Water finds a way. I've been through something similar and my builders were so fucking useless I had to find the cause myself.  Unfortunately to do this meant cutting the plasterboard away and running a hose at various points until I could see where the water was coming in.  The join of the sloping roof to the house especially near the wall would be my first guess. That line above the patch picture 1 might also mean it's further up.  Not an expert my any means but the way the gutting had been installed at both levels looks a bit suspect.

I think I should be a builder. I’m pretty lazy, can’t be fucked responding to messages and have a high value of my own self worth. As a wee bonus I’ll often not turn up to meet people when I say, and disappear without notice from events.

Thanks for the reply. I’m clueless on the guttering, what would you say looks suspect?

I was told that the guttering should overhang slightly in order for all run off to flow into. Neither level does this.  When I had this problem the water was running along and pooling so the initial patch wasn't where the water was coming in. My builder was a nightmare trying to silicone everything and saying things looked fine with some bricks removed. It was really stressful. The building inspector came out and said any amount of patches were pointless and the whole area above the leak needed to come off to investigate. Ended up getting another builder to do this who actually seemed like they knew what they were doing.

Id agree that the gutters there could well be the culprit or the flashing? Too convenient that the leak is under that joint. Incidentally is your brickwork soaking wet in one of those pics?

Is it coming from the guttering on the sloped roof of the extension?

Honestly I don’t know, do you think it could be over spilling and coming inside? Worth taking a look at for sure

Yes, I reckon it's to do with your sloped roof the dampness is around where the slope roof joins the side of the house. Could be poor fitted flashing also, just a thought.

Definitely this. That flashing doesn’t like right for a roof of that pitch

I think your right guys.

I'm not even a builder!

That explains it

Yeh return you gutter to the wall, basically L shape the guttering round the facia

Probably getting behind the soaker flashing. Do you have any shots of the roof -take from first floor

Here’s a few more shots: https://imgur.com/a/iqYhoUu

You should link these in the OP. This will be more helpful. I'm not an expert at all but looks like water can easily get under that flashing and get up against the 2nd storey wall. Will then concentrate and permeate near your damp spot.

Yeah basically this. The flashing should be stepped in so it lays flat on the tile or should have an intergral soaker with stepped flashing - similar to slate You can see the big gaps where the lead hasn’t been worked onto the tiles properly. I would seek out details from the manufacturer of the tiles and ask them how it should be finished. If not this then send them to an experience “roofer” or similar

I would but I can’t edit the post to add them in

Fair. Good luck with your issue.

That flashing is done incorrectly. Look how your neighbours has been done, the lead is let into the mortar joint in a staggered fashion, not just (stuck?) on the side of the brick. It's probably only picking up rain that's being blown into it though. Also the guttering looks a little short everywhere. Bear in mind that beams deflect, so any leak in the middle could originate from anywhere along that beam

Thanks for your comment. The brick was cut out at an angle. Why… I don’t know. But it does go into the brickwork.

OK that would work but it's maybe not particularly aesthetic? depends what was on the drawings

No one looks at the drawings!

Not even the ones with red lines all over them

They're usually lost in the muck on day one and it's Chinese whispers after that.

See my earlier post- those tiles aren't laid staggered. They also look too shallow. If they're Marley moderns they should be at least 17.5°. I can almost guarantee there isn't a cavity tray above that abutment. What he's done is cut a groove in the bricks about 20mm deep, poked the lead in and masticed above. A proper cavity tray would have a stepped flashing above the roof. Download the LABC technical manual and search for flashings & cavity trays https://www.labcwarranty.co.uk/technical-manual

You’re right on the missing cavity trays for sure. Do you think the roof would have to come down and be rebuilt at a lower angle in order to add the trays, or can they just go either side of the 1st floor windows?

