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…
Best Answer
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.