTIC
ATTIC
6
6
ATTIC
NA
HEAT PUMP
63
17
27
4500
3 1609
1210
13
1
ATTIC
ATTIC
3
3
ATTIC
NA
HEAT PUMP
65
35
26
C-7
-------
SECOND AIR HANDLER DATA (HOUSE 26 HAS TWO AIR HANDLERS REPRESENTED IN THIS SECTION)
HOUSE #SPLYCP REIT CFM NO SPLY NO RET LOC SPL LOC RET SPLY LK RET IK LOC AH CHASE HEAT TYP METL DOT BORD DC PLX DCT
1
2
3 1391 901 6 1 ATT ATT 5 2 ATT NA HEAT PUMP 34 66
4
5
6
7
B 1004 671 8 3 ATT ATT 3 10 GARAGE SEAL HEAT PUMP S 95
9
10 807 507 7 1 ATT ATT 7 5 GARAGE NA HEAT PUMP 50 50
11
12
13
14
15
16
17
IB 1392 1009 9 1 ATT ATT 3 3 ATT NA HEAT PUMP 50 50
19
20
21 805 676 5 1 ATT ATT 6 5 ATT NA HEAT PUMP 60 40
22
23 1400 1138 7 1 ATT ATT 3 3 ATT NA HEAT PUMP 60 40
24
25
26 1034 827 6 2 ATT ATT 3 3 ATT NA HEAT PUMP 60 50
27 852 650 5 1 ATT ATT 3 3 ATT NA HEAT PUMP 30 60
C-8
-------
HOUSE #
VENTILATION EQUIPMENT (CFM)
K1TCNEX JENAIR MST BAT BTH2 EX DRYR
LOG DRY O FN DS O FN EX
HOUSE #
1
190
S3
70
UTILITY
S. BTH
29
2
36
47
UTILITY
3
87
27
UTILITY
VACUUM
48
4
UTILITY
5
130
40
59
105
UTILITY
6
25
80
UTILITY
VACUUM
7
175
0
24
GARAGE
8
222
48
38
UTILITY
BATH2
69
9
37
50 ¦
UTILITY
BATH
61
10
40
34
UTILITY
BATH
29
11
UTILITY
VACUUM
12
175
43
110
UTILITY
13
34
66
UTILITY
BATH
58
14
396
27
42
80
UTILITY
BATH
38
15
75
46
63
125
UTILITY
16
85
98
UTILITY
VACUUM
80
17
190
61
72
92
UTILITY
18
210
25
38
UTILITY
.
19
50 '
20
26
125
UTILITY
20
64
59
UTILITY
21
75
18
150
UTILITY
22
25
33
125
UTILITY
23 •
158
10
21
100
UTILITY
BATH
30
24
170
46
73
70
UTILITY
25
26
112
63
22
100
UTILITY
BATH5
111
27
219
24
28
162
UTILITY
BATH
15
C-9
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
-------
BLOWER DOOR TESTING
E#
TESTDATE
ST TIME
END TIME
H ACH5Q
H CFM50
H ELM
HELA10
HELA50
0 ACH50
D CFM50
~ ELA4
D ELA10
D ELMO
1
a/14/9)
8:30
13:45
6.6
3786
188.8
367.3
491.9
0.9
515
183.8
342.4
66.7
2
9/11/91
10:30
11:46
8.9
3667
216.4
396.2
476.7
0.8
338
50.9
73.9
43.0
3
9/10/91
9:30
11:30
7.7
4377
282.4
477.8
589
0.5
263
0
109.9
34.2
4
10/8/91
10:45
15:45
6.2
2784
125.9
253,8
381.8
0.3
118
0
0
15.3
5
10/24/91
9:30
10:37
5,1
1418
845
154.3
184.3
0.2
52
14.7
15.3
6,8
6
9/26/91
9:30
14:00
6.5
1568
SO
167
£04
0.5
114
S
11
15
7
11/8/91
13:30
16:00
8,4
1302
123
189.8
189.3
0.2
34
46.4
50.7
4.4
6
11/1/91
8:00
14:30
4.8
2847
132
263.8
370.1
0.6
370
10.1
25.3
48.1
9
12/18/91
9:00
15.00
9.5
4111
214.2
410.3
534.4
0,8
406
58.5
88
52.7
10
11/8/91
9:00
13:00
10
4352
215.4
420.3
565,6
1.2
536
5.8
26.5
69.7
11
10/28/91
12:00
17:00
6.1
3221
201
340.5
418.7
0.5
287
42.6
57.6
37.3
12
1/31/92
9:00
15:00
6.1
2751
183.3
321.1
357.6
0.7
324
23,7
40.2
42,1
13
12/13/91
9:00
15:00
7.4
3333
197.7
381.3
433.3
0.9
422
34.2
56.5
54.9
1A
7/17/92
9:00
17:00
5.1
2086
100.1
197.6
271.2
0.3
120
23
33,9
15.6
15
2/4/92
9:00
15:00
6.5
2923
139
275.2
380
0.5
238
-9.7
-3 3
30,9
16
3/12/92
9:00
15:00
7.1
2229
123.1
230.9
289.8
0.9
293
15.3
29,4
38.1
17
8/4/92
9:00
17:00
3.9
1378
68.8
133.8
119.1
0.5
169
10.8
19,3
22
18
4/14/92
9,00
17:00
6.7
2470
103,5
214.5
321.1
0.6
232
19.01
32,7
30.2
19
7/14/92
9:00
17:00
5.2
1934
93.7
184.3
251,4
0.4
128
1.8
6,7
16,6
20
5/12/92
9:00
17:00
5.6
1648
67.3
140,8
214 2
0.7
216
-4.7
0 7
28
21
10/7/92
9:00
17:00
4.8
2099
78.5
169.6
272.9
0.6
276
0
0
35,9
22
8/20/92
10:30
17:00
4.6
1447
75.2
144.2
188,1
0.5
160
0
0,6
20.8
23
12/15/82
14:00
20:00
3.8
3405
232.4
403,5
442.7
0.2
147
0.8
7.2
19.1
24
25
12/15/92
8:30
16:00
5.3
2365
144.2
260.9
307.5
0,5
201
8,5
17.9
26,1
26
3/12/93
8:00
16:00
7.8
6373
521.7
648.1
828.5
0.5
373
20.5
38.4
48,5
27
12/18/92
8:30
16:00
5,4
2680
144.9
273.3
348.4
0.3
158
110
18.3
20,5
C-10
-------
BLOWER DOOR TESTING WEATHER DATA
HOUSE # WNDSP WND DIR TEMP DEW OUT TEMP IN DEW IN
BAR PRES
1
3
NW
91.5
70.2
82.3
62.3
1.017
2
2.5
N
85.6
76.4
79.4
59.6
1.011
3
3
N
83.1
74.9
80.4
62.3
1.012
4
6
NE
78.2
61.8
74
60.3
1.019
5
10
E
82.2
70.8
83.8
68.3
1.014
6
2.5
NE
81.3
T2 7
63.7
82.8
1.006
7
4
W
77.2
41.2
77.7
56.3
1.006
8
4
E
82.4
61.5
77.2
58.4
1.102
9
2,5
NE
60.7
70
63.2
58
1.018
10
2
W
69
48.1
72.1
53.1
1.008
11
4
NE
85
66.1
77.3
53.5
1.005
12
1.5
NW
78,2
70.8
77.3
63
1.019
13
2,5
NE
78
70.4
73.2
53.4
1.018
14
3
W
82
79.4
82.6
59.4
1.012
15
• 2.5
E
71
43.1
69
49.5
1.008
16
2.5
SE
54
35.1
72
50
1.01
17
0.5
W
84.3
73.6
82.4
58.7
1.006
18
7.5
NE
77.9
63.1
77.9
55.8
1.101
19
2
W
92.8
78.1
81.2
59.2
1.008
20
0.5
S
82
61.8
77.5
55.1
1.01
21
3.5
E
80.8
70
80.6
70.8
1.008
22
1
W
•98
70.8
84
62.3
1.003
23
1
W
73.6
60.6
75.6
60.9
1.008
24
1
W
63.8
58.2
70.7
56.8
1.007
25
26
5.5
E
79
62
78.4
58
1.005
27
1
SW
70.1
62.7
76
60.6
1.012
C-ll
-------
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
DIFFERENTIAL PRESSURE TESTING
AH OFF, DOORS OPEN AH ON, DOORS OPEN--— AH ON, DOORS OPEN, EXHAUST ON
DIO DSM DSR DSE AD IO AD SM AD SR AD SE ADEIO ADE SM ADE SR ADE SE
1
3.6
2.7
-0.3
0.7
1.2
0.1
0.2
-0.6
-0.1
0
-1.5
0,1
1,7
1.4
0.1
-0.3
1.5
1.5
0
0
2.2
1.8
0.6
-1.4
0.4
0.3
2.4
-1
0.7
0.8
2.1
-0.5
2.4
1.3
2.6
0,1
5.1
2.5
2,6
-0.6
3.2
1
2.7
1,4
-3.4
-0.4
9.2
0.4
0.3
-0.8
8.4
6.3
-3
2,9
11.1
0
0.1
0.8
0
0.6
-0.1
1.1
0
2,8
0.9
2,5
0.7
0.4
0.1
0.3
0.8
0
0
0.3
0.4
4.9
5.1
5,8
5
1,7
3
5.7
-0.8
-1,3
-0.1
-0.9
-0,7
-1.3
0
0.2
-0,5
-0.7
0
0.1
-0.7
2.9
2.9
3
-2.6
1.9
0.6
2
0,2
2.7
2.8
3,5
-1
0,7
0.6
0.3
-1,4
0.1
0.1
-0.4
0,1
0 9
0.6
0.9
0.5
-0.9
-1.4
-0.4
3
0.3
0
0,9
0.6
0,5
0.5
0,6
-1
0
0
-0.1
-0.9
-1.1
-0.3
-0.8
-0.8
-1.1
-0.2
-0.8
4.6
3.8
3.3
4
0
-0,9
-0.5
-0.3
-0.3
-1.2
-1
-0.7
2.4
0,3
1
0.5
0.2
-0.8
-1.3
0.6
-0.2
-1.6
-2.2
-0.2
1.1
0.9
1
2
-0.8
10.6
-0.1
0,6
-0.2
13.6
0.2
0.9
6
8.3
4.8
7
0.3
-0.4
-0,6
-0.8
-2,6
-0.9
-1.6
-2.4
2.7
3.8
3.1
3.1
0,4
0
-0,2
-0.4
0.7
-0.3
-0.2
-0.3
-3.3
3.4
3.9
3.4
0.6
-0.3
-0.5
-0.3
-0.1
-0.5
-0.7
-0.9
1.5
0
-0.1
-0.2
0.2
0
-0,4
0.4
-0.3
-1.5
0
-1.9
2.4
0.5
1.2
0
-0.6
-0.3
-0.2
-0.5
-1.1
-0.8
-0.3
-0.9
-0.6
0
-0.1
-0.4
-0.4
0.5
0.1
0.4
-0.4
0.2
0.1
0.5
1.4
2.1
1.4
1
-0.3
-1.1
-0.3
0
-0.8
-0.B
-0.2
-0.8
1.9
'2.1
1.8
2.4
-1.6
-0.7
-0.4
0.6
-2.1
-0.4'
-0.9
1.2
-0.1
1,6
1.3
0.8
0
0.2
-0.1 .
0.1
0
0
-0.1
0
2.7
2,4
2.5
1,3
C-12
-------
AH ON, DOORS CLOSED
HOUSE# AlO ASM A SR ASE A BR1 A BR2 ABR3 AB1 A B2 AU AG
1
-0,9
0
0
-1.2
-1.2
-10.4
-10
-1.7
-0.8
2
1.4
2.7
2.8
1.1
8.4
2,4
1.1
1.5
1.5
3
-1,9
0.1
-0.1
1,7
-8.2
4.7
3.4
6.5
2.7
4
0.5
4.3
2.5
2,7
3,9
15.8
20.4
6.4
0.8
5
5.2
1.1
3.2
11.6
13.6
7.4
6.7
5.8
2.8
6
10.7
10.1
11.9
7.2
17.4
14.6
49
6.4
9.4
7
4,3
3.5
4.5
3.9
10.5
5.1 •
8.9
4.5
8
9,7
11.7
9.9
2.8
0.2
3.4
9
0.4
0,9
2,3
1.5
4.3
2.4
1.5
7.8
10
1
3
2.7
3.5
11
2
15.9
5.1
1.2
2.5
11
-0.4
0.9
0.8
0.4
4.1
8.6
29.5
1.4
0.2
12
1.5
-0.1
-0,2
0.3
3.9
5.5
4.5
0.6
3.5
4.3
13
0.7
2.3
2.4
2.7
7.3
15,8
0.9
6.8
14
-0.1
-0.1
0
0
2.5
0.5
0,6
1
1.4
15
0.9
-0,4
0.8
2
5.5
11.2
4.4
0.9
2.2
1
16
0
0.5
1.2
0,7
0.5
5.3
5.8
0.6
17
-0.8
7.3
-2.5
1,9
-6.3
7.1
7.9
1.4
0,8
18
1.7
1,4
3.9
4
9
4.2
4.2
0.7
1.4
2.1
19
-2,2
2.2
2.8
2.5
17.5
9.9
3,6
3.8
3.1
20
1.8
1.6
0.7
0.9
4.7
3
2.8
2
21
8.1
5.9
7.8
7.5
12.6
21.3
20.5
12.2
2
22
1.7
2
7.3
2.2
12.2
5.3
12
0,1
2
23
1
1.9
1.2
1.1
1.8
10.1
3.3
3,2
24 ¦
0.5
2.5
1.7.
