Insulating top plate
I am curious about the best way to insulate my top plate?
currently the soffits are open and if I insulate the exterior wall from the outside I will be able to hide the insulation inside the soffit and it will insulate the top plate (see attached diagram)
The house is currently in climate zone 5a. The roof has r31 foam board with fibrous insulation between the rafters. The walls are flash/batt with 3 inches os closed cell spray foam.
initially I was thinking putting closed cell spray foam but then I would sandwich the blocking between the rafters with two vapor impermeable substances. Could open cell be used in this case? Are there any other methods out there?
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