# Leaking roof



## tapspanner

Hi all
I have a small leak in the roof of my van,after inspecting the seams on the roof some of the mastic on the seams is dry and cracked this is where i think the water is getting in ,would i be able to reseal this myself ? what mastic should i use ? would i need to remove the old mastic? some of you must have done this repair to there own vans if you could please pass on your experience pitfalls ect it would be very much appreciated thanks in advance


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## Jagman

Hi tapspanner. Looks like you're in Warrington area. I have had similar leak repaired on rooflight and it involved removing rooflight, removal of old hard mastic, cleaning surfaces and application of new mastic around the 'hole' and refitting hekki - took dealer about one hour and cost me nothing as I'd just bought the van second hand from him! That was three years ago, no problems since and not much use to you  especially as it was miles away!

However! I now get my van serviced at North Cheshire Caravans on a small industrial estate by the Sankey Bridges WA1 4DE (01925 418999) and they are brilliant, even though the place looks a bit of a mess. Ask for Anthony, he is very young but very experienced in rebuilding and refurbishing caravans as well as motorhomes and he will give you a diagnosis, give you a fair estimate for the cost of him doing it, and also give you advice about mending it yourself.

I was in there last week for my annual services on base vehicle including MOT and hab. check. In the past they have repaired minor body damage (skirts), fitted a new tap and mended the step. Very good honest people with huge experience and skill. Tell him the guy with the Pollensa recommended them!

Good luck

Jagman


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## Jagman

Bump!

Someone must have done it diy style!


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## JohnsCrossMotorHomes

Scrape of the old sealant using a hard plastic spatula or an old credit card.

Clean off with white spirit/turps. Put masking tape alongside the join so you get clean neat edges, apply mastic and then remove tape later.

Peter


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## HMFIC

*leaking roof*

Hi. might be a little late but will be good for someone else a a reference in case of a leaking roof.

Yes this can be done DIY style as long as you take the right precautions and use the correct mastic, by precautions I mean don't fall off the roof make it safe, as well as covering up the inside of the van where the roof window is located.

As said by JohnCrossmotorhomes the old stuff needs to come off and the surfaces need to be clean. White Spirit / turps is good however I found that Meths was the best stuff to get the old gear off.

I replace two roof lights (Fiamma), I also ended up having to replace a lot of the wall's and timber inside as well because it must have been leaking for some time prior to me getting the van.

Anyway back to the roof, once the old mastic is off and you are going to replace the roof lights / vents you should apply a mastic called "Sikaflex 252" this is the best on the market not only will it stick like s.. to a blanket but it is flexible and that is what you need for the Motor Home. It does not come cheap but better do it right first time and save any further damage later.

Anyway as I said this is most likely too late for the Jagman but could prove useful to someone else.

Good luck 
Paul


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## cheshiregordon

Hi Tapspanner,
I'm in a similar position to you with a leaking roof over the bed.

I've been advised to gaffer tap the seam to stop the water getting in until I can get it repaired early January.

I would like to do the job myself but don't have anywhere dry to work on it - so I've booked it into Hambeltons who will replace the offending section of roof strip and reseal @£100/mtre so I hope its a small leak.


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## ched999uk

I think Sikaflex 252 is for 'structural' use only. i.e. if you use it on a window it will never be able to be removed!!!! It bonds big time. You need a non setting flexible sealant.


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## iandsm

*sealing*

You need w4 sealing strip which comes in a roll and can be bought at any decent caravan accessory shop for about £10. All you need to do is ensure the joint and the underside of the rooflight are clean and dry and free of old sealant. Place the flat sealant strip around the appeture, replace the rooflight then tighten it down, However, do not over tighten because you want the sealant to stay in the joint, not squeeze out. Any excess can easily be removed with a credit card or similar. Have the sealant indoors overnight so its warm before you use it.

This sealant is non drying and flexible so will cope with expansion in hot weather etc.

Please do not use adhesive type sealants as you will be asking for further leaks because the majority of these are not flexible. Even if you do use a flexible one, you will probably be unable to remove the rooflight, should you need to, without damaging it.


