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Water lying on roof – will this be a long term problem?


Westminster14

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Posted

We have recently purchased a new Bessacarr E460, which we are extremely pleased with. There does however seem to be a design fault with the roof. Rain water is left lying on the roof after each day of our beautiful summer – it sits along one edge of the roof, as the drive has a slight slope. The “puddle” never seems to dry out, and I guess is about 1cm deep, as the roof design has a “lip” where the back and front plastic mouldings are sealed to the flat roof.

My concern is that over time, and particularly over winter with water freezing and thawing, this will do some serious damage. Having just lost a considerable amount of value on my old trade-in, due to damp the dealer found – that I didn’t know was present. I don’t want to fall into the same trap again in a few years time.

 

Has anyone else with this design found a similar problem?

 

Any advice on how to tackle this would be appreciated.

I’m due to go back to the dealer in the next few weeks to have a couple of small issues corrected, and will be raising this issue before I go. But any information I can get to further add to the “compliant” I will be making will be of great assistance.

Thanks

 

Posted

Hi

This type of thing isn't uncommon..and I suppose as long as it isn't sitting on any seam or around any skylight/vent, then it may not be a problem...However...I'd just park it up on some wedges(..just enough to cause it to run off)

 

I've made a pair from old bits of scaffold planks(ours are 3 planks thick)and I just leave them in place when we take the van out and they're wide enough to just run back up them without any fuss,when we get home....

 

Edit to add: Although not uncommon for water to stay pooled when parked up, it's also not uncommon for a roof surface to be designed in such a way that means the water is, near as damn it, pretty much "captive" !?...if this is the case with yours I'd be having a word with them about your concerns...not that they'd be an awful lot they could do about it. now..... :-S

Guest JudgeMental
Posted
drive up onto leveling blocks and let it drain...or else you could have problems if sitting on a joint/seam
Posted

First, I think it fair to say this problem exists, to varying degrees, on many motorhomes. Its cause, as you state, is poor design of roof joints.

 

If the "lip" to which you refer is closely examined you may find that it is a (often aluminium) joint cover strip, that is screwed down through the roof covering and the GRP front/rear moulding, where these meet. The cover strip will be bedded on a sealant, and the screw heads probably covered with a flexible plastic strip. It is possible that further sealant has been applied to the screw heads beneath this flexible strip. The screws will (I hope!) be stainless steel, and will be sealed as they pass through the bedding under the joint cover strip. This strip will meet the side-wall to roof junction cover strips at its ends. These, and their junctions, will probably also rely upon sealant for weatherproofing.

 

This system of assembly leaves sealants as the main means of defence against water ingress, and is completely reliant on the conscientiousness of the operative in maintaining an adequate flow of sealant while making the joint. To last, it also depends on the use of first class materials. Fortunately, modern sealants are very good, and have extensive service lives.

 

So, if the job has been well executed with good materials, and no damage to the roof is caused in use, the joint should remain weathertight during the life of the sealant which, depending on what was used, should comfortably exceed 10 years, and may be 20 or more years.

 

So, does your puddle matter? In an ideal world it would not exist and, if it did not, the joint would be given a better chance of remaining weatherproof in the longer term. In my opinion, you are right that its presence is liable to result in the joints leaking before they otherwise would have. I have no proof for this, just that it seems to me logical that something that is intended to be weathertight, but has water more or less continually lapping against it, is likely to fail before a similar feature that only gets wet when it is washed or when it rains.

 

Can you do anything about it? Realistically, if you mean elimination of the puddle, I think no. It is an inherent characteristic of the design. Besides which, if you also examine how the rooflights, and any other roof mounted items, are fixed/sealed, you will find pretty much the same story.

 

Your best bet, IMO, will be one of three things. First, don't keep the van much over five years or, if longer, not far beyond whatever period of water ingress warranty it has. Second, get a winter cover at least for the roof and use it when the van is laid-up. Third, if practical, keep the van under cover of a car port or similar.

 

If you really want complete freedom from this ponding problem, you will need to consider changing your van for one in which the roof is of moulded GRP that laps over the side walls, or one which has flush joints that do not hold back water. Unfortunately most, if not all, vans constructed in these ways are in the upper price bracket.

Posted

Brian

As it's a "New" Bessacarr, wouldn't the main roof panel and any side upstands/ribs (..which overlap the side walls)not all be one piece then?..

 

I would've liked to have thought that the days of designing a roof in such a way that it meant it's seams(if any!) relied on mouldings,screws and mastic, were a thing of the past... :-S

 

I know our previous '07 Compass had a horrible moulding & screw joint on the roof..but the whole build of that was very much in "traditional caravan method"...

