Do I need/want a vapor barrier?
I’m building a cabin in south-central Montana (zone 6b) using Faswall blocks for the walls. The roof will be prefabbed trusses with raised heels permitting me to get a minimum of 24″ of blown in insulation in the vented attic space. I plan on finishing the the ceiling with T&G knotty pine. What’s the preferred method of finishing this ceiling? Taped drywall then the T&G or should I put a vapor membrane (or barrier) between the drywall and T&G?
Given there’s no vapor barrier in the walls with the Faswall blocks finished with lime plaster on the interior and 3″ of Roxul Comfortboard under metal siding on the exterior, I’m inclined to skip the vapor barrier (or membrane).
I realize this subject gets beat to death but I want to do this once and I want to do this right. Thanks for the assist.