# Metal roof 'floor' needs sealing



## daddysgirl (May 31, 2008)

Hello all wise ones!

I've been looking through the threads here trying to find answers without bothering you all, but can't find exactly what i need.

I'm sure the ceiling of my 1992 knaus was completely unmarked when dad first got the van, but now there are two small damp patches on the ceiling. 

She has a metal sheet on the roof for standing on and while I was up there cleaning the roof I noticed that all but about 6" of the sealant (which I guess was all round the panel) has disappeared, so we need to reseal it. I've seen various sealants recommended here, but am not sure which would be best. I think the metal sheet expands when it's in the sun, so presumably the sealant needs to be pretty flexible?

Many thanks, Dee


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## brillopad (Mar 4, 2008)

no contest, sikaflex 512 about £7.95 a tube and thats why its the best, just ordered 6 tubes from world of tents, its the cheapest i could find. dennis


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## daddysgirl (May 31, 2008)

Thank you!!

D


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## time-traveller (Apr 23, 2007)

daddysgirl said:


> Hello all wise ones!
> 
> I've been looking through the threads here trying to find answers without bothering you all, but can't find exactly what i need.
> 
> ...


I think those damp patches need investigating. The metal tread panels on the roof don't contribute to rain water sealing - the missing sealant that has 'disappeared' is likely to be adhesive sticking the panel to the roof proper. And it needs investigating NOW rather than later - it's surprising how much damage water ingress can do in a comparably short space of time.


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## steco1958 (Mar 5, 2009)

I totally agree with "Time-Traveller", I had this self same problem in my last caravan.

Find yourself an independent caravan/motorhome repairer, and go and see him.

Sooner rather that later, don't put it off it will only get worse.


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## Carl_n_Flo (May 10, 2005)

Hear Hear!!!

Get it investigated now..........before re-sealing the metalwork.

If damp/water has got in, it needs to be rectified BEFORE sealing it up otherwise you will be storing up problems for later. The leak needs finding, damaged/rotten material removed and replaced THEN seal over.

No other way unfortunately....

Sorry.

Carl


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## Carl_n_Flo (May 10, 2005)

Extreme scenario I know but...................

this is what CAN happen if damp is not dealt with in time.....


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## time-traveller (Apr 23, 2007)

Carl_n_Flo said:


> Extreme scenario I know but...................
> 
> this is what CAN happen if damp is not dealt with in time.....


Yikes !!


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## daddysgirl (May 31, 2008)

Hi folks, 

I lost track of this thread before seeing the final few posts, thanks for the advice, and sorry if I appeared to ignore you all!!

On investigating further, we found several of the screws holding the plate in place were loose, and both the damp stains are below these, one with green slime between the plate and roof suggesting water had been there for some time.

As you rightly predicted, sealing the plate and screw holes has not cured the problem. We could not take the plate off, because the top box key was missing, but now we have that, and I'm thinking the best thing to do is to remove the box and plate, and hot foot it to the nearest repairer.

Oh woe!!!! should have done it in the summer.


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## hebronman (Sep 24, 2009)

Carl_n_Flo said:


> Extreme scenario I know but...................
> 
> this is what CAN happen if damp is not dealt with in time.....


Oh Help, how long would this kind of thing take to happen??

We've got damp - (due to old seals and the horrendous weather) is repair possible as a DIY job?, we're taking panels off at the moment and need to dry it out but cannot get the van anywhere near to power in order to run a de-humidifier into it. Any advice would be gratefully received.


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## Carl_n_Flo (May 10, 2005)

Not long at all!!!

You say you cannot get the van near to power - can you park it up in a dry barn or something similar? once you have removed the rot you can leave the van open (windows doors etc) to dry out naturally (after soaking up the worst with rags/paper etc). It is better that force drying.

The damage can get this bad in only a matter of a few months....but the longer it is left, the worse it will get as the water/damp will work its way along the timberwork by capilliary action.

The only rectification is to remove ALL damaged internal panelwork, then cut out infected timber and insulation, dry the surrounding area thoroughly then progress to the outside and investigate where the seals have failed.

Most common areas are:
Roof/wall joints
Rooflights
Pipes/flues/cables/aerials through the roof.

Generally, if it is not structural damage then it is down to ageing of the sealants used in the construction (on a generally older van) or poor workmanship on a newer.

This damage can also be caused by poor DIY mods (fitting awnings/bike racks/new roof equipment etc).

You MUST dry the internals first BEFORE investigating where the damage is coming from as it is not ALWAYS obvious. What IS obvious is that you cannot re-use the damaged panelling or timber!!!!

It is a b****r of a job, but it has to be done and is the ONLY way.
Just thinking that you have found the leak and slapping sealant all over it is just trapping the moisture and storing up masses of trouble for the future.

For interest, I am about to embark on the restoration of a 1973 coachbuilt motor caravan. Although it has been dry stored in a barn for the last 11 years, it is obvious that there has been water penetration in the past. I KNOW i am going to have to replace much of the ash framing that the caravan body is made of, and in addition I will be removing the aluminum skins as about 50% of them need replacement due to knocks and dents (have you ever tried to panel beat aluminium back into shape? Near impossible!!!

Good luck with it.....
regards
Carl


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## JohnsCrossMotorHomes (Jul 21, 2007)

daddysgirl said:


> Hi folks,
> 
> I lost track of this thread before seeing the final few posts, thanks for the advice, and sorry if I appeared to ignore you all!!
> 
> ...


I would be inclined to remove the screws, put some sealant in the holes and rescrew and reseal around the edges of the plate.

If you can remove part of the ceiling, use a hairdrier to dry it out.

Taking it to a commercial repairer could prove very expensive.

Peter


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## daddysgirl (May 31, 2008)

thanks peter, this is what we initally did, however we can now remove the top box, and so do a better job.

Following advice here, we decidied to bite the bullet and look for local damp repairers, and found the following two, both are very local to us, does anyone have any experience of them? Acare offer a free quote.

Taunton Caravan Services Ltd Caravan Repairs & Service 
Tel: 01823 618288| Gravelands Lane, Henlade, Taunton, TA3 5DL .
Caravan & Motorhome Repairs
Accident & Damp Damage
Any Make Or Model
Approved Workshop Scheme
Truma, Al-ko Serviced
Established Over 25 Years

and

Acare Leisure Ltd Caravan Repairs & Service 
Tel: 01984 618709| Ashfield Farm Estate, Crowcombe, Taunton, Somerset TA4 4AW .
http://www.acareleisureltd.co.uk/

thanks

XD


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