Check it, free from a local manufacturer. They're insulating some of their machines, these are the scraps, original use has something to do with roofing. Looks like a basic ~3" thick rigid foam insulation, but both faces are a sturdy cardboard, not the typical foil vapor retardant. I'm wondering if I can use it in a crawlspace under a bathroom. If so, any special installation needed? If humidity will be a problem for it there, I hope I can just stack it in the attic. I know there is some moisture movement through there as well, but nothing like a crawlspace. Think it's any good for either of these applications? Thanks for any advice or suggestions, I'd really like to use this to make a difference in how well the house holds heat.