What are Radon-resistant Construction Techniques?
The methods vary for differing foundations and site requirements, but the basic elements are:
A. Gas Permeable Layer
This layer is placed under the slab or flooring system to permit the soil gas to move freely below the house. In many cases, a 4-inch layer of clean gravel is the material used.
B. Plastic Sheeting
Plastic sheeting is set on top of the gas permeable layer and beneath the slab to help prevent the soil gas from coming into the home. In crawlspaces, the sheeting is then placed over the crawlspace floor.
C. Sealing and Caulking
All openings in the concrete foundation of the floor are sealed to reduce the soil gas entry into the home.
D. Vent Pipe
A 3 or 4 inch gas-tight or PVC pipe runs from the gas permeable layer through the house to the roof, to safely vent the radon and other soil gasses above the home.
E. Junction Box
In case an electric venting fan is needed later, an electrical junction box is installed.