Types of Foundation-Based Radon Mitigation

There are several types of foundation-based radon mitigation systems. The type you need will depend on your foundation and affect your costs.

• Active Sub-Slab Soil Depressurization

According to the U.S. Environmental Protection Agency, active sub-slab soil depressurization systems can reduce indoor radon levels by 80% to 99%, so they’re a popular choice for homeowners. These systems involve running a PVC pipe through the home’s foundation into the ground. Then a fan is used to create suction in the pipe, which directs radon gasses away from indoor living spaces and out through the exit point, typically above the home’s roofline.

• Drain Tile Suction

Drain-tile suction systems attach to your home’s water drainage pipes, which can fill with radon. Your pro will connect a fan to your existing drain tile, aka an underground drainage pipe, which will create a suction that helps to remove radon from the surrounding water and soil and blow it away from the home.

• Sealed Sump Pump Hole

These systems involve placing an airtight seal over the hole or entry point in your foundation to which your sump pump is attached. Like active sub-slab soil depressurization systems, they use a fan and suction system that draws out radon gas and directs it away from indoor spaces. 

• Crawl Space Encapsulation

In some cases, you can attach an airtight, plastic vapor barrier around the exposed earth of the crawl space below your foundation to prevent radon from making its way from the crawl space into your home. This process is called crawl space encapsulation.

After caulking the vapor barrier to the surrounding wall, your pro will install vent piping through the barrier, or membrane, which an attic-based extraction fan will use to blow radon gas away from your home. 

• Basement Sealing

If you have a basement, you can apply a sealant to prevent radon gas from penetrating your home. Typically, a pro will inject polyurethane foam or caulk into any existing holes and cracks before applying a compound to seal expansion control joints. Finally, they’ll seal any plumbing pipe entry points and cover the sump pump with an airtight seal. When used on its own, it’s not nearly as effective as other mitigation methods, and your basement will need to be resealed every few years.