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## jud

ched999uk said:


> I think Sikaflex 252 is for 'structural' use only. i.e. if you use it on a window it will never be able to be removed!!!! It bonds big time. You need a non setting flexible sealant.


hi ched999uk. you are dead right this is the non setting sealant that should be used for water tight seals windows - e.t.c available at good caravan shops .jud


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## jedi

cheshiregordon said:


> I've been advised to gaffer tape


Word of warning. I used gaffer tape as a temporary solution in Austria. After a couple of weeks it seperated. The top layer peeling off and flapping in the wind leaving the extremely sticky layer that did not keep the water out. When I got home the remains of the gaffer tape was a nightmare to remove.

Jed


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## Broom

Hi Jed

''Sticky Stuff Remover'' gets it off.

Best Regards
Broom


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## HMFIC

ched999uk you are correct

I checked and the Sikaflex I used was "512" thanks for bringing this to my attention and allowing me a chance to check what I used and correct my post

Sikaflex 512 caravan motorhome trailer adhesive sealant system 


Paul


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## howellsroad

:? All very useful information IF I need to remove the overcab rooflight on my Lunar Telstar which has just begun to drip water abover driver's seat. Still not convinced I have a leak and it's not condensation. The underside of the roof is damp when the cover is carefully pealed back and there is water collecting between the outer and inner clear cover. I suspect condensation since there is a tiny hole just above the bottom which is presumably a drain. The weather has been very up and down temp wise lately so could be condensation but never had this problem before. Any thoughts before I get drastic over Christmas?


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## The-Cookies

hi , howellsroad we had the same problem in our lunar although the water was leaking out at the sides of the over-cab bit, i removed the over cab inner bits and the roof was wet through mainly because just at the rear of it there is a steel strengthening bar this was ice cold and water droplets all over it, , i insulated this bar, and filled all the cavity of the over cab with insulation that was last year and since then we have not had any sign of dripping or condensation.

when i asked the dealer we bought it from he said it was a common problem.


John


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## howellsroad

Many thanks for that John. Nice to know I'm not alone. When the weather (and the drinking!) have settled down I will look to explore as you did. In the meantime keeping low heat and dehumidifier going in the van. Will report back on what I find. Main concern is that we still have an accumulation of water between the inner and outer perspex and not sure how I will remove this. Hopefully be able to sort it without too much difficulty because our Telstar has been a cracking van and this is first time we have had any problems of this sort.

Tim


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## Murano

Tim

Is this what you mean by 'drastic over christmas'

....As they say 'been there and done that'

Dave


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## howellsroad

8O 
Not I think for Christmas day John! maybe tomorrow. Great photos. As you say "been there"!

Once have arranged a suitable gantry to work from I look forward to tackling this one.

Will let you know how I get on.

Tim


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## Bill_H

howellsroad said:


> Main concern is that we still have an accumulation of water between the inner and outer perspex and not sure how I will remove this. Hopefully be able to sort it without too much difficulty because our Telstar has been a cracking van and this is first time we have had any problems of this sort.
> 
> Tim


I got rid of water droplets from between the layers of a plastic sealed caravan window by drilling two very small holes in opposite corners of the inner window panel, and sticking the vaccuum cleaner nozzle over the one hole with plasicene to seal round it, and running the vaccuum on suck, while aiming a hairdryer over the other hole to draw hot dry air in. Took a while, but worked ok.
Afterwards I filled the two small holes with a spot of clear mastic.


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## howellsroad

Worth a try Bill. When it stops raining (and I stop drinking!)

Tim


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## howellsroad

Update on my "leak". 

It has not stopped raining (and blowing) but I have stopped drinking! I am now fairly satisfied the problem is condensation and not a leak. I suspect the problem has been caused because the blind over the cab was left open during the warm/cold spells before Christmas. No further signs of water getting in but I am still left with a little accumulation between inner and out skins of the roof light. Have kept dehumidifier going in the van over Christmas and the blind closed. It seems as if the water has stopped building up so will not be taking the drastic action to remove the skylight, much as I'm tempted to follow your line John. Would not help with water between the two skins anyway. Will see if the water eventually disapears and if there is any unsightly mold build up which is likely to be difficult to shift. Thanks to all for the advice and comments.


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## howellsroad

8) 

Hi again Dave. 
Having endured the cold weather and having had dehumidifier and low heat in van for a while I still get a small accumulation of water between the skins of the overcab roof light when it rains. There may still be an element of condensation but I'm coming round to the view that I do have some small leak/leaks around top off the roof light. It also must mean there is a split between the skins as well. In the few dry spells we have had I have applied a small amount of captain Tolley to the seams and this may have helped but has not cured the problem. Nothing really serious, yet! but encouraged by your excellent photos I'm thinking of carefully removing said roof light and resealing. Not until we get a decent dry spell but before we start our travels in the spring.

