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Asked by: Ala Hilbrans
home and garden indoor environmental qualityHow do you install fiberglass foil faced insulation?
Thereof, how should fiberglass insulation be installed?
Gently push the insulation into the cavity, but do not force it or compress it, which reduces its insulating value. The insulation should fit snugly into the cavity with no gaps or spaces, filling it from top to bottom (or end to end). Fold out the paper flange along one side of the insulation.
Keeping this in view, which way does the foil face on insulation?
Foil insulation underlayment is recommended under a metal roof, and in most cases, the shiny side should be facing up, but there's a catch. Foil insulation is a radiant barrier, and it works by reflecting heat from the metal, but for it to do its job, there has to be a layer of air between the roofing and the foil.
Faced insulation has Kraft paper on one side to act as a vapor retarder and help prevent moisture from entering the wall cavity. Unfaced insulation is insulation only, for use when a vapor retarder isn't needed. State and local building codes determine vapor retarder requirements.