Is there special framing or structure needed for slate?
A good solid deck with 16 on center framing is preferred. Most structures are built to handle wind and snow loads that far exceed the weight of slate. However, a weak structure that has too much flex to it will result in a poorly installed slate roof. Ideally, one would use a thick tongue and groove deck on 2 x 12 rafters 16 on center. However, this is an expensive deck, and would be a rare sight today. Otherwise, it would be best to have at least 5/8 plywood or plywood over 16 on center trusses built to handle slate.
