United States Environmental Protection Aaencv Air and Energy Engineering Research Laboratory Research Triangle Park NC 27711 Research and Development EPA/600/S8-90/062 Sept. 1990 EPA Project Summary Interim Radon-Resistant Construction Guidelines for Use in Florida-1989 Thomas D. Pugh This project was initiated with the ob- jective of investigating, analyzing, and developing radon-resistant construction guidelines which are consistent with other building codes and which could be applied to Florida. A literature search was conducted in which available information was obtained on radon remediation techniques, new construction methods, and existing codes (e.g., those in Sweden and Canada) for radon-resistant buildings. Techniques identified by the research were amended, modified, or supple- mented for incorporation into draft model guidelines for new construction in format consistent with the Standard Building Code promulgated by the Southern Building Code Congress In- ternational, Inc. A technical review advisory commit- tee which included building'contractors, architects, engineers and representa- tives of federal, state and local govern- ments was formed during the develop- ment of the guidelines. The committee provided input and recommended changes to the draft guidelines. Although this project has resulted in guidelines for recommended construc- tion practices, it should be coupled with a carefully planned and implemented program of experimentation. Eventually this approach will lead to building code provisions which are scientifically de- fensible, cost effective, reliable, and easily incorporated into standard con- struction practice. This Project Summary was developed by EPA's Air and Energy Engineering Research Laboratory, Research Triangle Park, NC, to announce key findings of the research project that is fully docu- mented in a separate report of the same title ( See project report ordering infor- mation at back). Introduction Over the past decade there'has been growing concern about health effects asso- ciated with exposure to radon and its prog--' eny. Florida is the first state in the nation to establish standards which set limits on ra- don progeny in buildings. Many currently available publications address mitigation techniques; However, few studies docu- ment radon-resistant methods for new con- struction, and mitigation techniques may not be the most appropriate ones for* new construction. In addition, many factors in the southeastern U. S. make existing re- search conducted in the northeast difficult to apply here. These factors include geol- ogy, climate, common building practices, and lifestyles. The approach to identifying ideal radon- resistant features is two-fold: (1) it is neces- sary to determine the likely entry routes for radon into the building, and (2) standard building practices and details that appear responsible for allowing radon into a struc- ture should be examined to determine how they could be modified to create a radon barrier. These possible modifications re- quire much more investigation. The problem of elevated radon concen- trations in homes can be approached from two directions: by filtering out or'diluting the radon and its progeny once they are inside the dwelling, or by preventing the radon- ------- carrying soil gas from entering the home. Radon filtration/dilution is a less than perfect solution because: (1) it has a rather high initial cost, (2) as an active system it will require maintenance, (3) it is susceptible to owner interference, (4) it requires energy to operate, and (5) it has a negative impact on other energy conservation measures. Systems that prevent soil gas from enter- ing abuiiding may be further subdivided into two classes: those which are totally pas- sive, and active systems, those which require continuous energy inputs. Active systems, perhaps the mosttested and documented, can be further divided into those drawing soil gas from beneath the slab of a building and venting it to the outdoors where it is quickly diluted to safe concentrations, and those that attempt lo_ reduce the emergence of soil gas by con- tinually pumping a small volume of air be- neath the slab. Both systems have some negative characteristics. A thorough study of the literature, fol- lowed by detailed experimentation of the more promising methods for use in Florida, should lead to the establishment of firm protocols for radon-resistant new home construction. The guidelines developed in this report are based on the best information obtained to date. Procedures Aliterature search wasconducted in which information was obtained on radon reme- diation techniques, new construction methods, and codes (e.g., those in Sweden and Canada) for radon-resistant buildings. The Swedish codes had to be translated into Englishbefore they could be analyzed. The effectiveness of each technique was evaluated, and those techniques with spe- cific application to southern construction were noted. AlechnjcaJj«yJgwTiadvisory _CQmmjttee__ which included building contractors, archi-" tects, engineers, and representatives of federal, state, and local governments was formed during the development phase of the guidelines. The committee provided in- put and recommended changes to the draft guidelines. Results/Discussion The full report contains 11 sections: (1) General, (2) Isolation membranes, (3) Con- crete slabs in isolation systems, (4) Crawl space construction, (5) Slab below grade and basement construction, (6) Combined construction types, (7) Soil gas ventilation systems, (8) Other entry pathways for ra- don, (9) Space conditioning systems, (10) approved materials, caulks, and sealants, and (11) Illustrated details. Construction details and practices are divided into: (1) those that are most confi- dently recommended, (2) those which are recommended, but with less confidence, and (3) those which are recommended, but with least confidence. Conclusions Institution of these interim guidelines should be accompanied by the knowledge that further experimentation and additions to the literature may require revisions from time to time. T.D. Pugh Is with Florida A and M University, School of Architecture, Tallahassee, FL 32307 David C. Sanchez is the EPA Project Officer (see below). The complete report, entitled "Interim Radon-Resistant Construction Guidelines for Use in Florida --1989," (Order no. PB90-265 349AS; Cost: $15.00 cost subject to change) will be available only from: National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Air and Energy Engineering Research Laboratory U.S. Environmental Protection Agency Research Triangle Park, NC 27711 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati, OH 45268 Official Business Penalty for Private Use $300 EPA/600/S8-90-062 ------- |