Crawlspace Insulation Myths

Many homeowners with insulated crawlspaces, like those living in Granada Hills, CA, believe that as long as their floors and crawlspaces are insulated, they won't have to worry about mold, moisture, and other hazards. This is untrue.

Many homes have insulated floors because their crawlspaces are cold due to open vents. Vents should be closed permanently, making the home above warmer, especially during the colder winter months. Second, fiberglass insulation only works in a closed space, if vents are open, the air will just pass right through it. Paper-faced insulation attracts mold like a magnet, even more than wood in a crawlspace.

Mold grows on insulation because of the organic material in resin used to set the insulation's fibers. Even if it gets a little damp, it loses a lot of it's insulation value. Another myth about insulation is that foil facing insulation works 100% as a radiant barrier. Even if you face the foil to the heated side, you'll need at leas 1/2 ' of air space in front of the barrier in order for it to reflect heat. If it's jammed against the floor above with no air space, it's useless.