# Damp floor repair techniques



## the49er

I have an 06 bessacarr e425 with a bad case of floor rot under the van to the rear and one side in particular. So far I have spoken to two repairers and each have said they would tackle the job in a very different way. Repairer1 says he would tackle it from inside the van by taking off any furniture attached to the floor in the rear section then cutting the top floor out to get to the bottom rot. Repairer2 tells me he would tackle the job from underneath the van, so an outside job. Two seemingly opposite approaches. It made me wonder if both approaches are used depending basically on individual preference or if there tends to be one that is an industry standard? Taking the top floor out to get at the bottom seems a bit drastic but what do I know. I can also see how trying to re-board while working underneath might also be rather restrictive. My reason for asking is in case one of the two methods selected might scream 'amateur alert. Dont let this person lose on your van'!:surprise: Has anyone any thoughts on this please?


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## trek

Do they both agree on the source of the water ingress ?


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## Mrplodd

Do you have a single or double floor? 

If a single floor then my view (no expert) would be that it is essential,to,remove the internal fittings in order to expose the area of floor that needs to be replaced. It’s difficult to see how you could do that, from underneath, with the fittings in place. By doing that my view would be there is a risk to the internal fittings being damaged when cutting the floor from beneath.

If it’s a double floor (2 floors separated by air air gap) then if it’s only the bottom one that’s affected it makes sense to tackle it from underneath and not damage the integrity of the top one.

To add to Trek’s comment the FIRST thing that’s needed is to identify, and rectify the leak that has caused this problem.

Andy


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## trek

Both myself and MrPlodd replied on this thread i can only assume our comments were lost during the site outage

Anyway i think i asked :- have either workshop or yourself identified the source or the leak 


And then MrPlodd added the following 

Here is the message that has just been posted:
***************
Do you have a single or double floor? 

If a single floor then my view (no expert) would be that it is essential,to,remove the internal fittings in order to expose the area of floor that needs to be replaced. It’s difficult to see how you could do that, from underneath, with the fittings in place. By doing that my view would be there is a risk to the internal fittings being damaged when cutting the floor from beneath.

If it’s a double floor (2 floors separated by air air gap) then if it’s only the bottom one that’s affected it makes sense to tackle it from underneath and not damage the integrity of the top one.

To add to Trek’s comment the FIRST thing that’s needed is to identify, and rectify the leak that has caused this problem.

Andy
***************


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## trek

Ah hah ! previous posts are back


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## the49er

Hello trek and Mrplodd. 
Thanks for taking time to respond to my post. The rot has occurred because of a wonderful idea that Swift had on some models around the time mine was produced. Its a double floor and the manufacturer decided to use a plasticised type of material to laminate over the entire bottom of the lower floor. I'm guessing they thought this would make it impregnable to water, except it wasn't. I think the idea might have worked had they thought more about how the edges could also be sealed, but they didnt. The consequence was that water crept between the black plastic material and the lower floor boarding and sat there unseen, and it sat and sat and sat, with no way to evaporate. The boards, immersed constantly in water, simply began to rot away. I only noticed because at the time my brother had a similar van that had rot in one corner and that caused me to double check. What i thought was a good floor covered in a waterproof membrane was in fact spongy. When i cut through the fabric the trapped water poured out. i've done a check on the van ceiling and walls with a decent meter and all seems fine. There is some creep in one corner where the underfloor is most rotten up onto the top floor but it is limited. Both prospective repairers have seen the problem and know how it has been caused.


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## Charisma

Hi. Sorry to hear about this. I had a similar problem back in 2008 and if you want to read about it (long thread) its here http://forums.motorhomefacts.com/65-swift-motorhomes/36103-rotten-floor-2005-swift-suntor-590pr.html

Back then, the rotten floors were a huge issue for Swift and many vans were sent back to the factory for repair free of charge, although Swift did not issue a recall. I think that they did contact dealers about the cause which turned out to be a lack of sealant on the side skirts allowing water to get into the gap between the plastic sheet on the underside of the floor which had been fitted to protect the floor from road spray but in fact trapped water between it and the plywood underneath.

Swift repaired my floor from underneath by removing all the damp wood and then repairing the insulation and glueing on a new plywood sheet floor. The plastic sheeting was all removed and the replaced timber floor painted a black colour. Oh and the side skirts were removed and sealed to the side of the van walls.

First thing to check is if there is a black plastic sheet still under the van. If so then it has never been repaired before, but if it is just plywood painted black, then it may have been repaired once already by Swift. If it has been repaired previously by Swift, there may be some benefit in calling them for advice.

I am happy to help with any other questions you might have.


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## Charisma

the49er said:


> What i thought was a good floor covered in a waterproof membrane was in fact spongy. When i cut through the fabric the trapped water poured out. i've done a check on the van ceiling and walls with a decent meter and all seems fine. There is some creep in one corner where the underfloor is most rotten up onto the top floor but it is limited. Both prospective repairers have seen the problem and know how it has been caused.


