I just moved into a small 1950s home. The previous owner had purchased tons of unfaced fiberglass batts and they are still in their bags, piled up in the attic. So I'm going to clean up the little bit of loose fill insulation that was there, and lay the new stuff on a clean slate

What should I do so that this unfaced insulation will have the same effect as faced? A plastic vapor barrier? I'm getting mixed messages on those...

1 Answer 1


Nope, you don't need it. A paper facer on batt insulation is a vapor retarder, not barrier, and you don't want a vapor barrier or need a vapor retarder. Install it and be happy.

Additionally, save the loose insulation (assuming it's not asbestos-laden vermiculite...) and pile it on top of the batts once you're finished. If the final result isn't 12 inches thick, get more loose insulation, preferably cellulose or mineral wool, and keep on piling it up until you have 15 inches or more up there. Every little bit helps.

  • Thanks for the reply. I live in North Carolina where heat and AC are on about equal amounts, so I wasn't even sure what side to have the barrier or retarder on. Glad to not have to worry about it.
    – Evan
    Nov 11, 2015 at 4:25
  • The latex paint on your drywall is an adequate vapor retarder. In your climate, you don't want a vapor barrier anywhere. Those only ever make sense in really cold climates.
    – iLikeDirt
    Nov 11, 2015 at 4:50

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