2.3
3.9
2,9
1.9
0.9
0.4
25
26
2.1
1.6
1
2.4
3.9
11.5
6
1.4
0.5
27
1.3
1.2
1.1
0.8
9.9
4.5
5.8
2.1
2.8
2.2
C-13
-------
AH ON. DOORS CLOSED, EXHAUST FANS ON
JSE
AE IO
AESM
AE SR
AE SE
AE BR1
AE BR2
AE BR3
AEB1
AE B2
AE U
AE G
1
-2.4
-1.8
-1.7
-2.7
-0.5
-11.1
-10.5
1.5
2
1.5
3.3
3.4
1.5
7.1
2.7
1.2
1.6
1.7
3
A
-1.6
1.3
0.5
2.3
-8.5
5
3.5
6.6
2.9
4
5
13.6
6.7
10.4
16.5
15.2
10.1
14,3
1,7
0.1
6
13.2
11.8
13.2
7.6
15.9
14.2
46.5
3
7.9
7
13.1
13.6
14
13,7
16.1
9.8
12.9
5.2
8
13.S
13.5
8.1
4,8
-0.2
6.4
8.5
9
1.2
2
2.4
2.4
3
3.9
2,1
8.4
10
1 1
1.8
3.9
3.5
4.6
13.B
2.5
15
3.1
0.1
2.4
2.6
I i
12
4
2.6
2.6
2.3
6.4
6,5
5.1
0,4
1.8
2.9
13
14
5.4
3.6
4.4
4.4
5.2
1.8
1.8
1,7
0.2
15
4.8
4
2.6
5.3
8
12.4
5.4
0.6
0.2
0,2
.16
2.5
1.6
2
2.9
2.3
6.5
7.1
0.3
17
7.2
20.6
3,2
7.2
-3
6,5
6.5
0.2
-0.7
18
4.1
5.6
5.1
5.3
9.9
5.1
4.9
0.5
1.7
2,7
19
-7.4
7.4
B.1
7.7
18.1
11.3
5
3.6
1,8
20
2.1
1,9
1.5
1.5
3.9
2.4
1.2
2.2
21
11,4
8.9
10,9
10.1
12,1
22,2
21.5
9.3
-0.1
22
2.5
2.2
6.1
2,9
11
5.3
12
0
-0.5
23
3
3.5
3.9
4.1
3.6
9.7
4.3
1,7
24
3.9
3.4
4.2
4.3
5.2
•3.3
3.3
-0.4
0.2
25
26
1.5
3.9
4.1
5.2
3.3
12
6.9
0.2 .
0.2
27
6.5
6.3
6.2
3.1
10,5
6.6
7,5
2.1
3.4
0.2
C-14
-------
dP TEST WEATHER DATA
HOUSE # TEMP OU DEW OUT TEMP IN DEW IN WND SPD WND DIR BAR PRE
1
3.5
NE
1.012
2
95.1
71.2
87,5
62.6
2.5
N
1.01
3
94.2
71
79.6
62
4.5
NE
1.01
4
85.7
58.7
72.7
53.3
6
NE
1.019
5
82.2
70.8
80.1
62.8
5
E
1.104
6
91
73.2
85.6
68.6
6
NW
1,002
7
78.1
42.2
77.7
54.4
5
W
1.005
8
82,4
61.5
77 2
58.4
4
E
1.102
9
68.9
54
68.8
58
4
NE
1.017
10
73.8
44
74.1
52.5
4
NW
1.007
11
84.9
66
75.5
56.7
4
NE
1.005
12
75.2
69.2
73.8
61
1.5
NW
1.019
13
78.3
61
79
50
4
NE
1.018
14
98
70.3
81
58.7
2
W
1.008
15
70.1
44.1
67.7
46.8
2
E
1.008
16
60
39
75
49.9
1.5
E
1.008
17
97.6
69.7
81.9 .
63.3
1,5
W
1.005
18
78.4
59
72.8
60
7.5
N
1.017
19
90.7
69.6
81.9
65.1
2
W
1.009
20
89.1.
51.5
78.2
56.3
0.5
s
1.01
21
77.4
80
77.3
77
1
E
1.008
22
98
70.8
81
62.3
2
W
1,008
23
71
64
74
60
1
w
1.008
24
64
58
71
56
1
w
1.007
25
26
79
62.3
76.6
58.2
5.5
E
1.005
27
81.2
62.7
77.3
62.2
1
sw
1.012
C-15
-------
SOIL, SLAB. INFILTRATION, AND RADON DATA
HOUSE N NAT PERM NAT RN NAT RA NAT RN EM
1
6.00E-08
3851
0.7
0.37
2
2.00E-09
3547
3.6
1.47
3
1.00E-07
11055
2.9
0.3
4
2.00E-0?
2103
0.9
0.26
5
2.00E-07
902
1.2
0.46
6
1.10E-Q6
640
0.5
0.031
-7
2.00E-07
20858
10.8
ri
8
5.0CE-09
15371
1.9
0.87
9
6.00E-Q8
4500
6.2
0.61
10
S.OOE-OS
1T79
1
0.65
11
6.QQE-08
657
0.2
n
12
3.00E-07
1790
8.8
0.56
13
4.00E-09
574
0.4
0.12
14
2.72E-07
2330
8.8
1.36
15
2.09E-08
3440
5.4
0.65
16
8.26E-08
4080
3.4
0,6
17
8.S0E-09
- 947
5.9
2.1
18
8.78E-08
7263
2.6
0.7
19
2.71 E-07
1.5
0.6
20
4.59E-08
3000
21
7.96E-06
6860 .
11.5
3
22
1.635-07
853
0.5
0.1
23
2.S8E-07
1600
0.7
0.2
24 .
1:60E-G7
41 B '
0.4
0.1
25
3.42 E-07
13.4
1.1
26
4.83E-08
2210
3.4
1.2
27
3.58E-07
8450
8.6
2.8
28
2.74 E-07
6285
68.6
21.8
FiLRA F1LRNE FL MOIST FIL DEPTH TYPE
10.3
0.8
4
1
MONOLITHIC
18.8
0,68
5
1
MONOLITHIC
29.5
1
1.5
MONOLITHIC
16
2.65
10
0.5
MONOLITHIC
5.6
0.54
5
0.5
STEMWALL
1.5
STEMWALL
5.3
n
4
0.5
MONOLITHIC
0.7
n
7
0.5
STEMWALL
8.5
0.96
7
1
MONOLITHIC
2.4
0.4
9
" 0.5
MONOUTHIC
5.2
0.53
4
1.5
MONOLITHIC
1
MONOLITHIC
9,9
0.3
7
0.5
MONOLITHIC
1.5
STEMWALL
12.2
0.37
5
1
MONOLITHIC
10
0.8
10
1.5
MONOLITHIC
5.2
0.3
4
0.5
MONOLITHIC
13
1.8
5
1
MONOLITHIC
13.4
J.6
7
1
STEMWALL
10.6
0.8
6
1
MONOLITHIC
2.3
0.2
4
1
STEMWALL
2.5
0.7
1
_ 0,5
STEMWALL
7.4
0.1
5
1.5
STEMWALL
6.4
0.6 '
5
0.5'
MONOLITHIC
6,4
0.6
4
2
MONOLITHIC
5.6
1
5
1
STEMWALL
4.4
0.5
7
0.6
STEMWALL
5
0,4
11
2
STEMWALL
NAT MOIST
3
14
8
6
14
3
13
13
' 7
11
9
9
14
e
6
13
9
5
1
7
5
3'
7
11
9
8
19
C-l 6
-------
SLAB DATA
HOUSE# SLUMP ESTWATE EDGE EXJNT CNTRLJ SEAL RNFRCM
1
4
MONOFOO 20
WIRE/FIB
2
5
, 15
MONOFOOTER
WIRE/FIB
3
5
20
MONOFOOTER
POST-TE
4
4
MONOFOOTER
WIRE
5
5
CHAIR POUR
WIRE
6
5
CHAIR POUR
WIRE
7
5
MONOFOOTER
WIRE
8
5
CHAIR POUR
WIRE
9
MONOFOOTER
POST-TE
10
MONOFOOTER
WIRE
11
4
MONOFOOTER
WIRE
12
5
MONOFOOTER
WIRE
13
5
MONOFOOTER
CLR SEA WIRE
14
4
CHAIR POUR
WIRE
15
4
MONOFOOTER
POST-TE
16
5
MONOFOOTER
WIRE
17
4.5
MONOFOOTER
WIRE/FIB
18
4
MONOFOOTER
POST-TE
19
4
CHAIR POUR
FIBER
20
5
MONOFOOTER
WIRE
21
4.5
CHAIR POUR
WIRE/FIB
22
4.5
12
CHAIR POUR
WIRE
23
4
5
CHAIR POUR
FIBER
24
5
15
MONOFOOTER
WIRE
25
7
8
MONOFOOTER
WIRE
26
5
18
CHAIR POUR
WIRE
27
4
CHAIR POUR
WIRE
28
5
17
CHAIR POUR
WIRE
C-17
-------
CRACK DATA
¦E #
ELAP TK4
HRLN CH
H EQ
HRG
FINE CRK
F EQ
FRG
MED CRK
MED EQ
MED FIG
TIL CRK
CRK WDT SIB SQ
SLB FM3
1
3
0
0
0
54
0
54
0.016
391.4
2
3
0
0
a
t6
20
56
0.026
1924,1
3
3
D
Q
0
0
0
0
0
0
0
0
0
0
0
4
3
A
0,00048
0.0069
27
0
o
0
0
31
0.009
0.00049
50.4
5
3
5
0.00017
o.oaoB
44
0,001
0.0457
s
0.0007
0.0025
57
0.017
0,0112
50 7
6
2
0
0
0
9
0-0024
0.0063
0
0
0
9
0.016
0.0024
4.4
7
3
18.6
0.0031
20.62
0.0023
5.49
39.22
0.014
0,0054
27492.5
8
2
Q
0
7
0.00056
0-0007
33
0-0092
0.05(3
40
0.029
0 0098
79.6
9
3
29 3
0.00025
0,00087
13.08
0.00038
0,0071
0
0
0
42.33
0,01
0,00063
81.9
10
2
0
0
0
0
0
0
13
0-0083
0.112
13
0.031
0.0083
141.4
11
2
a
0
o
203.7
0,0732
0.212
39.75
0,0035
0.0762
243.45
0,041
0.C767
427
12
3
41,5
0
0
0
13.33
54.8
0,097
23fS
13
3.
54 B
342.33
26.83
_
400,9
0.02
624.5
14
7
3
—
—
0
0
0
276
— -
—
284
0.031
_
—
15
3
5
__
5
—
— .
o
Q
0
10
0.013
—
16
3
0
0
0
0
0
0
0
~
0
0
0
0
0
17
4
0
0
0
18
0.0103
0.0255
0
0
0
18
0,016
0,0103
B.64
18
3
0
0
0
0
0
0
D
0
0
0
0
0
0
19
4
7.5
—.
—.
30
—
.—
0
0
0
37.5
0,015
—
—
20
3
10,3
18
0,0062
0.102
0
Q
0
28.3
0.0'.9
0.0062
63.32
21
3
14
—
20.5
—
¦—
0
0
0
34.5
0,013
—
—
22
4
0
0
0
0
0
o
0
0
0
0
0
0
0
23
3
Q
—
15.7
—
—
16.5
—
—
33,2
0.027
—
—
24
3
97, S.
0.00244
0,0479
193.7
0.0136
0.396
0
0
0
291.3
0.024
0.016C4
16S5.S
25
2
36
0.0008
0
0
0
0
0
0
0
36
0
0.0008
S3.3
25
5
4
0
0
0
14
Q.0008
52.18
18
0-027
0.0008
3022,8
27
5
0
0
q
0
Q
0
o
0
0
0
0
0
0
28
3
113.2
0
0
0
36.5
0.00445
0.0908
154.7
0.017
0.00445.
