In a current thread, a radiant barrier paint above spray foamed insulation was suggested. That got me thinking, and I did a little research on it. The radiant barrier makes perfect sense. I know enough that heat is basically long wave light, and will reflect. ( More commonly accomplished with an aluminized sheet, and I have difficulty accepting that a paint will be close to as good, but the basic idea makes total sense ) In my mother's house, built around 1961, thats what they put in the walls.
Perhaps I am the only dummy on this forum who is not familar with this. Is it more commonly used than I think ? ( I mean the more common aluminized sheets, not the paint ) Why not ? Any roofers out there that can say if putting a reflective barrier on the undersiside of a roof helps shingle lifetime ?