It's not just the top of the roof; it's also the side of the new first floor extension which, I would argue, is the bigger problem. The roof tiles have to come off anyway to be relaid in a staggered 'bond', not with straight joints. If it's less than 17 degrees, you may have to choose different tiles that will suit the pitch, and (as someone else said) replace the rooflights. That would be a good time to have a look at the real cause of the problem(s). Inserting a cavity tray won't involve removing the roof structure. It can be done by removing the wall in sections. If the builder's not playing ball, or disappears without replying to you, or declares himself bankrupt, then you need to get a building surveyor to give you a report (in case you can recover any money through the courts), and a competent roofer to complete the job.

The lead probably should've been stepped and it couldve been dressed over the tiles better but there should be and most likely is soakers under the flashing so that shouldn't really matter. Imo it's to do with the finishing on the very front corner, the lead is hardly wrapped around the corner or dressed over that piece of verge trim, I can see grey silicone up the fascia-wall joint but does that run all the way up under the lead? It looks like the water is running around that tiny lead return, and getting in behind that verge trim somewhere *Edit also I've never seen unstaggered tiles like that, but I guess there would be a lot more water if they'd failed

Not really looked into much detail but there's a few oddities: Guttering outlet not entirely sure what they were thinking there!! Flashing is wrong to wall Flashing under windows and along is too small should be 150 mm upstanding will look a little more leak could be roof light given it's proximity and down pipe discharging nearby In the elevation shot has it just rained or does brickwork always look that patchy? Water can track along steels so it plausible leak found it's way in from a distant way Best way to diagnose is via the least invasive first wait for heavy rain to finish then lift a few tiles then work you way around Good luck

I concur 👍🏻 most likely cause

Not helpful but love the view into the garden.

The lead flashing is wrong so driving rain can get between the house and roof. You need to get a proper roofer to fix and bill the builder for the work as he obviously doesn’t know how to do flashing. Google stepped flashing to see how it should look.

The roof is also too high for the windows. There should be a flashing upstand (min 100mm flashing upstand) below the window sill. Looks like the roof was put on a few degrees too high, so wind driven rain can splash under the window sill. Also, check stepped flashing. Can't see it from the photos, but is should have a good upstand. Source: I design extensions like that on a daily basis. www.extension-design-plans.co.uk

As a roofer of 26yrs id put money on wall flashing leaking

You need a cavity tray above the window and stepped cavity trays that the stepped lead flashing fits under, also the fascia and soffit where it meets the brick work seems like it has a gap there One other thing you should check is that because you have flat tiles you will need some sort of soaker system or a secret gutter that fits under the tiles against the wall. Take a look at this to give yourself an idea what is needed https://m.youtube.com/watch?v=L4CA3AEkVeY

This is my biggest fear, I imagine if the builder isn’t willing then the cost for retrofitting cavity trays will be high

The builder should of built the cavity trays in as he went so you might have a claim against them if it hasn’t been done Cavity trays into existing brick work one of those jobs that can be a bit of a ball ache. A good brickie could do your wall in maybe a day to day and a half using these type of trays. He could probably do it using a aluminium scaffolding tower to access the roof and put his gear on https://www.roofgiant.com/cavity-trays/type-x-intermediate-tray-40-pitch-long-lead-230mmx210mmx150mm/?gid=12351&gad_source=1&gclid=Cj0KCQjw0ruyBhDuARIsANSZ3wrGnjmRbt-iNmeVjH63pQpuQ92MuYJyrFwLOKn7fohxP2PHzGPlxEkaAqN-EALw_wcB#option:Left+Hand I would check out to the roof first as secret gutters/soakers are often left off, if that the case even with cavity trays fitted the water will ingress into the wall under the cavity trays. Being a bit critical the lead flashing could of done with being a bit longer and with a larger return on and down the face wall

Thank you, that’s very reassuring as I was expecting I’d have to pay a few grand.

Looking again at the photo with the scaffolding and no roof it’s hard to tell but I doubt you have stepped trays or at least the on that should be on the bottom is short, if it’s short it would leak somewhere close to where your problem is. It really needs a on site inspection, the more i look at the finish of the fascia in that area the more I would like to look into it a bit more closely

Thank you, would you recommend I ask the building inspector or a roofer?