151.9
C-18
-------
TRACER GAS TESTING
TEST ONE, NATURAL INFILTRATION
HOUSE# ST DATE SUB Rn ST TIME ENDTIM TEMPO RH OUT DEW OUT WNDSPD WND DIR TEMP IN BH IN DEW IN NAT AC IN Rn
t
8/13/91
9514
13:40
14:40
67.1
S
NW
844
0.265
0.1
2
9/10/81
4906
12:10
13:10
65.6
5.1
NE
81.2
0.131
3
9/11/91
15:00
16:00
94.4
71.2
3.1
N
80 4
0.06
0,8
4
10/41/91
6570
12:30
13:30
83.1
. 3
E
73.7
54.8
0.132
4.3
S
10/28/91
614
13:20
14:20
85.2
4.2
E
78.5
56.7
0.19
3,6
6
9/24/91
883
12:10
13:10
66.1
3.2
E
79.7
0.296
0.7
7
11/8/91
4650
9:00
10:00
65.5
4.3
W
70,6
0.177
3.1
8
10/30/91
1483
11:30
12:30
81.4
10.3
E
76
55.2
0.21
1.7
9
12/13/91
6441
11:10
11:50
77.7
5
NW
698
89
75.2
0.455
0.4
1Q
11/13/91
18:20
17:20
72.2
3.3
E
72,6
42.7
47
0.18
0.8
11
10/29/91
2900
8:40
9:40
74.5
3.2
E
70.1
58.3
0.179
1.3
12
1/29/91
7097
12:10
12:50
. 77.3
85.7
78
3.2
S
77.6
62.4
75
0.056
2.2
13
12/12/91
11:50
12:50
81.5
2.5
sw
71.4
62.1
99.9
0.094
1.8
14
6/28/92
9:45
10:45
80.3
100
84.3
2.7
w
79.8
78.2
70.4
0.128
2.3
15
3/26/92
1550
12:30
13:30
75.2
50.7
10.5
NW
74.2
62.3
57.0
0.185
0.9
ie
3/19/32
3190
9:30
10:30
77.5
96.5
74.4
5.7
SW
77.2
68.7
67.8
0,12
2.8
17
6/23/92
424
14:30
15:10
84.5
89.6
79
5.9
SE
83.9
51
62.5
0,161
1.1
18
4/16/92
1085
9:30
10:30
73.6
72.9
79.5
5.8
E
73.7
69.1
61.9
0.061
iM
18
5/12/92
12:40
13:40
89
1.3
NW
81.9
47.1
58
0,187
3
20
5/11/92
7217
13:20
14:20
85.3
33.4
53.2
3.8
E
82.9
37.8
56.7
0.203
0
21
8/31/92
3420
14:30
15:20
67.1
58
0
81,9
64.2
65.2
0.117
2.5
22
8/14/92
2684
12:50
13:50
88,4
71.8
76.8
3.1
SW
83.4
63.2
69.1
0.13
0.2
23
10/5/92
2414
12:50
13 50
72.3
46.5
55.8
2
NW
80.5
58.9
66.1
0.31
0.2
24
11/2/92
2744
13:00
14:00
86.6
49.8
65,1
3.8
W
82.4
52.8
65.8
0.221
0.5
25
9mm
3796
10:10
11:10
84
86,6
80.3
4.3
NE
79.6
60.8
63.3
0.122
1.2
26
2/24/93
1710
12:40
13:40
68.3
26
33.1
1,3
E
76.7
50.7
53.5
0.268
1,3
27
11/19/92
6372
9:10
10:10
67.7
93,8
69,5
1.S
N
74.8
68.8
59.9
0.165
1.1
28
C-19
-------
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
TRACER GAS TESTING
TEST TWO, AH ON DOORS OPEN
ST TIME END TIME TEMP OU RH OUT DEW OU
14:40
15:40
92.9
13:10
14:20
89.8
10:20
11:20
76.9
13:30
14:40
85.6
14:20
15:20
85.2
13:10
14:20
90.7
10:00
11:00
66.1
12:30
13:30
84.5
10:30
11:10
72.7
17:20
18:20
66.3
9:40
10:40
75.5
12:50
13:50
80.3
12:50
13:50
83.6
10:45
11:45
79.5
100
87
13:30
14:30
75.1
42.3
50.1
10:30
11:30
79.4
73.2
69.8
12:50
13:30
83.7
58.7
10:30
11:30
76.2
13:40
14:50
89.2
37.5
53.3
14:20
15:30
88.1
13:40
14:30
84.8
53.8
11:40
12:40
66.2
77
13:50
15:00
76.1
51
56
14:00
14:50
8§.7
55.1
68.3
11:10
12:10
88.6
.72.5
75
13:40
14:40
69.5
26.5
365
10:10
11:10
71.1
75.8
67.3
TOTAL
D SP
TEMP IN
RH IN
DEW IN
AHACH
RLF
IN Rn
5.4
84.9
0.619
16
0,8
5
78.7
0.486
1.3
1.2
77.9
0.333
17.4
1.2
3.6
74
0.382
5.6
5
2.8
78
5B.7
0.248
3.4
3.7
3.1
80.3
0.877
5.9
2.4
3.3
71.8
0.503
7.6
1.5
8
76.6
0.198
20.4
1.8
4.3
69
0,558
10.4
0.1
0.5
73.5
0.303
18.8
1
4.9
663
0.367
6.9
1.6
2.6
82.6
0.204
7,8
1
2.6
70.1
0.468
8.2
1.4
2.6
79,4
90.3
77.8
0.443
4.8
3
11.6
74.3
59.3
58.8
0.501
4.6
0.6
8.9
77.2
68.8
64.9
0.608
7
2
5.1
84.5
67.5
73.7
0.474
1.8
0.8
5.5
74.8
70.5
63.7
0.18
0
1.8
1.2
81
49.3
61,4
0.263
1.7
4.9
3.7
78.6
46,3
58.2
0.515
11.2
0
0
79.4
71.9
70.8
0.263
8.2
2.7
3.8
81
67.6
69.7
0.361
6
0.4
1,8
78.3
62
61.9
0.458
8
0.2
.1,9
81.8
48.8
61
0.435
11.7
0.6
3.9
80.5
51.7
63.6
0.762
24.1
0.7
1.3
78.2
44.2
84.3
0.445
18
1,4
1.8
77.1
70.5
66.6
0.414
11
2.1
C-20
-------
TRACER GAS TESTING
TEST THREE, AH ON, DOORS CLOSED
HOUSE# ST TIME END TIME TEMP OU RH OUT DEWOU WND SP TEMP IN RH IN DEW) AH DC AC IN Rn
1
15;50
16:50
94.4
5.6
83.3
0.54
0.6
2
14:30
15:30
92.9
5.4
77
0.266
0.7
3
11:30
12:30
88.4
1
77.2
0.486
1.7
4
14:50
15:50
86.5
2,3
69,7
58.8
0.265
2.9
5
15:30
16:30
85
3,4
77.6
56.4
0.462
3.8
6
14:30
15:30
93.6
3.7
79
0.784
1,9
7
11:10
12:10
73.6
2.4
72
0.97
2.6
8
13:40
14:40
85.5
7.3
78.9
47.5
0.38
2.3
9
12:00
12:40
80
5.2
70,1
89.8
76.1
0.345
0.4
10
18:30
19:30
62.2
0,6
72.4
46.6
50,4
0.976
1.4
11
12:00
13:00
76.7
1.8
68,1
57.1'
0.295
2
12
1 1
13:40
14:20
84.3
2.3
78.4
83.9
76.8
0.288
1.2
f J
14
11:55
12:55
78.4
100
84.6
0
78.2
58.4
62
0.393
1.8
15
14:40
15:40
75
45.9
50.9
11
73.5
60.2
58.1
0.696
0.9
16
11:40
12:40
80.1
63.6
66.4
10.2
78.9
57,8
64.2
0.572
0.8
17
13:40
14:20
84.4
70.6
73.9
5,3
83.6
51.1
65.8
0.453
0.6
18
11:40
12:40
79.4
5.4
74.6
68.5
64.1
0.468
2.2
19
15:00
15:50
88.8
0.8
78.2
41.2
52.2
0.443
4
20
15:40
16:40
89.1
2.1
75.7
43
51
0.601
O
21
15:30
16:20
86.6
49.6
67.1
0
80.6
69.4
70.3
0,85
3
22
14:00
15:00
83.5
58.8
2.3
82
63.5
70.1
0.577
0.6
23
15:10
'16:00
79.1
49.7
56.5
2
77.1
54.6
58,3
0.536
0
24
15:00
•15:50
86.4
55
65.1
1.9
81,2
55.5
62.7
0,345
0.4
25
12:20 '
13:20
91.3
64.9
71.7
4
78.6
63.7
64.8
0.56
0.8
26
15:00
16:00
71.4
24
33.6
1.3
78.5
43.5
52.1
0.498
1.5
27
11:20
12:20
74.7
59.5
61.8
1.9
78,4
65.2
64.3
0.45
1.5
28
C-21
-------
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
10
19
20
21
22
23
24
25
26
27
28
JB Rr>4
2068
2080
2200
339
38 5
1290
1140
2330
1500
1550
1510
392
1290
3718
438
1336
1383
2883
TRACER GAS TESTING
TEST FOUR, AH OFF, MITIGATION FAN ON ONLY
ST TIME
ENDTiM
TMP OU
RH OU
DEW OU
WND SP
TMP IN
RH IN
DEW I
SSD A
SLF
IN Rn
17:00
18:00
87.6
6.3
84.4
0,14
5.9
15:50
16:50
87.4
8.1
79,7
0.216
38.3
0.3
12:50
13:50
92.1
1.6
77,7
0.223
13.6
1.6
16:00
17:10
86.4
4.1
71
54
0.282
9.6
3.4
16:40
17:40
81.3
2.4
76.6
53.2
0.112
7.2
2.8
13:50
14:50
94.1
4.1
78
0.626
2
1.9
12:20
13:20
76.2
4.7
73
0.471
14:50
15:50
82 5
6.6
77.8
48,6
0.228
5.4
2.2
12:50
13:30
81.7
3.4
70.2
87.4
75,9
0.478
2.3
0.01
19:40"
20:40
60.7
2.4
73.1
49.1
50.8
0.191
10
1.6
10:50
11:50
75.5
5.5
69.1
63 1
0.27
9.4
1.5
14:30
15:10
84.B
1.2
78.6
85.9
78.7
0.166
4.4
2
13:05
14:05
78,3
100
82.5
0.8
79.2
61
60.5
0.076
4.3
2.2
15:50
16:50
73.3
46.2
41.8
9.8
74.1
59.6
57.8
0.233
13.3
0.7
12:50
13:50
66.9
67.8
68.3
S.1
77.7
64.6
62.9
0.162
22
0.6
15:20
16:00
82.7
78,3
76.2
4.4
83
55.2
65.6
0.307
34.8
1
12:50
13:50
81.4
5.5
75.4
65.1
61.4
0.121
10
2.3
16:00
17:00
90.7
34.3
53.2
1
80.6
41
52
0.129
17,4
2.7
16:50
17:50
87.8
35.9
2,1
77.9
41.6
49.9
0,137
18.7
0
15:10
16:10
79.5
100
80.9
0
80.3
59.9
66
0.223
9.2
0.1
16:20
17:20
77.5
51.5
56.6
1.7
78.1
55.8
58.3
0.181
6.6
0,5
16:00
17:00
84.6
49.6
63.3
0.4
82.1
54,2
64
0.115
30.2
0
13:30
14:30
94
53.9
65,5
•3.6
81.1
57.1
61.6
0.079
6.9
0.6
16:10
17:10
70.4
26
34.1
1
78.1
42
51.9
0.197
14.7
1.5
C-22
-------
RADON STRESS TEST
DEPRESSURIZATION AT 10 Pa
HOUSE DATE ST TIME E TIME BTMP IN E TMP IN BTMP O ETMP O TIME10P CFM10P RnlOPA RATE 10P
1
8/14/91
14:25
17:45
84.4
80.9
.91.8
83
15:25
1643
0.4
310.2
2
9/12/91
10:00
13:35
79
80.5
76.9
92.1
11:10
116
0
0
3
9/11/91
10:40
14:25
76.2
78.1
78.3
87.1
12:15
338
0.2
63,8
4
10/4/91
11:55
15:25
77
78
76.5
82.5
13:25
1471
0.7
486
5
10/25/91
9:05
12:35
78.9
80
78.9
86
10:35
385
1.4
256
6
9/25/91
9:50
13:20
78
79
81.1
86.8
11:20
594
0.4
112.2
7
11/8/91
14:00
17:00
75.1
78
74.5
74
15:00
534
0.8
202.8
8
11/1/91
10:00
13:00
71,5
76.8
78.3
81.8
11:00
966
0
0
9
12/16/91
12:20
15:20
64
65.2
63.6
67.1
13:20
1588
0.7
527.8
10
11/13/91
13:00
16:00
78.1
71.6
69.4
76.2
14:00
1588
0.4
292.1
11
10/29/91
14:20
18:10
71.3
73,1
78.3
76
16:10
1197
0.1
56.8
12
1/29/92
8:30
11:30
77
80.1
65.3
71.5
9:30
816
2.6
385.2
13
12/12/91
8:15
11:15
71.2
70.6
66.4
68.4
9:15
1610
1.4
1070.3
14
6/25/92
12:45
15:45
• 79.1
77.9
80.1
76.4
12:45
690.6
1.1
361
15
3/26/92
9:00
12:00
72.1
72.7
65
70.2
9:00
973
0.8
367
16
3/13/92
8:50
11:50
72.4
75.5
55.6
71.6
8:50
973
2.7
1247
17
3/23/92
8:26
11:26
83.6
85.7
84,9
89.6
8:26
690.6
1.4
459
18
4/15/92
14:25
17:25
83
82.6
83
85
14:25
973
1,5
693
19
5/12/92
9:10
12:20
78,2
82
70.4
86.2
9:10
465.3
4,1
905
20
01
5/13/92
8:50
11:50
71.1
80.1
69.7
80.6
8:50
843.9
1.3 '
521
tm J
22
8/14/92
8:15
11:15
77
82
77.7
83.3
8:15
439
3.4
709
23
24 '
25
26
27
28
C-23
-------
RADON STRESS TEST
DEPRESSURIZATION AT 20 Pa DEPRESSURIZATION AT 40 Pa
HOUSE TIME20P CFM20P Rn20PA RATE20P T1ME40PA CFM40P Rn40PA RATE40P AVGRAT EX4PA Rri POT
1
16:40
2723
0
0
17:45
3011
0.2
284
198.1
1120
0.64
2
12:35
184
0.4
34.7
13:35
338
0,7
111.7
48.8
54
0
3
13:23
531
0.5
125.3
14:25
810
0.8
305.9
165
190
0.22
4
14:25
2151
0.5
507.6
15:25
3075
0.3
435,4
476.3
970
1.12
5
11:35
741
1.4
492.6
12:35
1295
1.1
676.4
475
175
1.76
6
12:20
899
0
0
13:20
1386
0.3
196.3
102.8
330
0,47
7
16:00
647
1
307.2
17:00
1088
2.1
1084.9
531.6
320
0,36
8
12:00
1588
0.2
164.8
13:00
2281
0.3
312
158.9
5200
0,04
9
14:20
2379
0.4
451.9
15:20
3318
0
0
326.6
990
1.38
10
15:00
2355
0.3
333.2
16:00
3631
0,4
633.7
419.7
913
0.21
11
17:10
1765
0
0
18:10
2773
0
0
18.9
660
0.04
12
10:30
1089
1.8
514
11:30
1386
3
654.2
517.8
550
1.01
13
10:15
2327
1
1104.9
11:15
2712
1
1287.7
1154.3
1120
1.87
14
13:45
1086.5
0.5
258
14:45
1530,6
1
727
448.7
420
0.65
15
10:00
1675.1
0.3
236
11:00
2501,4
0
0
301.5
460
73,3
16
9:50
1371
2.7
1758
10:50
2156
1.3
1331
1445.3
1300
2.3
17
9:26
843.9
1.2
481
10:26
1370.7
0.2
130
356,7
390
9.6
18
15:25
1453
1.6
1104
16:25
2102
1.4
1397
1064.7
590
1.7
19
10:20
1086.5
3.6
1858
11:20
1531
4.5
3271
2011.3
224
3.76
20
oi
9:50
1086.5
1.3
671
10:50
1604.5
0.7
533
575
560
2
c\
22
9:15
690
4
1311
10:15
1189
0.1
56
692
225
2.71
739
3552
1940
3200
C-24
-------
RADON DATA
HOUSE # SSRnCA SSRnPA SSRnAC INRnCAP INRnPAS INRnACT EFFIC.
