When installing fiberglass insulation in your home, be sure to put the paper or foil vapor barrier facing toward the heated and cooled living area of the home (down in attics, up under floors, in on walls) to prevent condensation from occurring.
If you are applying an additional layer of fiberglass insulation to your attic, use unfaced insulation on top of the existing insulation to keep from trapping moisture between the layers.
Watch this video for more information.
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