Hybrid rebuild help

Yeah, you are not the first to buy a decent looking rig and discovered a lot of water damage. I got lucky. I bought something that showed previous damage so I knew what my course of action was going to be. I also had the intention of insulating the structure so it could endure a Midwest winter with more comfort.

One of the better aspects of gutting the whole thing and starting over is that you can decide what fits your use and can design/build accordingly. I can't really convey what kind of improvement in comfort, feel, and lack of noise a really well insulated trailer is like. I live in MN so are summers aren't brutal but +90f and the sun shining is not atypical. At night, the temps go down. If I leave a vent cracked and a window open, at noon, the temperature inside the trailer is -10 to -15f from ambient. Last winter, I heated the TT with a small electric heater at it's lowest setting, 550w or so.

Yes, an interior wall partition or a full shower stall may be holding up the roof (especially true if the ends of the ceiling joists are rotten). What I did was build a jacking post out of 2x4 and raise said post with a small hydraulic jack. The link in my signature has pictures of how I repaired the ceiling joists and wall framing. Having an aluminum frame is a better deal, all of that should be in good shape.

If you can, please, post some pictures up of your progress. Having electrical skills is a definite +++++, you can do some upgrading of both the 120v and 12v systems.
I'm pullin' for 'ya!

Part of the walls are affected as well as the floor. The floor was just holding water because the barrier underneath wasent allowing the floor panel to dry out. I've already gutted everything in the trailer back to the bathroom and where the wallpaper had wrinkled is several places where I pulled those spots off it just continued to flake until I hit styrofoam. The only reason i havent ripped the bathroom completely out is because i was afraid the walls were working as ceiling support. I think you are exactly right about the floor being composite panels. I'm going to Completely gut everything in the trailer because At this point I really don't have anything to lose. May end up with a flatbed trailer when done. Lol. Im a master electrician and have a HVAC license. I have access to plasma cutters and breaks so I feel confident in getting the trailer back together nicely with advice. But I've never seen anything built this way and would like to limit the damage caused by trying to remove everything. The outside is in great shape I call the camper Dr Jekyll and mr Hyde because what happens when you open the door.

Wood and foam sandwich = composite panel.
The wood you are describing may be Luan, a generic label for three-ply hardwood plywood, mostly from Indonesia or other Asian countries. It is used extensively in the RV industry for paneling and filon backer.

If you have extensive water damage inside the walls, you'll need to access those areas and deal with them, any rotting wood will continue to rot. The dilute bleach solution will work to kill off any fungus, i.e. wood rot, mold and mildew. I use a spray bottle and cover the surface with the solution. You could also use Lysol (Original formula with phenol) or Listerine mouthwash (again, Phenol).

When you have the floors repaired and are ready to replace the foam, buy extruded polystyrene with radiant barrier. It has twice the R value of expanded polystyrene, AKA- bead board, Styrofoam and has greater structural strength. I'd also suggest to install a vapor barrier between the foam/wall framing and the interior paneling.

Are all the walls and floor affected or just some areas?

One way or another you must get rid of the mold completely. Probably the outside filon is laminated to a luan wood. I used one of those multitools to remove the foam, eliminate the mold with mold cleaner and sprayed with a mold preventative. All available at lowes. I then re-glued new foam onto the exterior luan and finished off the interior. It was a long and tedious project. Any other component that could not be replaced was cleaned with mold cleaner, and coated with an epoxy coating(after I used a heater for days to completely dry it out. PC epoxy My rv was so bad it turned into a whole summer project.
Could not have done the project with that multitool. It was invaluable.

Best of luck to you.

thanks for the reply im refering to the inside I pulled most he flaking off and theres just styrofoam there. It seems to be the same type of panels as the floor was made of maybe a 2 pieces of some type of 1/8" wood with 1 1/2" styrofoam sandwiched between the two pieces. I was afraid that the outside would be thin and glued to the panels. The floor and walls when wet were just deteriating so couldnt tell what that wood would have been. I was afraid that the outside would bubble and would not be unable to get it back smooth when attaching it to the new styrofoam causeing more of a problem than I already have. Ive read where people have just sprayed it with a bleech and water mixture but Ive been told that only works on smooth surfaces and it would be best to just replace anything that has gotten wet.

You will probably be OK removing the foam between the structural frame unless the foam is glued in place and onto the exterior. Depending on what type of foam is used and if it has shrunk away from frame members, the foam can add quite a bit of rigidity to the wall structure as a whole.

When you say "laminate peeling" is that interior or exterior?

You can look in the 'Cowboy/Hilton" thread in my signature to see how I dealt with water damage and framing.