1
0.6
2
4986
2068
4.7
4.9
2.9
0.000943
3
0.7
4
6570
2730
2200
3.7
4.9
5.4
0.000563
5
614
614
3.7
0.9
0.006026
6
1090
883
4.4
2.2
0.004037
7
5040
3090
4554
3.6
13.6
34
0.000714
8
1483
1140
3.7
1.8
0.002495
9
6506
6441
1.1
1.1
0.000169
10
1620
1350
1.1
2,1
0.000679
11
2900
3120
1,7
1.8
0.000586
12
7097
"2
0.000282
13
4032
5.4
1.8
0.001339
14
5584 "
4530 •
1.4
1,5
0.000251
15
2690
2840
1
1.9
0.000372
16 '
3639
3683
1510
5.2
4.3
'1.8
0.001429
17
7182
3647
3.4
3.7
2.8
0.000473
18
3460
2.1
3.4
2
0.000607
19
1158
988
3
4.4
1.7
0.002591
20
2673
3040
2.3
2.1
0.00086
21
4780
4760
5.6
4.8
2.88
0.001172
22
1240
1700
1.1
1.4
0.000887
23
2414
1090
0.9
2.8
0.000373
24
739
2664
2.5
1
0.003383
25
3552
4512
1.1
0.9
0.000310
26
1940
2230
2.5
2.8
0.001289
27
3200
3700
298
3.5
2.2
1.1
0.001094
28
1660
1320
0.9
1
0.000542
€-25
-------
PRESSURE FIELD EXTENSION DATA
Note: All pressures are in Pascals. All measurement point
coordinates are in feet with reference to the lower left hand
corner of house footprints as they appear in the figures. Fan size
for this test appears in parenthesis after each house number.
House 1 (4") House 2 (4")
#
X
Y
dP
#
X
Y
dP
1
44.1
33.3
241
1
18.58
31
.83
297.6
2
15.5
12 .1
152
4
2
36.00
25
.42
187 .1
3
7.6
6.2
200
4
3
36.00
31
.83
216.3
4
2 . 5
8.5
63
4
4
31.50
25
.17
217.3
5
14
5.3
129
2
5
3 .33
28
.33
175.2
6
22.4
4
124
0
6
31.50
31
.67
313.8
7
4.8
35
101
0
7
31.50
21
.67
103 .9
8
8.8
25 . 9
122
7
8
21.67
25
.33
254.7
9
13 .5
16.8
162
9
9
22 .67
23
.00
53 .53
10
47 .5
20 .1
134
7
10
22.67
10
.17
73 .67
11
46.3
22 .9
140
9
11
12.83
12
.17
174.2
12
37
37 . 6
198
3
12
7 .33
3
.33
49.00
14
31.9
43
191
4
13
2 .83
11
67
• 157.00
18
55 .5
33.8
123
1
14
7.83
11
67
265.50
19
' 63
33 .8
'64
0
15
14.92
37
00
200.30
20
63
46.2
64
6
16
. 12.92
41
08
168.7
21
55.5
54.7
' 110
8
17
8.5-8-
45
¦92
102 .7
24
44 .5
54 .7
174
6
18
4.50
51
67
0.10
25
41
54 .7
179
5
19
36 .42
38
42
3 85.00
26
41.0
70.7
55
5
20
49.67
31
83
121.6
27
51.0
70.7
170
3
21
63.50
28
67
24.79
28
56.0
70.7
105
9
22
49.67
25
42
86.62
29
46.0
70.7
121
7
23
64.00
47
17
5.64
30
56
46.2
224
5
24
60 .00
47
17
19 .32
31
11.1
12 .5
209
6
25
62 .00
55
00
22 .59
32
8.8
10.1
204
7
26
45.42
66
67
39 .94
33
21.1
3 0.1
226
7
27
52 .42
55
67
102 .5
3 4
46.2
47 .3
232
8
28
45.42
55
67
226.8
35
54 .7
48.3
219
6
29
52.42
45
67
42 .77
36
6107
49.3
205.
9
30
37 .22
47
67
227 . 6
31
34.00
56
33
87 .85
Note
: Missing points were
32
63.83
61
67
8.36
either plugged up
or were
33
45.42
38
42
332.2
located 2-4
feet
beneath
34
45.42
45
67
279 .5
the
soil-vapor barrier
35
29.00
38
42
341.3
interface.
3 6
7.83
24
5
276.2
37
12.00
27
00
2 9 0.2
38
60.00
38
45
305.00
C-26
-------
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
*
House 3
(6
")
•House 4
(4 *)
X
Y
dP
#
X
Y
dP
3.67
7.00
33
.78
1
57.0
62.0
23.8
7.08
10.00
87
.21
2
42 .7
62.0
54.4
12.00
13.00
140
.9
3
49.8
54.8
228.8
17.00
7.00
141
. 5
4
57.0
52.2
121.3
24.67
7.00 '
131
.6
5
35.4
53 .6
73.1
39.50
13.25
184
.6
6
32.2
44.4
102.5
39.50
21.50
296
.2
7
21.7
41.0
83.1
17.00
15.00
336
.4
8
50.0
44.0
230.0
3.67
19.00
152
.7
9
50.2
32 .8
231.3
3.67
34.50
198
.3
10
57.0
23.7
36.6
24.67
21.33
302
.7
11
40.0
23 .7
103 .3
24.67
26.67
342
6
12
38.7
30.7
234.6
13.67
34.50
299
0
13
33.0
10.8
42.3
17 .00
34.50
382
4
14
29.0
27 .8
224.1
39.50
26.50
339
6
15
15.9
15.3
71.2
33.00
34.50
422
6
16
13.8
3.0
9.0
24.67
39.08
343
5
17
3.0
3.0
8.6
24.67
49.17
233
7
18
3.0
20.3
48.2
17.00
49.67
144
1
19
13 .5
23.7
216.6
3.67
47.17
125
8
20
7.7
22.1
216.6
17.00
44 .23
368
7
• 21
10.0
36.2
214.5
64.00
22.00
216
4
22
11.0
44.9
48.0
64.00
7.00
85
66
23
2.5
56.0
5.7
63.00
12 .00
116
5
24
3.0
36.5
36.3
60.17
6.75
204
1
57.67
7.42
125
7
46.00
10.00
175
5
57.67
12.75
379
9
44.50
21.50
290
4
44.50
26.50
341
6
57 .42
34.50
255
0
51.00
2 9,. 2 9
389
3
-64.00
40.33
157
4
63.50
49.73
94
7
46.00
34.50
391
1
57.67
22 .75
384
8
C-27
-------
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
House 5 (4")
House 6 (4")
X
Y
dP
#
X
Y
dP
47.67
1.00
1.67
1
54
3
27.0
1.4
47,67
14.83
¦ 4.62
2
37
0
27.0
11.3
47,67
27.67
24.5
3
23
2
27.0
15.2
35.33
26.50
204.6
4
54
3
16.3
6.3
36.58
12.25
223 .0
5
54
3
1.0
0.3
35.67
8.00
223 .0
6
3 8
0
0.0
1.2
22 .33
1.00
1.55
7
28
8
1.0
13.9
1.00
18.33
0.66
8
1
0
27.0
1.4
22.33
18.33
41.8
9
1
0
15.5
10.2
21.00
40.67
27.0
10
1
0
1.0
1.2
18.33
53 .67
0,24
11
9
1
1.0
8.6
3 5.33
4 6.67
203 .1
12
19
0
1.0
'11.9
43 . 08
53 .67
1.49
13
7
0
15.5
197,1
58 . 67
53 .67
0.41
14
13
5
15.5
218.0
58 . 67
41.33
2.3
15
47
3
16.3
144.9
47.67
41.33
19 .4
16
37
3
16.3
177 .8
C-28
-------
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
House 7 (4"}
X
Y
dP
25.2
44.3
139.9
25.2
27.4
205.3
25.2
48.7
94.4
15.0
50.7
24.6
32.3
48.7
76.5
32.3
36.8
146.5
13.0
33 .7
74.8
14.0
20.7
102 .6
32.3
27.0
176 .7
1.0
17.7
13.2
1.0
3.0
7.1
25.2
9.9
202.2
32.0
1.0
50.4
40.4
9.9
101.6
49 . 0
27.0
44.5
47.0
14.6
58.0
49.0
1.0
22.1
14.0
1.0
16.5
House 8 (6")
#
X
Y
dP
1
1.0
24
.0
8.1
2
1.0
46
.5
5.8
3
20.5
34
0
160.0
4
20.0
48
0
127.9
5
9.0
65
0
16.8
6
25.0
59
2
221.9
7
9.0
83
5
12.9
8
25.0
75
0
103.4
9
38.5
83
5
10.3
10
38.5
61
5
8.7
11
78.5
36
0
41.6
12
67.5
36
0
290.1
13
71.8
26
0
180.3
14
78.5
9
5
1.7
15
78.5
61
5
1.7
16
37.5
34
0
63 .5
17
44.0
36
5
200.2
18
51.5
36
.5
306.5
19
31.5
24
.0
19.8
20
47.0
22
.0
68.7
21
66.0
19
.0
4.5
22
, 65.0
11-
.5
1.3
23"
56.5
61
.5
5.3
2 4
1.0
28
3
4.4
25
9.7
1
0
15.0
26'
18.1
9.
0
194.0
27
30.2
1
0
15.6
28
30.2
21
8
6.6
29
10.0
24
0
11409
30
10.0
21
8
90.2
C-29
-------
#
1
2
3
4
5
6
7
8
9
10
11
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
House 9 (4")
House 10 (4")
X
Y
dP
#
X
Y
dP
24.3
2
.5
5.4
1
18.7
14.0
228.5
2.5
3
.0
11.1
2
"1.0
1.0
32 .2
2.5
17
.0
19.8
3
3.0
14.0
82.4
2.5
32
.0
18.4
4
3.0
25.0
28.1
42.6
12
.1
173.3
5
10.0
14.0
210 .0
42 .5
32
.5
140.3
6
19.3
28.0
61.6
55 .7
32
.5
87.8
7
36.3
14.0
206 .4
72 .0
33
.0
173.4
8
38.3
3.0
53 .1
70.8
26
.0
230 .8
9
3 8.3
25.0
41.0
42 .8
«d 8
.0
248.0
10
61.7
1.0
14.3
31 .0
22
.0
230.0
11
47.3
14.0
201.8
12
18.7
3.0
49.0
13
61.7
20.3
16.3
House
11
£4"}
House 12
(4")
X
Y
dP
#
X
Y
dP
57 .0
56
0
17 .6
1
2.5
27.2
1.7
57 .0
39
3
78.4
2. '
2.5
2.5
0.0
49.5
38
5'
195.5
3
2 0 ..5
2.5
6.9
46.2
44
3
69.2
4
2 .5
" 49 .1
29.6
57 . 0
20
0
64 .6
5
2.5
66.4
21.8
53 .0
25
0
194.9
6
17.8
66.4
23 .4
57.0
3
0
2.6
7
26.6
59.4
33.7
46.7
3
0
7 .02
8
30 .8
49.9
45.2
42 .8
14
2
42.4
9
17 .3
49.1
285.0
46.8
26
4
197 .6
10
24.5
22 .3
77 .7
41.2
41
0
145.0
11
25.0
10.5
14.2
29.4
44
3
89 .1
12
33 .3
37.8
81. 6
17 .3
62
0
32 .4
13
56.2
37.9
31.8
3.0
62
0
21.3
14
41.1
33 .6
265.6
12 .0
55
8
213 .6
15
40.5
44.9
77.2
10.0
' 34
7
220 .2
16
50.1
49.9
51.9
3.0
42
8
81.2
17
54 .2
60.4
19 .2
3'. 0
22
7
23 .4
18
42.5
18.5
25.6
3.0
3
0
1.23
19
44.8
2.5
2.6
20.0
3
0
5.49
20
56.2
2.5
0.9
26.0
10
8
55.8
21
56.2
17.4
2.4
3 6.6
28
7
206.8
20.5
32
3
222 .2
C-30
-------
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
House 13 (6")
House 14 (6")
X
Y
dP
#
X
Y
dP
8.0
23.0
38.2
1
21.3
22.7
_
14.0
34.4
223.5
2
21.3
11.3
82.2
8.0
63.0
11.6
3
21.3
0
-
17 .5
57.0
227.0
4
3
0
18.0
8.0
43.8
123.3
5
3
11.3
36.5
25.5
23.0
35.5
6
3
22.7
30.7
24.3
63.0
86.1
7
10.8
18.8
451.3
2.0
2.0
0.0
8
10.8
22.7
-
24.0
2.0
0.1
9
10.8
25.7
371.0
32.2
50.2
120.1
10
0
25.7
50.0
23.5
33.4
231.9
11
0
0
-
25.0
9.8
21.2
12
0
11.3
36.5
44.3
15.3
98.4
13
24.3
25.7
26.4
53.3
50.2
78.5
14
24.3
0
9.6
62.2
57.0
28.7
15
27.7
24.7
21.4
64.0
30.2
53.2
16
27.7
41.3
17 .1
64.0
43.6
6.0
17
16.7
41.3
27.2
56.3
39.0
202.0
18
1
41.3
8.5
49.0
29.5
202.0
19
1
33.9
19.2
41.3
42.5
135.8
20
1
1
8.6
52 .5
7.8
197.6
21
7.5
12.7
83 .5
64.0
2.0
2.8
22
7.5
1
1.9
49.7
2.0
3.8
23
7.5
24.7
16.0
24
16.7
33.9.