I had assumed, wrongly by the sounds of it, that something like a new Bessacarr, would be designed better.... :-S

Posted
From David's description, the roof joints have "lips", which I take to be joint cover strips. I recently looked at the roof of a 2013 Dethleffs, and that had the same. It is, as I said, a very common technique. It suits ease of assembly, but does not favour longevity. "Proper" joints take longer to put together, increasing labour costs. Also, if I allow a bit of cynicism, who (apart from me :-)) looks at the roof when buying?
Posted

I hadn't realised that Brian

 

When ever I see these new vans, with the moulded "fibreglass" upstands/shoulders,I'd always assumed that they were part of a one piece roof panel..

 

I know ours is deemed a budget make..but apart from a seam running across the join between main roof and the low-profile section(which I covered by bonding on a upvc moulding with Sika),there are no other seams...

Posted
Westminster14 - 2013-06-19 4:12 PM

 

We have recently purchased a new Bessacarr E460, which we are extremely pleased with. There does however seem to be a design fault with the roof. Rain water is left lying on the roof after each day of our beautiful summer – it sits along one edge of the roof, as the drive has a slight slope. The “puddle” never seems to dry out, and I guess is about 1cm deep, as the roof design has a “lip” where the back and front plastic mouldings are sealed to the flat roof.

My concern is that over time, and particularly over winter with water freezing and thawing, this will do some serious damage. Having just lost a considerable amount of value on my old trade-in, due to damp the dealer found – that I didn’t know was present. I don’t want to fall into the same trap again in a few years time.

 

Has anyone else with this design found a similar problem? David, you say that this is a new E460 we also had a just over 4 year old one from new, which was found to have serious damp around the floor area which cost us lots of money to put right, however we had no problems with the roof area, I would imagine and would hope that swift have now solved this problem, it was out of warranty for us, however, please ensure that you have annual damp inspections on your van, and ensure that you get documentation on this, I believe that swift now offer a much longer water ingress warranty, enjoy your van.

 

Any advice on how to tackle this would be appreciated.

I’m due to go back to the dealer in the next few weeks to have a couple of small issues corrected, and will be raising this issue before I go. But any information I can get to further add to the “compliant” I will be making will be of great assistance.

Thanks

Posted
As Brian said in his earlier post this is quite a common problem with motorhomes (caravans too). From my point of view the problem with standing water on a roof is the amount of muck that it deposits which can lead to problems.The dealer will probably say "their all like that sir" and then will suggest to park it on ramps which will rid you of the problem of water on the roof but will mean more of the dreaded black streaks :'(
Guest JudgeMental
Posted
rudders - 2013-06-19 10:39 PM

 

Westminster14 - 2013-06-19 4:12 PM

 

We have recently purchased a new Bessacarr E460, which we are extremely pleased with. There does however seem to be a design fault with the roof. Rain water is left lying on the roof after each day of our beautiful summer – it sits along one edge of the roof, as the drive has a slight slope. The “puddle” never seems to dry out, and I guess is about 1cm deep, as the roof design has a “lip” where the back and front plastic mouldings are sealed to the flat roof.

My concern is that over time, and particularly over winter with water freezing and thawing, this will do some serious damage. Having just lost a considerable amount of value on my old trade-in, due to damp the dealer found – that I didn’t know was present. I don’t want to fall into the same trap again in a few years time.

 

Has anyone else with this design found a similar problem? David, you say that this is a new E460 we also had a just over 4 year old one from new, which was found to have serious damp around the floor area which cost us lots of money to put right, however we had no problems with the roof area, I would imagine and would hope that swift have now solved this problem, it was out of warranty for us, however, please ensure that you have annual damp inspections on your van, and ensure that you get documentation on this, I believe that swift now offer a much longer water ingress warranty, enjoy your van.

 

Any advice on how to tackle this would be appreciated.

I’m due to go back to the dealer in the next few weeks to have a couple of small issues corrected, and will be raising this issue before I go. But any information I can get to further add to the “compliant” I will be making will be of great assistance.

Thanks

 

 

Can you enlighten me at what age you needed to lash out on damp repair? seems very odd that you needed to pay yourselves.......but then again it is a Swift. With all the evidence of crappy build with these campers why do people keep buying them I wonder....

 

What I find disgraceful is, this floor problem you had was a widespread problem ( try googling swift

damp issues) be prepared for a long read, and you still had to pay yourself...bizarre!

Posted

In my view the problem with water lying on seams is that of frost, water freezes and the joint opens by a very small amount, repeat this many hundreds (thousands?) of times and even the best seam will fail.

 

There is no reason why the seams on roofs cannot be eliminated, it might cost a bit more but I for one would be happy to pay.

 

I was very impressed with the one-piece monocoque GRP bodywork of the Romahome R40 that I viewed at a show. Yes, GRP has some issues, but to my eyes a motorhome built like a boat hull is the way to go!.

