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GRP roof rain dripping behind gutter

Discussion in 'Roofing and Guttering' started by swebb99, 9 Sep 2021.

  1. swebb99

    swebb99

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    Hi,

    I had a flat grp roof done a few years back and its been fine, however I've had issues with the rain in places running over the edge and not in to the gutter but dripping behind it. Also when it is really heavy rain the gutter just can't take the flow.

    I've tried putting laying a roll of waterproof membrane plastic down the gutter and pushing it under the lip of the roof and that works for a while but it usually slips down and then the drips start again.

    I'm not sure the correct guttering was used and also I'm not sure the slope is correct. The trouble is if I re-mount and increase the slope at one end the gutter is even further below the roof edge/lip.

    Any idea without taking the roof off. Is there any kind of strip or something I can get which I can attach to the gutter to slip behind the lip of the roof ....

    Thanks in advance 20210909_141210.jpg 20210909_141309.jpg
     
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  3. catlad

    catlad

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    Cut down some felt support trays.
     
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  4. oldbutnotdead

    oldbutnotdead

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    If the gutter is overflowing then it's either not got enough fall or it may be undersized for the roof area (what size roof is it).
    Drips behind the gutter aren't a surprise looking at where the roof ends- bit more overhang would have helped. As @catlad , Travis Perkins have them at £1.50 a go at the mo, perfect for the job
     
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  5. swebb99

    swebb99

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    Yes the roof is at the back and side of the house (L shape around the house) and the main roof has two gutters also running on to it. Its about 35ft wide at the back, by about 7ft and the dog leg around the side is about 22ft by about 7ft.

    Yes I thought it needed more overhang. All the other work I was happy with but I was never totally happy with the roof as I don't think it has enough drop on it and I'm still not sure about GRP as a covering. It seems solid enough, but not something I've had before. It's actually a multilayer roof by Flexitec , fibre and then some rubber coating, just worries me how to deal with future leaks or splits.

    I'll have a look at the perkins deal, thanks. I assume I just slide them under the lip of the roof then and cut them to a size so they stay put under there and in the gutter. The current waterproof membrane strips just bend and slip down.

    Thanks again
     
  6. oldbutnotdead

    oldbutnotdead

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    Yeah that's the deal with the felt trays. Tinsnips or hot wire cutter or grinder & tile cutting disc are the quick ways to trim them, Jigsaw & handsaw doable but you have to stop the things flapping around.
    Next time it is chucking it down, have a careful look at the overflowing sketch- could be downpipe is blocked or got lots of elbows so slowing flow, could be low spots on the gutter.
     
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  7. swebb99

    swebb99

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    Just bought some from TP so I will give it a go over the next few days, thanks for the tips. The downpipe is in the corner of the L on the roof and is basically just straight down so I think the issue is that the gutter is a bit too small for when it's real heavy rain. Next time I'm going to get the ladder out when it is howling it down and see what is going on. I might end up getting a bigger gutter and check the line of it.
     
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  8. catlad

    catlad

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    The felt support trays will snap if you score them with a stanley knife
     
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