Damp Prevention

[Jcloughie]

We very much like our 2015 Lunar Clubman and so far it is a dry example. We have considered updating but can’t find a van which suits us more. Also, even if we bought a brand new one. It may be troublesome, I don’t want to face the continual guarantee returns again.

So how do I make sure the van we have stays dry for years to come???

Looking for advice. Should I get a price for removing and re-bedding the awning rails, any roof bars and perhaps the skirt rails.

What do I need to look out for?


John

 

[otherclive]

We very much like our 2015 Lunar Clubman and so far it is a dry example. We have considered updating but can’t find a van which suits us more. Also, even if we bought a brand new one. It may be troublesome, I don’t want to face the continual guarantee returns again.

So how do I make sure the van we have stays dry for years to come???

Looking for advice. Should I get a price for removing and re-bedding the awning rails, any roof bars and perhaps the skirt rails.

What do I need to look out for?


John

At 5 years old it shouldn’t need the rails etc rebeding. I would buy a damp meter and do your own periodic checks supplemented by a professional AWS check at service time and 6 monthly if you feel it gives you more confidence. In my experience damp creeps up on you and if not caught early that’s when it does damage to both van and wallet. I have mine checked 6 monthly and I then do periodic checks with my meter.

 

[Jcloughie]

I am informed that the industry no longer recommend using damp meters. Partly because some new vans have unsuitable construction. But also as miss-readings can occur due to an impervious outer layer. Mine is traditional construction. The last inspection was done visually and by feel. The engineer assured me that this was/is the current advice.

I understand your thoughts on the damp creeping up leading to a large bill, which is exactly why I am looking at prevention. The re-bedding of rail is the obvious thing to do, I am hoping to find out if there is any other precautions I should have done, and/or what to watch out for with those who do the work, is it in the realms of mobile engineers for example.

John

 

[otherclive]

I am informed that the industry no longer recommend using damp meters. Partly because some new vans have unsuitable construction. But also as miss-readings can occur due to an impervious outer layer. Mine is traditional construction. The last inspection was done visually and by feel. The engineer assured me that this was/is the current advice.

I understand your thoughts on the damp creeping up leading to a large bill, which is exactly why I am looking at prevention. The re-bedding of rail is the obvious thing to do, I am hoping to find out if there is any other precautions I should have done, and/or what to watch out for with those who do the work, is it in the realms of mobile engineers for example.

John

It won’t just be awning rail bedding then. What about windows, locker’ door and rooflight seals too, as well as transverse roof joint seals and roof penetrations, running lights etc. There are quite a number of other places and your van being a traditional construction I would not rule out use of a damp meter. The last three times I’ve had damp on vans none were awning rail leaks. In fact I’ve never had an awning rail leak. One a door seal, another a front window seal, the third was two different rear panel cracks and one front panel crack. The panel cracks on two different vans. Whilst I’m no caravan professional none gave any visual or tactile evidence. The panel cracks were found by inspection and the area of damp identified by meter. All the others were found by meter by AWS technicians. But I do accept that the newer caravan construction doesn’t easily lend itself to meter checks, and the vans have the advantage of less permeable materials that don’t rot.

 

[Jcloughie]

It is only on the last service in March that the engineer said about the NCC advice. Up until then a meter had been used. On year 3 a different engineer found a suspected high reading in a cupboard floor. Advice was to keep regular testing. Turned out it was just because the cupboard has been closed up.

Damp Meters are a simple thing and fairly foolproof but only if testing the actual material. Testing through a surface treatment can be an issue. In the case of the floor it was through lino. I don’t know if this is the same thinking as the NCC have used.
I mentioned the roof straps in the OP. Thanks for the other ideas, not too bothered about window seals as they are easy to change if necessary.

John

 

[otherclive]

It is only on the last service in March that the engineer said about the NCC advice. Up until then a meter had been used. On year 3 a different engineer found a suspected high reading in a cupboard floor. Advice was to keep regular testing. Turned out it was just because the cupboard has been closed up.

Damp Meters are a simple thing and fairly foolproof but only if testing the actual material. Testing through a surface treatment can be an issue. In the case of the floor it was through lino. I don’t know if this is the same thinking as the NCC have used.
I mentioned the roof straps in the OP. Thanks for the other ideas, not too bothered about window seals as they are easy to change if necessary.

John

When our van is in store the inside resembles an explosion in a furniture factory. Every thing is opened up, furnishings lifted and seat lockers and slatted bases all open.

 

[Jcloughie]

When our van is in store the inside resembles an explosion in a furniture factory. Every thing is opened up, furnishings lifted and seat lockers and slatted bases all open.

