I never see comments on using vapour barriers when building walls and roofs. Does anyone use it? I'm considering doing some kind of wrap on the outside just under the outer roof. The wall structure will have foam cutouts for insulation and I'm also considering a vapour barrier on top of that before installing the inner plywood finish, or maybe that sticky foil stuff. Is this overkill or do people do this? It gets quite cold and damp early on in the summer as well as getting into fall so I'm worried about condensation.
Along the same lines, I wonder how this will affect having an aluminum skin with a wrap right underneath it. The aluminum skin will only be on the front wall and halfway up the roof. Will this cause problems with condensation getting stuck between the aluminum and the wrap?
Here's my wall design:
The outer walls are blue. The inner structural walls are green with cutouts for foam insulation. There will be a 1/8" plywood finish on the green for the interior wall. I'm thinking of putting the plastic vapour barrier on top of the green structural part before putting the interior plywood wall.
Looking for any advice anyone has to give