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This Henrico, VA client contacted us because they wanted to address the insulation in their crawl space. Moisture had caused damage to the fiberglass insulation and it was sagging and falling to the ground. The unsealed, vented crawl space was allowing moisture to flood in and cause damage to the insulation as well as mold and mildew growth.
The homeowner wanted to not only reinsulate the crawl space, but they also didn't want to do it again in a few years. After reviewing their options, they opted to encapsulate the space. The crawl space was cleaned out and treated with an antimicrobial. Then, a new vapor barrier is installed sealing the crawl space off from the earth's moisture. Our team then air seals the space by blocking and sealing all vents and sealing any penetrations through the foundation wall to the outside.
Next closed-cell spray foam is applied to the foundation walls and rim band. A SaniDry Sedona dehumidifier is installed to control the relative humidity and help prevent future microbial growth. Finally, an interior friction-fit door is installed to air seal and insulate behind the exterior door, and an Everlast exterior crawl space door is installed on the outside.
The porous foundation walls on this Henrico, Virginia crawl space were left exposed, allowing moisture to seep through them and raise the relative humidity. The chalky-white efflorescence covering the crawl space walls indicates moisture infiltration. The open vents lining these walls also allowed the outside air and moisture to seep through them, which added to the overall relative humidity of the crawl space. To protect the crawl space from the outside, our installers sealed the open vents with precisely cut foam board pieces, which were placed within the vents and sealed with can foam. Then, our installers sprayed 1.5 inches of closed-cell spray foam insulation over the foundation walls. This amount of insulation has an R-10 value and will act as an air barrier and vapor retarder, protecting the crawl space from the outside air and moisture. A two-inch viewing strip is left at the top of the wall for termite inspectors.
The existing vapor barrier within this Henrico, Virginia crawl space was failing at protecting the crawl space from moisture rising from the earth. There were holes and tears in many areas, exposing the dirt floor of the crawl space. There were also large puddles in certain spots, and the floor was littered with debris and building materials. Our installers cleared the crawl space of the existing vapor barrier, as well as any debris and trash. A 20-mil 7-layer polyethylene vapor barrier, called CleanSpace, was installed over the dirt floor of the crawl space. This heavy-duty liner is wrapped around all piers, sealed with special vinyl tape, and mechanically fastened over the foundation walls six to eight inches above the outside grade. With this vapor barrier in place, the earth's moisture will find it much more difficult to infiltrate the crawl space and raise the relative humidity.
This homeowner contacted us with concerns about the joists in their crawl space. At the inspection, we found damaged and falling insulation, mold growing on the floor joists, and high humidity. To mitigate the problems under the home, and prevent them from reoccurring, we sealed the crawl space. The space was cleaned out, the mold was remediated, then we installed a new vapor barrier, sealed all the vents, rim & band, sill plate, and any holes through the foundation to outside. Next, we installed insulation on the foundation walls and installed a dehumidifier to regulate the relative humidity and protect the home from moisture damage.
A 20 mil vapor barrier is laid, seams are taped, and it is adhered to the crawl space walls, replacing the old and torn 6 mil vapor barrier. Spray foam insulation is installed on the crawl space walls and the sill plate, rim and band, and vents are sealed.