Our house, built in the early 1970s, has some rot in and under the siding on the north side, a gable end. A contractor recommends removing all the clapboards on that side, then removing and replacing all the plywood sheathing. I asked if we could improve on the insulation when the wall was opened up, but he said no, we can only replace what’s there. (The house has ordinary frame construction and fiberglass insulation – I believe it’s about R-11, but I can’t find a record.)

A reliable source tells me that (a) the first thing we should do is figure out where the water came from, and (b) then we should fix the underlying problem, and (c) we may not need to replace all the plywood, and (d) if we do remove the plywood, then yes, we can improve on the insulation. Does anybody know a contractor who is knowledgeable and experienced with this kind of work?