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Water under floorboards - high water table?

edited 30 November -1 at 1:00AM in Flood & Storms Help & Information
6 replies 9.8K views
LittleMissGiggles1980LittleMissGiggles1980 Forumite
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edited 30 November -1 at 1:00AM in Flood & Storms Help & Information
We've recently discovered approx 2 inches of water under our suspended wooden floor, following the very heavy rain a few weeks ago. (Lived there only 15 months, 1930s detached).

We vax'd out most of it and it has all since disappated into the ground.

We've had a broken rainwater gully fixed, had the drains checked and the water supply checked, no other leaks. The ground slopes towards the house and we are a 'low' point of the street, so it seems to be a water table issue.!

Chatting to the neighbours has revealed previous owners used to pump the water out (not disclosed to us when purchasing but thats another story and something we need to decide whether to pursue)!

What sorts of things can we do to mitigate this? I've over googled as per normal and now don't know what the best courses of action are to take...!

I've read about sump pumps - who could install these? We were about to install some lvt over the wooden floors but this would mean we couldn't monitor levels or access a pump.!

We are planning to get the driveway and garden tarmaced/re- paved (currently very old cracked concrete) - obviously we now need to consider drainage carefully, but it is an opportunity to install some better drainage - what should we consider - french drains, land drains, soakaways? Who would we go to for advice, driveway companies, landscaping companies, drainage companies or groundwork companies?!

Someone has also suggested a layer of gravel in the void to cover up to the level the water came up to - is this likely to help?

Any advice would be much appreciated, thank you.


  • TwoplusTwoplus Forumite
    43 Posts
    I owned a house for about 20 years that was built in the 1930s it had a suspended floor. The ground was about 4 foot below the floor and when it rained we had water under the floor boards. Sometimes the water would be about a foot deep but it never caused a problem.
    Like you I was quite concerned when I first saw the water, and spoke to a builder about it. He suggested I could install a pump for piece of mind, but it was probably not necessary, I decided against the pump and just checked the water level when it rained.
    You also need to make sure you have good ventilation under the floor boards to reduce the chance of the joists rotting.
  • Thank you for this, I know it can be very common and think it is 'normal' for the house but am worrying how bad it might get, about the electrics under the floor and any smell from water standing for a while. I have been advised against a pump in case of pumping away the clayey mud under the house and causing subsidence.
    I think the ventilation is sufficient as no sign of any damp/rot.
  • king132king132 Forumite
    109 Posts
    Part of the Furniture 10 Posts Combo Breaker
    I've had this problem while renovating my property, i've had a solid concrete front and rear extension and the existing suspended (wooden) floor in the middle, I was surprised when i noticed the ground under the suspended floor would fill up with quite a lot of water in the heavy rain - I also live in a high table/ clay area.

    You really need to deal with this from the source of the problem rather than trying to pump it out later once its in the property.

    I put land drainage into my garden and my drive to deal with it. You dig out a trench/es about 50cm wide and around 0.5m deep and lay a perforated pipe which you wrap in a pipe sock thing and lay it onto a bed of gravel. You connect the pipe at a slight slant so the water runs downwards, to an existing drain pipe gully or something and the water will drain away.

    It works really well. I have a constant stream of water from the garden land drainage whenever i check the manhole cover. Even when its warm - there's always water running.

    I'd recommend looking into it as a permanent solution which tackles the problem at source.

    Even if you get the drive tarmacked later you'll have the reassurance of knowing that any ground water is being taken away.
  • Thank you, I think some land drainage and maybe a soakaway is the answer. Have you found that was enough to stop any water coming through?
  • MojisolaMojisola Forumite
    34.3K Posts
    Part of the Furniture 10,000 Posts Name Dropper
    We've recently discovered approx 2 inches of water under our suspended wooden floor, following the very heavy rain a few weeks ago.

    We had this problem - it was partially improved when we reduced the level of the drive (the previous owner had built it up so much that water from the drive ran into the airbricks and flooded under the floors!) but we still had standing water during wet spells.

    At first we pumped it out but later had solid, insulated floors put in.

    The difference to the house had been well worth the disruption - the house is so much warmer and drier now.
  • Thank you, I'm not mad keen to fill the floors in, as it will involve moving all the electrics and a gas pipe but maybe thats a long term solution if we still get problems. How much disruption did you find and was it expensive?
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