Flash and Batt and moisture issues…
I am 2/3 way through a major remodeling project and insulation time is fast approaching. I am looking hard at sprayed foam insulation and have prices closed cell. I Iive in the outskits of D.C. so the climate is zone 4 with 5 not too far off and humid.
I have four areas to insulate:
1. First floor -existing Brick outside wall, airspace, 4″ block wall and treated 2×2 lathing. Proposed 1 1/2 pink foam board glued to block wall between lathing and then drywall over it. Q – is this a good plan and do I need to worry about a vapor barrier?
2. Second floor – new construction -Hardly board siding, tyvek house wrap, OSB sheathing and 2×6 studs. Proposed 1/2″ blown-in closed-cell foam insulation with 5″ of fiberglass batting (flash and batt) then drywall. Q – Is 1/2″ of foam the right thickness based on my region and moisture permeability or is 1″ or even 2″ a better plan? Is a moisture barrier needed on the inside house face of walls? Is blown-in fiberglass on top of the cc foam a better plan than the fiberglass batting? Or is open-cell the way to go for walls?
3. Attic – new construction – Insulation to be put on attic floor after drywall ceilings are installed on second floor. Proposed (following the drywall ceiling installation) – 1/2″ blown-in closed-cell foam insulation with 11″ of fiberglass batting (flash and batt). With the closed cell insulation barrier on the warm side of the house is this sufficient or should I look at 1″ or more closed cell?
4. Crawspace – existing – 2×10 floor joists on block wall with plank subfloor and hard wood flooring. Proposed – 1/2″ blown-in closed-cell foam insulation with 9.0″ of fiberglass batting (flash and batt). Once again is 1/2″ sufficient or should I look at 1″ or more in this area?
Thank you for any insights…
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