Sealing a Crawl Space in Henrico, VA
Challenge
This Henrico, VA client contacted us because they knew their crawl space needed to be insulated and wanted an inspection of the space.
Upon inspection, Corey, our Home Performance Advisor, found that the crawl space had no insulation and no vapor barrier. Open crawl space vents were allowing cold air to rush in during winter months and hot humid air to flood in during summer months.
With high relative humidity in the space as a result of moisture from the earth and warm, humid air entering through crawl space vents, microbial growth has occurred on the floor joists.
After discussing our findings and sharing photos of what's happening in the crawl space, the homeowner wants to address the mold and mildew growth, insulate, and prevent future microbial growth.
Solution
Our team begins by treating the mold and mildew on the floor joists with an antimicrobial. Next, they seal the rim band, sill plate, and crawl space vents. These are all huge points of air infiltration, by sealing and insulating in these areas, we can stop as much outside air from entering the crawl space as possible.
Next, our team rolls out a heavy-duty 10-mil vapor barrier, CleanSpace. This liner is designed to withstand service persons crawling on it to work in the space without the worry of rips or tears that would come with a conventional 6-mil liner. The CleanSpace is overlapped at all seams and sealed, it is wrapped and sealed around all piers, and it is attached and sealed to the foundation wall. This isolates the crawl space from the earth's moisture, preventing it from rising into the space and increasing the relative humidity.
Our technicians then apply closed-cell spray foam to the foundation walls at an R-10 thickness. Finally, a dehumidifier is installed to control the relative humidity of the crawl space ensuring it stays low enough to help prevent future mold and mildew growth.
