Insulated header design
We’re building a small house in North Idaho (climate zone 5). 2×6 exterior walls with most headers being built of double 2x’s. Planning to insulate them with 2”EPS. The options I’m considering for this are:
1) Double up the 2x’s, nailed together and set flush to the outside, 2” EPS on interior with 1/2” air space between EPS and drywall; or
2) Sandwich the EPS between the two 2x’s (joined with 5” lag screws from both sides) with half inch gap between innermost 2x and drywall.
Both header assemblies would have a flat 2×6 nailed to the bottom. I’m also planning to air-seal interior walls with ProClima Intello Plus vapor-variable air barrier membrane.
My question is is there a reason, (structural, moisture, performance, or otherwise) to choose one method over the other? I’m an owner/builder and not concerned with labor cost, mostly just don’t want to waste energy or grow mold in the walls. Thanks!
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