Leaky “new” roof might be the last straw

[Adsibob]

We had a Triflex ProTect “fully reinforced PMMA resin roofing system” installed about 18 months ago as well as a modular sedum roof on top. The roof pitch is about 20 degrees, but we were advised to go with this specialist system instead of GRP because apparently the angles and profiles were needed for parts of our roof were not suitable for Grp.

 

 The Triflex ProTect is fully BBA & ETA approved and certified and are covered by a 20 year guarantee.

 

 Today we spotted two damp patches about 5cm apart from each other. They are both quite small. One is very small, about the size of a 50 pence piece, the other maybe 6 or 7 times that. No drips of water that I can tell, just patches. The two patches are on the same perpendicular from the external wall, so I’m guessing the weakness in the membrane has occurred where two boards of OSB meet, as that is the substrate that  the triflex liquid membrane was applied to.

 

I emailed the installation company at 6:15pm to notify them of the issue,  with a photo of the damp patch. Owner called me an hour later and tells me he’s never had a leak with this product in over 10 years of using it. He has agreed to send the original installer back tomorrow. 
 

I’m not very good in these situations, because things like this make me quite upset and irrational (the roofing system cost a fortune, about £8k more than if we’d just used GRP. So that I can stay as rational as possible, what some I expect the company to do?

 

The internal decor of the ceiling is exposed clay plaster, which might look ok when the damp patch dries or it might not. We have MVHR so I’m expecting the plaster (which is incredibly thin, about 2mm on top of the plasterboard) to dry quickly once the source of the ingress is rectified.

 

If the decorative plaster ends up stained, is it reasonable to ask for that but if ceiling to be replastered?

 

What about the structure of the roof itself and the insulation? Should that be replaced or is it fine for it to just dry?

 

i haven’t got the exact build up in front of me, but I recall the roof insulation here is a mix of PIR and superfoil. The rafters are timber. On top of the rafters, plywood was laid, then the OSB. Then the triflex liquid membrane. Once that membrane cured a geotextile membrane should have been laid, to protect the triflex, then the modular boxes of Sedum. I didn’t check that they put the membrane down, but they certainly specified and charged me for it, because they said it was important to protect the membrane from being damaged by the Sedum boxes.

 

Shit like this had a tendency to push me close to the edge. Not healthy I know.

Edited August 2, 2023 by Adsibob

[SteamyTea]

Was it exceptionally rainy today?

If so, could it be caused by a failure somewhere else i.e. gutter.

 

There should not be a great deal of difference between your system and a GRP system as they are both reinforced resin systems.

[Adsibob]

8 minutes ago, SteamyTea said:

Was it exceptionally rainy today?

If so, could it be caused by a failure somewhere else i.e. gutter.

 

There should not be a great deal of difference between your system and a GRP system as they are both reinforced resin systems.

I estimate we’ve had 11mm of rain today, nothing excessive. Here is data for the last 31 days for a weather station about a mile from our house (showing 11mm there, today):

 

It’s not a gutter issue, as this is on a part of the roof above the gutter. In any case, I can see both gutters and neither is blocked.

 

When I was sold this product, I was told that even if water ponds on it, it won’t fail. The same company also install GRP, and there was an aspect of our roof (I think integrated gutters) which  made GRP unsuitable.

 

The guy on the phone today thought it might be that the roof was damaged when the Sedum was installed.

[Jilly]

Hey, go easy on yourself. S**t happens.

 

Nothing and no one in life is perfect. Ever. You can only do your best. Try to shrink things down in your mind and imagine you are advising a friend. Sure it's annoying and very unlucky, but it will get sorted out and repaired. And it will look absolutely fine.

 

I bought a little endoscope in anticipation of problems like this, to help diagnose things, but have only had to use it to look at spiders so far. 

 

I think self building does your head in a bit. 3am is a bad time. 

[eandg]

Pass on above the plasterboard stuff but on the surface you'll end up getting a wee residue of crystals as the moisture dries which can be easily painted over - personally I'd save any hassle of waiting for trades and jump on a ladder with a brush and get on with your life once the roof is sorted. 

