we have converted a farm shed into a pottery shed. We've added joists, flooring ,windows, heat ( wood burning stove, )small air conditioner. I'm getting ready to add the insulation in the walls ( R13)Kraft faced. The wall on one side of the shed is galvanized metal . The sun BAKES this wall.I was wanting to wrap the inside of pottery studio ( shed) with plastic sheeting after I install the insulation. From outside in .. metal wall, insulation , kraft facing inside, plastic sheeting. Should I do the plastic sheeting or no ?
Adding poly will be adding a second vapor barrier. The kraft paper is the first and the only one you need.
This is not part of your question but I would be concerned about possible condensation on the metal siding, and controlling that, if you are in a climate where that occurs. In Maryland I never seen that as a problem with my shop that had a metal roof, but now I am in WA state and the condensation is so heavy, it is like it is raining inside our metal barn. The metal siding has it as bad, but it just runs down to the gravel floor, the framing is galvanized metal so that will not trouble me. The dripping sure does though. Learned something there.