The back hatch of our old airstream had rot in the floor under the battery etc. We just replaced with exterior plywood and took care of the rot. However, there was also an alum. sheathing over the old plywood. We think this is where the water got trapped. Is the exterior plywood enough, perhaps painting it as well? Any suggestions would be greatly appreciated.
Have you figured out how the water got between the plywood and aluminum? Is it leaking around the trunk seal or a window? If you address the leak I would think re-installing the aluminum would be okay.
thank you for the advice...you are so right to find the origin of the problem and then go from there!