Water under wooden floor

[Mr.Ian]

Hi, been having an ongoing struggle trying to sort out why I have large areas of water under the front room floor (inches deep puddles in places). The floor is timber joist and sleeper wall type and has a 2' to 3' in places air gap underneath.
The underside of the floor boards and joists are wet and have droplets of water on them (condensation?) and it really smells bad under there.
The house is quite old and as such doesn't have a concrete surface uner the floor, it's just earth. The outside front wall has just one vent in the middle (outer wall is sandstone blocks) and I asume this vents under floor and wall cavity, but there are no other vents to the under floor area. The house construction means I can't get a complete through flow of air as the room behind has a solid floor, and obviously I can only vent to one side as the house is an end terrace and I can't see how this would vent the whole underfloor area as it's not end to end.
Would the water clear if air flow was increased?
There's no water leaks from my property as pipes are visible and the mains comes in at the other end of the building.
Could it be just the level of the areas water table? and if it was could venting improve it?
Thanks in advance for any advice.

[RemedialExpert]

if its a water table your stuck if its just a earth oversite... ventillation will do nothing if its actually sitting water, get a wet vac from a hire shop, remove as much as you can, then monitor how much returns and how quick....if its a day, then youv goto do something about it, if its a month then a slab to the oversite will probably hold this back. But to be honest there could be a multitude of reasons why and each has its own remedy, approach a damp company with a structural waterrpoofing surveyor, these differ from damp surveyors but some hold both qualifications. Go to the propertycare website and serch for a local to you surveyor.
Steer clear from the consultants as they can charge as much for a survey as the work to rectify could possibly cost..

[Mr.Ian]

Bit of an update and maybe the answer.
Floorboards have been removed here n there to monitor water levels which were quite low (puddled a couple of inches in places) .
Now today we've had rain rain and more rain and the water level has risen to about 4 inches deep in places and so there's a water level over the whole area.
Now the reason (well what I think is the reason anyway)
On the front of the house there is a cast rain water down pipe from the roof gutter, inside the house under the floor in the downpipe area ther is water actually dripping in to the under floor area.
The trouble is our down pipe is cast and runs straight under ground (there is no rainwater grid that the pipe runs into).
Will this be my repair or will it be local council?
as obviously it means digging up the pavement and digging down.

Thanks in advance for any advice.

[big-all]

heeelloo mr ian i have removed your duplicate question as it was the same as above and would cause confusion

the water under the floor could be anything a leak [mains or drains]
water table land run off from any direction
also the problem could be any off the above in any of the terraces in the block perculating along to your house

more reserch needed i think!!!

[thescruff]

Saving that BA the rainwater pipe sounds suspect.

You could cut it off at low level and stick a shoe on the bottom, also blank the bottom piece of with a few plastic bags for now and see if it makes any difference.

Another trick worth trying would be to get some builders dye and pour it down the rainwater pipe.

The water inside should change colour if it the problem.

[Mr.Ian]

Yes Mr.Scruff?? i'm sure that the rainwater drain is the problem as the water is dripping in directly behind (in the house) where it enters the ground outside. Obviously the fault is underground as there's no cracks/leaks visible above the surface.
So i'll try and split the pipe (cast too, that'll be fun) and run the rainwater onto the pavement outside and plug the stub left in the ground.

Would I be allowed to dig it out as it means digging up the pavement outside??

Thanks all

[thescruff]

No you can't dig the pavement up.

The builders will explain but there's all sorts of red tape.

A good hacksaw will pop through it no probs, get a shoe or 135 bend first so you know where to cut..

[Mr.Ian]

Bit of an update, had United Utilities out to check the drains front and side, we found the front downpipe didn't reach the coupling to the underground pipe and on top of that wasn't in-line with it either (council had re-surfaced the pavements a few years ago and re-sealed my downpipe out of line)
Thus the rainwater was getting directed towards my under floor area as now we've straightned the pipe there's no drips under the floor in that area.
But the other end of the room still has water that rises to about 6" deep when it rains and very slowly drains back to nothing within 2 - 3 weeks as long as it doesn't rain, if it does the area just stays underwater by 6" or so.
United Utilities bloke checked the drain near the area with dye but it showed nothing. He thinks it could be just down to the height of the water table.
Has anybody else had this problem? as we have a level of water 6 brick courses down from the floor joists and above the level of the soil.
Do I just raise the level of the earth under the floor (would this achieve anything with helping the water to dry out quicker?).
I'm worried as the internal wall appears to have dropped in the past the same side as this overly wet area and the house side wall has a sign of moving out, ever so slightly ie 1 cm.

