I live in the damp Pac. NW USA and I have always had prolems with condensation under the any metal roof building I have built. I know I should have a vapor barrier under the roof shiething if I can't/won't be allow a lot of air circulation.
I'm getting ready to build a large work shop and will only heat it occasionally, however I want to eliminate any condensation problems at all times.
I see the contractors/builders of commercial units putting a vapor barrier that appears tobe glass insulation with a plastic sheet on each side. I'm told that "their supplier" custom cuts it to the lengths that are going to be required for the roof span, etc.
I think I have seens something similar at Home Depot but I'm not sure that will be the cheapest way to get it for a large building.
When I was getting prices from various metal building vendors, they would quote about $.36/sqft for 2" vapor barrier. I'm going to build my building from locally available sources of material and use this price as my guide.
Can anyone point me to a vendor of this type of vapor barrier in the Pac. NW.??
Steve