jgra1 wrote:have moved on to rot, in the camper


Looks worse than it is John. Luckily, it's repairable so long as the RV body is of "traditional" construction (i.e alloy skin, wooden frame, ply face withinsulation between). If it is "Bonded Sandwich" then it's a slightly different ball-game. Bonded Sandwich is a sheet of ally bonded to dense foam which in turn is bonded to a ply face. There's not much framework on those as a lot of strength comes from the bonding.
I once rebuilt the complete front of a tourer with damp ingress problems that had rotted the framework and ply badly. So badly, the ply facings just crumbled at the slightest touch!
It's not difficult and you only need basic woodworking skills.
It's a case of making new frames from ash, carefully removing the alloy panels and transferring them to the new frames and then finishing the job with new polystyrene insulation and new ply facings. It's a lot of dismantling and it needs to be done under cover in a nice dry place so the damp can dry out completely. The roof will be of similar sort of construction I guess and looking at the standing water, that's where the problem originates. All soaked/rotten wood needs to be replaced.
Is the floor OK as that again is bonded laminate construction usually with a layer of insulating material sandwiched between two layers of marine ply. Repairs to floors can be a bit tricky.
Clear silicone sealant is no good. All joints need to be sealed with bedding mastic to ensure a watertight seal that's resistant to vibration. W4 make a great one.
It's a great summer project and at the end you can feel rightly proud
Haynes do an excellent Caravan BoL by John Wickersham. It goes into these repair jobs fairly well, or at least the older editions did. I can lend you a copy if the newer version currently available glosses over this..
I'll be watching with interest John and as always, if you need any help, you know where I am...