A rather large damp repair project (1 Viewer)

[olsgreen]

A brief(ish) summary of the story so far...

We bought a 2007 Hobby Toskana 650 GFLC privately in October just gone to live in full time. We love the layout, size and spec of the vehicle it's perfect for us! It's also plated at 3850Kg which gave us decent payload (cheaper road tax ), I'm a young'un so I did my medical & sat my C1 test within a few weeks to drive it.

I did some research on buying motorhomes (looking back on it no way near enough - but hey hind sight is a great thing), learnt a little about habitation checks, damp and a plethora of other points. We checked the vehicle mechanically, test drove it and had a poke around for damp. There was no damp smell as I've experienced before in other older motorhomes that have/had problems and it looked relatively tidy (no visible mould or mildew), no obvious water stains except one in the headlining of the cab that we raised and were happy with (at the time - now alarm bells would be ringing). We agreed to purchase subject to a Combi & fridge service, waste handle repair and habcheck, we paid a small deposit.

A few days later the owner contacted us saying that the the guys he usually uses to do the checks and for repairs are fully booked until November and he couldn't get anywhere to get the bits done before we pickup the vehicle, at the time, we had plans to goto Spain for the end of October and had planned to meet friends there. He proposed that he'd give us a discount for the remedial work, service, etc, so we (very stupidly) agreed and picked up the vehicle as he was going away on business. As I hadn't got my C1, he drove us home via a weigh bridge (our plan was to temporarily down-plate it) it weighed 3300kg so I just expedited the C1.

Fast forward a few weeks to the start of November, C1 passed and we've decided to delay Spain and go on a shake down run over to (rainy) Wales and see family. We had a great time, wild camping on the way over and found a nice spot in Carmarthenshire on the coast. We wake up on morning to find water dripping from the ceiling light over the table. It had pooled overnight on the table, ruined my new Mac Book Pro (I write computer software for a living), damaged other stuff, luckily our phones are waterproof! We were recommended a firm (Balmoral Motor Homes) back down towards Cardiff who kindly got us in and temporarily fixed the leak on the same day (thanks guys - saved our bacon on that day ?) We were advised of a rather extensive list of problems and some 'oddities' (which I'll touch on later), they ran a damp meter round the unit, let's just say it was painful. There were more 30%+ readings than you could shake a stick at, peaking at a full house of 100%. After a chat, a ring around and realising that we were looking at unfathomable figures to get professionals involved, we opted to have the roof resealed and made right and carry out the internal works ourselves. So we booked in within them a few weeks later and the resealed large parts of the roof that had long been neglected (again, stupidly, we hadn't properly checked the roof before purchase - knowing what I know now, we should have been up on ladders!).

We have agreed to house sit from January until April in Suffolk in which time I am planning to carry out the internal and external works myself. I've got a barn to put her in, dry her out and refit where necessary.

Started this thread as a progress report, have been greatly inspired by the following other threads on damp repairs, all of differing levels, age vans, desired finishes and all sorts.

@The_Kraken - My DIY damp repair project
Peter Waller - Replacing rotten flooring on Hobby 750 fmse 2001
scootir706 - Damp repairs started !!
scandude - Total newbie in need of MASSIVE help.
Wildbill - Project camper sorting out a damp

Relative newbie, I'm looking for advice & encouragement, definitely not a motorhome expert, but capable and willing to learn!

 

[olsgreen]

As I mentioned in the previous post, we've had large parts of the roof resealed. It's hard to tell whether it's still leaking at all as the plastic & foam covered headlining makes it near impossible for things to dry out on their own. So I'm taking it all off and will recover the ceiling.

We have four main areas of damp so far to my knowledge:

- Overhead cab/hab join + poorly fitted 4G/WiFi/GPS antenna
- Both wall areas behind the cab/hab joining rails & around windows
- Overhead area over the bed / kitchen (awning rails maybe?)
- Garage wall closest to the large hatch (possibly caused by seals as they seam quite common?)

The plan is to strip the interior down to the wall panels (or delicately to the frame if the panels are visibly damaged / have high readings) from front to back and asses from there, I've started and what I've uncovered is not pleasant viewing...

Past owners have obviously not dealt with progressing issues, completely obscured them from view by fitting new cupboards, lights and even just wallpapered over the visible areas. These are tell tail signs I suppose, shame I missed them!

