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Leak beneath stepped chimney flashing.

Discussion in 'Roofing and Guttering' started by frank999, 26 Jan 2020.

  1. frank999

    frank999

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    The full depth of the mortar joint was removed to fit this replacement flashing, wedges were put in and joints remortared. (a dry ridge system sits on top, last tile abuts chimney, thatwhich sits over and beyond the saddle is mortared)

    A small leak extists, that comes down the outside of the chimney stack - inside the newly constructed loft conversion - ie below the flashings, I can't see exactly up under to see at which point its entering, but suspect it is running down the chimney stack above outside (above the flashing) and somehow entering where the stepped leading's corner is cut from angled to horizontal.

    Any ideas, thoughts are to squirt some form of sealant behind the anlged lines of the flashing.
     

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    Last edited: 26 Jan 2020
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  3. datarebal

    datarebal

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    The Pointing is not perfect I can see a few holes on the raked cuts

    There appears to be no tray in the stack , if there is its now lower down within the new loft area.. tricky!
     
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  4. frank999

    frank999

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    Thanks for the reply.

    Are these the 'holes' you refer to (see 'Close up.jpg), it is here I propose to pull out the lead away slightly from the brickwork enough - to push the nozzle of a sealant gun behind and squirt plenty behind, then dress the lead back against the brickwork.

    Yes the pointing could do with some work.

    The flue/breast has been removed, and the remaining stack is supported on steel work, we didn't find any tray as we removed the breast, should I assume its somewhere in there (if not lead then slate), this is a 1930's Laing semi. The Stack was previously capped off, with a crude slate and cement covering (which doesn't fully go to the stack edge) - which is still in existance.
     

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    Last edited: 26 Jan 2020
  5. colind86

    colind86

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    The roofing work in the pictures looks perfectly water tight and dare I say maybe above and beyond! 11 out of 10 for effort to the roofer. Chimneys are notoriously bad for leaks and more often than not it comes from the top. Get the chimney re flaunched and see if that helps.
     
  6. bobasd

    bobasd

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    the roofing work in the pics is a perfect dogs dinner -

    amateur attempts at lead burning might have failed.
    and an amateur attempt at bossing the outside corner has distorted and weakened the lead.
    the lead saddle has what looks like a gap on the far side, and has needed a further soaker slipped under it on the near side - which suggests the rough line of saddle lead burning is allowing moisture in?
    are there soakers on every tile?

    the cap sheet is in bits and pieces. how come?
    the remaining damp patch suggests that ponding is taking place in that vulnerable area - if not ponding then what is causing the damp to remain?
    how is the flat roof meeting the pitched roof under the first course of tile?

    there's more but why bother listing it?
    from what i can see no qualified roofer or lead worker has been near that job.

    your best bet OP is to remove the lot, including some of the tiles, and maybe expose whatever is going on behind, and then post pics.
    and then have the whole lot re-done by a pro roofer.

    beyond saying that the majority of c/stack leaks are from flashing (mostly back gutters) then without pics of the stack flaunching its not possible to comment.
     
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  7. frank999

    frank999

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    Thanks for your detailed comments - your right, it could be a lot better, a first go at lead welding, and chimney flashing, done in a hurry, never good.

    Not proclaiming to be a skilled roofer, I have no formal training or had anyone to work alongside, just reading, respect what it takes to be such.

    Will check the lead welds on the saddle, I have since improved my lead welding skills.

    There are soakers on every tile, top soaker was just an extra precaution. Agree, cap sheet is a tapestry.

    Will pull it all off and take a look and post some pics, will also post up pics of the flaunching.

    Second time round it will be better - its on an unoccupied house I own, so no one is suffering, apart from some T&G flooring.

    A copy of The Lead Manual is on my christmas list, a beautifully illustrated book.
     
    Last edited: 27 Jan 2020
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  9. Nige F

    Nige F

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    Were you using Oxy Acetelyne and a proper torch for your burning ?
     
  10. frank999

    frank999

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    "Were you using Oxy Acetelyne and a proper torch for your burning ?" yes I bought an 'OxyTurbo' kit, and my welding has improved greatly since these pics.

    Found the leak, thanks to bobasd for mentioning the Stack Flaunching, where upon inspection found a 'hole' for rain to get in ... when the stack was in place rain running down this hole was not a problem, but we removed the stack inside, and supported it on steel work, with a 300mm plate under the stack flues, so rain had no where further to go down the flue, and went side ways into the loft, fixed by by reflaunching.
     

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  11. Makie

    Makie

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    The oxyturbo kits don't use acetylene (they have a ****ty gas). I would invest in a better kit that has the proper gas as the finish on your work will look much better
     
  12. frank999

    frank999

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    (they have a ****ty gas) - coud that be 's***ty gas'

    The OxyTurbo was quite 'handy' for hauling upwards on roofing, (useless for Aluminium welding - which I also had a go at) ... yes have been pondering something a bit more heavy duty, would 'better kit' also mean full sized bottles ?
     
  13. Makie

    Makie

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    They are handy kits and will weld lower codes of lead to a average standard. A better kit would be one with actual acetylene welding kit. They don't have to be huge because acetylene in it's liquid form can expand by about 600x if I remember correctly
     
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