Hi, On my new family room addition, I am considering installing beadboard for the cathedral ceiling (cedar beadboard). The GC claims that on the cathedral ceilings he was done in the past, he just nails it to the joist. Seeking out the advice of a carpenter (not part of the projects) and the framing cpaenter on the job, told me have him put up some plywood as sheathing then nail the beadboard to that for two reasons.
1) Don't have to worry about where your nail the beadboad 2) Acts as an extra layer of protection between the outside sheathing/insulation.So if I go with the plywood method, I guess 5/8 inch plywood should work, and should I have him staple rosin paper to the plywood to act as a relief between the beadboard and plywood (same principal of a wooden floor
thxs