Why doesn EPA recommend sealers?
EPA (1990): “Sealing cracks and other openings in the foundation is a basic part of most approaches to radon reduction. 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.” This is correct. Sealing openings is not enough, because radon penetrates easily through the concrete itself. And it easily passes through paints or surface sealers as tested by EPA. RadonSeal penetrating concrete sealer was not available in 1990. It is not a surface sealer but penetrates up to 4 inches inside concrete and seals it internally by a chemical reaction. If there are any openings or cracks, they also have to be caulked just like with all radon mitigation methods.