Before and after shots front of areas... a submarine would probably have less damp than we have at the moment. I'm preparing for rot under the lower mid sections, nearer the floor seems drier which is a bonus.

 

[Gaston aires]

Best of luck with this one matey. Hope it goes well.
From one Suffolk to another.
Phil

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[68c]

Do not panic, if you are a halfway reasonable DIY guy you can sort this.

I had similar with a 1998 Swift Sundance, even had water dripping out of the roof fluorescent lights.
Get a tarpaulin or a top half cover on it first. Work when it is not raining.
Get a 240v dehumidifier, blank off the fridge grills etc and keep emptying the dehumidifier catch tank.
Remove all the internal furniture, you will be surprised how little holds these vans together.
Remove all skylights, tv aerials, solar panels, roof racks, roof boxes etc.
Tear down the ceiling wall board, support structure and foam insulation.
In my case it had an thin alloy roof, after cleaning off all corrosion it looked like the night sky from inside!
Treat corrosion and seal holes with thick self adhesive alloy tape.
Paint inside of roof skin.
Rebuild the ceiling, this means glueing the replacement 3mm plywood to the alloy skin, use an impact adhesive as an air drying adhesive will not go off, use lots of battens and pit props to hold in place overnight.
Rebuild the wooden roof structure, the rough treated timber used when tiling a house works, use an external wood glue with another round of pit props.
Cut blocks of 'celotex' insulation to fit and again use impact adhesive, the celotex foam insulation has a plastic covrring so will not disolve with the glue.
Purchase proper 3mm caravan wallboading with the pattern of your choice and again glue into position, with ....yes, more pit props.
Seal gaps between and around wallboard with silicon sealer.
Refit the furniture.
I took the opportunity to fit larger skylights.
For the walls poke around and identify any rotten wall board and support structure, similar repair, unlikely to be as bad as the roof.
Finally cover the roof with a 2 part EDPM rubber solution seal, designed for motorhome roofs.
Took a few months but can be done.

 

[StitchesnFluff]

You sound as though you’ve got over the worst feelings of discovering this...
you will know your van inside and out by the time you've finished. I hope all goes well

 

[Wildbill]

Good luck with your project as far as i know the van i done is still ruining and the guy is full timing in it with no damp issues just take yore time and it will turn out ok
bill

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[olsgreen]

gillnphil Thanks, I need it!

68c Tips appreciated, it looks like mines got the current polystyrene insulation bonded directly to the aluminium roof and side walls, with the 3mm wallboard bonded to that. (haven't taken down a full panel yet as I need to move it a few miles down the road and don't want to undermine the integrity too much before I do)

StitchesnFluff Yeah, I'm over the worst of it. Stripping out the furniture so I can start seeing the extent of the problem is helping. I'm learning tons regarding the construction methods, I'm finding it really interesting stuff, just time consuming!

Wildbill Cheers Bill, good to hear

 

[olsgreen]

Slow one today, I got hung up trying to remove the cupboards above the kitchen and had to go shopping for an angled screwdriver to get at some interestingly positioned screws. Once I had removed the cupboards I was met with more damaged roof panel. Finding this has cemented the decision to remove everything on the roof and reseal the lot.

Also, started removing the bench under which the fresh water tanks sits, another fiddly one as it's hard to get to certain screws to remove the surround due to the tank being in the way, but you can't move the tank without removing the surround! Got there in the end though.

So tomorrow I'm draining her down, removing the water tank and Gaslow system before starting on on the kitchen unit.

Some shots of the damage found above the kitchen cupboards, the boards are in a pretty bad state, de-laminated ply and water damaged padded vinyl...

 

[Figaro]

That looks like quite a project.
Take it steady and you`ll get there

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[rangi]

Softly softly catchee monkey

 

[Riverbankannie]

It seems like you have the ability and, more to the point, the time and nice space inside a barn to get this sorted.
Wishing you well and looking forward to your progress.
I wish we could virtually talk to every MH buyer before they buy but sadly there will always be stories like yours and I’m just happy for you that you have an opportunity to sort it.

