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Velux window leaking. Help needed

Discussion in 'Roofing and Guttering' started by Waseem1, 21 Aug 2016.

  1. Waseem1

    Waseem1

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    Hi I had a single storey extension done and installed velux windows the roof pitch was too low and the windows were leaking so I had to install velux roof kerbs to increase the pitch because the leak was coming through the velux. Well last night after heavy rain had a further leak but not sure if it's the window or the roof.
     

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  3. catlad

    catlad

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    What size slates are they and what is the pitch of the roof?
     
  4. Waseem1

    Waseem1

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    Roof pitch Is around 10 degrees. Slates are 500mm with 75% overlap. The velux kerb is dressed with ubiflex. Any help will be appreciated.
     
  5. catlad

    catlad

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    Those slates at that pitch are not going to work very well, I suggest you go with a rubber roof.
     
  6. Waseem1

    Waseem1

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    The rest of the roof is OK just after having the kerb installed leak in that area. Not sure if it's the window or water getting underneath flashing which Is overlapped. The reason why I installed the kerb is to stop the windows leaking and now got this new leak. Really stressed
     

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  7. ^woody^

    ^woody^

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    Surely that a problem with the joint at the bottom of the kerb and the roof, and not with the roof light itself?

    Are you sure that the pitched roof underlay is adequately lapped up the kerb and sealed at the corner?

    That's a poor detail and it really should have a lead gutter and flashing between the roof and kerb, with a ply support around the kerb too.
     
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  9. Waseem1

    Waseem1

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    The material used is ubiflex and is a lead substitute is supposed to be one of the best. The material is dresses under the slates. Sealed with ubiflex high tack. The felt is actually lapped all around the kerb. The roofer used a substantial amount and was lapped all the way up the side of the kerb.
    http://www.diynot.com/diy/threads/velux-or-roof-leaking.403700/

    This person had a similar issue
     
  10. vinn

    vinn

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    This must be disheartening for you but I would suggest that it all stems from the original decision to install Velux in a low pitched roof.
    Why not, working from the bottom of the roof /kerb abutments slowly water test your way up the abutments?
    Allow time for drying off and then water test the Velux frame itself?
    I dont think those slivers of slate are doing you any favours - larger slates could have been cut down to suit. But you do seem to have ample width soakers.

    Photo 209.9 shows a slipped slate.

    Just a long shot but given that Ubiflex dont offer corner pieces in their pdf catalogue perhaps the outside corners from the "back gutter" of the kerb might have become distorted while you turned them round the corners?
     
  11. Waseem1

    Waseem1

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    It's very disheartening few times I've felt like giving up have already spent £2500 rectifying other leaks was supposed to move in last year. The rear corners what you see those are just overlaps of ubiflex it's all overlapped. I will start from the bottom and use a hose to spray it down. Thanks for your help appreciated
     
  12. ^woody^

    ^woody^

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    I'd consider making a hole in that plaster ceiling or in the lightwell side above that damp patch, so that an entry point can be viewed when it rains or you test it.
     
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  13. chappers

    chappers

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    You say the kerb is dressed with ubiflex, how has this been done. Each slate should have a soaker up the abutment of the kerb.
    As Catlad said you have an issue with the pitch and the slates, which you have to a certain degree addressed by increasing the headlap, however in picture two and five at the top left of the kerb the gauge/headlap appears to have been lost.
    How you find the source of the leak is one thing, either way you are going to have to take it off to fix it. For what it's worth I very much doubt the velux itself is leaking
     
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  14. Waseem1

    Waseem1

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    Yes I can see one particular slate where the bigger headlamp has been lost. This has been done on counterbattons and on osb board. That's the Base. I've also used permavent easy slate strips. The ubiflex has been flashed vertically under slate and the ubiflex is itself overlapped. That is the soaker. I will see if I can upload a pic
     
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