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Plugged rainwater runoff gully

Discussion in 'Plumbing and Central Heating' started by Loofah, 15 Sep 2021.

  1. Loofah

    Loofah

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    We bought a house and fixed it up etc but there is one issue with a gully on the 'old' bit of the house. We're getting water ingress at the back of the fireplace.
    On the exterior wall there's a cement plug in a gully and I have no idea why. The downpipe now runs to an adjacent gully, not blocked, but both have been built up to the DPC. I think that the cement plug might be hiding an issue but wanted to ask more informed people first before I go smashing it about.
    Pics show what I mean a bit better. On the other side of the wall behind the downpipe is the fireplace, the blocked gully being central to the opening. I wondered if it might have been a water runoff for water coming down chimney but have never seen that before.
    In heavy rain, water overflows the guttering and splashes around the gullies; I've plugged a few holes in the wall and dug out the soil from the DPC but there's still some seepage happening.
    Could there be a really good reason not to open up the gully or is this perhaps just an old house issue and I need to repoint the wall? And sort the overflowing guttering...

    PXL_20210904_154024161.jpg PXL_20210904_154017556.jpg PXL_20210904_130313007.jpg
     
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  3. Hugh Jaleak

    Hugh Jaleak

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    Unfortunately, without digging it up, it's difficult to say if there are 2 gullies there, or it's one with a back inlet connection, such as this type from Knowles Drainage.
    Knowles gully.jpg

    Does appear though the brick surround on the Gully is bridging the Damp Course, and if the water is splashing around and soaking the adjacent brickwork during heavy rain, it's not going to help matters. If you're brave enough, I'd look at removing the existing arrangement, cut back the outgoing pipe and fit a new Plastic Back inlet Gulley in place of the current affair, connect the downpipe directly into the back inlet, and ensure the water goes where you want it to, (i.e. away) and is kept off the wall.

    If the Gutters are overflowing in heavy rain, make sure they are clear of debris, are falling towards the outlets, (doesn't have to be a steep fall), and that they are correctly positioned to avoid the rainwater overshooting as it comes off the roof.
     
  4. Loofah

    Loofah

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    I hadn't thought of that sort of configuration so thanks for the pointer. When I get a bit of time I'm going to remove the plug at least to see what's in there and if there's time either do as you suggest or at least address the bricks bridging the DPC.
    I'm not sure what I can do with the guttering as it seems to run toward the downpipe and it's a 4" gutter which to my eye looks to be positioned OK. Clearly not as it overshoots lol would adding in another downpipe help in this respect? I could direct it to a rainwater garden or something

    Thanks for the help :)
     
  5. Tricky-Dicky

    Tricky-Dicky

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    I would remove the shoe from the bottom of the down-pipe, and see if the flow goes straight down the gully, rather than splashing around. You might need a short piece to extend the pipe. Also you could remove the grid, and let the rain water pipe flow straight into the gully. Some say the grid stops leaves etc from blocking the drains, but this has not been a problem for me.
    The 'pointing' around the chimney stack as it passes through the tiled roof looks very suspect to me, and might explain the damp fireplace. Surely some flashing is required.
    Regards
     
  6. Loofah

    Loofah

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    OK, the hammer came out and the plug of concrete removed. I also took out a pile of hardcore and smacked the right side brick away. There was a small hole above what is clearly another drain so I widened that after exploring a bit more; it's easily deep enough to breach the DPC so that's at least one point of entry.

    I'm puzzled why a drain would point into / under the house??

    The gully with the downpipe looks 'OK' in as far that it doesn't seem to have any concerning holes so for now I'm leaving that alone.

    I'm planning on tidying the smashed off drain entrance then sealing, maybe with a balloon then concrete (good or rubbish idea?) and the hole below the DPC will be filled with mortar. Area in front to be left open to keep moisture away from the wall.

    Does that seem like a reasonable idea?


    PXL_20210920_132453662.jpg
     
  7. JohnD

    JohnD

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    these old clay gullies are often cracked and leaking, so I would wish to dig around it enough to find out what it is, and if it needs replacing.

    Multiple "repairs" have often been attempted before the thing gets dug out and replaced.
     
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  9. Loofah

    Loofah

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    I've carried on with the plan. The hole was backfilled and mortared and the pipe stuffed with some plastic bags and again mortared closed. Will see how it progresses and if I continue to get any damp I shall be back!
     
  10. Hugh Jaleak

    Hugh Jaleak

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    Very odd setup, so the redundant capped gulley outlet goes under the house? I'd expect to see such a setup if the pipe going under the house connected to to something internally e.g. a sink or basin, and drained externally, keeping waste water and rainwater separate, otherwise I'm at a bot of a loss to understand the intention.
     
  11. Loofah

    Loofah

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    Me too. The wierdest thing is that it's clearly a gully to catch rainwater as it scoops upward so if it were connected to a sink for example, it would never have drained out. It just looks as if someone placed a water runoff under the house. Which is dumb.
     
  12. Harry Bloomfield

    Harry Bloomfield

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    Might it go completely under the house and come out the other side, then to a main drain? Odd that it should be plugged though, if that is the case.
     
  13. Loofah

    Loofah

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    Maybe it used to but why would anyone choose to do that?! I'm parking it in the 'odd' category and forgetting about it I think or it will give me a headache. It's definitely just a piece of pipe, disconnected bother ends, now, whatever it was before
     
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