Redsky wrote:
VHB tape is used even on aerospace applications. It does work well if the surface is properly cleaned with the recommended cleaner beforehand.
Screws only work if there is enough thickness for 3-4 threads to bite and hold. Most RV roofs do not have a very thick roof all the way across. If you don't trust VHB tape the best alternative is 1/2" rubber Well-Nuts. They take a 1/2 inch hole and then a 8-32 stainless screw is threaded into the Well-Nut to expand its diameter. Finish by applying sealant to the screw head so not water can penetrate.
I used stainless self taping screws on my solar panel rack but I had 4 feet on an edge that was screwed every 8 inches into the edges where there are two tubular aluminum framing sections. I had 20 plus screws holding the frame down to the roof.
Why don't you post some pictures detailing this work? We would love to see this...
