Water at foundation level help!

Discussion in 'Builders' Talk' started by Vanessa83, Sep 13, 2023.

  1. Vanessa83

    Vanessa83 New Member

    Hi. Our living room smelt of damp and on inspection the floorboards were a bit rotten and the crawl space is damp.
    We presumed it was water coming in from under the concrete path directly around the house so we have removed it and dug down to foundations. The clay/rubble/soil around it was sodden and holding water to the house, presumably running through the grass and through to the clay. Now it’s all removed we’re not sure how to proceed. The garden slopes towards the house so the rain water is now going through the grass and pooling in the trench that’s been dug. Do we backfill it with clay soil again and compact? Put down a membrane against the house? Also, there’s a long sloping bit of concrete that was under the path (see photo). Can we remove it? Any ideas what is is and why it’s there?
    Any help would be extremely appreciated!! 71EF26BA-66ED-4993-8717-8C93EA2950FA.jpeg 245B9A9A-42F6-4603-90A2-56BAF6A1E216.jpeg
     
  2. BuildingMad

    BuildingMad Screwfix Select

    Air bricks imply you have a suspended timber floor.
    If the ground level outside is higher than the sub floor level under that timber floor, water will pool on the sub floor as it cannot escape.
    Ascertain the sub floor level & ensure backfill outside is slightly below it for at least 600mm width & the problem is solved.
    Dependant on levels & water table height you may need to go further with a land drain.
    A small area at a higher level to get you into doors etc will be OK.
     
    Last edited: Sep 13, 2023
  3. Vanessa83

    Vanessa83 New Member

    Thanks for the reply. You’re right it is suspended timber floors.
    If we only backfill to subfloor level that leaves a huge channel between garden and house as the garden is only slightly below airbrick level.

     
  4. BuildingMad

    BuildingMad Screwfix Select

    I did edit my original post to :-
    Air bricks imply you have a suspended timber floor.
    If the ground level outside is higher than the sub floor level under that timber floor, water will pool on the sub floor as it cannot escape.
    Ascertain the sub floor level & ensure backfill outside is slightly below it for at least 600mm width & the problem is solved.
    Dependant on levels & water table height you may need to go further with a land drain.
    A small area at a higher level to get you into doors etc will be OK.
     
  5. qwas123

    qwas123 Screwfix Select

    OP,
    You dont seem to have a proper gulley - where does the water thats going into the makeshift gulley from the down pipe discharge to?
    Remove the bank of wet soil we can see, this side of the gulley, in the photo and then post a new pic?
    Clean off and dig clear of soil for, say, 1.5m of the sloping concrete - then post new pics?
    What's the condition of any other gullies around the house?
    Can you see any manhole covers on or near your property?

    Whats happening inside the house - with the flooring, the joists and wall plaster?
     
  6. Vanessa83

    Vanessa83 New Member

    There is a drain between us and next door (you can see it on the next photo I posted). We’ve had a hose down to check it’s not coming from there and it doesn’t seem to be. No other drains nearby, all on the other side of house and are all clear. We put a hose on the grass and the water appeared in the hole we dug so had gone through the grass towards the house. I presume that’s what’s happening each time it rains. 1308E7AB-0730-48F1-839D-1D06C1BBA2F9.jpeg .


    1308E7AB-0730-48F1-839D-1D06C1BBA2F9.jpeg
     
  7. qwas123

    qwas123 Screwfix Select

    OP,
    I'm still interested in the only "gulley" in the pics - whether its shared or not is irrelevant at the moment.
    There are also the other questions I asked?
     
  8. Vanessa83

    Vanessa83 New Member

    The downpipe from the gutters goes straight into a drain. The joists are fine, the plaster is fine, the floorboards next to the wall were a bit rotten. When we lifted them the subfloor was damp and the outer wall was also damp and the whole room still smells of damp.
     
  9. Vanessa83

    Vanessa83 New Member

    This is the concrete slope, it runs all the way across the front window (maybe further) 902C9FDD-C340-400B-81D1-E97AE729889B.jpeg and slopes towards the house. We can’t slope the garden away from the house as it’s in the way. Any ideas what it is and why it’s there?
     
  10. Vanessa83

    Vanessa83 New Member

    If we leave a gap around the front of the house that’s around sub floor level and the rest of the garden slopes towards it, doesn’t that mean the water will flow into and sit in the lower level gap around the house? Sorry if I’ve misunderstood.

     
  11. BuildingMad

    BuildingMad Screwfix Select

    Which is where the land drain I mentioned, comes in.
     
    Vanessa83 likes this.
  12. techie

    techie Screwfix Select

    op, we can all see there's a drain there, the question was where does it run to?
     
  13. Vanessa83

    Vanessa83 New Member

    Oh ok, it runs across next doors drive at a 45 degree angle from the house.
     
  14. dray

    dray Screwfix Select

    Are you sure that the downpipe is not overflowing onto the ground on the dug out side? If it is it will have trouble draining because it is sitting on top of what I think are the concrete footings at that point. The separate concrete at the top looks as if it has been put there perhaps to stop water splashing up against the airbricks? Would be interesting what happens of you dig small trench at right angle away from the house to see if it then drains better there than on the concrete against the house.
     
  15. Vanessa83

    Vanessa83 New Member

    Yes it’s definitely not overflowing at all, we had a hosepipe running and buckets of water chucked down and it flows down the drain freely.

     
  16. Vanessa83

    Vanessa83 New Member

    Here’s how it’s looking now a bit more soil has been removed. 41E53342-85E1-4CF5-801C-4AFFCC4B4CB4.jpeg
     
  17. dray

    dray Screwfix Select

    When you pour buckets of water down that drain does any water appear in the trench, just wondering if the gully is leaking below the ground level.
     
  18. Vanessa83

    Vanessa83 New Member

    No none at all. However when we poured water into the grass it ran directly underground and to the trench.
     
  19. dray

    dray Screwfix Select

    Then it is due to the ground slope and as Building Mad has said you need a land drain to collect and get the water away from the side of the house. Have a read of the attached link to get the idea, then you need to see where you can move the water to. May well be that you can feed it into a ditch or down hill or possibly join it into the pipe going across the lawn but depends on the depth of that pipe to get the falls needed.

    https://www.drainagepipe.co.uk/land-drains/land-drains-overview-layout-installation/

    Plenty of advice on here about the way to do it once you find somewhere to discharge the water.
     
    Vanessa83 likes this.
  20. Vanessa83

    Vanessa83 New Member

    Ok, we will give the land drain a go. Not sure where it will drain to as the garden is so small but we’ll figure something out. What material do we put up against the house? It was previously a mix of clay soil and rubble. Do we put that back? Is there something better? Will membrane against the house help?
    Thanks for all the help so far.
     

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