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Flat roof water ingress

Discussion in 'Roofing and Guttering' started by jalexs, 21 Oct 2019.

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  1. jalexs

    jalexs

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    Hi All,

    We have a flat roof over the porch, and there has been some water getting in over the past few weeks.

    It is a 50s concrete flat roof, and although you cant see from the pictures there is a drip groove which does filter a lot into the guttering.

    There is still a fair bit still working its way back to the brickwork and back down, which is finding its way inside.

    I've checked the drip groove and there is nothing stuck in there to cause a bridge.
    On the right hand side of the guttering in the picture, the gutter bracket does seem to be right up to the concrete edge which cant be helping but doesn't seem wet there.

    I cant see why the water may be getting back to the brickwork further up.
    I'm wondering why it is doing this as next door has the same setup and no issues, perhaps a bit more of a felt overhang down past the edge.

    Is it a case of getting the flat roof replaced, or would there be a retrofit solution?

    Thanks in advance, James
     

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  2. bobasd

    bobasd

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    your exterior pics are too dark - snap new pics one with a length of guttering removed (show any fascia or drip board) - and one showing the top of the roof at the drip edge will help?
     
  3. jalexs

    jalexs

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    As you can see, the drip edge isn't majorly effective. A lot is going into the guttering but there's obviously an amount that is meeting the wall..
    There are also small gaps in the pointing, could this be the entry point?

    If so then both issues may be working in tandem!
     

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  4. bobasd

    bobasd

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    does the roof have falls into the gutter?
    ponding is occurring.
    are the walls solid or cavity?
    the flat roofer should have fixed a drip board dropping below the thickness of the concrete, and then dropped the drip edge capping over it with the gutter set lower down the wall..
    the pointing doesn't look too bad but you could rake out and re-point the top courses?
     
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  5. jalexs

    jalexs

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    I can't vouch for how long the flat roof has been on, I'm guessing over 11 years.
    There is nothing directing it into the gutter as such. I believe it is solid walls in that part of the porch.
    Would the sensible thing to do be to have a new flat roof installed with decent drip edges (given the age too)?

    What would a sensible price be for replacement and presumably new boarding? It's roughly 3*2 Metres. We are south east (Essex).

    Thanks
     
    Last edited: 30 Oct 2019
  6. bobasd

    bobasd

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    there's not much more i can say.
    get a local flat roofer on site and go from there.
    the cover looks to be in good shape but i dont know how it was installed or if its even leaking in the field - only someone on the roof could tell.
     
  7. ^woody^

    ^woody^

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    The problem is almost certainly related to the drip from that concrete – water is running back and missing the gutter.
    It could be that a tiny bit of concrete has come off or a bit of something stuck on, and a tiny channel/route for water been made.

    Give the drip a good clean and wire brush and make sure it's intact. Increase it with a grinder if need be, or run a bead of silicone along the underside.
    You may want to coat that exposed vertical concrete with a bitumen paint to prevent water soaking in to it.

    And then when refitting the gutter, make sure the drip is within the gutter and the gutter edge not touching anything.

    Alternatively, you could lift the felt edge, and insert a strip of felt or polythene/bitumen DPC and drape this into the gutter, to acheive what it should have been done like in the first place.
     
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  8. martin hill

    martin hill

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    Hi There. For a quick fix till you get the roof sorted you can use these.

    https://www.wickes.co.uk/Proplex-Bl...jtutWLyKE1RW7l6xmhwaAnhCEALw_wcB&gclsrc=aw.ds

    Cut into 2.4m strips wide enough to tuck under the felt and into the gutter. Bitumen paint the concrete edges first then slip the strips under the felt and use some exterior grillfill to hold in place. I used these sheets as felt trays on my roof till i sorted and they worked a treat and cheap.
     
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