Vented Crawl Space in Chester, VA

The open vents allow moisture and outside air into the crawl space. This makes it extremely difficult to control the overall relative humidity underneath a home. The dry winter air entering the vents will cause the floors above to feel cold and drafts, as well as raising the energy costs to keep the house comfortable. And in the summer, the wet, hot air will carry moisture into the crawl space, raising the relative humidity and allowing mold and mildew to thrive.

The foundation walls of this crawl space have been sprayed over, using a closed-cell spray foam that provides not only insulation but blockage from outside air moisture, while the open vents were sealed with foam board and covered in the same closed-cell spray foam. When closed-cell spray is applied at 1.5” thickness, it acts as an air barrier and vapor retarder. Sealing off the outside air and moisture provides the homeowner with more control over the relative humidity in the crawl space.