Tuck under garage insulating
Hi,
I am sure this has been addressed at some point in the past, however I’m not a member of GBA yet and don’t have access to whole articles I’m finding out…
Anyways, if you’re feeling generous today, here’s my question:
I’m in climate zone 6B (Minneapolis, MN) and I’m going to insulate my tuck under garage (both on the block foundation walls and in the joist cavities in the ceiling. I’m doing bats in the joist cavities and I stapled 6 mil poly to the joists, out of habit, but then I got to wondering: technically I am putting poly on the exterior side of things (I’m not trying to condition the tuck under garage, merely trying to keep the cold out of the family room that is above it and the bedroom that is next to it — and maybe use it as a shop in the winter). So, would using tyvek, or some other housewrap, instead make more sense?
My second question: the best rigid foam for the inside of the block foundation? I’ve just heard soooo many different opinions… If I understand right, all are pretty much fair game except foil faced correct?
Thanks for any time you take to respond!
– Luke
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Replies
Luke,
Your best bet is to take the poly off and not replace it with anything but the drywall. The first thing to do is meticulous air-sealing between the garage and living spaces to stop fumes from getting through the wall and ceiling. Then once the drywall is on, air-seal all penetrations. If you really want to make sure the family room above has a warm floor, add an 1 1/2" of EPS insulation to the underside of the joists before the drywall. I'd use EPS on the block walls too.