The double-sided tape doesn’t work because of the texture.
Screws won’t work because the material is too thin.
What do I do?
We have found a solution to this in the form of well nuts. A well nut is a style of expansion plug that works great for creating a strong hold on thinner roof materials such as 1/8” or 1/4″ plywood that is becoming more commonly used on ultra light weight trailers.
If you’ve never heard of this hardware check out the video below to see how they work. The expanding rubber of the well nut also creates a waterproof seal, along with proper sealant, to help ensure that water will not penetrate and damage your RV’s roof.
Below are some reference photos of one of our 3-hole mount feet being secured with well nuts.
We regularly use well nuts for thin plywood rubber roofs but that’s not the main reason we choose them for this particular project. The roof had a thin PVC membrane that felt solid, but when we removed the old panels, we found that the PVC membrane tore easily. Because of this, taping out of the question since taped mount feet would just rip the PVC when exposed to torque. We tried screwing down the feet, but the screws weren’t getting enough grip. Well nuts were the only option. The downside to using them is that they stick up above the roof surface. We overcame that using the butyl tape. They also put a 1/2in hole for every well nut, so 8 per panel, so only use them when absolutely necessary.