Lots of damp - where to start

May 20, 2024
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I have just posted on the new member introductions board. We have just bought our first caravan (Bailey Senator Indiana 2006), which is a bit (a lot!) of a project, and needs a lot of work. I want to give this a go, and hopefully learn something along the way. The first (and main) issue is damp. I know there will be a good bit of re-boarding to do, for definite the front around the windows will all need doing, and the along the side where the fixed bed is. I think I want to be belts and braces and make sure I basically re-seal absolutely everything on the caravan, or is this overkill?

Should I start at one end and work my way along re-sealing the outside, then replacing any rotten timber and re-boarding as I go?

One of the things I've been worried about is whether the outer shell will be ok when it has less framework supporting it, like when cabinets are removed and boards and timber are being replaced. I saw someone whose shell looked like it had almost rippled. Will it be ok if I just do the damp repairs a section at a time?

Apologies in advance, as I will probably need talking through each part of the project step by step!
Mar 14, 2005
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Diving into a damp caravan is full of unknowns. Generally speaking by the time dampness becomes visible, it means its been damp for an extended period of time, and is likely to be far more widespread than just the visibly damaged surface. Dampness begets rot, and all the affected material needs to be exposed and the wood and possibly the insulation may need to replaced. The spoors of wet rot can spread further than the dampness, so you need to strip back into the unaffected material.

As to damage to the structure whilst work is underway, that's difficult to predict, as it depends on how much of the framing has been removed to eliminate all signs of the affected material.

There is some sense to work progressively through the caravan, but it might mean having to make purchases in smaller quantities as you discover what's needed, where as exposing the whole job in one go might give you some options for bulk purchases at lower prices.

We are guilty of advising most caravanners to run a mile if a caravan has any history of damp. It certainly make a caravan far less desirable, and that is reflected by what people might be prepared to pay for an afflicted caravan. So its worth putting the rose tinted spectacles down and using head rather than heart to research the possible value of your caravan after it has been repaired.

For some, there is a value to the activity of repairing such a caravan, and they are happy to use it to build practical experience, but that won't what most caravanners are seeking.

Good luck
Jan 20, 2023
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I have been restoring classic cars for 35 years and the one piece of advice I always give to anyone restoring anything that has a “structure” is to work in small areas at a time. Chopping away large areas of anything structural can result in datum points and adjacent areas moving out of alignment. Have a good assessment of the area first and if a lot needs cutting out, add some temporary bracing to keep everything in place as even rotten wood is stronger than no wood. Also take and record lots of measurements at the start and as you progress so you can spot any movement early.
Feb 23, 2024
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Hi and welcome, having worked through galloping damp issues and water ingress on our old 1993 van the first thing I would say is it will take quite some time to work through. Water will even run up seams with capillary action so more often than not the obvious points of ingress are sometimes the easiest points to fix.

I agree with GaryB although water ingress may have been going on for some time the structure of the van could more than likely be ok depending on how wet it has become. Prof may well point out that old vans could easily experience a 'Rapid Unplanned Disassembly' however if you plan on getting it watertight I figure you'll know how sound things are as you progress, or at very least have a good guess how strong it is.

Just for the record our van is now dry and has no obvious signs of water ingress and I didn't strip everything out, I did however start on the inside and work out, which on reflection was a mistake. Yes use a damp meter and find the worst areas note the readings to see improvements - but start outside.

If I was doing another van again I would start by sealing anything and everything outside where there is a gap, places where the roof meets the walls, look for any areas where there has been bonding or in our case riveting and clean out and re-seal all those areas with good quality sealant such as sikaflex etc. Next look at the window seals, door seals and make sure they are all good, I found that some of the latches had shifted so although the rubbers were good the window wasn't tight enough to seal the gap.

I know all the 'pros' would say take every skin off and re-seal them properly but I only have a driveway and no barn to store a van in otherwise I would have stripped all the skins off. We mear mortals have to work with what we have.

One last thing I noticed was that although some spots were wet inside when I fixed the leak they dried out and registered low on my damp meter, which to me was a saving as I didn't need to spend money on more ply board etc.

Lastly I have settled on the opinion that I have an old caravan I paid less than £600 for it and have had more than a good few grands worth of holidays out of it. Yes it will probably leak again but I have learnt loads in understanding how to trace the leaks and fix them, that is invaluable knowledge. Plus the van is all working and looking great, a proper home from home.

Tracing leaks is super frustrating at times and like pushing water uphill but you either grab the nettle or step away, it's almost a part of owning an old van, it will leak and you will fix it, it will be dry and then inevitably it will leak again. Even new vans leak so in more ways than one it's part of caravaning - nature will always win in the end.

Enjoy the ride
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Reactions: toad a caravan
Jul 18, 2017
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If you start sealing before removing the damp, you could be trapping the damp inside for it to cause further damage at a later date?
Feb 23, 2024
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It's a fair point well made. I kept all the windows on vent and used a dehumidifier and it's been fine, but then again I did already remove the areas with mould spores. So yeh you're right for sure on that score - sorry for any confusion
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Reactions: Buckman
Sep 23, 2023
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You may have difficulties removing cupboards etc as some are fasten from the outside in IE from aluminium side..I have used ID 99 bitumastic sealer on my awning rails etc as it remains semi set.If you are removing wallboard and the window seals this may show what condition the timber frame is in.