 

[68c]

Yes, looks very like my van. You have to try to imagine how they built the van.
Probably made each wall separately, A wooden frame bonded to the outer skin, polystyrene insulation and 3mm wall board inside. Then the screwed them into a box shape and added the roof structure, in my case an outer plain 3mm ply, the frame and insulation and finally the ceiling 3mm wall board. The alloy skin then laid on top, bent over the sides and secured with the alloy trim strip.
Of course that means many of the assembly screws are now inaccessible. In my case much of the top edge wooden structure was so rotten it pulled away in my hands, you could see the corroded alloy trim screws sticking through. Once I had removed all the rot I wondered if it was worth continuing. After a long think I realised the van was worth nothing now, maybe I could realise a few hundred pounds by scrapping it but thought that too much effort for little return.
So, I bit the bullet, went to my local B&Q looked at the rough cut treated timber, and sheets of polystyrene.
I ordered wall board, taking the opportunity to change to white textured board rather than the 1990s beige.
I removed the rusted alloy trim screws and glued in the wooden frame, originally the roof frame sat on top of the wall frames, as the alloy skin was left in place I screwed the new roof frame to the side of wider top sections of the wall. This was when I made the frame to suit the new larger roof skylights, it also got round a section of corroded alloy skin . Then I glued in the polystyrene, mistake, the No-nails would not dry, took it all out and tried evo stick, it melted! That was when I tried the 25mm celotex insulation, used spray contact adhesive, worked well. I used odd sheets of 12mm ply offcut with pit props and weights on the roof to get it to bond. Then I ran in all the wires for the lights and glued up the ceiling wallboard, used wood glue on the frames and spray adhesive on the celotex and back up with the pit props etc. I had two areas of the wall with rotten wallboard and frame, much the same approach, to clamp up the new side frame parts I built a frame of 4x2 timber around the van, wedged it tight against the outside skin the used pit props sideways to secure it. New wall board attached in the same way. Our rear longe bed was only 4ft wide to I altered the furniture to get a 4ft 6 bed, a set of second hand caravan seat cushions and all well. Once finished we ended up with a pretty and more comfortable van. So will you.

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[Captain Yoghurtpot]

As I mentioned in the previous post, we've had large parts of the roof resealed. It's hard to tell whether it's still leaking at all as the plastic & foam covered headlining makes it near impossible for things to dry out on their own. So I'm taking it all off and will recover the ceiling.

We have four main areas of damp so far to my knowledge:

- Overhead cab/hab join + poorly fitted 4G/WiFi/GPS antenna
- Both wall areas behind the cab/hab joining rails & around windows
- Overhead area over the bed / kitchen (awning rails maybe?)
- Garage wall closest to the large hatch (possibly caused by seals as they seam quite common?)

The plan is to strip the interior down to the wall panels (or delicately to the frame if the panels are visibly damaged / have high readings) from front to back and asses from there, I've started and what I've uncovered is not pleasant viewing...

Past owners have obviously not dealt with progressing issues, completely obscured them from view by fitting new cupboards, lights and even just wallpapered over the visible areas. These are tell tail signs I suppose, shame I missed them!

Before and after shots front of areas... a submarine would probably have less damp than we have at the moment. I'm preparing for rot under the lower mid sections, nearer the floor seems drier which is a bonus.

View attachment 356072
View attachment 356073
View attachment 356074
View attachment 356075

Good luck with your repairs.
May I ask where you got the damp meter from please.
Thanks

 

[Baldeagle7470]

Just read this and totally admire your tenacity and ability to repair what must have initially appeared a daunting and never ending task.Sure you will have a lovely dry fresher looking van and put the start behind you and enjoy many miles and smiles.

 

[olsgreen]

Thanks Riverbankannie, Baldeagle7470, rangitira & Figaro

Good luck with your repairs.
May I ask where you got the damp meter from please.
Thanks

It's from RS Components, great company that I've used for most things electrical for years. The one I've got is the RS-128M, they do a range from around £30 up to £1000+.

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[The_Kraken]

Hi Olsgreen. The worst bit us over. Coming to terms with the fact that someone had one over you and how bad it seemed at first were difficult for me. Once I’d levelled those thoughts and made the decision to have a go myself all I had to do then was to keep telling myself that I could do it. Once you start ripping out all the bad parts the tide starts to turn and you begin to get a sense of achievement.

There’s a wealth of knowledge on this forum alone. If you need any help, just ask. To be honest though, it looks like you’ve got a good handle on it. Please keep posting updates. You’ll be surprised just how many will be looking in.

 

[olsgreen]

Time for an update! It's been a slow old slog removing internal fixtures, bagging and tagging the fixings but I'm getting there!

