Is Radon in Your Home?
Think about all of the houses of your friends and family. Chances are that one of them lives with high radon levels.
Or it could be you.
Roughly 1 in every 15 homes has high radon levels, and 20,000 Americans die of radon-related lung cancer annually. In fact, radon is the second-leading cause of lung cancer in the United States behind smoking. The surgeon general often reminds Americans to have their homes checked for radon.
Radon is an invisible, odorless, poisonous gas that comes from the soil. It results from the breakdown of uranium.
But don't get too worked up now, because there are easy ways to test your home for radon. You can
call a professional to test for radon in your basement (or the lowest part of your house), or even test for it yourself (follow this link for a
discounted test kit [.pdf]).
When testing, you want to make sure that your home tests lower than 4.0 pCi/L. The average home has 1.3 pCi/L.
If your home tests higher than 4.0 pCi/L, it is quite simple to lower it to safe levels.
Most professionals will use a technique called soil depressurization. They will run a PVC pipe through the slab (which means drilling a hole in it) or underneath the membrane in a crawl space, and then route it up through the roof. A fan is often attached in the attic area, drawing the radon from below the slab (or membrane) and venting it above the roof.
Radon-Resistant New Construction
The best way to protect a home from radon is to build the home with the PVC pipe from the beginning. This will cost around $500 for materials and labor (much less than the $1000 to $2500 it could cost to retrofit the house).
Although each home is unique, the same basic five steps
recommended by the EPA apply.
A. Gas Permeable Layer: This layer, often 4 inches of gravel, is installed below the slab or crawlspace to allow radon to move freely underneath the house.
B. Plastic Sheeting: 6-mil polyethylene is placed directly on top of the gravel base to prevent the radon from entering the home. It should be placed either below the slab or over the crawlspace floor. Make sure it is properly sealed along the edges and at seams.
C. Sealing and Caulking: Seal all openings in the concrete floor to prevent the radon from entering the home.
D. Vent Pipe: Install a perforated T-fitting under the plastic sheathing. Connect a 3 or 4 inch piece of PVC to the T-fitting and run it through the roof. This way the radon will bypass the home through the stack pipe.
E. Junction Box: Install an electrical junction box near the pipe in the attic so that if radon levels get too high, an electric venting fan can later be installed.
U.S. Environmental Protection Agency's
Radon FAQ's from Southface
Radon-Resistant Construction for Builders [.pdf]
Who Can Test or Fix Your Home?
National Safety Council's
Discounted Radon Test Kit [.pdf]
Tips on Indoor Air Quality
Content updated on 6/7/2007