Just how far does the rot go?

Removing the kitchen and toilet showed I had a pretty serious damp problem.  This had caused the plywood wall boards along the back edge to rot and turn into pulp in several places.  Just how bad could this be?  In order to find out I had to remove wall board to expose the caravans skeleton.  A scary proposition I thought.  I wasn't familiar with how a caravan was constructed at this time, but I know a lot more now!

Removing the wall board was a feat in itself.  Like the floor the wall is a sandwich of three layers, all bonded together.  Where the board was totally rotten I could quite easily remove most of it with a wall paper scraper  leaving a dirty brown mess behind.  I guess that is all that is left of the inner face of the ply.  Removing the still good parts of board was a little harder, but it does come off a lot cleaner if you do it right.  As it is bonded you can't just rip it off, not without damaging the polystyrene.  My searching on the 'net had found someone recommending the use of an 'oscillating multi tool' for the job.  Despite being reasonably clued up on DIY I'd never come across one of these so I did some more research.  It did indeed look like the tool for the job. The idea is to cut the wall board inner ply into sections and remove each section in turn using a wall paper scraper.

Argos had the Stanley Fatmax tool for sale at a reduced price and I had some Nectar points to use so off I went.  What an amazing piece of kit!  It comes with various blades all packed in a very tough carry case and has been invaluable in the whole strip down and rebuild process.  If you don't have one then get one now!

Here you can see what I mean about cutting the board in to sections before removal.  The multitool comes with a semicircle blade that you can use to just cut through the inner board.  You then insert the scraper keeping it a flat as possible and wiggle and push it between the board and the polystyrene taking each square of in turn.  Time consuming but it leaves most of the polystyrene intact.

I also removed some board on both side walls chasing the damp to see where it was coming from.  So far I suspected the awning rails both side, possibly one handle and with a very strong suspicion that something was wrong behind the plastic moulding that carries the lights and number plate on the rear of the 'van.

In the left corner (as you face the back from inside) near the toilet hatch there was rotten timber.  The horizontal frame piece under the toilet door, the horizontal piece in contact with the floor, the floor itself, the piece at 45 degrees and the vertical pieces were all rotten.

On the right hand side it was a similar story.  Damp had moved along from the back and started soaking along the bottom timbers.  The 45 degree piece was just mush, as was a lot of the vertical piece.

At this point I was starting to think this may all be getting a bit much for me to cope with.  Time to go home, pour myself a Whisky and look at the pictures I'd taken, then I needed to try and come up with some sort of plan.

Simon.