[joe90]

46 minutes ago, Jilly said:

Hey, go easy on yourself. S**t happens.

Very much so, but different things cause different people stress. I found my build completely stressless but a different aspect of my life ( @Adsibob knows what that is) caused me much stress leading to yet another cancer. It’s very difficult to do but try to be pragmatic about it and if necessary find someone else to act on your behalf when dealing with the roofing company.

[saveasteading]

It says on thr triflex spec that it suitable for sedum (not all systems are). So it shouldn't be that.

 

I'd only say that leaks often originate elsewhere and migrate to a point which makes them drip.  That leak point will usually be directly upslope from the drip. The eaves perhaps.

 

Your leak is tiny, (a pinhole)so it may simply silt up and not recur,   so don't rush into anything , stay calm with the roofer then note what he has said. Photograph the damp bit and record the position in distances from walls.

[Adsibob]

2 hours ago, eandg said:

Pass on above the plasterboard stuff but on the surface you'll end up getting a wee residue of crystals as the moisture dries which can be easily painted over - personally I'd save any hassle of waiting for trades and jump on a ladder with a brush and get on with your life once the roof is sorted. 

Except that we don’t have a painted finish. It’s a clay plaster finish, applied by a specialist. 

[Dave Jones]

roof supplier on hook for fixing the roof, remember you tend to get more out of people by not shouting at them  however tempting it may be...

 

All consequential damage is home your insurance I would say otherwise they would have unlimited liability.

[Kelvin]

How easy is it going to be to investigate it? One of the best tools I’ve bought is a non-destructive moisture meter. I’ve found it very useful at mostly putting my mind at ease. It might help you trace the problem. They do throw up false positives (screws/nails) 

[Jilly]

Doesn’t clay absorb and release water, so it might be possible to smooth it out quite easily? 

[MikeSharp01]

If you have superfoil you can get water flowing a long way from the leak... So that may need thinking through as well. 

[Lofty718]

Adsibob sorry to hear this, hopefully it is a small issue that can be rectified.

 

I do recall from your previous thread you were shelling out a fortune for project managment/architect, did they not supervise and check how the roof was built?

[joe90]

18 hours ago, Adsibob said:

The Triflex ProTect is fully BBA & ETA approved and certified and are covered by a 20 year guarantee.

Right @Adsibob, breathe and count to ten. Your roofer and/or supplier must sort this out fir you, it’s not like you did it yourself. With your extensive knowledge of legal procedure I am sure you will know you’re rights as a customer and how to proceed if either of them try to dodge the issue 👍

[Adsibob]

Roofer came, good news and bad news.

 

 Good news is he spotted some minor issue which he patched up pretty quickly with another coat of the triflex membrane on a small area. Also good news is that they didn’t forget the fabric membrane that goes between the sedum trays and the triflex, that’s been there all along.

 

Bad news is that as @saveasteadingforeshadowed there appears to be an issue further upslope from the site of the leak: a large 4m by 1m skylight. Of the 10m perimeter of that glass, the two short sides and the long side at the bottom are all fine. However about 1m of the 4m top side is not bound by a wall. That 1m should have an overhang of glass that surpasses the upstand. But it doesn’t. It meets the upstand approximately half way across it. There is then silicone covering the join with the upstand. That silicone has failed/cracked.

 

According to the roofer , who says he worked for 20 years in glazing previously, putting in new silicone will only ever be a temporary measure because it is still vulnerable, due to the lack of overhanging glass. He said that these types of designs never work long term and that I should look at replacing the roof window. From my perspective, that is prohibitively expensive, I think it cost c. £3k and removing it would also create potential damage to the roof. I asked if as an alternative they could install a flashing to cover the vulnerability, he said it would not stick because of the self cleaning glass is designed to have nothing stick to it.