Ha! We seem to have cross posted. I can only assume that your van has been kept under cover for most of its life. You seem to have spoken to people who are aware of the problem so I suggest you go with who you trust the most to do a good job. I suspect the underneath fix will be cheaper than removing all the furniture and doing an inside repair. As long as the floor inside is not damp then replacing the underside plywood skin and sealing the side skirts would be my choice.


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## the49er

Thanks Charisma. It definitely still had the plastic sheathing so hadn't been touched though i've removed most of it myself now. The van was already 6years old when we bought it but had a very low mileage. I'm resigned to having to spend on a repair job as my wife loves the van and is prepared for the expense. I'll put it down to one of life's learning experiences!! I just have to make a decision between people who have suggested two very different approaches. Interesting that you mention Swift repaired your floor from underneath.


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## Mrplodd

As it’s a double floor I would be inclined to go with the repairer who say they will effect the repair from underneath, but ONLY if the “upper” floor is damp free.

My reasoning being there is no sense in having to pay someone to remove the internal fittings, cut out a section of (perfectly serviceable) top floor, effect a repair to the bottom floor, THEN have to repair the (unnecessary?) damage done to the top floor, and then refit all the internal fittings. 

By attacking the problem from underneath “all” that needs doing is to cut out the rotten section and replace it. No impact on the top flooring and no requirement to remove internal fittings. Much less time involved, so therefore much less labour charge. But you need to be 100% certain that the top floor is damp free. 

Well that’s my reasoning anyway.

As it is a VERY well known issue with that particular MH it might just be worth contacting Swift and seeing if they will make some contribution towards the cost, particularly as your vehicle clearly was not returned to them earlier in its life despite the fact they were clearly well aware of the inherent defect present in the entire range at that time. 

The very worst is they say no and they might just say yes.

Andy


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## Charisma

As far as I am aware, Swift never used a double floor on these vans. It was just a sandwich of insulation with a layer of plywood top and bottom. The top layer was then covered in a vinyl flooring sheet and the underside with a plastic sheet for so called protection. Swift changed their view on this in later vans and did not fit the underside plastic sheet.

I suspect that this van was stored under cover in the first 6 years of its life and if a low mileage was only used in dry weather. As the water ingress was between the lower plywood and the plastic sheet cover it would seem unlikely that there would be much damp on the top surface. There may be some damp which has seeped up into the wall boards though which could spread into the top of the floor. I would get a thorough damp test done and see what readings you get inside. If they are high but the wood is still sound then maybe it could be dried out without replacing it.

The underneath plywood on my van had rotted completely and was leterally falling away from the insulation in handfulls soaked in water. You could squeeze water out of the wood! On my van Swift replaced about 50cms width of plywood on both sides and across the rear as that is how far the damp had spread. I hope that yours is not that bad, but sealing the side skirts is essential to eliminating the cause.


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## Pudsey_Bear

I can't help more than to remind that David David did a YouTube video of his Hobby floor repair in quite a lot of detail DIY, and that it may be a good ide to join swift talk as there might be a few comments on there if allowed.

https://www.swift-talk.co.uk/


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## Pudsey_Bear

David-David floor repair video, there are three parts.


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## Devonboy

As others have said, the repair technique will depend on the location & severity of the damage. I am guessing your floor is of a sandwich construction. IF the water has not passed through the insulation into the upper layer then a repair from underneath would probably be the better option. But this will depend on the area to be repaired. If the area is large then cross-members & supports under the van will cause problems especially if you need to add a large piece of flooring. Does the floor inside the van feel spongy under foot? This would be a good indicator of upper layer problems.

The problems with floor repairs is that when the vans are built, the floor is the first fitting followed by all the furniture so backwards engineering can be a challenge.

I do sympathize with your situation, we had to make the same decisions some years ago on an AutoSleeper Luxor A class, which had a similar floor construction. We decided to keep the van & spend the money on repairing the floor. Not a decision taken lightly as we ended up with the entire interior removed & a new floor fitted, followed by re-fitting the interior. As I said not a decision taken lightly. To be fair the repaired floor was far better than the original & will probably last for many years.


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## Mrplodd

Slightly off topic, The first thing I did with my Bailey was to give the underside, particularly in the corners (which apparently is where, IF they get a problem, Baileys of that age suffer water ingress into the floor) 5 or six coats of Creokote (it’s a modern version of Creosote) wood preservative. It’s messy smelly stuff BUT it is a brilliant preservative, it’s oil based and really soaks into the plywood, thus preventing water from doing the same and causing rot. 

Time will tell IF I keep the caravan long enough of course, but a few hours work COULD end up saving me a lot of grief (and expenditure!) 

Andy


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