Since the popcorn ceiling in older houses often contains asbestos, I wonder if this is because the "popcorn" is vermiculite which often contains asbestos naturally? Or did they purposefully added asbestos in old formulations?
I hear the newer non-asbestos containing popcorn ceilings are made out of Styrofoam or paper based material, but this doesn't tell me what the asbestos containing ceilings are made out of, especially the "popcorn".
Thanks