Bad Basement Insulation Detail
One of the worst basement insulation details that we see on a regular basis involves framed walls adjacent to concrete foundation walls. The cavities of the framed walls are filled with fiberglass insulation and a vapor barrier is installed between the studs and drywall.
This basement insulation detail is a really bad idea. As the concrete dries and gives off the water vapor it get’s trapped between the concrete wall and the vapor barrier. This causes the fiberglass insulation to become saturated with water. Water laden fiberglass is extremely inefficient and very prone to mold growth.
As you can imagine once the fiberglass becomes soaked in water it’s nearly impossible for it to dry out. The fiberglass must be completely removed and disposed of. It’s also very likely that mold will have grown on all the studs, drywall and floor joist framing above.