I have a 94 Skamper Pop-Up that the roof had leaked prior to me purchasing it. I now have the task of repairing it, I have pulled the ceiling out of the camper which was Foam and now I wish to replace the material with something more sturdy, but I don't want to put too much weight on the lift system. I had thought of 3/4 Treated Plywood but that would be way too heavy. SO what can I use??? and What type of Adhesive can I use to hold it up on the roof? Yeppers this is a Delema in the biggest way! I just spent $300 getting the lift repaired I don't want to have to do that again.. Thank you Robert in Houston..