Rick Jay wrote:
While it's probably not necessary, I would recommend that you use marine grade plywood behind the fiberglass. It adds a bit to the price but you won't have to worry about water that splashes up on it from underneath the vehicle degrading the plywood.
I'm also considering a plastic or aluminum sheet (leaning towards aluminum), but both (especially aluminum) are much more expensive than plywood.
See this
IRV2 post (post #12).
Rick Jay wrote:
PLEASE keep us up to date on the repair. I'm really interested in seeing how this turns out for you.
You bet. I may try fixing the fiberglass to make it more structurally stable this fall, but probably won't be complete until Spring.