dormer higher than ridge tiles

also, I hadn't noticed but the dormer roof leans from left to right. The others around here don't. Are all the scrape marks on tiles just from cutting? I'm presuming this will look better once its been rained on a bit.
Box dormers are never gonna win any medals for architecture, but I would like it to look quite neat and tidy
View attachment 95077

The marks on the tiles is just the dust from the cutting - they will go eventually.
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the builders amended dormer roof to keep below top of ridge tiles. they trimmed the firrings and will direct water under the ridge tiles and on to front roof. I've attached a couple of crude not to scale diagrams and a picture. I hope they can tidy it up a bit, doesn't look so neat now. The felt is 3 layers torched on. Never heard of this method before, I wondered if this is a good way of keeping a roof water tight?

View attachment 95075 View attachment 95074 View attachment 95076
I think that's a recipie for disaster.

Just looking at the 3rd pic, of the dormer cheek.
Don't want to pour cold water on it but I suggest it could have been done a little better. The capping on the fascia is not right; they seem to have missed a course of tiles at the top on the front, and the junction between the cheek and the existing roof looks suspect. Have they just mortared or mastic'd it up?
These things make one wonder what else might not be right. But it's the ridge tiles that are patently wrong and the main problem. Perhaps you should have left them as they were, even if they were a touch higher?
yep would agree, you'll get water pooling behind the ridges definitely missing a course of tiles and no the roof shouldn't be running left to right
thanks for replies guys. The builders say they will use special ridge tiles with holes in that let water flow under. I've never heard of these. Has anybody else?
I wish Central London Lofts would discuss before things like this. The plans show the dormer tucking in under the ridge tiles, but they built above it rather than lowering the ceiling a bit. Didn't bother to discuss with us. The project manager said they shouldn't do it without talking to client first. I sent them an email last night asking them to discuss with me how this could be amended. I thought maybe they could just trim the arris rail back a bit so it wasn't visible from street, but they just go ahead and slope the dormer roof under ridge tiles without talking to me first.
I really don't know what can be done about this
The builders say they will use special ridge tiles with holes in that let water flow under.

Never heard of them either - would seem to defeat the object of having ridge tiles - but I might be wrong.
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thanks for info tony1851. I''m not sure what the capping on the fascia is? Is it the way it fits to board underneath? It was neater before they amended it.
The junction of cheek and roof has lead flashing running all the way down
Bloody hell, what a hash up, why was it changed anyway - the consensus here was that it being a very minor breach and enforcement extremely unlikely?

For some reason, specialist loft conversion company's seldom seem to do a great job and I will put money on it that their inspector is private and is the one they use on every single job.
haha cheers Freddie. The inspector came yesterday and gave it a proper look over. Planning isn't his remit but he will raise the weather proofing aspect with the project manager.
If we'd known the alternative we would ask to leave it alone for sure.
They now say the firrings will be re instated using the off cuts. I imagine they will overlap some flashing over the ridge tiles. They can also use 50 mm arris rails apparently instead of 100 mm so its less noticeable. Not sure if this is necessary, don't wanna risk more hassle
I agree its better to get a trusted local guy who's work you have seen to do your loft conversion. The only 2 guys I know round here are booked up for over a year.
The loft company guys work really hard but its hard to get any time with the project manager as he's darting about all over the place managing loads of jobs, and they are under pressure to turn it around quickly.
I've attached in image showing before and after tiling. Its missing a row of tiles at the top of the dormer face because there is an extra batten on the sides so they can add another row. Not sure if this affects weatherproofing?
Tt is pretty sheltered under the soffit at the back of the dormer face but the fact is that it is just plain wrong and not weathered properly.
The tiles should be double lapped ie tiles should reach down to cover the top of the tile two rows below it or else be replaced by a flashing that does. In this instance there will be a small space at the top of the top row where water could get in and not run down the face of the tiles on the second row down and run down behind instead. They either need to fit another row of tiles or a suitable flashing.
Also judging by their other roofing work and ideas, whilst they may have a lead flashing to deflect any water coming off your dormer cheeks, I would be more worried that they might not have used soakers under the tiles of the neighbouring roofs where they abut your dormer cheeks. easy to check, bend up the flashing that you can see flat to the roof and between each of the tiles up your neighbours roof abutting your dormer there should be a lead or zinc soaker which turns up your dormer cheek a little bit.
thanks for info chappers, really appreciate it. I have seen other dormers nearby that have flashing along the top row on the front. I'll certainly mention it to the guys and also the inspector. Good point about the soakers. I did see a big pile of them and I know some have been used around the door and windows. They are putting the flat roof back to the way it was now. They are also using 5 cm arris rail instead of 10 cm so it doesn't peak above the ridge. I don't mind if they keep the 10 cm arris rail if that offers better weather proofing. The consensus on the forum is that a minor technical breach of permitted development is very unlikely to be enforced, and we can wait 4 years before applying for a certificate of lawful development
dormer roof is sorted now. the guys have done a great job, new front roof too and ridge tiles, smaller arris rails, looks bob on.
here are latest pics. they are just finishing off ridge today so I imagine the felt along the sides of dormer roof where it meets the fascia board will be tucked in a bit tighter when done.
I would like some flashing along the top row of the dormer face as previously advised on here. Is that a lot of work now that the fascia and gutter have already been fitted?
LeftCheekNearlyFinished.jpg RightCheekNearlyFinished.jpg NewRidge.jpg
Update on Central London Lofts:
oh dear, whilst decorating I realised how out of square the whole dormer is. Walls are out of square, there is a 62mm variation in the height of flat ceiling. some of this is the floor sloping but also the ceiling is higher at garden than at ridge. So I climbed out of skylight and tested the gradient of roof with a bucket of water. It flows back towards the ridge. When it rains there is a large pond up there.

The inspector is due one more visit for signing off. I will have to point this out and see what he says

FullWidthCeilingHeight.jpg dormerFaceLeaningRoof.jpg CeilingChimneySide.jpg roofPond.jpg
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update: well the good news is the leaning floors and ceiling and out of square walls are just "poor quality workmanship and do not affect the structural integrity" according to building inspector. Unfortunately the dormer roof deck does not meet building regulations and has to be stripped off and re done.
The arris rail drip on the sides make it look worse. have you a pic from the elevation?

The white (scruffs) at the side of the windows is dust from cutting. as its tile hung it will take a while to was away.
Bucket of clean water and soft brush ..while the scaffolds up.

On the angles (corner tiles) its rub marks from transportation.

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