Is Radon Lurking in Your Crawl Space?

Many homes and buildings across the U.S. have crawlspaces with radon gas problems. Radon makes its way into the crawlspace from the ground underneath. Crawlspaces with exposed soil floors have no barrier to slow down or prevent radon entry. It can navigate through the floorboards into occupied areas like bedrooms, living rooms, and offices. The best way to prevent radon entry in crawlspaces is to seal them and install a radon mitigation system.

In crawlspaces that have dirt or gravel floors, we seal your crawlspace with an airtight membrane called a vapor barrier. All stored items and debris must be removed from the ground before the installation of the vapor barrier. This helps prevent the plastic from being ripped or torn when placing storage items back in the area.

Following the sealing of the crawlspace, we proceed to install the vapor barrier, a minimum 6-12 mil cross-laminate. We secure the plastic membrane to the foundation walls. Once the plastic is secured, we seal the entire perimeter, including any seams, splices, and penetrations, to create an air-tight barrier that blocks the radon gas. The radon mitigation system is then tied directly to the soil under the membrane. This system, which operates twenty-four hours a day, creates a vacuum that continually pulls the radon out to vent above the house's roof.

In a crawlspace with concrete floors, radon levels can be reduced by creating a vacuum in the soil under the concrete slab. Many concrete crawlspaces have a large number of cracks. These cracks, along with the corner where the floor meets the foundation wall, are sealed meticulously to create a more airtight barrier. This sealing process is a crucial step in reducing radon levels. The radon system is then installed by drilling a hole through the concrete to access the soil underneath. The mitigation system creates a constant vacuum in this soil to vent the radon out above the roof of the house.