I've stripped back a channel along the bottom of the driver side wall and the cab/hab joining rail to assess how far the water has got (turns out a long way). The entire rail has been leaking badly (as well as the antenna above it), the water has run down the join and sat along the main horizontal floor timber (which was wet but thankfully not rotten). Also, started cutting down the horizontal ceiling and wall supports to try and find some good wood!

The outside joining rail removed:

The rail is screwed in from inside and held in place with a 30mm ply strip, this was so badly rotten and damp it disintegrated into small bits during removal.

Removing the leaky antenna, roof rack rail & cab/hab joining bar:

The vehicle has clearly had work on this side, except whoever put it back together didn't take the time or couldn't level/line things up! The GRP fairing / aluminium roof joint has about 10mm height difference on the drivers side, that was filled with sealant. I've checked the lower half of the vehicle is square, roof strike on this side at some point?

As it's going to be another nice day today I'm going to finish cleaning the sealant from the surfaces and get the roof and moulding lined up properly ready to rebuild the internal structure.

 

[Riverbankannie]

Wow thats some job. Hope it stays dry for you even if its a bit chilly !

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[Simon Select]

Unfortunately some vans can get problems. I owned a Hobby 750 once. I loved the layout.
Unfortunately (A quick damp check and everything was fine) Within 6 months I discovered all the lockers were rotting, the aluminium was corroding etc. At the time all was fine damp ok. Its amazing what some people can do with a de-humidifier! I am sure the vans are fine but it did put me off Hobby!

 

[Lenny HB]

You are doing a sterling job, well done.
A bit of advice, you may already know. When refitting the internal wall panels make sure you brace the outside of the wall as well or you will end up with a curved wall. (Guess how I know).

 

[olsgreen]

Unfortunately some vans can get problems. I owned a Hobby 750 once. I loved the layout.
Unfortunately (A quick damp check and everything was fine) Within 6 months I discovered all the lockers were rotting, the aluminium was corroding etc. At the time all was fine damp ok. Its amazing what some people can do with a de-humidifier! I am sure the vans are fine but it did put me off Hobby!

I think this is down to neglect, people cutting holes in stupid places and repairs being done incorrectly. I've found a fair few 750 projects while researching, mind you every manufacturer seems to have 'ballsed' up one or more models in the design department somehow....

You are doing a sterling job, well done.
A bit of advice, you may already know. When refitting the internal wall panels make sure you brace the outside of the wall as well or you will end up with a curved wall. (Guess how I know).

Lenny HB Good job the walls on my van are curved already! (No joke, they are curved by design ?) What adhesive did you use for the polystyrene/aluminium bond and also for the polystyrene/ply wood bond? I'm assessing my options at the moment... I'm even considering not stripping all of the non-damaged polystyrene from the walls to leave a tiny bit of strength, levelling and bonding the new ply back to that using PU adhesive. Thinking out loud... haven't finished the research yet.

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[Lenny HB]

I think this is down to neglect, people cutting holes in stupid places and repairs being done incorrectly. I've found a fair few 750 projects while researching, mind you every manufacturer seems to have 'ballsed' up one or more models in the design department somehow....



Lenny HB Good job the walls on my van are curved already! (No joke, they are curved by design ?) What adhesive did you use for the polystyrene/aluminium bond and also for the polystyrene/ply wood bond? I'm assessing my options at the moment... I'm even considering not stripping all of the non-damaged polystyrene from the walls to leave a tiny bit of strength, levelling and bonding the new ply back to that using PU adhesive. Thinking out loud... haven't finished the research yet.

It was a caravan I repaired 20 years ago I used a grp resin boat resin "West system" I think you would be better using the correct adhesive for the job sorry I can't help further.

 

[The_Kraken]

I think this is down to neglect, people cutting holes in stupid places and repairs being done incorrectly. I've found a fair few 750 projects while researching, mind you every manufacturer seems to have 'ballsed' up one or more models in the design department somehow....



Lenny HB Good job the walls on my van are curved already! (No joke, they are curved by design ?) What adhesive did you use for the polystyrene/aluminium bond and also for the polystyrene/ply wood bond? I'm assessing my options at the moment... I'm even considering not stripping all of the non-damaged polystyrene from the walls to leave a tiny bit of strength, levelling and bonding the new ply back to that using PU adhesive. Thinking out loud... haven't finished the research yet.

you should use wallboard adhesive to bond the plywood to the polystyrene.

