I apologize if this is the wrong forum to discuss this particular attic question...but, I've asked a few "experts (insulation contractor, general contractor)" and nobody seems to have an answer. I had a little water damage on a second story ceiling, determined to be caused by a leaky vortex vent. When pulling away the cellulose to troubleshoot, I noticed metal sheeting under the insulation, preventing me from getting to the actual ceiling below. I pulled up the insulation in various parts of the atttic, and the same metal sheeting exists. Any thoughts?