I’m looking to buy 3″ polyiso from a local seller that is reclaimed from commercial roof tearoffs. Two Questions: 1. The seller says they have a hard covering on one or both sides. I’ve used foil faced polyiso, but am not familiar with the hard covering that (I’m assuming) is used in commercial roofing. Any problems using this as outsulation on a house? My thought is it can’t be any less vapor permeable than foil faced, so it should work the same from that standpoint. How about difficulty of installation with the hard covering? It would be a couple hour drive to look at the sheets, so I wanted to figure this out and be ready to buy. 2. I read somewhere, maybe here, that there has been shrinking problems with polyiso made for commercial roofing. Does the shrinking occur over a long period of time where I would need to be concerned? Or does it occur fairly quickly and I can assume the sheets are final size? Reusing material is great, saving money is great, but not if the building will perform poorly down the road….. Thanks! Bill