Sealed Crawlspace Barrier System: Raleigh

Sometimes a radon mitigation system is installed, but the radon levels remain higher than expected. That's exactly what happened for this homeowner.

After receiving disappointing test results and becoming frustrated with the lack of professionalism from the company handling the testing, she contacted Triangle Radon Defense for a second opinion.

During our inspection, we found that the existing mitigation system was installed beneath a large, vented crawlspace with a loose, unsealed vapor barrier. Rather than creating a sealed collection area beneath the barrier, the original installer had simply extended multiple sections of 2-inch PVC beneath the plastic in an attempt to improve soil gas communication.

While creative, this approach could not effectively collect and control radon across such a large crawlspace.

After discussing several options with the homeowner, we recommended installing a sealed crawlspace barrier system. This approach would allow the mitigation system to create consistent negative pressure beneath the barrier, dramatically improving the system's effectiveness.

The existing fan was properly sized and remained in good condition, so we reused it while completely redesigning the piping beneath the crawlspace. Because the crawlspace exceeded approximately 3,000 square feet, we installed two strategically placed extraction points to provide better pressure distribution throughout the entire area.

The results spoke for themselves.

Even with the previous mitigation system operating, the home's radon level measured 4.9 pCi/L. After completing the new sealed crawlspace barrier system, follow-up testing showed the radon concentration had dropped to below 1.0 pCi/L.

Every home is different, and sometimes improving a radon system isn't about installing a larger fan, it's about designing the right system for the home's unique construction. That's exactly what we strive to do on every project.