I have a garage that used to be a carport. Therefore the ceiling, clad with stucco, is not insulated. Do I need to pull down the stucco to properly have a vapour barrier when I insulate? or is the stucco enough of a vapour barrier?
Is there a second floor? You don't really want an extra "vapor barrier" on anything that is (now) an interior surface.
And in general you want one and only one vapor barrier: all building spaces need to exchange humidity in at least one direction. Put up two vapor barriers and the space in the middle will have the wrong humidity.