449.8
25
16.4
24.7
43 .4
Note; Points 1-14 are on
the garage level and
are measured from
the lower left
corner as pictured.
Points 15-25 are on
ground level and are
measured from the
lower left corner of
the house as
pictured.
c-31
-------
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
House 15 (6")
House 16 (6")
X
Y
dP
#
X
Y
dP
59.0
0.1
27 .89
1
30.8
25.5
46.7
40,7
1.2
44.0
2
2.5
31.3
13.1
40.7
8.1
91.30
3
14.8
25.5
28.7
58.1
26.6
32.28
4
12.2
51.5
46.3
59.2
63 .1
3 .17
5
2.5
2.5
2.2
40.7
63 .1
24.97
6
20.8
2.5
0.8
59.2
41.1
54.67
7
2.5
51.5
10.0
34.0
56.8
50.29 •
8
19.8
62.5
18.3
37.0
29.6
185.5
9
17
41.8
291.7
28.9
8.8
76.99
10
27.2
51.5
94.2
15.2
1.1
29 .82
11
31.0
41.8
310 .7
0.8
0.1
36.47
12
42.7
41.8
306.9
0.1
29 .9
98.17
13
43 .7
51.5
107 .6
21.5
42 .1
179.4
14
57 .5
51.5
23 .5
10 .8
43 .1
119.3
15
57.5
38
20.1
0.1
58.2
2.26
16
57 .5
25.3
2.4
0.1
41.1
77 .64
17
36.7
32.2
102 .5
5.1
37 .0
327 .2
18
43 .7
25.5
23 . 0
45 .1
37.0
427 .7
45 .1
•50 .7
161.6
40 .4
37 .0
450.2
• House 17 {6")
X
Y
dP
40
5
75.3
0
62
68
0
75.9
5
33
40
8
55 .0
37
39
40
8
40.0
22
22
57
1
40 .1
376
40
65
4
40 .1
174
50
40
8
9 . 5
85
70
60
1
9.8
88
57
73
4
27 .0
250
6
105
0
44 .8
68
05
105
2
68 .8
37
99
86
1
46.3
436
6
105
0
27 .3
15
43
84
5
27.3
164
7
73
3
46.1
439
4
80
5
63 .1
222
3
House 18 (6")
#
X
I
dP
1
80.6
2
8
89 .8
2
80.6
18
6
256.1
3
78 .
29
6
163.3
4
62 .1
28
9
2 63.6
5
48.5
29
263 .8
6
59.5
8
1
132 .6
7
40.1
5
8
95.9
8
75
18
9
393 .2
9
45.1
51
5
38.0
10
30
52
2
40.6
11
16.2
51
8
22 .7
12
13 .1
37
7
101.6
13
3.2
31
9
28.5
14
14.8
25
6
190.9
15
40.1
23
0
323.1
16
33
27
0
417 .4
17
29.6
38
1
379 .4
18
25
27
9
395.3
19
18.6
2
8
129.1
C-32
-------
House 19
(6")
House 20
(6")
#
X
Y
dP
#
X
Y
dP
(basement)
1 .
25.0
38.8
410.8
1
10.5
15.9
371.5
2
29.0
51.0
369.4
2
1
23
3 .7
3
41.5
38.0
75.5
3
19
23
1.1
4
3 9.5
13.5
27.9
4
19
14
26.2
5
41.5
50.5
47.7
5
27
13
0
6
22.2
20.6
374.1
6
27
1
0
7
26.2
13 .0
37.6
7
1
1
7.1
8
12 .5
37.5
28.1
8
13.3
1
18.2
9
12.5
57.5
15.4
(top
floor)
10
12.5
23.8
75.0
1
40
34
11.38
11
30.3
57.5
61.4
2
26.5
34.9
45.29
12
2.5
2.5
10.2
3
40.0
20.7
7.14
13
18.8
2.5
45.5
4
27.7
20.6
83.27
5
28.4
27 .3
295.2
6
18.2
23 .7
295.2
7
15.0
34.9
33.90
8
1
34.9
29.58
9
14.2
19.1
73.92
10
8.7 '
18.8
109.6
11
3.1
1.6
7.80
12
14 .2
1.6
17.42
House 21
(6")
House 22
(6")
#
X
Y
dP
#
X
Y
dP
1
21
55.6
110.4
1
1
42
5.4
2
3
55.6
8.9
2
1
60
2.0
3
14
43.6
342.8
3
24.5
60
0.8
4
3
31 -
2.8
4
1
23
7.3
5
-22
38.5
148.9
5
24.5
39
28.8
6
24.5
36.5
118.0
6
27.5
35
73.0
7
21
29.3
48.3
7
56
37
0.7
8
30.7
24.5
39.5
8
56
8
0.1
9
30.7
11
31.6
9
22
8
81.5
10
39.5
31.3
385.4
10
37
10.5
. 17.0
11
44
41.3
153 .5
11
13
44
290
12
72.7
32.5
165.5
12
13
32
299 .7
13
72.7
47.6
33.3
13
25
22
417.8
14
59.4
47.6
48 .0
14
44
22
296.3
15
60.7
27.0
416.6
16
50.2
27 .0
269.9
17
40 .7
13 .0
127.3
18
55.7
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124.3
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72 .7
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72 .7
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C-33
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#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
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¦ 1
2
3
4
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House 23 (4")
House 24 {6")
X
Y
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House 25
(6")
House 26
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. X
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C-34
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#
1
2
3
4
5
6
7
8
9
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House 27 (4")
House 28 (6")
X
Y
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' 1
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C-35
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APPENDIX D
PROPOSED FLORIDA STANDARD FOR
RADON-RESISTANT BUILDING CONSTRUCTION
PURPOSE AND LIMITS OF USE OF THESE BUILDING STANDARDS
Radon is a radioactive gas which occurs naturally in soils. It
has been found in high concentrations in some areas of many
states, Including Florida. Radon can enter buildings through
floors and foundations and accumulate in buildings. Its
radioactive decay products can cause lung cancer when breathed.
The following building standards have been developed in
accordance with Section 553.98, Florida Statutes, to decrease the
exposure of occupants to indoor radon concentrations in newly
constructed buildings. This standard targets the state health
standard for exposure to radon indoors established by the
Department of Health and Rehabilitative Services in accordance
with Section 404,056, Florida Statutes.
This building construction standard provides two options for
assuring that accumulations of radon in buildings, due to radon
bearing soil gas entry, do not exceed the state indoor radon
health standard. Both options require a common core set of
building construction practices. Each option also requires an
additional measure which is necessary to assure that the building
iTicc t ific j. nQOui icuun jicQXtn oioDQarQ •
The core set of construction practices limit radon entry into
buildings by:
1. increasing the resistance of the building shell to radon
entry) and
2, limiting building depressurization forces which cause
soil gas entry.
¦These coze set of construction practices are based in large part
on extrapolations from fundamental engineering principles and
when taken alone, lack the foundation of demonstrated
effectiveness necessary for a building construction "standard".
The practices, in their current state of development, are widely
accepted by the construction industry to constitute building
construction "guidelines.
In order to assure the level of effectiveness requisite for a
building construction "standard", at least one of the following
additional measures is required:
1. a post construction indoor radon test; or
2. a sub-slab depressurization system (for slab on grade),
a sub-membrane depressurization system (for off grade)
or a crawlspace mechanical ventilation system (for off
grade) ,
D-l
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The core set of construction practices coupled with the post
construction indoor radon test provide a passive systems -approach
to radon control in buildings. The core set of construction
practices coupled with the mechanical depressurization of crawl
space ventilation systems provide an active systems approach to
radon control in buildings. The choice of approach is left to
the judgement of the designer or builder.
D-2
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TABLE OF CONTENTS
Chapter 1 General
Page D-
101 Intent-* ...... ............ .....a............*...*....*.. 4
102 Scope 4
103 Compliance 4
Chapter 2 Definitions
201 General
202 Definitions'.
Chapter 3 Minimum Structural and Mechanical
Construction Requirements
301 Genera1............................11
302 Sub-Slab and Soil Cover Membranes... ,11
303 Floor Slab-On-Grade Buildings...... ....11
304 Slab-Below-Grade Construction .16
305 Off-Grade Floor Buildings With Crawl Space.....' .17
306 Elevated Buildings •. 18
307 Combination Floor Systems Buildings........ .18
308 Space Conditioning Systems (HVAC) ..18
Chapter 4 Systems For Active Radon Mitigation
4 01 General 22
4.02 Sub-Slab Depressurization Systems............. 22
403 Sub-Membrane Depressurizat ion Systems... 25
404 Crawl Space Ventilation Systems .25
Chapter 5 Testing For Mitigation Effectiveness
501 General 27
502 Procedure 27
D-3
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CHAPTER 1
GENERAL
Provisions in the following chapters and sections shall
constitute and be known as and may be cited as the Florida
Standard For Radon-Resistant Building Construction, hereinafter
referred to as "this standard."
101 Intent
101.1 General This standard shall apply to design and
construction of buildings as defined in Section 102 "Scope" in
order to enable control of human exposure to indoor radon and its
progeny.
101.2 Limits This standard is intended to improve indoor air
quality with respect to radon. These standards are based on the
principle of limiting radon concentrations to a four picocuries
per liter level which is accepted as meeting the "not to exceed"
.02 working level standard established by the Florida Department
of Health and Rehabilitative Services, hereinafter referred to as
HRS, and authorized by Section 404.056, Florida .Statutes.
102 Scope
102.1. Applicability The provisions of this standard shall apply
to the construction of new residential buildings and additions to
or renovations of existing residential buildings.
102.2 Existing Buildings When the cost of renovation exceeds 50%
of the current value of the building, the entire building must
meet the requirements for new buildings in Section 103.2.
'Buildings having a change of occupancy to residential
classification must meet the requirements for new buildings.
Exception to this can.be made, where shown by pre-construction
test, conducted in accordance with Chapter 5 of this standard,
that radon does not exist above the HRS standard and no
alteration, modification or addition is made to floor and
foundation components during construction.
103 Compliance
103.1 General The standard provides different paths by which
compliance can be determined. The compliance options include:
(1) Passive mitigation with a post-construction/pre-occupancy
test, and
(2) Passive mitigation combined with active mitigation by
mechanical systems.
103.2 New Buildings and Additions All new residential
buildings and additions to existing residential buildings
D-4
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shall at a minimum meet one of the following compliance
options of this standard:
(1) Passive Mitigation (a) Compliance with all parts of
Chapter 3 and,* (b) a post construction/pre-occupancy indoor
radon test, conducted according to Chapter 5, which
demonstrates that each residential unit meets the radon
exposure standard established by the Florida Department of
Health and Rehabilitative Services.
(2) Passive Plus Active Mitigation Compliance with all parts
of Chapters 3 and 4 of this standard.
103.3 Exemptions Exempt buildings are as follows:
(1) Buildings of occupancy classifications not listed in
Section 102.1 Applicability, and
(2) Residential buildings built on piers or pilings that are
elevated above grade a minimum of 6 feet and which comply
with all requirements of Section 306.
D-5
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CHAPTER 2
DEFINITIONS
201 General
For the purposes of this code, certain abbreviations, terms,
phrases, words and their derivatives shall be set forth in this
chapter. Where terms are not defined therein, they shall have
the meaning as noted in the applicable locally adopted code.
Words not defined in any locally adopted code shall have the
meanings in Webster's Ninth New Collegiate Dictionary, as
rev is ed.
202 Definitions
AGGREGATE - crushed stone, stone, or other inert material or
combinations thereof having hard, strong, durable pieces.
ADDITIONS - An extension or increase in conditioned floor area of
a building or structure.
AIR CHANGES - [per hour (ach)] - the number of times within 1
hour that the volume of air inside a building would nominally be
replaced, given the rate at which outdoor air is infiltrating the
building. If a building has 1 ach, it means that all of the air
in the. building will be nominally replaced in a 1-hour period.
AIR DISTRIBUTION SYSTEM - For the purposes of this standard air
distribution system components include ducts, plenums, air
handlers, furnaces, single package air conditioners, etc..
¦AIR PERMEABILITY (sub-slab) ~ a measure of the ease with which
soil gas and air can flow underneath a concrete slab.
AUTHORIZED GOVERNMENTAL AGENCIES - as relates to testing required
by this standard; the Florida Department of Community Affairs,
the Florida Department of Health and Rehabilitative Services, and
local enforcement agencies.
AUTOMATIC - self-acting, operating by its own mechanism when
activated by some personal influence, as for example, a change in
current, pressure, temperature or mechanical configuration.
BOND BEAM - in masonry construction, a solid beam that ties the
structure together around its perimeter and acts as a diaphragm
flange.
CAULKS AND SEALANTS - those materials which will significantly
reduce the flow of gases through small openings in the building
shell. Among those used are:
D-6
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Urethane - a crystaline ester-amide used as a gelatinizing
agent for cellulose acetate or cellulose nitrate. A component
of polyurethane used in making flexible and rigid foams,
elastomers, and resins for coatings and adhesives.
Epoxy - a thermosetting resin characterized by adhesiveness,
flexibility and resistance to chemicals and used chiefly as a
coating or adhesive.
Polysulfide rubber - a synthetic rubber characterized by
impermeability to gases and used in adhesives, binders and
sealing compositions and in coatings.