 

 I’m just wondering if that is really that accurate? there is some lead flashing which has been stuck to the glass by using Tesco’s Vana Pro Clima airtight tape sandwiched between the glass and the leaf flashing. Reading up on the specs of that tape, it is only designed for 6 months of outdoor use, but I wonder whether we got away with that as being sandwiched between glass underneath and lead flashing on top, it is not actually “outdoors”.

 

Trying to stay calm, but very difficult.

[saveasteading]

15 minutes ago, Adsibob said:

putting in new silicone will only ever be a temporary measure

Good news mostly then.

 

He  is correct to some extent.

 

Silcone, along with cans of expanding foam, should only be issued to builders with a prescription from the building designer.

 

However there are products that don't harden in the sun (UV)and so may work for much longer. If you can find a way of flashing over, as suggested, then so much the better.

 

Photo please.

 

Only buy stuff with a recognised brand name. Own brands (with some persuasive names) can be very variable.

 

I have taken a liking to Everbuild. There is a big range and their spec sheets are clear.  You'll be wanting uv resistant and permanently flexible.

Everbuild appears to be owned by Sika.

 

You are going to need the tiniest smear of it to fix the leak, but it is probably worth replacing it all at that area.

[Big Jimbo]

Can you get access to the roof easily ? You have to take care of the safety aspect of you jumping up there with a couple of tubes of whatever fella. It's not right at the top of the house is it ? Hopefully, a flat roof area above a single storey bit. I fitted a bloody expensive aluminium roof lantern. Asked the supplier what size externally the hole needed to be. When the blinking thing arrived it was exactly the size of the hole that i had built. No blinking overhang. actually, in view of the rubber membrane which came up the upstand, it was actually slightly smaller than the opening. I feel you pain... I thought about getting some sort of aluminium frame made up that would increase the size, but in the end i ran some of the rubber roofing non setting mastic around it. Still ok after about 8 years.

[SteamyTea]

You can treat glass with a silane and alcohol solution to help it bond. It may need a bit more to make it further weather proof for the next ten years though.

More details will be needed before a creative solution is thought up.

[Adsibob]

2 hours ago, Big Jimbo said:

i ran some of the rubber roofing non setting mastic around it. Still ok after about 8 years.

This sounds promising. Can you expand on the detail of this product please.

[Adsibob]

2 hours ago, Big Jimbo said:

Can you get access to the roof easily ?

Luckily, yes. It’s a skylight in the roof over the ground floor extension, and I can easily climb onto that roof from a couple of first floor windows. Requires trampling over some Seedum, which is a shame (already from today’s visit and patch up by the roofer, it looks a bit trampled - hopefully it will recover quickly).

[Adsibob]

2 hours ago, SteamyTea said:

You can treat glass with a silane and alcohol solution to help it bond.

So I raised this as a possibility with the roofer, and he said that the problem with that is that once you damage the non stick coating of the glass, even on just one portion of it, “the coating starts to peel off the whole pane”. Not sure how current his knowledge is, given he’s been in roofing for many years, and was in glazing prior to that, but he has seen lots of skylight issues as part of both careers.

 

I will post some pictures over the weekend to explain it better. But imagine a slanted sheet of glass that should be bigger than the upstand it is covering to overhang it by a couple inches on each side of the upstand, but instead of being bigger and overhanging on all sides, it doesn’t overhang on one 1m length of upstand. It is that 1m which has the exposed joint of silicone.

 

Luckily the roofer removed the existing “blown” silicone and applied a new thick bead of his preferred product, which he says is very good, but even he wouldn’t guarantee such a silicone joint for longer than a year or two max.

Edited August 3, 2023 by Adsibob

[Big Jimbo]

25 minutes ago, Adsibob said:

This sounds promising. Can you expand on the detail of this product please.

I will look it up in the morning fella.

[dpmiller]

so who measured/ supplied/ installed the glass?

[SteamyTea]

18 minutes ago, dpmiller said:

so who measured/ supplied/ installed the glass?

@Pocster

[Big Jimbo]

Morning @Adsibob I used Soudel, Butyrub Polybutele non setting mastic. Hope you get it sorted.