 

[olsgreen]

The_Kraken ? Funnily enough, I decided on this PU insulation adhesive last night.

PU Adhesive Insu-Stix for Insulation Boards - 6.2kg Tub | Insulation Superstore®

PU Adhesive Insu-Stix for Insulation Boards - 6.2kg Tub (INSUSTIX/6.2). Order Helpline ☎ 01752 692 206

www.insulationsuperstore.co.uk

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[olsgreen]

I cleaned up one of the cab/hab joining rail areas yesterday using some 'No nonsense' sealant remover from Screwfix. It's damn good stuff, I would highly recommend for anyone looking to remove the remainder of any non-setting sealant or Sikaflex type adhesive.

No Nonsense Sealant Remover 100ml - Screwfix

Order online at Screwfix.com. Effective gel formulation for the removal of cured acrylic and silicone sealant residue. Works on a range of non-porous surfaces. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

 

[olsgreen]

Long overdue update, hope everyone's safe and well!

With all of this sunny weather and the 'lock down' in place, I've had more time to crack on.

Finished cleaning the cab/hab jointing area and painted ready for the new jointing bar to be bonded over it which has just turned up.

I've stripped all of the old board, insulation and glue from the first roof section leaving just the thin aluminium skin. Warning to others, even after 6 weeks with a heater and dehumidifier on 24/7 the deeper insulation was still very wet.

I've also cut out all of the rotten structural wood and replaced it with hard wood. Owing to the current circumstances I was unable to get treated. (Note that it was placed in the photo not screwed and bonded so there are a few gaps!)

Before bonding the new insulation I painted the skin with metal primer to protect it and provide a good surface for the new contact adhesive to bond to.

I decided to replace the insulation like for like, in my case 30mm EPS (Expanded Polystyrene). I did think about using Kingspan or Celotex, but was concerned about using a completely different material with different properties for no massive gain.

The insulation was bonded into place with some contact adhesive (Reactacure 1835) recommended to me by Glues Direct that has a low solvent attack on EPS insulation. I'd highly recommend these guys, very helpful and knowledgable as what to use to bond various substrates.

Aluminium plates (0.75mm) were also bonded into place to provide reinforced hang points for the cupboards that will be mounted there.

Finally, I re-boarded the section using 3.6mm birch ply bonded using the same contact adhesive as the insulation. You can see below that I have also added a wiring channel just behind the support member so I can run cables from one side of the motorhome to the other, the holes will be in cupboards.

I've remade the side cab/hab jointing rail supports (curved wood on the right hand side of the second photo) out of sections of 12mm & 18mm ply bonded together as the manufacturer did. I scribed round the joining rails and added some for good measure.

I've followed the same stripping/painting process for the N/S wall and reinstalled the joining rails with Sikaflex 512. By the looks of it, they've failed multiple times using non-setting bedding sealant so after speaking with multiple technical departments of the sealant / adhesive manufacturers I decided to go with this option.

The forward forward boards above the cab area have been replaced as they were also partly rotten... I'm painting the ceiling with bright white emulsion, I think it will look quite nice, it'll also work out much cheaper than using m/h roofing board and will allow me to blend existing ply that's ok

Chipping away at the project, it's definitely larger than I initially thought. I have some days working on it when things don't go to plan and I must say I find my self thinking about sending it to the scrap heap! Other days I make great progress and get a really good feeling. More over I keep on telling myself it will be worth it!

Aiming to get her water tight over the next week, reinstalling windows roof joining bars, covering screw holes and sealing the roof! Fingers crossed the fine weather holds ?

 

[ambulancekidd]

Your certainly making hay whilst the sun shines, excellent progress, looks really great.

In some ways the lockdown is a blessing, I've got loads done in our old motorhome that I wouldn't have managed to do while using her.

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[Raul]

Excellent work, keep it up and you will enjoy it. You come sooo far and put so much effort, there is only one way for you: forwards. Forget about scraping. You will appreciate all this later and you will be rest assured the job is a 100%.

 

[Riverbankannie]

Great job.

Can I have those bags of compost when you have finished with them for weights? All the garden centres here closed, not that I can go out!

 

[lunarman]

Great job.

Can I have those bags of compost when you have finished with them for weights? All the garden centres here closed, not that I can go out!

Annie,

If you phone Almondsbury garden centre you can order and they will deliver.

John

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