CEMENTITIOUS MATERIAL - including natural cements, hydraulic
limes, slag cements, and granulated blast-furnace slag.
CONDITIONED FLOOR AREA - the horizontal projection (outside
measurements) of that portion of space which is conditioned
directly or indirectly by an energy-using system.
CONDITIONED SPACE - all spaces which are provided with heated
and/or cooled air or which are maintained at temperatures over
SOT during the heating season, including adjacent connected
-spaces separated by an uninsulated component (e.g. basements,
utility rooms, garages, corridors).
CONTRACTION JOINT - formed, sawed, or tooled groove in' a concrete
slab to create a weakened plane and regulate the location of
cracking resulting from drying and thermal shrinkage (also
sometimes called control joints).
CRAWL SPACE - an area beneath the living space in some houses,
where the floor of the lowest living area is elevated above grade
level. This space (which generally provides only enough head
room for a person to crawl in), is not living space, but often
contains utilities.
DEFRESSURIZATION - in houses, a condition that exists when the
air pressure inside the house is slightly lower than the air
pressure outside or the soil gas pressure. The lower levels of
houses are essentially always depressurized during cold weather,
due to the buoyant force on the warm indoor air (creating the
natural thermal stack effect). Houses can also be depressurized
by winds and by appliances which exhaust indoor air.
ELASTOMERIC - that property of macromolecular material of
returning rapidly to approximately the initial dimensions and
shape, after substantial deformation by a weak stress and release
of stress.
HIGH RANGE WATER REDUCER - a water reducing admixture capable of
producing large water reduction or great flowability without
causing undue set retardation or entrapment of air in mortar or
concrete (also sometimes called superplasticizer).
D-7
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HVAC - heating, ventilating and air conditioning.
INFILTRATION BARRIER - a product or system designed to limit the
free passage of air through a building envelope component (wall,
ceiling or floor). Such products and systems may be continuous
or non-continuous discrete elements which are sealed together to
form a continuous barrier against air infiltration.
MITIGATE - make less severe, reduce, relieve.
OCCUPANCY - the purpose for which a building or part thereof is
used or intended .to be used. For the purposes of determining
changes of occupancy for this code, the occupancy shall be
r'rt'ne i HotdH +¦ K/a m a i at* rsr* r* 11 rsa n r'tf nfAi in £»e4* aKl t *
Lunaiueiea une iuajoir occupancy gxuup ycsiynauxons estaDiisneu Dy
the locally adopted building code.
OUTSIDE AIR - air taken from the outdoors and, therefore, not
previously circulated through the system.
PARGET - to cover or coat a wall for damp-proofing protection.
PICOCURIE (pCi) - a unit of measurement of radioactivity. A
curie is the amount of any radionuclide that undergoes exactly
3.7 x 10 radioactive disintegrations per second. A picocurie
is one trillionth <10~12) of a curie, or 0.037 disintegrations
per second.
PICOCURIE PER LITER (pCi/1) - a common unit of measurement of the
concentration of radioactivity in a gas. A picocurie per liter
corresponds to 0.037 radioactive disintegrations per second in
every liter of air.
RADIUM (Ra) - a naturally occurring radioactive element resulting
from the decay of uranium. It is the parent of radon.
RADON - a naturally occurring, chemically inert, radioactive gas.
It is part of the uranium - 238 decay series, it is the direct
decay product of radium - 226.
REMOTE SPACE - a space isolated from the main conditioned area of
a building by intermediate non-conditioned spaces.
RESIDENTIAL BUILDING - residential occupancies which include
single-family and multifamily buildings that are three or fewer
stories above grade. Hotels, motels and other transient
occupancies are considered non-residential buildings for the
purpose of this standard.
SLUMP - A measure of the relative consistency of stiffness of
fresh concrete mix.
SOIL DEPRESSURIZATION SYSTEM - a system designed to withdraw air
below the slab through means of a vent pipe and fan arrangement
D-8
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(active) or a system designed to lower sub-slab air pressure by
use of a vent pipe to the outside but relying solely on
convective air flow of upward air in the vent (passive).
SOIL GAS - gas which is always present underground, in the small
spaces between particles of the soil or in crevices in rock.
Major constituents of soil gas include nitrogen, water vapor, *
carbon dioxide, and (near the surface) oxygen. Since radium-226
is essentially always present in the soil or rock, trace levels
of radon-222 will exist in the soil gas.
SOIL GAS RETARDER - a concrete slab; polyvinylchloride (PVC),
ethylenepropylene diene terpolymer (EPDM), neoprene, cross
laminated HDPE or other flexible sheet material; 02T OtllGX* system
of materials placed between the soil and the building for the
purpose of reducing the flow of soil gas into the building.
STACK EFFECT - the upward movement of building air when the
weather is cold, caused by the buoyant force on the warm building
air. Building air leaks out at the upper levels of the building,
so that outdoor air (and soil gas) must leak in at the lower
levels to compensate. The continuous exfiltration upstairs and
infiltration downstairs maintain the stack effect air movement,
so named because it is similar in principle to hot combustion
gases rising up a fireplace or furnace flue stack.
SUB-SLAB MEMBRANE - A sheeting material placed under the slab and
over the slab base which retards the flow of soil gas to the
slab's -lower surface. Typically the sub-slab moisture barrier
forms a sub-slab membrane, but it may also be a special purpose
product.
SUPERPLASTICIZER - see High Range Water Reducer.
•VENTILATION - the process of supplying or removing air, by
natural or mechanical means, to or from any space. Such air may
or may not have been conditioned.
VENTILATION AIR - that portion of supply air which comes from
outside (outdoors) plus any recirculated air that has been
treated to maintain the desired quality of air within a
designated space.
VENTILATION RATE - the rate at which outdoor air enters the
building, displacing building air. The ventilation rate depends
on the tightness of the building shell, weather conditions, and
the operation of appliances (such as fans) influencing air
movement. Commonly expressed in terms of air changes per hour
(ach), or cubic feet per minute.
WATER COLUMN - a term used to describe air pressure. Part of a
water gauge.
D-9
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WATER GAUGE - an instrument for measuring a moderate air pressure
hydrostatically as in a ventilating system usually expressed in
inches of height.
D-10
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CHAPTER 3
MINIMUM STRUCTURAL AND MECHANICAL
CONSTRUCTION REQUIREMENTS
301 General
This chapter provides minimum design and construction criteria
for passive mitigation of radon entry into residential buildings.
Construction to these standards will limit radon entry points
through buildings' floors and foundations and will limit
mechanical depressurization of buildings which can enhance radon
entry. Passive mitigation is believed to be effective up to
certain, as yet unidentified, levels of radon in soil gases under
buildings. For buildings over soils above those levels
additional actions are required. Buildings shall comply with all
provisions of this chapter applicable to the floor system, space
conditioning system and ventilation system types incorporated in
their construction.
302 SUB-SLAB AND SOIL COVER MEMBRANES
A membrane shall consist of a minimum 6 mil single layer of non-
corroding, non-deteriorating polyethylene or equivalent placed to
minimize seams and to cover 'all of the soil below the building
floor. The membrane shall be cut in cross shape for pipes or
other penetrations; the membrane shall extend to within 1/2 inch
of all pipes or other penetrations. .All seams of-the membrane
shall be lapped at least 12 inches. Punctures or tears in the
membrane shall be repaired with the same or compatible material.
303 FLOOR SLAB-ON-GRADE BUILDINGS
303.1 General
All concrete slabs supported on soil and used as floors for
conditioned space or enclosed spaces connected or adjacent to a
conditioned space shall be constructed in accordance with the
provisions of Section 302 and this Section.
303.2 Concrete for Slabs
303.2.1 Mix Design Mix designs for all concrete used in the
construction of slab on grade floors shall specify a slump not to
exceed 4 inches. Total water added to the mix (including plant,
transit and site added water) shall not exceed:
(1) For Mixes Using Natural Sands - 275 pounds per cubic
yard or the amount required to achieve a maximum 4 inch
slump, whichever is less.
n_i l
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(2) For Mixes Using Manufactured Sands - 292 pounds per
cubic yard or the amount required to achieve a maximum
4 inch slump, whichever is less.
303.2.2 Workability For concrete used in the construction of
slab on grade floors/ the following shall apply for concrete
poured on site;
(1) Slumps of concrete, as measured on site at the point of
discharge from the delivery vehicle, shall not exceed 4
inches except where high range water reducing
admixtures are. used. On site addition of water shall
be in compliance with ASTM C94 and in no case shall
exceed the amount required to achieve'the maximum 4
inch slump and the limitations of Section 303.2.1 of
this standard.
(2) High range.water reducing admixtures shall be utilized
to achieve the slumps in excess of 4 inches. Water in
excess of the limitations of Section 303.2.1 of this
standard shall not be used to achieve the slump in
excess of 4 inches. Slumps of concrete containing high
range water reducing admixtures shall not exceed 8
inches.
303.3 Slab Design
,303.3.1 Contraction Joints Contraction joints should be
constructed in concrete slabs-on-grade in areas known to have
significant potential for radon in the soil gas. Contraction
joints should be constructed at intervals not greater than 15
feet in each direction and placed in a way that the ratio of the
slab sides of the resultant panels should not exceed 1.5 to 1.
Contraction joints should also be located at re-entrant corners,
'such as the inside corner of L or U shaped slabs and where an
abrupt change in thickness of the slab occurs. Contraction
joints are not necessary in post-tensioned slabs.
Contraction joints shall be constructed by placement of crack
inducers at the bottom surface of the slab or by saw cuts or
other means of slotting at the slab's upper surface. Where
contraction joints are induced at the slab bottom surface, the
crack inducer should extend into the slab at least 1/2 thickness.
Contraction joints shall be sealed against radon entrance with
waterstops; waterstops shall be placed at the top of the soil gas
retarder before the construction of the slab according to Section
303.5.1 and shall be embedded in the concrete, thus inducing and
sealing the contraction joints. Waterstops shall be positively
joined to provide a continuous seal. Contraction joints
constructed at the slab's upper surface shall be formed in during
the slab pour using premolded joint product or by saw cuts after
.the slab -is poured. The recesses should be a minimum of 1/4 to
1/3 of the slab thickness. Contraction joints installed by the
sawcut method should be installed within 4 to 6 hours after
D-12
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placement of the concrete. Contraction Joints installed by
proprietary sawcut methods having demonstrated success with
lesser contraction joint depths and/or earlier sawcutting times
shall be allowed. The joints shall be sealed using approved
.sealants according to 303.5.1.
303.3.2 Slab Reinforcement Slabs-on-grade shall be reinforced by
steel reinforcing bars at re-entrant corners such as inside
corners of an L-shaped slab and at rectangular openings or
penetrations greater than 6 inches outside. Re-entrant corners
shall have two pieces of #4 reinforcing bar 36 inches long placed
diagonal to the corner 12 inches apart with the first bar placed
2 inches from the corner. Openings shall have four pieces of #4
reinforcing bar placed diagonal to the corners with each bar
extending a minimum of 15 inches past the intersection with the
adjacent bar. All reinforcement shall be appropriately
positioned in the upper third of the slab. If reinforcing mesh
is used in slabs it should be cut at the contraction joint. If
fiber reinforcement is used, such fibers shall comply with ASTM
C-1116, "Standard Specifications For Fiber-Reinforced Concrete
and Shotcrete". Their use in construction shall be in accordance
with the practice recommended by the fiber manufacturers and the
ACI Committee 544, "State of the Art Report on Fiber Reinforced
Concrete".
303.3.3 Slab Edge Detail Slabs and foundations shall be
constructed using the slab edge detail which provides the minimum
vertical edge joint and is consistent with other construction
constraints, such as terrain. Monolithic slab construction should
be used where possible. Only the following slab edge detail
options may be used:
(1) Thickened Edge Monolithic - The sub-slab membrane
(soil gas retarder) shall extend beyond the outside
face of the slab edge.
(2) Stem Wall Capped by Slab - The sub-slab membrane shall
be laid between the stem wall and slab and shall extend
- . to the outer surface of the stem wall. The stem wall
shall be sealed either by (a) a solid masonry unit
placed immediately underneath the slab, or (b) a
thickened slab edge forming a minimum 8 inch thick
perimeter beam.
(3) Slab Poured Into Stem Wall - Where concrete blocks are
used as slab forms the slab shall be poured onto the -
stem wall and extend to the inside surface of the block
outer face in one of the following ways: (a) using
solid header Blocks with a solid base of 4 inch minimum
thickness as stem wall caps, the sub-slab membrane
shall be placed over the solid base of the cap block
and shall not extend up its vertical face, and the
concrete shall be placed against the vertical face to
form a continuous and solid stem wall cap of minimum 8
inch thickness? or (b) using a bond-beam or lintel
block or a header block, the sub-slab membrane shall be *
D-13
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drawn to and turned down along the inside surface of
the stem wall, and the concrete shall be placed against
the outside face and into the cores of the
header/lintel block, forming a continuous and solid
stem wall cap of minimum 8 inch thickness.
303.4 Slab Construction Practices
303.4.1 Backfill Compaction Backfill shall be compacted to a
relative compaction of 90 percent in accordance with ASTM D698
Standard Proctor Density Test.
303.4.2 Curing Concrete slabs shall be continuously cured for a
minimum of 7 days. Curing shall be accomplished with one of the
following procedures:
(1) moist curing by means of ponding, fog spray or wet burlap;
(2) moisture retention by means of impermeable sheet materials
conforming with ASTM C171; or
(3) liquid membrane forming compound conforming with ASTM
C309.
Curing compounds shall be compatible with materials specified in
Section 303.7.2.
303.4.3 Loading Loading or use of the slab shall be delayed for
a minimum of 48 hours after pouring. When the slab is used for
material storage after the mandatory delay period, caution should
be used to prevent impact loading.
