Pole barn — ceiling vapor barrier?
I live in Alaska.. far northern Zone 7 probably zone 8. I have a pole barn that has metal siding and a metal roof on large wooden rafters. Shop/Barn is 45x50x14 and 8/12 pitch with stud walls and lathe is currently in place for the ceiling. The attic area as you can see is quite large due to the size and pitch of the roof
I am thinking about using metal interior panels as the ceiling (basically metal roofing without the UV paint protection) as opposed to sheet rock.
If i use the metal panels is a plastic vapor barrier needed. If the answer is no then what is the recommendation to seal the laps to ensure air tight seal and how much of a lap is needed?