Water under house

[14-7]

After all the rainfall we've had in the last two days I got home tonight to find water pretty much all around the house about 6-8 inches deep. Being a bit curious I decided to quickly lift a floor board under the utility room at the front of the house to discover that there was about 4 inches of water there. Moved to half way back in the house and lifted another board only to find about an inch of water but water actually flowing from back to front.

Now I've done a bit of digging and am quite happy it is just surface water due to all the rain and the advice seems to be fit a ground pump however where should I drain it to?

The drain at the front/side of the house is bubbling up as the road out front, which is about 20 metres away, is also flooded so I can't just drain it there.

The pond at the back has filled so much it's overflowed so I'd imagine the ground around it is sodden as well. The rest of the garden goes back another 80 or so metres but all the drains run back to front right from the back of the garden. After that there are nothing but fields. I'm a bit stuck as to where I could drain it to.

Other research has included fitting a concrete floor however surely the same issues would still arise with water flooding in under the concrete floor?

Any experts or advise (apart from pay someone to come in)?

Thanks all.

[LaserTam]

I'm no builder or expert - however, my parents had the exact same problem. Unfortunately it must have been happening for many many years (house was built in 60's) and they only noticed when some of the floor started to sag. Further investigation revealed half the joists were rotten. Neighbours had discovered the same problem, which seemed to be the same cause, rising ground water had no where to go, seeping through into the void. They live in a cul-de-sac, bottom of a hill.

A neighbour went for the ground drain option, with a small well and an auto pump taking it out and out the back of the house somewhere - but as you say, you need a drain that isn't full. My parents went for the tanking option. Its a massive undertaking, whole of the down stairs floor joists up (but most of theirs were rotten anyway), waterproofed/tanked and the new joists.

[Equus]

14-7 said:

Being a bit curious I decided to quickly lift a floor board under the utility room at the front of the house to discover that there was about 4 inches of water there.

You know what curiosity killed, don't you? If you hadn't gone around lifting floorboards, you'd have been none the wiser

I'm assuming you have a timber suspended floor at the moment?

If it has been built correctly, the timber joists will be sitting above the damp proof course, so any standing water can't be transmitted up to the timber, and the underfloor void will be cross-ventilated with air bricks, so will eventually dry out (though it might take a while in this cold weather). If the current flooding is a one-off, due to extreme weather conditions, it's therefore not really too much to worry about.

If it's a regular occurrence, you need to lower the external ground levels to below the level of the oversite concrete (underneath the floor) and if necessary provide a route for the water to drain out naturally.

Approved Document C to the Building Regulations covers the basics, and in particular take note of paragraph 4.4(a)ii and Diagram 6:

[bazjude2998]

See replies to RIW post

[Big Al.]

Here:- https://www.pistonheads.com/gassing/topic.asp?h=0&...

[Equus]

bazjude2998 said:

See replies to RIW post

Not quite the same issue: the RIW post relates to good, old-fashioned rising damp as well as standing water; the issue in this case is simply standing water in the floor void

With standing water, so long as it's not present regularly/for protracted periods, the damp proof course and underfloor ventilation should prevent serious problems in terms of decay of the timber floor.

[33q]

We moved into our house almost 30 years ago and within months found groundwater under the suspended floor.

After about a year of debate with NHBC they paid for all the floors to be removed and replaced with concrete and a floating wooden deck over Jablite. All services run in ducts.

Took about 6 weeks where we lived mainly upstairs

Fixed the problem and nice warm floors. Our detached neighbours have the problem, made worse when ours were fixed....they never pursued any remedy as they didn’t want any disturbance.


It turned out that the previous owner had had some work done but had not declared it to us...and the tanking had failed

It cost NHBC about £20k

[gretsch-drummer]

Just finished fitting a sump pump to the parents house. We found that after a good rain there would be 3-4" of water under the house. I found a pre dug sump (which the surveyor seemed to have missed 3 years ago) when I went crawling under the house.

The sump was directly under a vent hole and there was a perfect gap for my solvent weld waste pipe to fit between 2 water pipes, very lucky:

20171017_203946

2017-11-23_09-33-03

20171105_124829

2017-11-23_09-44-53

The pump was kicking in every 10 minutes last night after the heavy burst of rain we had in Leeds.

Edited by gretsch-drummer on Thursday 23 November 10:07

[14-7]

Thank for all the replies.

As the evening went on it got worse and worse to the point it flooded the house so it wasn't just a case of water not draining properly but rather the rainfall drains not coping with the amount of rain. Neighbours have also been flooded however I do like the idea of possibly a drain away down the garden but that would be around 60 metres from the house as the garden is slightly higher and wasn't affected at all to the rear.

The only things I need to do now are figure out if a pump would pump that far and how far down the clay level is. I think it may be more of a get a professional in though.

Thanks again.