How do you insulate a mansard roof outside bathroom wall?
I have a mansard roof home in the Chicago area. With recent weather, I had some frozen pipes and tub drain. They are, unfortunately, on the outside wall on the southern face of the house. I recently had the bathroom remodeled, with sub-zero temperatures arriving near the end of the process. The pipes and drain have been on the outside wall since I have lived here (15 years), and I believe since the mid-1980s when the house had been last remodeled.
My thought was to use insulation baffles in the rafter/stud spaces, with fiberglass insulation over it. That could be covered with caulked-in closed-cell rigid foam. Behind the new plumbing, my thought was to stack bats of fiberlass insulation in the space. This is pretty much as it was before the remodel.
It also occurred to me that I might build a compartment out of closed-cell rigid foam to fit around the pipes themselves. As for the drain, I think I am going to have to cut a hole in the ceiling below to access the floor joist space, and build up insulation there.
I guess I'm asking if this seems reasonable, or if anyone who has experience with the migtmares called mansard roofs has a suggestion.