A homeowner from Aylett, VA contacted us because the had noticed the fiberglass insulation in the crawl space was wet and there was puddling on the vapor barrier.
The homeowner did not have a bulk water issue; however, we did find that the open vents and earth were allowing a lot of moisture into the crawl space. This moisture was being absorbed by the fiberglass insulation. The saturated insulation was holding moisture against the floor joists. Condensation collected on foundation walls and moisture puddled on the vapor barrier.
To address the insulation concerns and puddling the homeowner chose to first have the old vapor barrier and any debris removed. We then installed a new heavy-duty vapor barrier, overlapped and sealed all seams, sealed and wrapped all piers and fastened and sealed the liner to the foundation walls. This isolated the crawl space from the earth’s moisture, preventing the water vapor from rising and being absorbed by the insulation.
We sealed all penetrations through the foundation wall as well as the sealing the sill plate and rim and band. All vents were sealed with foam board and air sealing foam from the inside. Air sealing the crawl space prevents outside air from flooding into the crawl space and bringing moisture with it. Sealing vents from the inside also allows us to maintain the exterior aesthetic of the home.
The final step the homeowner took was installing a dehumidifier in the crawl space to control the relative humidity. The dehumidifier will remove excess moisture from the air and circulate dry air throughout the crawl space to help prevent microbial growth from occurring.
The homeowner chose not to remove the existing fiberglass batts in the floor at this time. However, we did recommend removing the saturated insulation and treating the mildew growth on the floor joists with an antimicrobial and reinsulating from the crawl space walls. Insulating from the walls would have brought the crawl space into the thermal boundary of the home and helped to improve the energy efficiency and mitigate cold floors. The solution the homeowner chose to move forward with will reduce the humidity in the crawl space and help prevent moisture from collecting, mold from growing and help keep the insulation from becoming saturated again.