Window sealants (1 Viewer)

[DL42846]

Its been pouring down with rain all day and I have noticed a small trickle of water inside the van from the bottom of one of the windows. It appears its leaking from where the actual window frame is attached to the van, not the plastic glass inside the window frame if that makes sense. Is there a special type of sealant for this or can one use a bathroom sealant from any DIY store.

 

[tonyidle]

You will need to remove the window and re-seal using butyl mastic most conveniently available in strip form from a caravan accessories store (or eBay). Don't assume the leak is near where water appears. The only certain way to find it is to remove the window.

 

[DL42846]

You will need to remove the window and re-seal using butyl mastic most conveniently available in strip form from a caravan accessories store (or eBay). Don't assume the leak is near where water appears. The only certain way to find it is to remove the window.

Many thanks. I just had a look on YouTube. I'm wondering if one window has gone if it's best to do them all. It doesn't look too difficult. The van is a 2009. Moncayo. Italian job. From my experience anything Italian doesn't last long at the best of times.

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[Lenny HB]

I would use one of the Sika adhesive sealants and steer well clear of the mastic strips very difficult to get a good seal with and need replacing every 3 or 4 years.

 

[Terry]

Your windows have a rubber seal on them that you should replace and not need any butal tape (it's shit anyway)..No one ever replaces rubber hence they use tape or other sealents.....a lot easier to simply mask around your window 2 mm onto body and window frame then seal around with PurFlex 40 type sealents...smoth off with a wet finger then pull tapes off
Terry

 

[funflair]

I would use one of the Sika adhesive sealants and steer well clear of the mastic strips very difficult to get a good seal with and need replacing every 3 or 4 years.

Serious question, what do Hymer use at the factory? our N+B windows are fitted with Butyl tape, I did read a while ago a post from a "funster" and he said that the factory had to cut the front window out of his Arto to repair it to me this would be the effect of fitting a serviceable part with an adhesive sealant, and yes of course I refitted our with non setting mastic.

Martin

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[funflair]

Your windows have a rubber seal on them that you should replace and not need any butal tape (it's shit anyway)..No one ever replaces rubber hence they use tape or other sealents.....a lot easier to simply mask around your window 2 mm onto body and window frame then seal around with PurFlex 40 type sealents...smoth off with a wet finger then pull tapes off
Terry

Hi Terry

I have just had a look at Dometic Seitz web site and downloaded the fitting instruction YES some windows have a rubber seal the S4 and S5 do but others S7 don't, but they still say to put a non setting mastic in the groove behind the rubber seal.

https://www.dometic.com/en-gb/uk/products/climate/windows-and-doors/windows

Martin

 

[Lenny HB]

Serious question, what do Hymer use at the factory? our N+B windows are fitted with Butyl tape, I did read a while ago a post from a "funster" and he said that the factory had to cut the front window out of his Arto to repair it to me this would be the effect of fitting a serviceable part with an adhesive sealant, and yes of course I refitted our with non setting mastic.

Martin

Hymer use a Butyal sealant but it is far superior to the tape avalable in the accessory shops.

 

[tonyidle]

Your windows have a rubber seal on them that you should replace and not need any butal tape (it's shit anyway)..No one ever replaces rubber hence they use tape or other sealents.....a lot easier to simply mask around your window 2 mm onto body and window frame then seal around with PurFlex 40 type sealents...smoth off with a wet finger then pull tapes off
Terry

I don't understand your antipathy towards strip butyl mastic. I'm not in the trade so haven't done that many - maybe 6 items in all. But what has impressed me most is the ones I've removed that weren't leaking. I've done two or three rooflights changed for different types and in every case the mastic tape could have been re-used. It sticks like the proverbial and remains soft effectively for ever. I'm interested to understand how, correctly applied, it could ever fail.

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[funflair]

Hymer use a Butyal sealant but it is far superior to the tape avalable in the accessory shops.

So why do you say use a Sika adhesive sealant yes Dometic say Sikalastomer 710 as an example which is a non setting Butyl sealant.

Martin

 

[funflair]

I don't understand your antipathy towards strip butyl mastic. I'm not in the trade so haven't done that many - maybe 6 items in all. But what has impressed me most is the ones I've removed that weren't leaking. I've done two or three rooflights changed for different types and in every case the mastic tape could have been re-used. It sticks like the proverbial and remains soft effectively for ever. I'm interested to understand how, correctly applied, it could ever fail.

I took the awning rail off a 12 year old caravan and as you say all was as good as new and it had been fitted with mastic strip, likewise when I took the window out of our Flair at 10 years old the sealant was as good as the day they fitted it the only problem being that it had fallen off the vertical edge of the frame when they fitted it so missed a bit of seal at the top, aluminium inside and out so no problem after a 10 year old leak.