303.5 Sealing of Joints, Penetrations and Cracks in Slabs
303.5.1 Contraction Joints Where occurring, contraction joints
_shall be constructed as per 303.3.1 and sealed against soil-gas
"entry by either: (a) for bottom surface induced joints, the use
of approved waterstops of width not less than 6 inches made of
material that is impermeable to air passage and shaped as an
inverted T-split ribbed waterstop, or (b) for top surface induced
joints, the use of an approved sealant (see Section 303.7)
applied according to the manufacturer's instructions. (Note:
most sealants require the concrete to be cured and dried.)
303.5.2 Penetrations
303.5.2.1 Stake Penetrations The use of grade or support stakes
which penetrate the sub-slab membrane should be avoided.
Permanent and/or temporary concrete blocks or screed chairs shall
be used when practical.
Whe re stakes are used to support plumbing, el@ctrx.cal conduits or
other objects which penetrate the slab, they shall be sealed to
the slab in accordance with Section 303.7.2 and they shall be
solid or have the upper end sealed tightly by installation of an
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end cap designed to provide a gas-tight seal. Such stakes shall
be of non-porous material resistant to decay, corrosion and rust.
303.5.2.2 Large Work Spaces Where large work spaces are -formed
into a slab, such as beneath a bath tub drain, the slab shall be
reinforced according to Section 303.3.2 and the exposed soil
shall be fully covered with a solvent based plastic roof cement
or other approved material to a minimum depth of 1 inch.
303.5.2.3 Pipe Penetrations Pipes shall be in contact with the
slab along the slab's depth by casting the concrete tightly
against the pipe. Where pipes are jacketed by sleeves they shall
be sealed by one of the following methods:
(1) have the joint between the sleeve and the slab sealed with
an appropriate joint sealant, as in Section 303.5.2.4, and the
pipe sleeve sealed by prefabricated boots placed on the*top of
the sleeve, or
(2) formation of a slot in the slab around the pipe and casting
.with an approved sealant from the slab to a point above the
sleeve.
(3). pipes and wiring penetrating the slab through chases or
conduit shall be sealed by placing an approved sealant between
. the pipe or wiring and chase or conduit. Plastic sheath, foam or
insulation material shall not be used alone around pipes or
conduit for sealing purposes.
303.5.2.4 Vertical Joints Through Slabs Vertical joints through
slabs including but not limited to joints in dropped panels shall
be formed with a recess of not less than 1/4 inch by 1/4 inch and
sealed with an approved sealant. Exception: Vertical joints
between the slab and header/lintel blocks used as forms {see
Section 303.3.3(3)(b)}. An approved sealant (see Section 303.7)
shall be applied according to the manufacturer's instructions.
•(Note: most sealants require the concrete to be cured .and dried.)
303 .5.3 Cracks Cracks with-widths less than 1/32 inch need not
be sealed. Cracks with widths between 1/32 and 1/16 inch shall
be repaired by the application of an elastomeric material capable
of withstanding at least 25 percent extension. The elastomeric
material shall extend at least 4 inches beyond the length and
width of the crack.
Cracks with widths larger than 1/16 inch shall be routed to a
recess with minimum dimensions of 1/4 inch by 1/4 inch and sealed
with an approved sealant.
303.6 Sealing Walls Framed walls placed on slabs on grade shall
be sealed or gasketed to the slab. Penetrations for electrical
receptacle and switches, wiring, plumbing, etc. in the interior
surface of the concrete block walls shall be sealed.
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303.7 Approved Sealant Material
303.7.1 Waterstops Material shall be preformed from plas-tic or
other noncorrosive material and shall be of the flat ribbed or
base seal type of waterstop. Waterstops shall.be impermeable to
soil-gas. .
303.7.2 Sealants Acceptable polyurethane, polysulfide and epoxy
caulks and sealants shall cpnform with ASTM C920-87 "Standard
Specifications for Elastomeric Joint Sealants" and ASTM C962-86
"Standard Guide for Use of Elastomeric Joint Sealants." Sealant
material and the method of application shall be compatible with
curing compounds, admixtures and floor finishing materials;
withstand light traffic; be impermeable to soil-gas; and have an
allowable extension and compression of at least 25 percent with
100 percent recovery. Sealants shall be applied to dried and
cured concrete in accordance with manufacturers' instructions.
Soil-gas impermeable backer rods may be used to support sealants
in cracks_ and, joints.
Sealants shown to have equivalent adhesion and durability may be
used as alternate materials.
304 SLAB-BELOW-GRADE CONSTRUCTION
304.1 General For the purposes of this standard, slab-below-
grade construction is defined as any habitable space with the
finished floor below finished grade at any point.
304.2 Slab' Construction Slabs shall have a sub-slab membrane in
conformance with Section 302 , and shall be, placed in accordance
with Section 303.
304.3 Sealing Walls
304.3.1 Walls Below Grade Walls surrounding slab-below-grade
space shall be constructed with a continuous waterproofing
membrane applied to the outside surface from the top of the
footing to finished grade. This membrane should be sealed to the
top of the footing to completely seal the joint between the
footing and the wall.
304.3.2 Utility Penetrations All utility penetrations through
walls in partial or full contact with the soil, shall be closed
and sealed with an approved material on the interior and exterior
faces of the wall.
304.3.3 Hollow Cavity Walls Below grade hollow walls in contact
with the soil shall be fully sealed by solid concrete blocks, a
concrete bond beam, or other approved means above finished grade.
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The interior surface of hollow walls in contact with the soil and
bounding conditioned space shall be pargetted and coated using
cementitious or elastomeric coatings from floor to the cap block
level required by this Section.
304.4 Sumps
Any sump located in a habitable portion of a building, or in an
enclosed space directly attached to a portion of a building,
shall be covered by a lid. An air tight seal shall be formed
between the sump and lid and at any wire or pipe penetrations.
305 OFF-GRADE FLOOR BUILDINGS WITH CRAWL SPACE
305.1 General For the purposes of this standard, off-grade floor
buildings with crawl spaces include all buildings with floor
supported above grade which do not meet the requirements of
Section 306.
'305.2 Reinforced Concrete Floors Reinforced concrete floors
constructed over crawl spaces shall conform to all applicable,
provisions of Section 303.
305.3 Wood Framed Floors Wood framed floors constructed over
crawl spaces shall include an air infiltration barrier in
compliance with the "Florida Energy Efficiency Code for Building
Construction", 1991, sections 903.2 (f ) 2 and 903.2(g)lb(1). Radon
resistance is dependent upon strict compliance with the following
provisions'of that code:
305.3.1 Penetrations All penetrations through the subfloor,
including but not limited to plumbing pipes, wiring and ductwork,
shall be fully sealed with an approved caulk. Where large
'openings are created (such as at bath tub drains), sheet metal or
other rigid materials shall be used in conjunction with sealants
to close and seal the opening; and
305.3.2. Vertical Joints Any vertical joint between the subfloor
and foundation wall or the subfloor and any vertical plane of the
building, which extends from the crawl space to the top of the
subfloor, shall be sealed with an approved sealant or caulk.
305.4 Sealing Walls and Doors Penetrations from the crawl space
into wall cavities shall be fully sealed with an approved caulk
or sealant. When a door is located in a wall between a crawl
space and the conditioned space, it shall be fully
weatherstripped or gasketed.
305.5 Closing and Sealing Other Paths Any openings which
connect a crawl space and the space between floor or ceiling
joists, wall studs, or any other cavity adjoining conditioned
space shall be closed and sealed.
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306 ELEVATED BUILDINGS
306.1 General For the purposes of this standard, elevated
buildings (typically found in flood plain and coastal zone
areas), are those supported substantially off-grade by pilings,
poles or other supports over an unenclosed area which satisfy all
of the following;
306.1.1 Vertical Separation A minimum of 6 feet vertical
separation between the soil and the bottom side of the sub-floor
at all points under conditioned spaces; and
306.1.2 Perimeter The perimeter of the building from the ground
plane to the lower surface of the floor shall be totally open for
ventilation, except for the occurrence of enclosures complying
with Section 306.1.4; and
306.1.3 Soil Contact Points All pilings, posts or other supports
shall be solid, or if hollow shall be capped or sealed; and
305.1.4 Enclosures Enclosures of any kind, including chases,
storage rooms, elevator shafts and stairwells, etc., that connect
between the soil and the remainder of the structure shall be
sealed at the surface of the soil with a construction complying
with the sealing provisions of this chapter and shall have a soil
contact area of less than 5% of the total building floor area.
307 COMBINATION FLOOR SYSTEMS BUILDINGS
307.1 Floor System Construction Where slab-on-grade, slab-
below-grade, crawl space or elevated building construction are
combined in one structure, the provisions for each construction
type shall be met.
307.2 Walls A wall located between a crawl space and habitable
space shall be designed and constructed in compliance with the
"Florida'Enerov Efficiency Code for Building Construction", 1991,
903.2(g), and the provisions of the applicable Sections 303
through 306 of this standard.
308 SPACE CONDITIONING SYSTEMS (HVAC)
308.1 Equipment Rooms and Enclosures
308.1.1 Garage Ventilation Garages containing air distribution
system equipment and clothes dryers shall be vented to the
outdoors, but not to the attic, by non-closing air transfer
openings. These openings should be sized to not less than 100
square inches for each dryer. Vents are not required if a dryer
'is located in the garage not containing an air handler.
Combustion heating devices shall be provided with outside air for
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combustion and dilution in accordance with local codes for
confined spaces. These provisions for combustion air are in
addition to the venting requirements listed above.
308.1.2 Garage Floor and Wall Sealing Cracks and joints in floor
slabs of garages containing air distribution system equipment
shall be sealed in accordance with Sections 303.5, 303.6 and
303.7.
308.2.3 Crawl Spaces Return ducts# return plenums, and air
handlers shall not be located in crawl spaces. Crawl spaces
shall not be used for supply or return plenums.
308.1.4 Condensate Drains, Piping and Wiring Chases Condensate
drain pipe joints shall be sealed (chemical weld, soldered, etc.)
gas tight and shall terminate outside the building perimeter at a
height of at least 6 inches above the finished grade ground '
level. A portion of the condensate pipe shall drop a minimum of
two pipe diameters below the height of the condensate outlet, or
a trap shall be installed to prevent suction of outdoor air into
the air handler. Chases through which the condensate and
refrigerant lines run shall not terminate in the return sections
of the air distribution system. Where chase lines terminate
within the house or garage, they shall be sealed.
308.1.5 Air Handler Clearance A minimum 8 inch clearance from
adjacent walls and floors shall be provided for access to air
•distribution system components located in a closet, utility room,
garage, attic, or other'enclosed space. When enclosed by walls
on three sides, clearance shall be 8 inches minimum at the back
and on one side, and 14 inches on the other side.
308.2 Air Distribution Systems
308.2.1 Sealing All ducts and plenums shall be made airtight,
constructed and installed in accordance with the "Florida Energy
Eff 1 ciencv .Code for Building Construction", 19'91. Where rigid
fibrous glass ductboard is used, the seal must be on the foil air
barrier side of the ductboard.
308.2.2 Return Plenums and Ducts Return air shall be separated
from any floor that is in contact with the soil or a crawl space,
by a plenum or duct fabricated in compliance with Section 308.2.1
and all local codes. Construction of the return plenum or duct •
shall provide a continuous air barrier that completely separates
the depressurized plenum or duct from adjacent building
components including but not limited to floors, walls, chases,
enclosures, etc.
The support platform shall not be used as a return plenum. Where
the support platform provides a protective enclosure for a duct,
one side shall have a removable panel or door to provide access
for inspection and/or repair of the duct and duct-to-air handler
connection. Ducts shall carry the return air from the return
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grills or return plenums to the air handler and shall have a
positive airtight seal to the air handler. A closet shall not be
used as a return plenum.
308.2.3 Return Grill Connection The return pathway from the
return grill shall be a part of the return duct or plenum and
shall have a continuous air barrier along its boundary. Where
the return pathway passes through a wall cavity, the cavity shall
be sealed around the duct in all directions to prevent the
leakage of air into the return air stream.
308.2.4 Location of Returns Return ducts and plenums shall not
be located in crawl spaces (see Section 308.1.5) nor below
concrete slab on grade floors. Where a door closes off a
conditioned portion of the building from the space containing the
distribution system's primary return, the enclosed room or rooms
shall have provision for return air transport, by means of return
ducts, transfer grills, transfer ducts, door undercuts, or other
applications. If return ducts are provided to individual rooms,
they shall be sized to carry the same air flow as the supply
ducts. Return ducts and transfer openings shall be sized in
accordance with Air Conditioning Contractors of America or Sheet
Metal and Air Conditioning Contractors National Association, Inc.
sizing guidelines.
308.2.5 Crossing Zones Where zones can be separated by door
closure, supply air from one zone should not be provided to
portions of the building which are in another zone. Where such
zone crossovers are unavoidable provisxons shall be made for a
properly sized return to match the crossover supply.
Supply air shall not be provided to remote spaces, such as remote
storage or utility rooms, without provision for an equal amount
of return air or makeup air to the system. Supply air shall not
¦be provided to garages and workshops from systems serving main
living areas. Such spaces when conditioned, shall have a
separate space conditioning system.
308.2.6 Supply Box The junction of supply boxes to supply
registers shall be sealed and secured. Boxes shall be secured by
straps pressing the box down to the register. The connection
between supply boxes and the sheet rock shall be sealed. All
seals shall be made with mastic or mastic plus fabric.
308.3 Supply Ducts and Plenums Supply ducts and plenums shall
not be located below concrete slab on grade floors.
308.4 Exhaust Fans
308.4.1 Bathroom Fans Bathroom exhaust fans shall be controlled
by an independent switch. Manually operated timers should be
.used as applicable.
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308.4.2 Kitchen Fans Kitchen exhaust fans shall be controlled
their own switches independent of other appliances.
