I plan to insulate my home. I live on a beach...bungalow that's built on sand....no concrete foundation. I am replacing the plywood sub-floor and was thinking about insulating underneath the new sub-floor with fiberglass batts. Do i need a moisture barrier? If so, which way to install batts? Paper side up or down? Also , will be installing fiberglass batts in the attic as well. The attic floor to be exact... (between the joists),over the living space. Same question...paper side up or down. As far as the attic "roof", I was just planning on using polyfoam board to add as more insulation. Having a new roof put on, so want to make house as energy efficient as possible. Bungalow is old...from the 20's, and if it helps..i am in the Northeast....thanks
Last edited by googoo; 11-08-2010 at 11:37 AM.
Any kind of vapor barrier typically goes to the warm side of the space, in a heating-load area like the NE. I would personally never use fiberglass under a floor, unless you can ventilate it and keep it dry. It is not very good insulation, btw. Can you get ahold of mineral wool in your area? Closed cell foam, though spendy, may be a good choice for the floor. Blow in (or batts, if you don't want the minor hassle of blowing in insulation) cellulose instead in the lid.