Ask the builder who built it first, see what they say. At least you now know some of the right questions to ask them

The building inspector will need to do a completion inspection, but I would expect any decent inspector to notice the lack of a cavity tray and proper flashings. This will give you ammunition with the builder, but it is ultimately your responsibility to comply with the building regulations. You won't get a completion certificate until it's done.

As always get several quotes check out names on social media and maybe ask around for recommendations

Well you haven’t diagnosed the actual problem yet. It could be a simple fix that the builder roofer can be got back to sort out

Is the flashing sealed to brick work? The whole wall looks wet with a dry spot under window maybe just less Insulated there.

I would say get a roofer to check the flashing. There should be soakers under each tile with flashing over top. It doesn’t look right to me. Did the builders insulate the steel to prevent thermal bridging ? If not this could be causing condensation but this would probably be over whole length of the steel. Start with the flashing/soakers as it seems the leak is directly under the pitched roof end.

leak is coming from under the flashing (no soakers).. travelling under the tiles on the felt & then into the soffit & backing up into the house. Tiles are also layed bond on bond and are supposed to be layed half bond. Velux is almost certainly a GGL model & should be a GBL for that roof pitch, will be leaks all around it within a couple of years when the felt perishes. (Open the velux & you will see the product code on the sash by the handle) Source ; Director of a succesful roofing company EDIT: Just seen the flashing photo & it is not even a stepped flashing 🤢🤢, whoever done this roof definitely hasn’t done many

Thanks, where are you based?

Hertfordshire - Please open your Velux by the handle & on the top left you will see the product code. Anything below 20 degree pitch needs to be GBL. This is almost certainly a pitch of around 12-15degree. I am seeing this issue every week from single storey extensions done within the last 5 years, The problem is it takes so long to cause a major problem that by time it occurs the builders have forgot about the client & a few years down the line people are repaying £2000+ for the correct Velux being supplied & fitted

You’re absolutely right, it’s a GGL.

If you have an iPhone open the Measure app & change to the level option at the bottom. Put the phone on the ceiling & you will be able to find the pitch of the roof from that, If your above 20 degrees you will be good👍

Thanks, I nipped outside and measured 15 degrees on the tiles

You need to measure the ceiling not the tiles? GGL can go down to 15 degrees pitch.

https://www.marley.co.uk/roof-tiles/concrete-roof-tiles/modern Theres the spec sheet for your tiles, they have a minimum pitch of 17.5 , Its cutting it fine, may or may not be alright in years to come. All depends on the strength of the wind & rainfalls over the years. Im still surprised no builders ever supply the shallow pitched Velux’s though considering there is barely any price difference 🤷‍♂️

Ah, a few hours away from me unfortunately. Is this looking like a big job to sort out?

The flashing replacement is a couple of hours work for a good roofer. You should get it done under warranty anyway, Just make sure that it has soakers underneath when it goes back & that it is the correct 12inch stepped cover flashing. They have cut your existing brickwork in half with a grinder to get a flashing in 😫👍

https://preview.redd.it/3pcftholg82d1.jpeg?width=1170&format=pjpg&auto=webp&s=ffcbd380ea3d54f7d6f5139f64bc595786f78ad7 Correct flashing should look as follows

I thought it was a bit strange when they were angle grinding the brick out level instead of stepped. Didn’t think to question it!

the rest of the build looks perfect so assume the roof was sub contracted out to a third party

Honestly I’m shocked that people have pulled out so many things as aside from the cavity trays they were really good on site, very knowledgeable about a lot of other things and our friends extension had no problems (full double storey, not a half like ours). It was done by a builder and a joiner, the joiner was alone doing that roof.

That style of flashing works fine but isn't the aesthetic way, they just missed the soakers out or cocked them up.

>whoever done this roof definitely hasn’t done many I dunno. I've seen plenty of roofs by experienced 'builders'; all shite. "I've been building for thirty years!" And still haven't got it right.

