Originally Posted by Dino
Fould a water leak behond one tail light.
Now up to 5 confirmed cases on this forum.
I had the same issue, but I caught it before the wood rotted. I did obtain a drawing from Thor and the only plywood is around the tail lights as a mounting surface (and where the stanchons of the ladder mount).
So the good news is the rotting issue is pretty much localized to the tail light area and not structural.
At least on my 2011 28Z, but I would assume yours might be the same design and construction.
From the drawing below, you can see the plywood is localized to around the tail light:
I had a bit of delamination of the plywood, and I fixed it - as well as waterproofed the area by encasing it in epoxy.
If the shop wants to replace the end wall, it will be very expensive. And there may be an alternate solution. Before going ahead with something like that, I would take it to a boat repair facility that specializes in fixing rotted transoms.
There are epoxies available that are penetrating and will soak into the rotted wood, and solidify it. This is often done in older boats to repair wood transoms that have rotted away when they are not otherwise economical to repair any other way.
Especially since the plywood is probably not structural, repairing the plywood as if it were a transom should be pretty effective.
You can also do this yourself, by using a product called CPES (Clear Penetrating Epoxy Sealer). The stuff I have used is made by a company called "The Rot Doctor".
Here is their link: www.rotdoctor.com
There are case studies there showing various forms of rotted away plywood, and their ability to repair them.
While this is not a boat, it is not unlike a transom on a fiberglass boat that is encapsulated in fiberglass but has rotted away due to leaks that allows water to rot away the wood.
If you have little experience with working with epoxy to fix issues, you may want to have someone that has done it before help you. In your case, Florida is probably the rotted fiberglass boat transom capital of the world due to the high humidity and heat, so there should be some help available.
I would trust a boat repair shop that has repaired transoms more than a RV dealer, unless they have tackled this problem before and recommending fixing the problem with CPES.
Here is also another link at Rot Doctor showing customer repairs and photos. There are even a couple of RV repairs there:
I have used their products before, and have had good luck with them.