I am normally the same. But on this occasion a small cupboard was left closed over winter by mistake. To make matters worse, this cupboard has no underfloor vent. I did intend to drill a hole in the floor and put vermin proof vents on them but never got round to it. But since then the doors been open.

John

 

[DaveA1]

I leave well alone. My last two Swifts a Corniche 15 years and Challenger 8 years (so far) bone dry.
Had a small split in rear panel and had the the caps fitted, 5 years ago. This was, I thought better, because all that disturbance replacing the panel, could cause more problems than it solved, and the guarantee on new panel's only a year.

 

[Raywood]

With a Lunar you have a wooden fame so the comments on modern construction do not apply and a damp check is needed. It is recommended that you leave all cupboard doors open to let air circulate but beyond that I think there is very little you can do short of a full cover but even that only masks and reduces a problem if one develops.

 

[ProfJohnL]

I with Otherclive on the list of potential problem areas.

Basically its the manmade joints that are the weakest link, and pre-emptive maintenance could make a significant difference to the long term sealing of the caravan.

I am aware of one 1996 caravan from a high end, low volume manufacture where within 6 Months there was corrosion an bubbling showing where the awning rail and other fittings had been fixed to the caravan. After investigation it turned out the rails had insufficient sealant and steel rather than stainless steel screws had been used.

It's things like that which if not picked up quickly that would have lead to significant water ingress and damage after a relatively short time.

 

[Dustydog]

John,
Buy a decent damp meter. There are some good German ones. Make sure you test their readings against a top grade professional one.
If you don’t know where, find out exactly where you need to take readings.
I do not recommend destroying joints for the sake of it. Don’t fix it if it isn’t broken.

An annual damp check by my professional engineer satisfies me. However one area which has been fixed I check more often myself.
I have found from experience damp caught early is not expensive nor a disaster to fix.

 

[Jcloughie]

John,
Buy a decent damp meter. There are some good German ones. Make sure you test their readings against a top grade professional one.
If you don’t know where, find out exactly where you need to take readings.
I do not recommend destroying joints for the sake of it. Don’t fix it if it isn’t broken.

An annual damp check by my professional engineer satisfies me. However one area which has been fixed I check more often myself.
I have found from experience damp caught early is not expensive nor a disaster to fix.

I do admire your confidence in the use of meters in caravan construction. Both from the above and from the other topic about damp readings. But it is something I don’t share I am afraid. I do know it mostly depends on the user, training and use. I used to be involved in teaching the wood trade in assessing different types of timber for joinery and carpentry use. And that is comparatively easy and foolproof in comparrison.

However I am much in favour of keeping a close eye on things.

I feel that re-bedding the rails by a trusted expert should be a lot better than the lottery that is what we get from the factory.

John

 

[Dustydog]

I do admire your confidence in the use of meters in caravan construction. Both from the above and from the other topic about damp readings. But it is something I don’t share I am afraid. I do know it mostly depends on the user, training and use. I used to be involved in teaching the wood trade in assessing different types of timber for joinery and carpentry use. And that is comparatively easy and foolproof in comparrison.

However I am much in favour of keeping a close eye on things.

I feel that re-bedding the rails by a trusted expert should be a lot better than the lottery that is what we get from the factory.

John

John. It’s your money. Resealing an awning rail is no simple nor cheap job. Eg can you salvage and clean up the rail itself? Or will you need a new one if still available? Removing the original sealant is a thankless task. Nothing short of elbow grease removes it. Then on close inspection have you seen how many different sealed joints there are, all windows etc etc. I wish you well.

 

[Jcloughie]

John. It’s your money. Resealing an awning rail is no simple nor cheap job. Eg can you salvage and clean up the rail itself? Or will you need a new one if still available? Removing the original sealant is a thankless task. Nothing short of elbow grease removes it. Then on close inspection have you seen how many different sealed joints there are, all windows etc etc. I wish you well.

I damaged 1 section of the rail a while back. Each side is in 3 sections. I had to have a new one fitted. It was not as much as I expected.

But you have raised a point I had stupidly not thought about. I doubt I can get hold of the older Lunar parts now.

John

 

[Mandarin]

I'm not sure why damp meters came into this when the question was about preventing damp rather than finding it when it's happened.

Personally I'm hoping that using a good quality cover over the winter months will help. I'm working on the basis that keeping joints free of freezing water, the floor dry from water running down the body in the worst of the year has got to help, (it certainly paid off when we had a boat) and so far after 6 years the services have found no damp. And yes the inside also looks like an explosion right now, just like otherclive mentioned.