 local building codes to determine whether additional radon requirements apply. In January 2013 ANSI-AARST published a standard of practice for “Reducing Radon in New Construction of 1&2 Family Dwellings and Townhouses (CCAH-2013),” available at www.aarst.org/bookstore.shtml.
- Elevated levels of radon have been found in homes built in all three zones on EPA’s Map of Radon Zones. Consult your state radon program for current information about radon in your area. Go to www.epa.gov/radon/whereyoulive.html and click on your state for contact information.
- EPA recommends, but does not require, that all homes built with radon-resistant features in EPA Radon Zone 1 pre-emptively include a radon vent fan. EPA also recommends, but does not require, radon-resistant features for homes built in EPA Radon Zones 2 and 3. EPA further recommends that all homes built in EPA Radon Zones 2 and 3 with radon-resistant features be tested for radon prior to occupancy. A radon vent fan should be installed when the test result is 4 pCi/L (the EPA action level) or more.
- The U.S. Surgeon General and EPA recommend that all homes built in Radon Zones 1, 2 and 3 be tested for radon. Provide buyers with EPA’s Citizen’s Guide to Radon, encourage them to test for radon and refer them to www2.epa.gov/radon for more information.
- If soil or groundwater contamination is suspected on or near the building site (e.g., former industrial sites), volatile chemical contaminants from soil gas or vapor intrusion into a building may pose an IAQ risk. In such cases, EPA recommends radon-resistant features consistent with Specification 2.1, which can minimize or prevent the vapor intrusion into a house. See the EPA Vapor Intrusion Primer or ASTM E2600 for more information. You should also consult your state, tribal, or local environmental regulatory agency for information on the location of contaminated sites, including those subject to Superfund (CERCLA), Resource Conservation and Recovery Act (RCRA) cleanup requirements, or the Brownfields program. Visit EPA’s “Where You Live” for more information.
Section R408.1 Ventilation. Ventilated crawlspaces should have at least 1 ft2 of vent opening for each 150 ft2 of floor area, unless the ground is covered with a Class 1 vapor retarder, then 1 ft2 of vent area is required for each 1,500 ft2 of floor area.
Section R408.2 Openings for under-floor ventilation. Ventilated crawlspaces should have at least 1 ft2 of vent opening for each 150 ft2 of crawlspace floor area, unless the ground is covered with a Class 1 vapor retarder, then the total area of ventilation openings should be equal to 1/1,500 of crawlspace floor area.
Section R408.3 Unvented crawl space. Ventilation openings are not required in the crawlspace if the exposed earth is covered with a continuous Class I vapor retarder with seams that are overlapped by 6 inches and sealed or taped and with the edges fastened and sealed to the foundation walls at least 6 inches above the ground level.*
*Due to copyright restrictions, exact code text is not provided. For specific code text, refer to the applicable code.
Foundation Capillary Break over Aggregate = Foundation Floor Water Barrier