Hymer B644: Rotten timer under garage floor at rear corner

scotjimland

scotjimland

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Was alerted to this potential problem by Philip, @JeanLuc and only just got round to investigating.. Once I started poking with a screwdriver I found the problem..

It's the rear corner under the garage floor.. which is a sandwich construction.. the timer is the frame..

Have scrapped away most of the soft wood.. but it's still damp, it also looks like woodworm.. :eek:

wondering what's the best way forward.. replacing the timber would be big job.. that would be the best solution.. but was thinking on cutting it back to dry timber and treating then covering over with marine ply.. basically bodge it..

(sensible) suggestions please.. this area is about 9" x 6"
IMG_0116.jpg
 
Sorry you've found some damp Jim
Could you scrape back the rotten bits then fill and smooth with an exterior grade filler?
You could also pre treat with a good wood preservative
 
Sorry to hear you have damp. Years ago we had problems with a caravan and due to moisture the aluminium went white powder on the inside and left pin holes in it. Not know if you have aluminium panels in a hymer, if you do it might be worth looking. Hope it's not to bad of a job.
 
I too can recommend the hardner stuff you paint on rotten wood. It won't restore much strength but it will seal it and stop the rot. Then another bit of ply over the top perhaps?

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I've done a lot of work with glass fibre over the years, it's saved my Burstner. Sort of, cut back to solid timber, dry out ( this took 2 months ) then knit it all together with glass cloth for strength and wood to add needed thickness. All this in pretty tight conditions.
 
I am sure you can repair it once back to good wood but can you eliminate the cause of it?

Pipped at the post by the previous one which came on while I was typing. I wouldn't worry about putting ply over the area it would make a decent strong repair
 
I think the water ingress comes from below .. spray from the rear wheel.. there is no damp on the floor or walls inside.

some good ideas.. thanks

will post as the bodge progresses
 
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If it's spray from the wheels is it worth when fixed looking at spray suppression mud flaps like on trucks. I know fine mist water gets everywhere.

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You should know better Jim Hymer & damp are two words you are not allowed to mention in the same sentence (dam done it again).:)

Doesn't look too serious obviously not been using it enough to get woodworm! As @hilldweller says once dried out should be easy to treat with resin then build up with glass mat and resin.
 
scotjimland said:
I think the water ingress comes from below .. spray from the rear wheel.. there is no damp on the floor or walls inside.

some good ideas.. thanks

will post as the bodge progresses
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I'm sure you'll do a great job of it don't we know :cool:
 
Lenny HB said:
You should know better Jim Hymer & damp are two words you are not allowed to mention in the same sentence (dam done it again).:)
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yes.. I thought it would have had more sarcastic comments.. but it's early days .. :LOL:

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scotjimland said:
I think the water ingress comes from below .. spray from the rear wheel.. there is no damp on the floor or walls inside.

some good ideas.. thanks

will post as the bodge progresses
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Is the floor inside bare wood or does it have some covering. Give it a good press to see if it's spongy.
 
Sorry to hear you have the problem Jim. I would make a booking with Peter Hambilton. He fixed ours by cutting out and replacing the damaged section, then re-sealing it all. You would not know it has been repaired. He will do a first class job and you will have the security of knowing he is a Hymer repair expert. He has a courtesy car that you can use and it will probably be an overnight stop to ensure everything is properly dried and set before you leave. We stayed at a nearby CS the night before taking it in, and at Preston South Premier Inn for the following night which is really cheap if you book on-line well in advance. Preston has interesting history and is worth a visit in my view.
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JeanLuc said:
Sorry to hear you have the problem Jim. I would make a booking with Peter Hambilton. He fixed ours by cutting out and replacing the damaged section, then re-sealing it all. You would not know it has been repaired. He will do a first class job and you will have the security of knowing he is a Hymer repair expert. He has a courtesy car that you can use and it will probably be an overnight stop to ensure everything is properly dried and set before you leave. We stayed at a nearby CS the night before taking it in, and at Preston South Premier Inn for the following night which is really cheap if you book on-line well in advance. Preston has interesting history and is worth a visit in my view.
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Is this something which would be discovered during a damp check? The reason I ask is that Peter performed a damp check for us last summer and the only place that gave a reading that warranted further investigation was the T join on the roof above the drop down bed. Thankfully, it was a relatively quick fix which Peter carried out for us.
 
