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Foam board over existing siding

kkuneman | Posted in General Questions on

Thoughts on adding continuous foam board over existing cedar plank siding? I’m renovating a vacant home to be all-electric and extremely airtight/energy efficient. The home was built in 1929 and has 2×4 stud walls with no insulation. The current plan is to do dense-packed insulation from the exterior before wrapping with continuous foam board. I get mixed reactions on this.

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  1. creativedestruction | | #1

    You need a plan for a continuous air barrier. Depending on your climate, it often makes sense to locate it in the plane of the structural sheathing, which can be tricky if the existing siding stays in place. Define your air barrier.

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