Mitigating Moisture & Mold in a Norfolk, VA Crawl Space

Challenge

This Norfolk, VA homeowner reached out to us when they noticed some moisture problems in their crawl space.

At our inspection, we found that the crawl space had no vapor barrier in some areas, and in others, it was unsealed, displaced, or damaged. This was allowing moisture from the earth to rise into the space. There was also mud and efflorescence along the foundation walls, evidence that bulk water had been entering the crawl space.

Moisture floods into the crawl space through open vents, the rim and band, the crawl space door, and any other space air can flow through. The excess moisture had resulted in mold and mildew growth on the sub floor and floor joists. Mold requires a relative humidity of about 60% or higher and moderate temperatures to grow on organic material. Mold growth in the crawl space results in musty odors inside the home and diminishes the indoor air quality of the home.

Solution

To fix this crawl space, we began by removing any debris from the crawl space and treating the mold and mildew with an anti-microbial. Next, we installed a heavy-duty 20-mil CleanSpace Vapor Barrier. CleanSpace is durable enough to be attached and sealed to the crawl space walls, sealed at all seams, and wrapped and sealed around all piers. The system isolates the crawl space from the earth’s moisture and is resistant to rips and tears.

Air sealing the crawl space is the next step. Our team seals all crawl space vents from the inside. They use foam to seal the rim and band, sill plate, and any penetrations through the foundation to outside. This stops air carrying moisture from freely flowing into the space and stops cold air from rushing in during winter months, leaving the homeowners with cold floors.

We then insulated the foundation walls with closed-cell spray foam. An R-10 of spray foam is applied to the walls at about 1.5-inches creating an air barrier and vapor retarder. Insulating from the foundation walls extends the thermal barrier of the home and helps reduce heat transfer, better controlling the environment in the crawl space. A 2-inch viewing strip is also left at the top of the foundation wall to allow for termite inspections.

The final piece was to install a SaniDry Sedona dehumidifier. This unit is designed specifically for crawl spaces and basements, it pulls the excess moisture from the air, filters it, and circulates dry air throughout the entire crawl space. The unit only cuts on when the relative humidity rises over 55%, keeping the crawl space safely below the 60% point where microbial growth can occur.

This solution has allowed the homeowners peace of mind that their crawl space is clean and dry, improving their indoor air quality, protecting their home’s foundation, and making their home more energy-efficient.