Falling and Damaged Insulation
As fiberglass insulation absorbs the moisture trapped in the crawl space, it begins to degrade. Moisture damages the fibers of the insulation causing them to separate and fall away. The excess weight as a result of the absorbed moisture pulls the batts away from the floor.
Mold and Mildew on Floor Joists
Wood absorbs infiltrating moisture and saturated insulation holds water against the joists. The high relative humidity in the crawl space coupled with warm temperatures allows mold and mildew growth on the floor joists.
Crawl Space Moisture
Moisture infiltrates the crawl space through porous foundation walls, open crawl space vents, natural gaps in construction, and from the earth. This moisture becomes trapped in the crawl space, resulting in damage to insulation, microbial growth, and the ideal environment for pests, critters, and snakes.
Stopping Moisture Infiltration
After all of the debris was removed, from the crawl space the vents are sealed, the sill plate and rim band are sealed, and a heavy-duty vapor barrier is installed. This vapor barrier is a 20-mil heavy-duty liner, similar to a pool liner, that is overlapped and sealed at all seams. The liner is also installed and mechanically fastened to the foundation walls 6-8 inches above outside grade and wrapped and sealed around all piers. This seals the crawl space from as much outside moisture as possible.
Insulating the Crawl Space
A continuous R-10 of insulation is required in an encapsulation. Closed-cell spray foam is applied to the crawl space walls leaving a 2-inch viewing strip for termite inspections. To ensure that we have a continuous R-10, we also installed a friction fit, interior crawl space door air sealing, and insulating behind the exterior door.
Dehumidifying the Crawl Space
Even though we have done everything we can to keep infiltrating moisture out of the crawl space, there is one final piece of the puzzle to ensure we control the relative humidity and protect the crawl space from future mold and mildew growth. The dehumidifier will keep the relative humidity below 60%, the point at which mildew/mold can begin to grow as well as filter and circulate dry air throughout the crawl space.
