How to Seal Out Radon

Sealing cracks in your foundation or walls will not seal out radon completely. Radon is a radioactive gas that can cause lung cancer. Sealing cracks can, however, increase the effectiveness of a contractor-installed system to lower radon levels in your home.

Difficulty: Moderate

Instructions

1. Buy a radon sealant. Some products can be sprayed directly onto a concrete basement floor.

2. Apply the radon sealant according to the manufacturer's directions.

3. Check radon levels again after a few days to see if there has been any decrease in levels from application of the sealant.

4. Consult with a contractor if radon levels are still high to see what other measures can be taken to effectively seal out radon.

Tips & Warnings

• If you have a radon problem in your home, be sure to visit the EPA website to find out more information. Don't take any corrective measures without understanding the problem fully.
• The Environmental Protection Agency (EPA) does not recommend using a sealant alone to decrease radon levels in your home. The EPA urges homeowners to contract with a qualified professional to install a venting system if the radon levels in your home are above 4 picoCuries of radon per liter of air (pCi/l).
• There is no safe level of radon. The 4 pCi/l figure was developed in the 1980s because contractors could not reliably provide lower numbers than that with the products then available. Improved venting systems now exist which usually achieve results lower than 4 pCi/l.
• Contractors point out that you cannot completely seal radon out because you cannot seal every pore in the concrete from inside your home.

Resources

• Visit the EPA website for further information about radon.