When SRE HomeServices measures radon levels in a home and finds the need for a mitigation system, homeowners sometimes ask if sealing their basements will be enough to reduce their radon levels.
The answer is: No. Sealing needs to be done as a good first step for mitigation, according to the U.S. Environmental Protection Agency (EPA).
“Sealing cracks and other openings in the foundation is a basic part of most approaches to radon reduction,” the EPA says in its Consumers Guide to Radon Reduction. “Sealing the cracks limits the flow of radon into your home, thereby making other radon reduction techniques more effective and cost-efficient. It also reduces the loss of conditioned air.”
Sealing should start with obvious openings, adds Val Riedman, owner of Healthy Air Solutions. “Open sumps are huge entrance points for radon and moisture, and sealing can prove to be worthwhile. Also, crack sealing with a good polyurethane caulk and filling large holes like rough-ins for future tub and shower drains can help,” he says.
But over time, sealing cracks and openings is not the complete solution for reducing radon to acceptable levels in a home or office building.
“Radon reduction requires more than just sealing cracks in the foundation,” according to the National Radon Program Services at Kansas State University. “In fact, caulking and sealing of foundation openings, on its own, has proven not to be a reliable or durable technique. However, sealing is done in conjunction with other mitigation steps.”
Riedman explains why sealing is not enough.
- Caulk has a limited life span, especially in basements — where constant moisture changes can be expected in cement foundations and floors.
- New cracks can occur as the basement ages.
- Even the best sealing efforts can easily miss hairline cracks. These can turn into significant radon gas entry points.
- Block wall foundations can be very difficult to seal properly, especially if there are open cores along the top course.
“EPA does not recommend the use of sealing alone to reduce radon because, by itself, sealing has not been shown to lower radon levels significantly or consistently,” according to the Consumers Guide. “It is difficult to identify and permanently seal the places where radon is entering. Normal settling of your home opens new entry routes and reopens old ones.”
For more information about radon and keeping it out of your home, call the experts at SRE HomeServices: 402-970-1350.