Michael writes again from Severna Park, Maryland: "I plan to remove any moldy insulation. I also plan to foam any penetration points I can find. Unfortunately the original insulation underneath is cellulose with no vapor barrier. I could have all the insulation removed and re-install new insulation. However, there are only certain areas that have discoloration from mold. Should I remove all the insulation, even that which isn't discolored? If I leave the insulation that has not been contaminated, can I remove the cover to help the insulation pass any warm air vapor that does penetrate the ceiling so that it won't get caught where there isn't any perforation holes in the plastic, or where there is overlap. Unless I remove all the cellulose I'm sure I won't be able to seal all penetrations. Most of the problem is around the center attic access vent which I plan to replace with a more sealing access panel."

Answer: Remove insulation that shows any signs of mold. If there are no signs of mold, it is ok to leave the insulation in place. It is up to you if you want to remove the perforated plastic or not. Owens Corning also has a PINK Cap® attic stair insulator that you can use to insulate over the access point to help the energy efficiency of your attic. There is a convenient dealer search at www.itseasytoinsulate.com.