I'm frightened to death of starting our damp repair after reading this thread.....worried that if we start, we'll find a horror and never stop. I'm sure now that the bloke that sold us the van knew about the damp and that's why we got a "bargain"....ha ha ha more fool us, for being so trusting!!!!
Thank you.... Just hope it's not worse than we expect. But all the info on here and via wizard and the fix it club, has given me the confidence to think that we can do it.
The thing to remember when starting these jobs, is where to stop.
If you have loads of time and DIY skills, it can be VERY rewarding and even enjoyable, but too often folks overreach themselves and end up scrapping the van.
The pictures posted show just how bad it can get, and this happens in new vans as well as oldies, so look around for one that is relatively recent but has a low price due to damp.
We built our 6-wheel drawbar trailer from scratch, took a couple of months outside the house and was really great fun, but we had looked at all the issues beforehand, sorted out proper drawings and sourced all the materials first.
If you do the same with this sort of repair you can have a caravan in super condition and no worries about future issues, and more importantly you know it inside out.
Hi
As a thought why don't you fix the foam board then line with the bubble wrap as extra insulation / vapour barrier then finish as you were going to.
Being in architecture but knowing bugger all about DIY I would avoid any air gaps, especially on the cold side of the insulation as it would need ventilation to avoid interstitial condensation.
Then you would have to think about ventilation of the inside of a super insulated and sealed space!
I would forget the bubb;e wrap. the insulation needs to be fully bonded to the outer skin of the caravan and the wall boards also need to be fully bonded to the insulation board as well as the timber suports/frame. This is what gives the caravan its strenght, the same as a composit panel.
I bough a caravan wall panel for a repair to a previous caravan. The plywood panel looked as though it had a sealer coat on the bare side. this could act as a vapour barrier.
I ended up using PVA it worked quite well...just wait till it goes tacky then fit celotex..still got to board out yet...but I will coat in PVA again before tacking the board in place...