basement insulation question
I have a new basement addition, the contracter put up a foil faced insulation (foil to the room). I noticed water along the floor to day that was dripping off the inside of the foil. the insulation is wet, but the wall is dry? Is the insulation installed correctly? It runs 2/3rds down the wall, they nailed 1x2s to the wall to staple the insulation up.( poured wall foundation, basement is not conditioned space.) my existing basement never had any water issues .
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Is this foil-faced fiberglass, I presume? Is it covered with drywall or just bare?
Insulating a basement wall is always tricky. When you cover it up, the space between the concrete and any vapor barrier will generally tend towards 100% humidity (due to moisture coming through the concrete), resulting in condensation. This can be made worse if air from the basement is allowed to slowly infiltrate due to a poorly sealed VB, since the basement air, when cooled to wall temps, will often be super-saturated.
It's probably better to insulate with some sort of non-absorbing foam, either a closed-cell foam or the foil-faced stuff. And seal tightly around the edges so that interior air can't get through.
(Note that foam insulation should generally be covered with drywall, for fire safety reasons.)
Edited 8/14/2007 8:08 pm by DanH
Yes its foil faced. it is not covered by drywall. the back of the foil where it is attached to the fiberglass is wet. it is not happening everywhere, pretty much on the west wall. Is there a ridged fiberglass i can put up without covering it with drywall right away. (budget issue at the moment). thanks for the reply.Ask the right person the right question you get the right answer.
Any FG insulation is a bad deal in a basement.http://www.buildingscienceconsulting.com/resources/foundations/default.htm
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Bill, What about spraying closed cell on the wall? Think that would work well?
-Lou
Yes, sprayed works.But you can use sheet foam and seal the edges also. Typically that is cheaper and more practical for a limited area like a basement..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.