Originally Posted by sflamedic
I live in south Florida and am helping my dad paint inside his house. When we took off the covers for the air vents we noticed that the fiberglass is black. Is the normal with age or is it a problem? If it is a problem what wouldwe need to do to fix it? Thanks
Did it look discolored (not really black), or did it look like black fiberglass mat? If it is the latter, this is a more expensive boot/insulation designed to prevent mold/mildew growth. It is very common in Florida. Here is a picture of lined duct board:
They make boots with this fiberglass matting on it as well.