Wall assembly zone 6
I’m building a house in Wisconsin. Contractor typically uses spray foam. I’m vehemently against spray foam so looking at different wall assemblies and getting a bit confused. We are using hardie siding and likely some masonry on the front.
i was originally wanting double stud walls but seems like overkill. Now looking at Outsulation. Siding, rain screen, foam insulation?rockwool boards?/ blue wrap, plywood sheathing/ rockwool bats and dry wall.
im understanding you don’t need a vapor barrier on the inside so wall can dry to protect he inside? Could also consider intello.
firstly do we need the foam on the outside at all? If so-
what is the best insulation for the outside of this assembly that wont lose R value and also wont cause condensation? do we need the inner vapor layer?
thank you!
RIK
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Replies
Zone 6 in VT here also. I have done 2 wall assemblies on my 1950's existing ranch. The main older house we used 2.5" R-12 Zip R panels fastened directly to the 2x4 studs for a thermal break. Outside assembly was Homeslicker rainscreen and then boral trim with Hardie siding. Interior side was R-13 Rockwool/ intello/ 1/2" sheetrock.
Last year we put an addition on the house and used the same assembly with a 2x6 wall stud and thicker rockwool. I can tell you that through the winter while I was completing both parts of my house, even on the coldest days I didn't have any condensation on the walls only insulated by the Zip-R panels at the time . For me it was also having a happy medium of comfort to budget and I felt like this assembly is less costly than some of the others which you may never live long enough to see a ROI on.