Since you have already been drastic with your Lunar have you any specific tips for this task, removal of old sealer, your preferred new sealer, how to prevent cracking the perspex etc would be appreciated. I have already constructed a working platform and will include photos when I do the job. Not urgent but will want to tackle in next few weeks.


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## Murano

Tim

Just sent you a PM

Dave


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## TIM57

*Leak on a seam*

My MH is a Dethleffs Globetrotter 'Premium Class' . Got an occasional leak on the front over cab roof seam, where the front section joins the middle sections, it is covered by a metal strip. Questions.

Do you need to remove the metal strip or can you clean the old sealer off and reseal with a thin bead of sealer?

If the metal strip has to be removed, is it stuck on or fixed with clips?
Will it go back on again, or will it require replacing?

Do you have to buy the sealing strip or will gun on sealer be ok?

I do have experience using sealant as I am in the building trade.

Tim.


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## BIGrog

Hi Tim

I do not know how your roof is constructed but, I have found that where the water drips the inside the MH may not be the place that lets the water in!

I have just recently replaced the complete roof on my Tiffin Allegro and once I had the ali roof off, the largest amount of water ingress was 3 feet away from the wet area inside.

With regard to a quick fix which I did three years prior to the strip was to open out and clean all the roof joints, Sikkaflex all of the joints and cover them with foil backed self adhesive roof band flashing.

This did do the job for three years until I had major leaks thro the aircon unit and light fittings.

Just from an interest point of view I am writing a piece for the ARVE Magazine with pictures to show what we found/did after removing the roof.

Hope this helps [a bit].

BigRog


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## TIM57

*Dethleffs seam leak*

Thanks for reply BIGrog
The MH is an A-class, the leak, water ingress is on one of the major seems, see my previous post.
Tim


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## BIGrog

Hi Tim
Thanks for that. If I were in your position I would in the first instance rake out and wire brush the seam clean, then apply the sikka ensuring there are no gaps it will surface harden over night, then you can paint it and cover it with the flashband. You will need to check the seam fairly regularly to make sure it is still in tact and watertight. Good Luck.

Bigrog


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## TIM57

Raining again here, any suggestions to my post earlier today.
Tim


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## howellsroad

You may all have noticed it has stopped raining so the bullet has been bitten! The real cause of my "condensation" problem is revealed and is definately a leak as the two parts of the window were coming apart. I now have two cleaned pieces, the outer dome and the inner flat sheet of acrilic which I need to re stick/glue together before replacing the whole back into the van. Dave (Murano) has been very helpful as regards removal and replacing the complete unit and I have all the gear ready to do this --- once the pieces are back together. Anyone restuck separate parts together successfully? Advice on adhesives? Just 3 days of sunshine left so be quick!

Tim


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## BIGrog

Hi

I have just completed re-roofing my Tiffin Allegro [1980] and replaced all of the roof furniture with Sikkaflex 512 sealer.

I managed to get a secondhand roof light from an old RV which was sealed with the 512, it is possible to remove it if you use a little heat.

BIGrog


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## howellsroad

Jobs a good un! (so far at any rate) completed just hours before the weather broke!
Many thanks for all advice, particularly Dave for your advice on Sudal Fixall and giving me the confidence to do the job. Sudal proved fine to work with when putting finished assembly back. Also thanks to Richard from Bondrite who recommended and supplied 50 cl of WC105 for sticking the two halves of the acrilic together again. Once I realised they were separating they came apart quite easilly. If doing that again make good use of masking tape when cleaning up as you can scratch the acrylic very quickly. Pictures show stages in process. The type of bulldog clip used incidentally gives excellent pressure while setting and will be useful in future as also will be cut off pices of plastic file binders. First real test is to Isle of Wight in a couple of weeks. Will report back after that. Happy Easter all.

Tim


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## howellsroad

Just back after 10 days of the worst weather in April for 100years, so they say. Repair stood up to all the wind, hail and rain that the Isle of Wight could throw at it. As good as new. Thanks again for all the advice.
Tim


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