roof lantern and roof leaks

[joe90]

8 minutes ago, Onoff said:

I've this mad idea for a central skylight on a big flat roof

I wonder where you could buy some glazing for a flat roof, perhaps you could even walk on it ?

[Russell griffiths]

4 hours ago, PeterW said:

Thanks - what was the cost in the end ..? Only thing that put me off was they only sell thickener for a 25Kg tin not the 6kg and that’s enough to do about 15sqm 

Fark me, the thickener was £65 for a litre, I think I used 150ml, so that is a right con

but if you build the £65 in with the total amount to do the whole job

25kg desmopol.  £175

1 litre thickener £65

matting £40

so £280 did 10m plus 7m upstand. 

[PeterW]

Thanks @Russell griffiths that’s worth knowing. I was looking at doing a big shed roof in it which is about 12sqm plus some bits so that comes in about the same price as GRP and much less weather dependent. 
 

And I’ll give you a tenner for the left over thickener so it’s £270 for the whole job .. ?

[Onoff]

I really like the idea of the Desmopol type coatings. Two things put me off, experience of "similar" roof repair products like Flexacryl, Cromapol etc on my flat roof not lasting too long and reviews like this. (Saying that my failed felt substrate is poor to start with). 

 

https://www.pistonheads.com/gassing/topic.asp?h=0&f=92&t=1559067

 

I really though like the idea of it as in no laps or joints and the fact it's easily over coatable. 

[Russell griffiths]

1 hour ago, Onoff said:

I really like the idea of the Desmopol type coatings. Two things put me off, experience of "similar" roof repair products like Flexacryl, Cromapol etc on my flat roof not lasting too long and reviews like this. (Saying that my failed felt substrate is poor to start with). 

 

https://www.pistonheads.com/gassing/topic.asp?h=0&f=92&t=1559067

 

I really though like the idea of it as in no laps or joints and the fact it's easily over coatable. 

Reading that it looks like the bloke didn’t put it on thick enough, I also don’t think you use the accelerator any more. 

I phoned the technical helpline and they told me that they do not recommend the accelerator anymore as roofers could not work out the amount correctly, they said as long as it was 5 degrees and rising you could install. 

I did it on a day that was 7 rising to 10 degrees, I had it all on by 3 pm and it was picking up starting to go by then, by the morning it was like a sheet of rubber. 

 

I haven't actually looked at it since I did it. 

[tillywiz]

hi joe

most of the lantern people do the flat skylights that one can walk on i will look and see for you as they use them to add light to basements as well as roofs some of them look absoluely super

Edited December 30, 2020 by tillywiz
spelling

[joe90]

1 minute ago, tillywiz said:

hi joe most of the lanter people do the flat skylights that one can walk on i will look and see for you as they use them to add light to basements as well as roofs some of them look absoluely super

@pocster, (I think I have a buyer fir you, dont forget my 10% ?)

[Pocster]

3 minutes ago, tillywiz said:

hi joe

most of the lantern people do the flat skylights that one can walk on i will look and see for you as they use them to add light to basements as well as roofs some of them look absoluely super

Oi ! PM me ! . I’ve got everything you need girls , drugs , walk on glazing .......

[MJNewton]

9 hours ago, Onoff said:

@MJNewton, you used Desmopol, how's it fairing? 

 

Well, funny you should ask actually. It's been on for two years now and recently I noticed that along some of the edge it was beginning to look like I could see the trims underneath. Actually, at first I thought it was dust/dirt, perhaps from birds sitting on the trims, but getting up there and rubbing it showed this not to be the case.

 

 

(Not the prettiest of finishes there, but the rest of the roof is better when viewed as a whole)

 

I got in touch with the builder who in turn contacted his roofing sub-contractor who said he'd come and take a look. To cut a long story short he never did and so I got in touch with the supplier as they arranged the warranty (product only) when it first went up. They came out to visit (really great bloke from Raven Roofing in Swindon) and despite being very familiar with the product and its use over many years he'd never seen this before. He didn't think it was UV degradation (as I thought might be the case) as this tends to make it go chalky when it happens (usually in far hotter countries where it is used a lot more than here in the UK) and we agreed it didn't actually seem like the white was the trims underneath as there's no definable 'edge' - it really does seem like it has just discoloured. Still not desirable and so he is going to get in touch with the manufacturer and see what they say and, ultimately, seek them providing replacement product to recoat the whole roof (only 15m2, less a 2.5m x 1.5m lantern opening). Amazingly he even said he'd do the recoating himself given I was having so much trouble getting my builder's roofer interested (not to mention all the issues I had with the poor finish when first applied which ended up getting a recoat even then).

 

So, I do seem to have an issue here but I think I'm still a fan of Desmopol. Sure, this arguably shouldn't have happened, but despite it having done so the remedy seems straightforward - just repaint it like you would a painted wall. I think that is really one of the beauties of PU liquid coatings - very easy to repair and renew (indeed the warranty gets extended by 5 years every time you recoat it). The other benefit is that it can be used with zero falls due to there being no directional laps to worry about (it is actually used in full immersion situations eg swimming pools).

[Onoff]

@MJNewton, thanks for that, very informative.

 

Does the same warranty stand if you DIY it like @Russell griffiths griffiths did?

 

What are those two little diagonal lines that look like splits?

 

I'm still sold on it I think like you just for the ease of recoating.

[MJNewton]

I think the 'splits' are just where the fibre matting isn't smooth and so the coating isn't either. Even though things are a bit rough in places the camera really hasn't done it any favours.

