air & moisture barrier retrofit for post & beam structure
I’m working on a project for a client who has a timber frame/post & beam garage that was built a few years ago. The garage was sided with 1×8 T & G vertical pine directly over the frame, so no bldg. felt, house wrap or sheathing exists.
He would like to finish the second floor which has 2 gable end walls, with 4′ high knee walls on both sides. I was planning on insulating the exterior walls with 2″ of closed cell foam & 5″ of open cell foam. While closed cell foam acts as an air barrier, the bigger concern is the lack of felt or house wrap under the siding to act as a weather barrier/drainage plane.
is there any option other than removing the siding in order to install house wrap over plywood sheathing & then reinstall the siding? Maybe leave the siding in place to act as the sheathing, then install house wrap & new siding?
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