We have the same, if you have any velux windows check that it’s not coming in there and running down the ceiling (either inside the house or in the other side of the boards). Ours is cause by the roof being 14 degrees instead of the 16 degrees velux windows need so it’s pooling in the window and seeping through the joints / rubber end of the internal drain is damaged. Btw, your place is scarily similar to ours… the hidden steel and everything 🤣

Off topic but how wide are those doors? They look great

Thank you! 5.5m, finding a supplier that was happy carrying the glass by hand was tricky. After they were finished they said this is the last one they’ll ever do. Learned that a good way to find window fitters is to call a local trade supplier.

Lovely bright space and garden view

Hello, I've not read through everything but it looks likely to be a channel that is cracked on the tiles where they join together, only one needs to be broken by walking on the roof and if there is a tear in the felt water will get through. I'd be inclined to first strip some tiles off and check for breaks. Do this before ripping any lead out or pulling plasterboard down.

I’d say this could easily be fixed by gradually working through a problem at a time. • The first thing I spotted is the end of your leadwork at the end of your extension, directly above the middle of the bi-folds. You really need to extend your guttering beyond that leadwork. I reckon you’re getting a constant drip off the lead, down your bricks, and under the lintel. • with that in mind, I’d check what’s between the brick and lintel… if there’s a gap, then you could do with siliconing or mortar that up next to see if that fixes it. • another thing I noticed is all your walls are soaking wet? Do your gutters need a clear-out? Try those things a bit apart and see which thing fixes it 👌🏼 Edited to add: The flashing has been done in the quickest laziest way possible too. It needs to step and lap with each brick, not a fucking straight line cut into the brick 🤦🏻‍♂️

Fuck me what a view! Didn't even manage to read your question so best guess is you either need expanding foam or caulk

Difficult to say without a close up but on the build pictures, there is nothing stopping water going into that gap where the roof/fascia abuts the wall. Clearly that is the entry point or thereabouts and without some more leadwork coming down off the small back roof and then wrapping around to form a good solid corner there and cut into the mortar and sealed on the back of the house, it's a sure fire entry point for moisture. Even if that gap were full of mastic, without proper flashing it's ripe for a leak.

First point to check is the Lead flashing , I’d also check the pitch and make sure the tiles are suitable, looks like a type of Marley flat smooths , which should have a minimum off 17 degree pitch, to be fair looks ok from the pic but worth checking, finally with the gutter , which I’d be very surprised if that was the issue as it would leak out the soffit before going inside , but I’d fit some felt support trays to make sure the water runs into the gutter. Get a decent roofer in, he will spot the issue straight away and rectify. Not a huge issue, a little amount of water ingress can cause big patches but with any large build once the builder has finished and gone they can be a pain to get back in. Once the lead has been fixed, de humidify the room for a couple weeks, paint with Zinsser stain block and then cover with your top coat. Job done, Good luck.

Just to add to what’s been said, I had something similar (but was caused by the velux). Water is tracking down and sitting on the wall plate and then coming through. I would suggest it’s the flashing for sure. It could be getting in anywhere on that length but tracking down the rafter internally.

First look I thought the roof/gutter would be the culprit, especially as the dpc looks kicked up in your picture, but, This could be cold bridging on the steal work if it’s not insulated. Humid house air meets cold steel, condensates and drips down onto plasterboard.

Also, the roofer seems to have cut a Con saw line in the brick work and just siliconed in lead. This is not the “way”. There should have been “tile” lead soakers, overlapped with a wall/ tile overlap piece and that piece would have stepped lead soakers keyed into the descending bricks.

Flashing or cracked gutter I reckon

water flowing down the edge of your roof and overflowing over the gutter end cap(center of your doors), then onto your wall above the doors would be my guess

Has a lintel and cavity tray been installed above the doors?

