Mildew/mold has grown onto the floor joist in this crawl space. Mold can grow on any organic material in the crawl space, including floor joists, subfloor and the paper backing on fiberglass insulation. This can cause allergic reactions and asthma, as up to 50% of the air in the living space comes from the crawl space.
This 6 mil vapor barrier is typical in the crawl space of most homes. This liner is not sealed nor attached to the walls of the crawl space which allows moisture from the Earth to enter the space. The constant stream of vapor within this crawl space increases the relative humidity until the air within the space reaches its dew point, releasing the moisture causing condensation. This results in puddling on top of the liner.
The fiberglass insulation within the floor joists of this crawl space are beginning to pull apart and fall. The insulation acts like a sponge when there is moisture in the space. The fibers begin to tear apart from too much weight and then gravity pulls the insulation to the ground. The lack of insulation protecting the subfloors causes the living space floors to be cold in the winter.
This Mineral, VA homeowner had concerns about what was happening in their crawl space. Upon inspection, we found that there were moisture and mold concerns.