Martin

 

[Tom A]

Its been pouring down with rain all day and I have noticed a small trickle of water inside the van from the bottom of one of the windows. It appears its leaking from where the actual window frame is attached to the van, not the plastic glass inside the window frame if that makes sense. Is there a special type of sealant for this or can one use a bathroom sealant from any DIY store.

Out of interest are your window frames aluminium ?

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[DL42846]

Hi, Thanks everyone for your comments, I do very much appreciate them as it gives me lots of food for thought before I have a go myself. I'm still wondering if the window that has sprung a bit of a leak which I think happen when I put the pressure washer on it whilst I was cleaning it a while back. The window hasn't leaked since even though the last few days its poured down none stop. I don't like to think the water might be going somewhere that doesn't show at the moment. A question I have is how often should the sealant be renewed. Should I just do the one and leave the rest, or is this an indication that perhaps its time to do them all. I prefer preventative maintenance but don't want to waste time and money. Is there a general type rule on this sort of thing?

 

[Gromett]

I used the non setting mastic tape when I installed the windows in my self build 8 years ago. Still no leaks.. I prefer it to sika flex for this purpose.

 

[funflair]

Hi, Thanks everyone for your comments, I do very much appreciate them as it gives me lots of food for thought before I have a go myself. I'm still wondering if the window that has sprung a bit of a leak which I think happen when I put the pressure washer on it whilst I was cleaning it a while back. The window hasn't leaked since even though the last few days its poured down none stop. I don't like to think the water might be going somewhere that doesn't show at the moment. A question I have is how often should the sealant be renewed. Should I just do the one and leave the rest, or is this an indication that perhaps its time to do them all. I prefer preventative maintenance but don't want to waste time and money. Is there a general type rule on this sort of thing?

My guess would be that you have "blown" some water past the rubber seal between the double glazed window and its rubber seal and then inside.

How often should the sealant be renewed? in my book it should never need it but others might not agree.

If you are worried just invest in a damp meter.

Martin

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[Terry]

In answer to the above without quotes....I think half the problems are caused by the people who work in the factory...they don't give a toss whether the sealents is correctly in position or not ...they have a few mins to stick a window in .....so near enough is probably the order of the day.... once they are in position they are sandwhich between the skins / outer and inner.One man outside and one inside screwing the inner frame/ blinds appliing pressure to hold the sandwhich together...too much pressure and blind does not work too little and seal does not fit tight ....small amount of water freezes making a slightly bigger gap allowing more water to freeze making even bigger gap eventually leaking
Then we have two different types of material , say plastic and alloy roof both expand and contract at different rates in the sun again allowing slight gaps where the butal dries out a tiny bit hence another leak
That is why I fit windows and roof lights with flexible sealents not butal...once it's stuck it remains flexible but does not allow any water ingress....if you need to remove for any reason you simply use a sharp scrapper to cut through it ....as I have said before in other posts they don't use it in factory simply because it squashes out and is messy to clean surplus off ....using tape it's simply cut around window and pull off surplus,quick wipe and job done .....bare in mind they work in dry warm factories in ideal conditions while we meet mortals have to work in probably not ideal conditions and also make sure things don't leak hence using tried and tested sealants that do the job ....only My take on it all ...you use tape if you want ....old saying you can take horse to water etc, only passing on experience
Terry

 

[Lenny HB]

I don't understand your antipathy towards strip butyl mastic. I'm not in the trade so haven't done that many - maybe 6 items in all. But what has impressed me most is the ones I've removed that weren't leaking. I've done two or three rooflights changed for different types and in every case the mastic tape could have been re-used. It sticks like the proverbial and remains soft effectively for ever. I'm interested to understand how, correctly applied, it could ever fail.

I spent 10 years as the Techinal manager for a manufaturer / distributer of caravan/motorhome accessory and the stuff sold & manufactured in the UK is far inferior to sealants the Germans use, mostly sourced on price rather than performace.

So why do you say use a Sika adhesive sealant yes Dometic say Sikalastomer 710 as an example which is a non setting Butyl sealant.
Martin

I was just making a general comment meaning use a quality product like Sika and as you say they do Butyl sealants.

I took the awning rail off a 12 year old caravan and as you say all was as good as new and it had been fitted with mastic strip, likewise when I took the window out of our Flair at 10 years old the sealant was as good as the day they fitted it the only problem being that it had fallen off the vertical edge of the frame when they fitted it so missed a bit of seal at the top, aluminium inside and out so no problem after a 10 year old leak.

Martin

Wasn't fitted with the inferior aftermarket products.