3 in vs 6 in fiber glass


Old 08-22-15, 12:22 PM
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3 in vs 6 in fiber glass

Is there any difference in putting 3 in or 6 in fiber glass in a 2X4 out side wall. Is one any better or is the cost just a waste.I understand it might be better sound proofing.Just wondering.
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Old 08-22-15, 12:25 PM
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Yeah. You use 3 1/2" with a 2x4 wall and 5 1/2" in a 2x6 wall. If you want the best fiberglass for a 2x4 wall, get r-15.
Old 08-22-15, 12:59 PM
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You don't compress insulation, as it loses its ability to insulate the more the loft is reduced. As Brant says, look for the best for the space you have. Or if you want to get more insulative quality per inch, consider installing Roxul.
Old 08-22-15, 12:59 PM
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As XS said, they make a high density fiberglass insulation that will fit those 2x4 walls. FG insulation is actually rated in r-value per inch. When you compress the insulation you reduce the number of inches and thus the total achieved r-value. Besides, trying to stuff 6" insulation into a 3.5" wall is a pain.


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