I recently purchased an older home (built in 1965) and I'm getting ready to add more insulation to the attic since there's barely 3 inches of fiberglass insulation up there. There are also sheets (maybe 4 feet by 4 1/2 feet in size by 2 inches thick) on top of the beams that I'm trying to figure out if they contain asbestos. I can't find any identifying writing on them. The sheets are made up of 3 layers, the top layer is some sort of heavy black paper like material, the middle layer appears to be a foam and the bottom layer I'm not sure about. It sort of looks like a compressed cellulose material but I don't know. I'd just like to know there's no asbestos in this stuff before I go moving them around any more than I already have. I may end up having the stuff tested but though I'd see if anyone could make a positive ID first. Check out the pictures below.
What you have is combination ISO board insulation. It is an iso-cyanurate panel laminated to a fiber board. It is used under built up asphalt roofs, either hot or cold applied. The black tarpaper side is adhered to the roof deck with either hot asphalt or mastic. The base ply is adhered or hot mopped to the fiber board. I doubt this material would have any asbestos. Somebody must have gotten a hold of some left overs from a roof project. You can figure about R-8 per inch of thickness of the ISO.