Hello I read on the web, that a guy had soffit vents and ridge vent in his shed. He put the foam rafter vents from the soffit to the ridge vent and then put insulaion on top of that. After a while in the cold weather the insulation was soaking wet! However I am not sure if I am reading this correctly? From >http://boards.hgtvremodels.com/eve/forums/a/tpc/f/9001020091/m/4521068913 question"3. I was going to use that thin rigid foam stuff in between the roof trusses that allows air to pass from soffit to ridge, then cover it with 3-1/2 insulation. As far as aesthetics go, I don't mind looking at paper backed insulation in between the roof trusses, but I've heard that this can be a fire hazard and should be covered. What is suggested? As soon as I regain access to my pic hosting site, I'll post some pics if that will help."Answer"I've seen installations where those foam channels were installed all the way from soffit to ridge vent, and the insulation was soaking wet,I believe because they acted as a partial vapor barrier. I don't believe they were ever intended for that use, but only where insulation would be "pinched" at the roof/wall intersection, for maybe the lower two feet of the roof. You need to allow a minimum of 1 1/2 inch continuous clear air space above the roof insulation, and I would caution against the use of the foam channels for the entire distance."So how do you properly insulate a shed ceiling or a cathedral ceiling in a house?I thought if the Reflectix foil is stapled over the rafter vents and then the fiberglass insulation is put under that, then there will be a nice vapor barrier to prevent the insulation from getting wet?