Boringfrog said:
Is the floor inside bare wood or does it have some covering. Give it a good press to see if it's spongy.
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the floor is a sandwich bonded construction, inside it's covered plywood.. there's no sponginess.. it's solid and sounds solid when you knock it.. having reinspected I'm fairly confident the rot is confined to that corner, it hasn't travelled up the rear or across the back.. and was probably caused by road spray

thanks for advice @JeanLuc I'm sure Peter does a great job,.. but I'm going to repair myself..
 
JeanLuc said:
Sorry to hear you have the problem Jim. I would make a booking with Peter Hambilton. He fixed ours by cutting out and replacing the damaged section, then re-sealing it all. You would not know it has been repaired. He will do a first class job and you will have the security of knowing he is a Hymer repair expert. He has a courtesy car that you can use and it will probably be an overnight stop to ensure everything is properly dried and set before you leave. We stayed at a nearby CS the night before taking it in, and at Preston South Premier Inn for the following night which is really cheap if you book on-line well in advance. Preston has interesting history and is worth a visit in my view.
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@scotjimland. Jim, exactly what @JeanLuc posted above.

We had a similar problem back in 2007/8, and we booked into Peter Hambilton's. According to Peter, ours was due to a Hymer design problem, and affected the S Class and E Class Hymers with the integrated rear bike racks. Peter and his team installed a couple of aluminium mods to redirect water coming off the roof, and also did a smashing repair job timber wise. Being a bit wiser and more informed now, it's a job I would be happy to tackle, but with a bit of help.

Re your situation re splash from the rear tyres, please PM me (as I have to go out), but I'll reply in the morning.

Cheers for now,

Jock. :)

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Fairly common problem I believe, yes P Hambilton does a good job, at a price!, but it's not structural, you can do it yourself by letting a piece in then just make sure you seal / waterproof it, then underseal sprayed on should do the job. Have you checked the other side? probably the same.....
Cheers, Dave(y)
 
Figaro said:
Is this something common to Hymers, should I be getting my prodder out at the weekend ?
PS I don`t have a garage
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I think it's worth keeping an eye on. My previous B544 was showing very early signs of delamination (slight cracks/splintering) when I sold it... I regularly check now...

Regarding a fiberglass repair, it's certainly the route I'd take.
With a generous splash of catalyst, the repair will only take minutes. Use a paddle roller for a smooth finish (y)

*edit* full kit and youtube video here (suspect you could buy what you need for less)
 
Figaro said:
Is this something common to Hymers, should I be getting my prodder out at the weekend ?
PS I don`t have a garage
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Can't honestly say if it's 'common' or not.. or if it's only certain models, but I've heard of several cases on three different models.. The garage is not a common factor.

The areas to check are the underside of the floor behind the rear wheels.. the transverse timber (behind the bumper) and a vertical corner timber.. which join at the corner with the side timber, the one shown in my picture.. get your prodder out..

I believe this damage is caused by road spray from rear wheels, so am going to fit rear mud flaps..

Having considered all the suggestions..
My plan is to remove all the soft wood (mostly done already) then treat with Ronseal We Rot Wood Hardener .. then infill with Ronseal two part epoxy wood filler..

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I'll check at the weekend for signs. I did a visual at last mot when tester allowed me into the pit and all looked good but nothing prodded.
Must admit I hadn't realised there was so much timber used in construction.
I do have mud guards on rear wheels but also a dirt skirt on tow tee bar which may keep some moisture under vehicle ?
 
Figaro said:
Must admit I hadn't realised there was so much timber used in construction.
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was also a bit surprised.. would have been much better if they had used an alloy or steel box section for the framework.. and thicker marine ply on the underside..

in saying that mine is 15 years old.. but not a high millage , so no excuses.. it's poor
 
I had a prod around this evening and all looks solid, couldn`t find any wood apart from the flat sheet decking (plywood ?) used for the lower floor which seemed to have a thick layer of waterproof membrane, so all looks good.
Only rot was on the chassis, particularly the tow bar extensions, so maybe a job to do there sometime.....
 
JeanLuc said:
The timbers need re-treating with stone-chip / weather resistant sealer every couple of years. You can get a Hymer-branded aerosol spray, or nowadays, I use this (as recommended by Peter Hambilton:
http://www.halfords.com/motoring/pa...moval-treatment/hammerite-underbody-seal-2-5l
... make sure you do it on a warm day when the timber is completely dry. It's easy to brush on.
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Yep, that's the one I use too Philip, and as you say, recommended by the man himself. :)

Cheers,

Jock. :)

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