 

Good question about the warranty and DIYing it. I'll ask the supplier when I next speak to him as I suspect I'll be recoating the roof long term (for maintenance) as I know I could do a better job than my roofer did so I'd take my chances even without a warranty. Whilst it might not necessarily avoid failures/problems it does mean I don't have the stress of blaming someone else and trying to get them to fix it (or indeed stress of knowing I paid them to do a 'professional' job but may not have got anything more than what I could've done myself as an amateur).

 

Incidentally, I could be falling for the oldest trick in the book, but the relatively high cost of Desmopol when compared with similar-sounding products sold more for patch repairs by the likes of B&Q, makes me think it really is a quality product and should be viewed as 'reassuringly expensive', if you know what I mean. Looking at their Facebook page it seems to constantly used on very expensive commercial buildings all over the world. I do recall the supplier suggesting to me that we are often quite shy of moving on from 'traditional' building materials and techniques in the UK for some reason and that many other countries have moved on to better modern approaches.

[ajp]

hi i have the thing going on here and i have been looking for a long time for this. 

how have you got on with the repair. 

did you manage to get advise as to why its happening. 

mine is the type of lantern and wet / damp/ stains in the same places on my ceiling however my is actually in about 12 different places all over the roof. 

 

ill share some photos shortly 

 

thanks 

On 28/12/2020 at 18:25, tillywiz said:

hi mr newton the epdm has a felt backing do not know the make  and the installer put it on in meter widths because that was the roll he got or had already no fall on the roof so pooling all acros the back where the roof tiles come down the lantern was not the one we were told per contract we think we have tracked the make down to stratus but it looks like anyone and his dog can produce the stratus make under licence.the roof leaked before the lantern was put on and was supposed to have been fixed first at one side but now looks like both back sides and one end at the front .also the lantern itself seems to be leaking through the peak at one side  and the inside cover appears to be glued on with {evostick) type glue.the two roof pics showing the epdm as it was before the lantern was added and we were told that the corners had been recified.i have only been able to add a couple of the internal leak but i think you will see the level of water ingress.

the company are supposed to be getting back to us after the holiday but finding all the leaks and leaving all the joins would not be satisfactory so we would like an independant person as we feel the whole thing should come off and be redone also it appears that the upstand is not high enough and goodness knows what has gone on under the tiles and my concern is that they are just going to want to bodge things again .if he does not want to redo the job properly i would like to know the correct price for someone else to do the whole roof from scratch the condensation is terrible and is right the way up both sides of all the truts and all the way along just above the upstand on the edge of the lantern.if you want pics i will do them on the next bit.

 

[ajp]

so i had the same issues as tillywiz. nov,20 dec20 still going on jan 21. 

im literally so gutted as this has been going on for about 3 years now. 

my roofer ( meant to be a friend ) did the job for he is a roofer and has a company etc. 

he put fibreglass roof but when it happen last year he came back to add another top coat. 

it happened again and i managed to get him back again another top coat was put on. 

now 28th dec 2020 im an the end of knowing what to do. i called him he came back and put touch on felt. 

 

seems likes its got worse ( maybe because the felt i snot wrapped around the edges of the roof ? maybe because he scrapped away fibreglass particles ?  

i have no idea. it was never this bad last year. only ever haves in november / december time. 

 

could this really be an install issue or the way he has boarded the roof ?

between the top coats he never scrapped much away just brushed loose flakes of topcoat, never sanded, never fibreglassed its.... 

maybe teh boards were not bandaged proper or at all ? 

 

any suggestions and any local companies that can actually fix this ( even if that means a new roof ) or a pitch roof instead ? and totally throw away the lantern ?

[annl6512]

Hi just reading through this post & wondering if anyone can help us. Lantern leaks in same area but not all the time. We have had it taken off & lifted as it was not high enough. The flat roof has been re-done with rubber stuff & this has been checked but every now & again we get this patch. The cap ends on the end are missing where this is happening-would this be anything to do with it ? We've had very heavy rain since works were done last July & no leak appeared during heavy rain but then twice since then during light rain. Could it be condensation? 

[Dave Jones]

couple questions, what is the flat roof make up. is it warm or cold ?

 

Did they lap the rubber up and under the bottom row of tiles all the way round ? Water will be 100% overflowing under those tiles and dropping into the roof.

 

It's not great, id be inclined to get a professional in to re-do the lantern upstand and insulate it, pull down the plasterboard and see what state its in. If its a cold roof then there is no ventilation that I can see and if it was a warm roof the vapour barrier isn't up to much.

 

so annoying the amount of cowboys there are out there.

 

[annl6512]

Hi just reading through this post & wondering if anyone can help us. Lantern leaks in same area but not all the time. We have had it taken off & lifted as it was not high enough. The flat roof has been re-done with rubber stuff & this has been checked but every now & again we get this patch. The cap ends on the end are missing where this is happening-would this be anything to do with it ? We've had very heavy rain since works were done last July & no leak appeared during heavy rain but then twice since then during light rain. Could it be condensation? 

[annl6512]

Sorry if any confusion but the following pics are of the outside of our roof. I'm pretty sure they have run the rubber right under the tiles & the lantern is now at the correct height although as shadow on the pics it may not look like it. It does look messy as he came back out & put sealant on the top of the rubber incase  this had expanded.The leak is directly below the bar shown here, no leaks anywhere else. As you can see the 2 end caps are missing- would this be of any significance? Thanks for your response btw not sure what you mean by a hot or cold roof ?  

 

[Kumar]

Have you tried to put it on a upvc sill?

Presume it 69mm ...will fit on to a sill 

[tillywiz]

just to let you know we had lantern removed roof redone and new lantern fitted correctly company called thermal roof did the rubber as you will see from the first pics to the ones now the difference

[Andehh]

Blimey, that looks much better!

 

Thanks for coming back to update.

[markc]

Big difference