An ABI with damp, now there's a surprise

[SheffSean]

Hello everyone,

My 1991 ABI Sunstar has an extensive damp problem, I'm pretty good at joinery which is just as well because it's bad, that said I'm new to caravan damp repairs, I've stripped out as much of the damp as I could without our caravan flat packing its self but I need help and advice on the different adhesives and sealants I need to undertake this job please.
1. what adhesive will I need to bond the new timber framework to the inside of the aluminium panelling.
2. I've stripped off all the rotten plywood but it's left a kind of powdery residue stuck to the polystyrene insulation, do I need to remove this residue or will the new plywood adhesive bond without removing it or will I need to renew the polystyrene insulation and start afresh.
3. Once this work has all been done, what adhesive will I need to bond the new plywood to the wooden framing and polystyrene insulation please.
I do hope you guys don't mind me asking such a long and drawn out question with me only just signing up but I didn't know what else to do, YouTube clips aren't very good at explaining in depth or explaining adhesives, thanks in advance.

Sean.

 

[Damian]

Hello and welcome to the forum.
Sorry to hear that you have extensive damp in your van, but it is fixable, just time consuming.

As for the old polystyrene, it depends what condition it is in, but having gone as far as you have it would be sensible to replace with new now, then you know there are no nasty surprises hiding away.
Glue for the wood to aluminium, Gorilla Glue is suitable, and gives good results.
To stick the polystyrene use Soudall Fixall, and the same to fix the inner plywood to the polystyrene.

Don't use any spirit based adhesive as it will dissolve the polystyrene.

 

[SheffSean]

Hello Damian and thanks for your help, the polystyrene is in good condition for its age, not cracked or split, I did think about trying to clean off the residue with a fine flat sanding disc fitted into my Makita battery drill as I've got no access to mains electricity, but if you think it's better to remove the polystyrene I'll do that, just one other question, where can I buy some from, it's 22mm thick, thanks again.

Sean.

 

[Gagakev]

Hi Sean, when I did my repair I got the polystyrene and wall board from Here
Cant find The polystyrene on the web pages so suggest you give them a ring, hope this helps.

 

[Damian]

You should be able to get polystyrene at B&Q in sheet form.

 

[SheffSean]

Many thanks indeed for the help again gents, we'll take a look at B&Q for the insulation, all I seem to be able to find so far is 25mm insulation, if o'learys don't sell 22mm we'll have to renew more than we first intended to, thanks again.

Sean.

 

[SheffSean]

Thanks to GigaKev, after reading this post again I've just discovered that O'Leary's is in East Yorkshire and on the way to where our caravan is in storage, plus at their shop the FC40 sealant/adhesive is only £3.99 a tube so it's a win win situation, plus there's a MKM builders merchants and B&Q in Bridlington for plywood which is only eight miles from our storage site, I've also bought myself a table saw and got my hands on some clean timber so I can rip it down to size, I see light at the end of the tunnel, thanks to all who have helped with information.

Sean.