The techniques vary for different
foundations and site requirements, but the basic
elements are:
Gas Permeable Layer
- This layer is placed beneath the slab or
flooring system to allow the soil gas to move freely
underneath the house. In
many cases, the material used is a 4-inch layer of clean
gravel.
Plastic Sheeting
- Plastic sheeting is placed on top of the gas permeable
layer and under the slab to help prevent the soil gas
from entering the home. In crawl spaces, the sheeting is
placed over the crawl space floor.
Sealing and Caulking - All openings in the concrete foundation floor are
sealed to reduce soil gas entry into the home.
Vent Pipe - A 3- or
4-inch gas-tight or PVC pipe (commonly used for
plumbing) runs from the gas permeable layer through the
house to the roof to safely vent radon and other soil
gases above the house.
Junction Box - An
electrical junction box is installed in case an electric
venting fan is needed later.
Ways to reduce radon in your
home are discussed in EPA's publication, Consumer's
Guide to Radon Reduction.
When Should
Radon-Resistant Construction Be Considered?
Find out if you are buying a home
in a high radon area. EPA's
map
of radon zones
indicates areas having the greatest potential for
elevated indoor radon readings. Homes in places with
high potential, called Zone 1 areas, should be built
with radon-resistant features. Also contact your
state
radon office to learn whether
radon-resistant features are recommended or required in
your area.
If you are planning to make any
major structural renovation to an existing home, such as
converting an unfinished basement area into a living
space, it is important to test the area for radon before
you begin the renovation. If your test results indicate
a radon problem, radon-resistant techniques can be
inexpensively included as part of the renovation.
Because major renovations can change the level of radon
in any home, always test again after work is completed.
What are the Benefits
of Radon-Resistant Construction?
Radon-resistant techniques are
simple and inexpensive. Besides reducing radon levels,
they also lower concentrations of other soil gases and
decrease moisture problems. They make a home more energy
efficient, and can save an annual average of $65 on
energy costs.