308.4.3 Attic Fans Attic exhaust fans shall be installed with
unobstructed vent areas in accordance with the minimum areas
prescribed by their manufacturer. In no case shall effective
open areas be less than the minimum area prescribed by the
manufacturer.
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CHAPTER 4
SYSTEMS FOR ACTIVE RADON MITIGATION
401 General
This chapter provides design and construction criteria for active
radon mitigation systems. Active mitigation systems in
conjunction with passive mitigation .construction is currently
recognized as being reliable in the mitigation of radon in
buildings. Buildings built on slabs on grade shall comply with
all requirement of Section 402. Buildings built on off grade
floors shall comply with all requirements of either Section 403
or Section 404.
402 SUB-SLAB DEFRESSURIZATION SYSTEMS
402.1 General ¦ These systems apply to residential buildings with
floor types identified by Sections 303 or 304 of this standard.
The operating soil depressurization system shall maintain under
the entire building a pressure less than the indoor air pressure
by strict adherence to the requirements of Sections 402.2 and
402.3 and 402.4, and either 402.5, 402.6, or 402.7 as
appropriate.'
402.2 Suction Fans
402.2.1 Rating The ratings' specific to system type shall apply
(see Sections 402.5.4, 402.6.4, 402.7.4).
402.2.2 Fan Suction shall be provided by a fan, rated for
•continuous operation and having thermal overload with automatic
reset features.
402.2.3 Seal The suction fan shall be designed and manufactured
to provide an air-tight seal between the inlet and outlet ducts
and the fan housing. The fan housing must remain air-tight at air
pressure equal to the rated maximum operating pressure.
402.3 Alarm The soil depressurization system shall include a
system failure alarm which shall be either a visual device, (a
light of not less than 1/5 footcandle at the floor level)
conveniently visible to building occupants, or a device that
produces a minimum 60 db audible signal.
402.4 Vents
402.4.1 Material Piping material shall be of any type approved
by locally.adopted codes for plumbing vents.
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402.4.2 Grade The vent piping shall have a minimum slope of 1/8
inch per foot in order to drain any condensation back to soil
beneath the sub-slab membrane. The system shall be designed and
installed so that no portion will allow the excess accumulation
of condensation.
402.4.3 Terminals Vent pipes shall be terminated above the roof
and at least 10 feet from any operable openings or air intake or
other air distribution system equipment and directed away from
any operable openings or air intakes.
402.4.4 Labeling All exposed components of the soil
depressurization system shall be labeled "Soil Gas System" to
prevent accidental damage or misuse. Labels shall be on a yellow
band, two inches wide and spaced three feet apart on all
components.
402.5 Depressurization Systems in Sands or Granular Soils /
Suction Pit Design
Depressurization systems in sands or other granular soils {known
to have an air permeability greater than or equal to 10 m ), at
least 8 inches deep shall meet the requirements of Sections
402.2, 402.3, 402.4, 402.5.1, 402.5.2, 402.5.3 and 402.5.4.
402.5.1 Arrangement A minimum number, of suction points shall be
equally distributed as follows;
(1) A maximum of 1300 square feet per suction point;.and
(2) Each suction point shall be located not less than 6 feet or
more than 18 feet from the perimeter; and
(3) Multiple suction points shall be located within 36 feet of
each other.
402.5.2 Pits Suction point pits shall conform to one of the
following designs t
(1) A hemispherical open pit at least 22 inches in diameter and
11 inches deep, with a cover of 1/2 inch minimum thickness
press are tursstsd plywood or other decay-resistant material,
installed below the soil-gas barrier; or
(2) A pit at least 32 inches in diameter and 16 inches deep
filled with 1 inch or larger washed gravel and covered by
the soil-gas barrier; or
(3) A manufactured ventilation mat having a minimum net suction
area in contact with the soil of 10 square feet, installed
below the sub-slab membrane.
402.5.3 Pipe Size Suction pipe shall be a minimum of 2 inches in
diameter and shall be carried full size through the roof.
402.5.4 Fan Rating Each suction fan shall be rated for not less
than 10 cfm at 5 inch water column.
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402.6 Depressurization Systems in Sands or Granular Soils /
Continuous Ventilation Mat(s) Design
Depressurization systems in sands or other granular soils (known
to have an air permeability greater than or equal.to 10"^ at
least 8 inches deep and utilizing a continuous ventilation mat
shall meet the requirements of Sections 402.2, 402.3, 402.4,
402.6.1, 402.6.2, 402.6.3 and 402.6.4.
402.6.1 Arrangement Suction points shall be equally distributed
as follows:
(1) The suction point should be centrally located along the
length of each unconnected strip of mat; and
(2) Mat strips should be oriented along the central axis of the
longest dimension of the slab; and
(3) A minimum of one strip shall be used for slabs having
widths up to 50 feet (Additional strips should be added for
each additional slab width of up to 50 feet width.); and
(4) The mat strip shall extend to not closer than 6 feet of the
inner stemwall at both ends of the building; and
(5). A separate suction point and fan shall be installed for
each 100 feet linear length of ventilation mat.
402.6.2 Ventilation Mat Ventilation mat shall have a minimum of
216 square inches of suction area per lineal foot.
402.6.3 Pipe Size Suction pipe shall be a minimum 3 inch
diameter and shall be carried full size through the roof.
402.6.4 Fan Rating Suction 'fans must be capable of developing
minimum flows of at least 100 cfm, at 1 inch water column
pressure.
.402.7 Depressurization Systems in 1 Inch Average Aggregate Fill
Depressurization systems in aggregate shall meet the requirements
of Sections 402.2, 402.3, 402.4, 402.7.1, 402.7.2, 402.7.3 and
402.7 .4 .
402.7.1 Arrangement Suction points shall be equally distributed
and centrally located with a maximum of 2500 square feet floor
area per suction point.
402.7.2 Aggregate Aggregate shall be equal to or larger than
the following; 100% passing a 2 inch grate; 90 to 100% passing a
1-1/2 inch grate; 20-55% passing a '1 inch grate; 0-15% passing a
3/4 inch grate; and 0-5% passing a 3/8 inch grate. The aggregate
shall form a continuous layer which is a minimum of 6 inches
deep.
402.7.3 Pipe Size Suction points shall be connected to the
'depressurization fan by a minimum 3 inch diameter riser and shall'
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begin with a "tee" fitting, or another approved means that
provides for air flow from the gravel layer,
402.7.4 Fan Rating Suction fans must be capable of developing
flows of at least 100 cfm at 1 inch water column pressure.
403 SUB-MEMBRANE DEPRESSURIZATION SYSTEMS
403.1 General These systems apply to residential buildings with
floor types identified by Section 305 of this standard. The
operating soil depressurization system shall maintain under the
entire building a pressure less than the indoor air pressure by
strict adherence to the requirements of Sections 402.2, 4 02.3,
402.4, 403.1, 403.2, 403.3, and 403.4. Soil cover membranes
shall meet the criteria of Section 302 of this standard. For
unenclosed crawl spaces only, the membrane shall be protected
from wind uplift in accordance with locally adopted codes.
403.2 Sub-Membrane Systems on Sands or Granular Soils / Suction
Pit Design Sub-membrane soil depressurization systems of
suction pit designs covering sand or other granular soils at
least 8 inches deep (known to have an air permeability > 10
m2} shall meet the requirements of Sections 402.2, 402.3, 402.4
and 402.5.
403.3 Sub-Membrane Systems on Sands or,Granular Soils /
Continuous Ventilation Mat(s) Design Sub-membrane soil
depressurization systems of continuous ventilation mat design on
sands or granular soils at least 8 inches deep shall meet the
requirements of Sections 402.2, 402.3, 402.4 and 402.6.
403.4 Sub-membrane Systems on 1 inch' or Larger Aggregate Fill
Sub-membrane suction systems covering a minimum 6 inch deep layer
of aggregate having a 1 inch average diameter stone shall satisfy
the requirements of Sections 402.2, 402.3, 402.4 and"402.7.
404 CRAWL SPACE VENTILATION SYSTEMS
404.1 General These systems apply to residential buildings with
floor types identified by Section 305 of this standard.
404.1.1 Ventilation Rate One or more electrically driven
ventilation fans shall be installed to cause not less than 3 air-
changes per hour in the space exposed to the soil by blowing
outside air into or drawing crawl space air from the central
region of the crawl space.
404.1.2 Vents Screened vents connecting the crawl space with
outside air shall be sized according to locally adopted codes and
shall not be equipped with closures of any kind, and shall be
distributed equally about the perimeter wall.
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404*1.3 Soil Connection Foundation walls and piers or other
intermediate supports that intersect the floor plane shall be
solid across the entire horizontal section at a point above the
ground plane.
404.1.4 Plumbing Plumbing located in the crawl space shall be
adequately protected from freezing by insulation or means other
than restriction of ventilation air.
404.1.5 Floor Sealing The floor must be sealed in accordance
with Section 304 of this standard.
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rwaPTTR K
TESTING FOR MITIGATION EFFECTIVENESS
tni rruruiT
This chapter establishes testing and test data interpretation
criteria for determining compliance with this standard. The
Florida Department of Health and Rehabilitative Services (HRS}
standard establishes "not to exceed" limits for exposure to radon
progeny in terms of annual average working levels (.02 WL) . This
chapter provides relationships between short term (measurements
less than one year duration) measured radon concentrations and
annual average progeny concentrations for compliance
determination.
502 PROCEDURE
502.1 Contractors All tests will be performed by radon test
contractors certified by the HRS.
502.2 Test Methods and Compliance Criteria
502.2.1 General Test Procedures Testing shall be conducted
according' to the procedures in the appropriate sections of EPA
520/1-89-009, "Indoor Radon and Radon Decay Product Measurement
Protocols" (US EPA, 1989).
502.2.2 Acceptable Devices The following combinations of test
devices and applicable test periods are approved. In each case
the device shall be operated according to the appropriate Section
of EPA 520/1-89-009.
(1) Continuous radon monitor - 48 hours to 1 year
(2) Electret-Ion Chambers (High Sensitivity Electret) - 72
hours to 28 days with provision that test is valid only if
final electret voltage is greater than 200 volts
(3) Electret-Ion Chamber (Low Sensitivity Electret) - 14 days
to 1 year with provision that test is valid only if final
electret voltage is greater than 200 volts
(4) Charcoal Canister (open face) - 48 to 72 hours
(5) Charcoal Canister (diffusion barrier) - 5 to 10 days
502.2.3 Compliance Criteria The building will be in compliance
with-the standard if the short term concentration, determined by
approved testing, is less than the value in Table 5.1. If
multiple measurements are made, the average of those measurements
shall be used to determine compliance.
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The values in Table 5.1 have been determined to assure with
80% confidence that the annual average radon concentration does
not exceed four picocuries per liter. The four picocuries per
liter level is accepted as meeting the "not to exceed" .02
working level standard established by the Florida Department of
Health and Rehabilitative Services#
Table 5.1 Compliance Criteria for One Radon Measurement
Device Measurement Concentration
Period (PC i/11
Continuous Radon 5 days to 10 days 3.4
Monitor 11 days or longer 3.5
. Electret-Ion Chambers 5 days to 10 days 2,7
{High Sensitivity) 11 days or longer 2.4
Electret-Ion Chambers 26 days or longer 2.6
(Low Sensitivity]
Charcoal Canister 4? hr. to 73 hr. 2.5
(open face)
Charcoal Canister
(barrier) 5 days to 10 days . 2.7
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TECHNICAL REPORT DATA .. i,,,,...,,,...¦ .
(Please mad Instructions on the reverse before compter I I ||| II |||| ||| 1IIIIIIIIII11
1, REPORT NO. 2,
EPA - 600/R-9 5-159
3. i in mi II mil iiiiiiiiiiiii 11
PB96-121512
4, TITLE AND SUBTITLE
Demonstration of Radon Resistant Construction
Techniques, Phase II
5. REPORT DATE
November 1995
6. PERFORMING ORGANIZATION CODE
7. AUTHORIS)
James L. Tyson and Charles R. Withers
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Florida Solar Energy Center
300 State Road 401
Cape Canaveral, Florida 32920
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
EPA IAG RWFI.933783
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Air and Energy Engineering Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final; 11/91 - 2/93
14. SPONSORING AGENCY CODE
EPA/600/13
is, supplementary notes _/\FERL project officer is David C. Sanchez, Mail Drop 54, 919/
541-2979.
16. abstract rCp0rt gives results of a demonstration of radon resistant construction
techniques. Sub-slab mitigation systems were installed (in accordance with draft
standards) in 15 new Florida houses in 1992, and these houses have undergone exten-
sive testing to validate techniques used to prevent radon intrusion. Soil radon levels
ranged from just under 500 to over 8000 pCi/L. All systems have been determined
to extend negative pressure to practically all areas under the slab. Slabs tended to
crack less than expected. Intact vapor barriers under new houses prevent radon in-
trusion through slab cracks in most instances. Slab pipe penetrations not sealed in
accordance with standards contribute relatively higher amounts of radon into the
house. Eleven mitigation systems were installed using ventilation matting, and four
systems used wellpoint suction pipe. Both systems perform well as long as they are
installed carefully. The highest indoor radon level with the mitigation system caoped
off was 5.6 pCi/L for a 48 hour period. Ten houses were under 2.9 pCi/L, the actior
level for a 48-hour measurement by continuous radon monitor, and did not require
activation of their mitigation systems. Five houses required activation of their miti-
gation systems after the uncapped system test. All houses are currently under the
action level.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution Barrier Coatings
Radon
Residential Buildings
Construction
Slabs
Ventilation
Pollution Control
Stationary Sources
Indoor Air
Vapor Barriers
13B 11C
07B
13 M
13 C
13A
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report/
Unclassified
21. NO. OF PAGES
230
20. SECURITY CLASS {This pageJ
Unclassified
22. PRICE
EPA Form 2220-1 {9-73}
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