Relative Moisture Reading in the Crawl Space
The moisture level was at 85% relative humidity. With this high of a humidity level, the wood moisture level could potentially be above 17%, in the danger zone for wood rot and mold growth.
Falling Insulation and Ineffective Vapor Barrier
The plastic vapor barrier on the ground was not covering a majority of the ground and it was unsealed, allowing humid air into the space. The humid air saturated the insulation until it fell from being too heavy.
Water Seeping into the Crawl Space
At the base of the perimeter crawl space walls, there were signs of groundwater seeping into the space. The darker concrete is from sediment being pushed through the brick along with water.
Barrier Stapled to the Joists
We recommend fixing a vapor barrier directly to the joists in the crawl space. This can actually make the problem worse by allowing humid air in, but not allowing moisture to escape once it condenses. This happens until the moisture pools on top of the vapor barrier or soaks into the insulation. Eventually, the weight of the water causes the insulation to fall as seen here.
