Tyvek with closed cell spray foam?
Second floor – over an ICF first floor. I’m looking at doing a DIY closed cell spray foam kit on the exterior (OSB) (12″ thick walls to match the ICF) walls. Spray foam will likely only be 2″ thick and the rest filled with fiberglass or rockwool as code/finances allow.
I’ve read conflicting data online as to type/requirements of a vapor barrier on the outside of the OSB. This 400sf space will be conditioned by a 9,000 btu minisplit system. What say you as to need/type of vapor barrier?
FYI – There is no attic space above the second floor – it is technically an unvented attic space as this area will only be used for part of the year. 8″ of EPS directly above this second floor – metal roof. Hardie board siding on top of the OSB.
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