Sealing and Insulating a Richmond, VA Crawl Space

This homeowner in Richmond, VA called us out to discuss insulating their crawl space. We sent one of our Home Performance Advisors to inspect the situation and found that there was an abundance of mold growth on many of the floor joists in the crawl space. This can occur on any organic material in the crawl space so long as the relative humidity reaches over 60% during warmer temperatures. We used an antimicrobial, called Shockwave, to eliminate mold growth in any affected areas. We also removed the existing liner and any fiberglass batts from the crawl space. This was so we could replace it with a durable 10-mil vapor barrier, called CleanSpace Light, which would protect the crawl space from the earth's rising moisture. The liner gets wrapped around all piers, sealed with vinyl tape, and mechanically fastened to the foundation walls six to eight inches above outside grade. We also noticed that the foundation walls were made with porous cinderblocks, which was allowing the outside moisture to seep through and affect the relative humidity. Open vents lined these porous walls to also allow the outside air and moisture to infiltrate the crawl space. We used custom foam board pieces to internally block off these open vents, then we used Foamax to insulate the crawl space walls. Foamax is 1.5 inches thick, giving it an insulation value of R-10. It acts as an air barrier and vapor retarder and helps to protect the crawl space from any outside influence. Finally, a high-performance dehumidifier called SaniDry Sedona was installed in the crawl space alongside a LittleGiant condensation pump to regulate and control the temperature and relative humidity. A hygrometer was given to the homeowner to monitor this at all times, and they should feel a definite increase in comfort and decrease in energy bills, as their crawl space is now insulated and sealed off from the outside.