High water Table / water under Floorboards

[Thewedge55]

We have a 3.5ft drop under our floorboards in the kitchen - we have noticed that we get approx 4inches of water when there is rain - I am pretty sure this is the high water table (I have dug a pit in the garden and the water accululates in the pit at approx the same depth of the water under the house.

Do anyone know any solutions to this problem?

Someone mentioned filling approx 6-7inches with concrete upon a DPM - any one tried this?

Many thanks - I really want to sort this as it can smell after prolonged rainfall due to stagnent water.

 

[LooPrEvil]

You could consider digging a small hole say to accomadate a bucket. Put a submersible pump with a float switch into the bucket. Take a flexible hose from the bucket to a grid and when the water fills the bucket the pump will swith on, and drain away most of the water.

 

[merlin50]

filling it is the best way, if you pump it out it will just return.

 

[Thewedge55]

I have considered the pump but wanted a permanent fix - any one ever tried the concrete fill, are there any potential problems with this?

 

[LooPrEvil]

The pump could be left in situ, hence a pump with a float switch. It will automatically turn on and off as required.

 

[Burnerman]

I had exactly the same scenario that LooPrEvil proposes....this was a semi detached house, and no matter how water tight I tried to make it, in times of flooding water came in from the house next door - via a flooded garden and air bricks, to be precise.
So, I dug a hole, gently sloped the sub floor so water would run there and put a pump with float switch in. I couldn't think of any other way!
John

 

[Thewedge55]

It is useful reading replies, much appreciated, I have considered a pump but would like to check if there is any permanent method first - I am beginning to think the pump is the only viable solution.

 

[Burnerman]

Probably the best solution is to see the maximum level of water that collects, then put a membrane down and fill over that with concrete to a level of a few inches higher.
This should work so long as water cannot access at any other point.
Do make sure there is a good draught under the floor via the air bricks and look for any water rising through sleeper walls and all should be well.
Be lucky!
John

 

[Thewedge55]

Thanks Burnerman, I will check this avenue - the concrete seemed a good idea but was worried if it would affect the foundations at all - of if it has to be any special kind of cement.

 

[hi1]

Bear in mind that if you put concrete in the bottom of the hole the water can still rise up through the brickwork, rising damp, surrounding your new concrete and flow back over the top and then it will have nowhere to drain away to being kept there by your newly installed dpm. I presume you have a damp proof course in the walls and this is preventing rising damp appearing above this point. If you really want to stop the damp you would have to tie in any dpm you install with this damp course either by filling the void with a hardcore, concreting on top and joining up the damp proof systems/ Alternatively if you can get access to the void you could put the concrete and dpm in the bottom and tank the walls with a waterproof coating again tying in with the damp course. I have seen this done in cellars but there is usually the insurance of a sump and pump incase water does enter.

 

[LooPrEvil]

Thewedge: You really need to ask yourself the question: 'is this really causing you a problem'. It is a common occurance for many people during the damp months.

 

[Thewedge55]

The water itself does not case any major probelm at the present, but when standing for a while - it does make the house smell horrible of stale water.

 

[LooPrEvil]

You could scatter a few loo blocks around, or pour in some of that chemical loo stuff that they use on boats / caravans (google Elsan Blue). It will freshen it up and possibly be absorbed into the ground, so next time you get water it will be freshen by what has previously soaked into the ground.

I cannot guarantee it will work, but if it does, it is a low cost solution. Worth a try?

 

[RigidRaider]

Sump pump is the best solution but just hope that you don't suffer the problem my brother had in the USA - a massive storm flooded his cellar then the power went off! After an hour of frantic bailing through a tiny high up window to keep the water out of his boiler ("furnace" as they call them) he gave up and dashed to the DIY store to buy a small gen. Dragged the thing in and rigged it up - relief, it worked. Power came back on and he switched off the gen and went to bed, forgetting that he had disconnected the mains supply to the pump while using the gen. Next morning he work up.... flooded cellar and ruined boiler! D'oh!