Dave writes from Saint Cloud, Minnesota: "I have recently found out that we have a very wet attic. It is so wet that a number of stains have shown up on the ceiling drywall. The house was built in 1973 with no vapor barrier in the ceilings. It has 14 to 16 inches of blown in fiber glass insulation but inadequate soffit ventilation. My question is should the existing insulation be removed since it is so wet or will it dry out when warmer weather returns here in Minnesota? I have had two differing opinions from insulation contractors."

Answer: Fiberglass insulation will dry out and retain its R-Value. The concern is whether the insulation was contaminated with dirt in the water. If that is the case there could be mold issues. In other words, fiberglass won't support mold growth but the dirt that got on the insulation along with the water could do so. Given the amount of dirt and dust in a typical attic, I recommend taking out the insulation and adding adequate ventilation before installing new insulation.