Help with Insulation on ceiling

[ford88]

I have a 24x30 pole building,It is 17ft at the peak ,the ceiling is 10 ft at the bottom of the rafters it has a metal roof.I live in the northeast so it gets pretty cold in the winter months.Before I close the ceiling off what type of Insulation should I use also should I use any vapor barrier.After reading some posts on here I think I have to redo my walls I used 1\2 inch form board on the walls with no vapor barrier and covered it with 1\2 plywood.Can I just spray in some loose Insulation before I close off the ceiling.

 

[carrerakid]

Metal does not breath so metal buildings tend to sweat. Therefore you need to keep the dew point away from the metal (good insulation) and use a vapor barrier. No vapor barrier is 100% effective so you should design for worst case. Whatever you use make sure you completely fill the cavity between the metal and the plywood or drywall. I would use foam or fiber glass. Cellulose absorbs moisture, and turns into mush when it gets wet.

 

[rodnok1]

If you kept the foam away from the steel on the walls you might be able to get away with nothing else, condensation will form on the steel. Without adding a vapor barrier or at least having the foam well sealed I wouldn't pack the cavities full of insulation. If you are going to close off the ceiling, you should have some vents to allow moisture out of attic area. I would use a moisture barrier and use either fiberglass bats or blown in.