 

Now if Romahome only made a slightly bigger van I could be interested.

 

By the way, an old towel or similar laid over the roof edge will wick up water and take it over the side and lets it drip away.

 

H

Posted
Brian Kirby - 2013-06-19 7:19 PM

 

... Also, if I allow a bit of cynicism, who (apart from me) looks at the roof when buying?

 

Or behind furniture panels, or at the fit and finish of other 'out-of-siters' like plumbing / wiring runs, sealing runs, appliance installation, waste tank bracket work, and other very telling signs.

 

If more people did, fewer poor quality builds would get sold. Slap-dash workmanship is rife, it's one of the main reasons I went DIY.

 

Simple answer to OP is if the water is pooling on a seam where two panels join then yes, it may fail.

 

Also, there are monocoques larger than Romahomes out there and they do make massive sense for anyone looking for a 'keeper'.

Posted
fjmike - 2013-06-19 10:58 PM....................The dealer will probably say "their all like that sir" and then will suggest to park it on ramps which will rid you of the problem of water on the roof but will mean more of the dreaded black streaks :'(

Undoubtedly they will! Problem is, they are probably right on the first point! But, using ramps will not eliminate the lake. Seams that stand proud of the roof become, in effect, small dams. Tilting the van will reduce the volume of the lake, but it cannot eliminate it (at least, it can't unless the van is about 45 degrees to horizontal!). To eliminate the lake, one has to eliminate the dam. Ask the Dambusters! :-)

 

The floor rot problem is another case in point. Wood framed panels joined together on the underside of a vehicle. The floor panel has ply both faces, the wall panel an aluminium outer face and a ply/wallboard inner face. The edge of the floor panel is exposed. Then wheel arches are added, and a largely decorative "skirt" is screwed and stuck to the base of the wall. Fine: water will thus run down the walls, over the skirt, and drip harmlessly away at the bottom.

 

But, when you drive on a wet road there is a malestrom of spray, grit, silt, sometimes salt or other chemicals, that swirls endlessly around the underside of the van at very high speeds and pressures. This mix will penetrate the smallest crevice, and capillary attraction will draw the moisture further in. Once in, it will cause wooden framing to swell. It will take a long time to dry out, especially if parked on damp ground because, once parked, the underside of a van is relatively poorly ventilated. But, as they dry, those wooden frames will shrink back, in the process leaving more gaps for the next lot of water to enter. And so on! So, how to protect it from this process? A coat of bitumenous paint - itself prone to shrink as it ages! Of course the floors suffered damp penetration and the ensuing rot. This is shed construction applied to a vehicle! It is hopelessly inadequete for the job. Yet, it is commonly used.

 

The solution is to sheet the underside of the floor panels with GRP or some other impermeable material, that wraps around the exposed edges. This approach now appears to be being adopted by more and more converters, which is good. One has to ask, though, why it has taken so long to get to this point.

Posted

Thanks everyone for your input.

I have now realised that the lip at the front of the van is much lower - 2 mm probably - so I think the design is supposed to drain off the front .. Unfortunately - I have to pull forward onto my drive - which slopes slightly upwards - hence the puddle sits against the higher lip at the back.. So ramps at the back might help..

I also noticed when I'm parked on the road - slightly down at the front - the water runs nicely off the front moulding - straight down into the drain channel under the window screen - which should go through a little tube out under the front wing - but this has already got clogged with the "muck" off the roof! -so it goes into the engine compartment if it rains heavily. - another well thought out design feature.

 

I'm more inclined to think about a cover, as long as I can pull it tight enough to prevent the water lying on top - the roof lights and aerial should help to create a "tent" - to give some slope..

 

So more expense - perhaps Swift will contribute !!

 

Anyway thanks one again - I will let you know what the dealer says.

Guest JudgeMental
Posted

so you have a joint width ways across the van..now that sounds like bad design....

 

I had a problem with my overcab CB, because I had to drive on to my hardstand nose in, and it was not flat. so water collected where roof rose to overcab section, and would pool and poor over the side. used the leveling ramps and it just run of the back of the camper...but that was a one piece roof with just joints on edge....

Posted

Oh, I see now Westminster' ..I'd got the wrong end of the stick before.

When you said it "sits along the one edge..", I'd wrongly assumed that this lip(seam?)was running from back-front(the full length). :$

 

Using ramps would be my chosen route..although a cap-cover wouldn't hurt if it's going to stay put for a while.

 

Just to add, does the lip at the rear go the full width?...as they do usually stop a little short either end, so as to allow some run off?(..well..ours does anyway..).

 

As your drive is "front-high" ,could you not run the front up some wedges/levellers, so that any crud ran over the back instead of onto the cab/vents/scuttle etc

..or is the rear "lip" a vulnerable seam as well?

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