Roof leaking, Velux window problems?

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Hi, I hope this is in the right sub-forum, figured roofing was more appropriate than windows or doors.

We recently moved into a brand new house, it's a traditional construction, brick with z tiled roof.

It's a three story house with a master bedroom and en-suite on the top floor. The roof has a slightly unusual deisgn as it is not a traditional pitched roof, it actually has a flat top. The top floor has a traditional dormer type window at the front and two velux windows to the rear (one of which is in the en-suite itself).

Example of the roof type and positioning of windows (neighbours house, ours is similar but a mirror image of this)
DSCN2308.jpg


We've had a recurring leak for a number of months now and the original roofing contractor to the housebuilder had been out on a number of occassions and was not able to resolve the issue. The leak first became visible in the en-suite, initially we noticed some water marking around the velux window and then after heavy rain water started to come through from various parts of the ceiling. I appreciate that where the water leaks isn't necessarily where the source of the leak may be. Following even heavier rainfall we then had severe water ingress and leaking into the room below the en-suite.

I won't mention the name of the housebuilder as it would not be fair on a public forum.

The housebuilder then arranged for a specialist roofing / general building contractor to look at the problem. They've errected scaffolding and I've also been up to have a look myself. Initially they found a tear in the felt which has seen been patched however following rain this has still leaked.

Looking at the position of the velux I now fear that the window may be positioned too high. I understand that there are different types of frame that need to be used depending upon the type of tile etc. However my core concern is that the velux to the ensuite is situated so high it's effectively on the ridge. There isn't a course of tiles above this velux. The other velux for the master bedroom is actually situated lower and has a course of tiles above it.

Some pictures appear below. I would appreciate any feedback, thoughts and suggestions about the positiong of the velux window. I believe that we need a smaller Velux in the en-suite to allow the window to be re-positioned lower in the roof line and allow a course of tiles around the whole frame.


Close-up of the en-suite window with the patch repair to the felt.
DSCN2309.jpg


Another close-up of the en-suite window
DSCN2307.jpg


Window to Master bedroom
DSCN2311.jpg
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If you look closely at the picture above some of the tiles at the bottom do not appear to be flush. Is this any cause for concern? We have had no issues with leaks around this window!

Many thanks in advance...
 
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I think you're on the right track with your thinking; there does not necessarily have to be a course of tiles above the Velux but there does certainly need to be enough room (approx 200mm) for the rear flashing to lay in the same plane as the rooflight.

However there are other issues with your roof that may well be contributing to the problem.

The correct method of construction where a pitched roof meets a flat roof is to have a lead flashing onto the tiles and then the felt to be bonded to the lead. Your felt has been taken onto the tiles which is totally unacceptable.

Also it would appear from your photo that where the felt roof meets the back wall there does not seem to be an adequate upstand and the lead cover flashing is not dressed down. I would suggest that you inspect this area closely as this may be the main cause of water ingress.
 
The tiles not flush isn't an issue, they never sit down next to the velux as the flashing units push them up.

Hmm, agree with the comment about the felt taken down over tiles, it should be lead and you could hacve future issues with wind uplift at this point if the felt adhesive deteriorates.

I have to say that the dry vent system looks a bit untidy to say the least and looks as though it has been put on off centre, bigger upstand needed there I think.
 
I have to say that the dry vent system looks a bit untidy to say the least and looks as though it has been put on off centre, bigger upstand needed there I think.

You're right - it is a Dry Vent ridge - I thought it was coping stones over a lead flashing
 
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That is absolutely woeful.

Either the planners want fu****ng or the developers/builders want flogging for not realising the ridge height allowance.

Their solutions are abysmal.
 
what a nasty horrible piece of roofing detail!!!! mineral felt to cap off from that disaster of a ridge :confused:
 
When Veluxs are fitted it's necessary to cut a hole in the roofing felt. As bad as the Velux fitting instructions are (!) they do show that a 'nappy' should then be made which seals the hole in the felt with the edge of the window. This maintains the secondary protection of the felt.

I know that the nappy isn't always fitted - the Builders didn't install them at my house. I've had a leak and just had to strip off some tiles and fit a nappy, but it hasn't rained yet to see if it's worked.

If you can get a hold of some fitting instructions you can see what should be done - but there's no way of checking without getting on the roof and lifting some tiles.
 
When Veluxs are fitted it's necessary to cut a hole in the roofing felt. As bad as the Velux fitting instructions are (!) they do show that a 'nappy' should then be made which seals the hole in the felt with the edge of the window. This maintains the secondary protection of the felt.

I know that the nappy isn't always fitted - the Builders didn't install them at my house. I've had a leak and just had to strip off some tiles and fit a nappy, but it hasn't rained yet to see if it's worked.

If you can get a hold of some fitting instructions you can see what should be done - but there's no way of checking without getting on the roof and lifting some tiles.
The current problems he's got appear to run a lot further than just faulty Velux installations, there have been fundamental mistakes made both with both the design and the installation.
 
FM,

I totally agree that there's more to sort out than just the installation of the Velux's, but the integrity of the felt is another thing to add to the list.

And however bad the rest of the installation is, if the felt is doing it's job, then there shouldn't be any water coming through into the building.
 
FM,

I see what you're saying - I was talking about the felt under the tiles. The felt on the ridge is awful and should indeed be lead.

Can you believe it, a difference of opinion between members dicussed without insult! Anyway, sorry to hijack - back to the posters problems.....
 

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