Andrew Jobe
Hi Pete, It sounds like the old insulating liner or the backing for it. I've just done a job with this on the walls but the walls were plastered so I could shave it off with a heavy duty scraper but it was a laborious task. If it's pretty much stuck to the walls still I would remove the loose areas and then prime the walls. When dry rub down the edges and the fine fill where it's pealed off. Rub down and size the filled areas and you're good to go. Hope this helps