[thescruff]

Water table is easy to check by digging a hole out side, then comparing it with the water level inside, don't sound right to me for what it's worth.

Maybe worth diverting the rainwater at the back down the garden with a couple of lengths of pipe to see it it makes any difference, could even drop it into the top of an inspection chamber as a temp.

[Mr.Ian]

Well this evening I aimed a hose pipe up the rainwater downpipe so it would pour out just as it would if it was chucking it down, left it running full bore for at least 2 hours to see if there was any movement in the water level under the floor. Nothing, no increase in level at all and no movement in the water either, (water level has started to drop now as we've not had rain for a couple of days).
At the moment it's looking like a high water table, which as you say MrScruff sounds strange as it's only 2 foot lower than my floor boards, and as my house is quite old the wooden floor is the same height as the pavement outside so in theory the water table is only 2 foot beneath it.
I asume that United Utilities manhole chambers in the street are sealed as both are far deeper than the level of water i've got under my house (I thought i'd see a level of water under their cover when it was removed but it looked about 10 - 12 foot deep).
Gonna get some plumbers dye tomorrow from Jewsons as bloomin B&Q didn't have any, and check all my drains again.
I shouldn't think the wall would be letting in that much water would it?
There are small areas that need repointing and when they're done i'm gonna seal the wall with the clear paint on sealer.

[Mr.Ian]

Well this evening I poured 10 litres of dyed water down every drain on my property, I then went and took out 50 litres from the underfloor area to see if any red would appear but there was no sign, just want it to rain now really as my under floor level of water isn't at it's highest at the moment.
Surely foundations being soaked like this are going to weaken over the years as these won't be just damp but immersed in water.
I'm completely stumped really as it stands as I was sure i'd find a drain leaking but apart from the slight leak on the front downpipe (that's now been sorted) there doesn't appear to be anything wrong drain wise, I can't see the wall would be letting in this amount of water with it's odd pointing bits n bobs needing sorting.
So it looks like i'm left with a high water table or maybe someone else in our block of 4 houses has a problem with a rainwater leak, next doors gutters feed into my downpipes so no problem there but the end 2 are separately drained.
I'm just completely in the dark now with no real clue as to what to do, or who could help.

[thescruff]

Have you got the water supplier in yet to check the water, could be mains.

[Mr.Ian]

I was asuming that if it was a mains leak from my property i'd see some sort of movement in the water somewhere, also it rises with rain fall and gradually lowers when the weather's dry so I thought drains.
The United Utilities bloke didn't even mention checking mains supply pipes anywhere, he just checked the drains.

[thescruff]

In that case I think I would dig a trench along the back of the property and see if any water is running in.

If it is you could maybe form a culvert, and discharge it into the drain, once you locate the source, even a pit and sump pump would keep it from the building.

There's is one further problem that needs to be addressed, and I think an expert is needed, and that is if you do dry it out, consideration has to be given to cracking of the sub soil/clay as it dries.

[Mr.Ian]

I think before I do anything else i'll unearth my mains supply pipe, I know you've said it might be mains water MrScruff and I was of the opinion that it couldn't be.
BUT
Thinking about it my water supply pipe does run the length of the property , under the suspended wooden floor front room and under the yorkshire stone floor of the kitchen (I didn't think it did at first).
Brainbox has been cranking away and i've come up with an idea LOL
Say it had a slight leak in the lead supply pipe somewhere (which is burried).
Eventualy over a period of time this would saturate my underfloor area, but would this also raise the water table in the area of my foundations ie so as when it rains the natural drainage through the soil can't cope with the added leak of my mains water???
I know it's a complete stab in the dark but as i'm going to be running new cables under the floor in the front room and also re-laying the kitchen floor slabs I think I might as well dig out the lead pipe and check for leaks but change it anyway for the new type MDPE plastic pipe.

AM I going a bit potty here or could this be a possibility.