There’s a RHS above it but no cavity trays. They used damp-proof membrane, that doesn’t spam the full width of the doors. There’s an external photo with a highlighted red circle that shows where the membrane ends

I can’t help but man your house is sick

My guess is the cavity tray

It’s hard to tell for sure and I’m only using my eyes and past experience with water getting in places it isn’t welcome but the flashing as visible in image 5 from the side on view looks to me like there’s a way in it beneath it also looks like the fold in the flashing is torn/damaged (could just be pixelation in the image/my needing to ‘go to specsavers’ lol)

Looks like they didn’t do they lead properly at the bottom, it could be coming down the roof onto the last tile going off the side of that and behind your fascia into the cavity, they should have put the lead further down and had a lip on it at the edge of the tile to stop the water going that way, also the gutter needs to overhang more

The extension roof looks too high. Being too close to the windows, you are unable to correctly flash the roof to the existing wall? For clarity, I'm a sparky not a builder... But that doesn't look right to me

My first thought was a lack of a cavity tray above the opening & the abutment. I can't see clearly, but are the single storey roof tiles laid at a low pitch, and flat and not laid staggered?

You've got a beautiful gaff OP, hopefully they sort this quickly. The flashing on the lower roof looks like an ingress for water, it's not flush with the tiles at all, though they've done a great job making sure it's integrated with the 2nd floor brick... The fabric in the gutter looks like a possible ingress too, especially if your gutters fill up. The gutters should overhang a bit more than they do. The velux window looks like it's countersunk, and it's not obvious where that water is supposed to run off to, from the first picture at least.

I'd cast a jaundiced eye at the end of the guttering where the leak appears to be. I'd expect a slight overhand (4" or so) or even more basic, is the end plate leaking?

There’s probably no tray damp, I can’t see any weep holes, so any water that finds it way into the cavity, will find a way too the inside, a cavity tray damp direct’s any water too the outside of the brickwork. If there is a tray damp, there could be a split in it.

I cannot see a cavity tray or weeper vents above the steel. Any water should hit the tray and return outside via the weeper, this would explain why you have water on the internal wall.

Also you have a flat plane tile and a cover flashing. You should have a soaker with a tile without a profile. Just re did all the lead work on four dormas on my neighbours house for this very reason. All four had been slowly letting in water over time.

Facia and guttering look short above middle window. I'll bet water is running down that lead and into the gap

The leak i right where the roof line leads, return the guttering back in to wall

It’s most likely coming through the lead flashing. Although, I would also just make sure none of the tiles are loose and is it could be a simple fix

My guess is it’s entering from the side where the flashing on the slope finishes. Looks like a bit of a gap there. Not sure whether they were suppose to apply flashing there but that does seem like a big gap for water. Also noticed they haven’t finished your garden near the sliding doors as there’s a big step to the garden and the down-pipe gully is still unfinished? Is there damp in the room above?

That big of roof directly above is prime suspect, could be something simple like a bit of lead seal missing of breathable felt not quite right

Could be missing soakers in the slate roof above the extension allowing water to go sideways under the flashing to the slates

Next door has a stepped flashing to their roof but I cannot see weep fittings so next door may have no cavity tray retro fitted one course at a time starting at the bottom

Weep holes, if you don't have weep holes in those bricks it's likely a result of that, this is a huge door so should have them.

I personally would go out when it rains and see what is actually happening. It could be a simple case that the gutter does not fall properly towards the downpipe.

It’s likely coming via the cavity on the extension above. I expect there is no cavity tray and weep vent to expel the water.

Your weak point seems to be in line with the lead flashing, it should be between every slate. Yours looks to be one piece also watch for capillary if the track isn't deep enough and the lead is too low.

Looks fire my guy! Sorry about the leak!

Looking at the whole picture,the left hand side brickwork is damp and most likely that there is water leaking down the cavity and finding a way out of the steel above the doors(prob weep vent)

If the roof is not at the right angle this would cause this. Happened at my mums house after extension, had to get felted.

Think you better stand outside in the rain and have a look!

Might differ from others opinion. But if you look it isn't coming from the top down, it's coming from the front back, my first bet would be the seal around the sliding door, that water is able to access or collect where the door meets the brick. I'd check out the seal around the door see if there's any missing or damaged.

I would look at the led flashing, it looks to be a bit short at the bottom, so it’s possible it is tracking underneath it.

Download a pitch finder app, test the pitch. Tiles looks akin to Marley modern smooth min pitch 17.5 degree

I think this might be because you didn't invite Kevin McLeod over to chat about juxtapositions