Removing standing water from a sub-floor

[John Laird]

I have a modest amount of standing water in the sub-floor of my humble abode, which I would like to get rid of before I go crawling about, endeavouring to find where it has got in. Having wasted lots of time with Google, I've not really found any simple, inexpensive, pumps that would do the job, so does anyone have any clever ideas ?

The water is maybe 1" deep at its worst, and as far as I can tell, most submersible pumps will struggle to get down to half that before cutting out. I found a "puddle-sucker" on one or two sites, which will go down to a few mm, but at a price. (=A3100+)

I expect I will end up using my Vax wet'n'dry cleaner, carefully ;-) It won't care about a bit of grit or the odd small stone, as long as I avoid letting it overflow...

Once the floor is dry, I thought I might scatter some tell-tale powder around in order to track the water origin (assuming it's not coming up, which seems unlikely). Again, any advice much appreciated.

TIA.

--=20 "I'm easy to please as long as I get my way."

[Phil L]

If the surface of your subfloor is below the water line outside (water table) then you won't be able to drain it properly...what you can do is dig a sump hole about a foot wide and deep and have a submersible pump running in this via a float switch, or you could build a soakaway...either way, atempting to fill cracks etc is a waste of time and effort.

It could be a leaking pipe, have you never noticed it before?

[John Laird]

The locality does, as far as I know, suffer from a high water table. I am aware it may be a problem with no easy fix, but obviously I would like to find out as far as possible where the root cause lies. I could live with a sump pump if it is simply a water table issue. Clearly, a leaking drain would require more investigation.

I doubt it is a pipe. The water appeared quite suddenly, I think, and is slowly evaporating. The sub-floor ventilation is good and I have no immediate concerns about damp affecting the timbers unless the problem persists for a long time (and even then, adequate ventilation will keep the RH down). I've only recently moved in, by the way.

Ideally, I would like to catch it next time when there's only a small amount of water lying about, if possible, and attempt to see if it is coming from one area or if it is coming up somehow. The sub-floor is concrete, but that's not to say it's in any way water proof throughout.

Thanks for your comments.

[The Medway Handyman]

Hire a wet vac with an internal sub pump like this;

't go to HSS myself because they are pricy, local independant hire shop might have one.

The vac will suck the water up and when the tank fills the internal sub pump gets rid of it. The vac will dry the floor completely - apart from any absorbed water.

[John Laird]

[It might be a bit of a struggle getting something that size into the sub-floor void, mind you.]

--=20 "I am in total control, but don't tell my wife."

[Brian Sharrock]

Water pooling in a void is (usually) a sign that the drainage of the ground surrounding your house is inadequate. The water is probably pooling in a hollow below grade. Inspect your properties _exterior_ . Is there land (lawn, garden, patio .... ) that is higher than your house's grade? Unless properly drained with 'weep holes' leading to a drain/sump; such land will act as a sponge and rain water will seep from it (under gravity) and gather in any hollow - perhaps in the void under your floors! If this is the case then a pump will be on a hiding to nothing because as you pump it out water will seep back! On the other hand; you may have a leaking pipe ..... :)

[John Laird]

The back garden slopes down to a patio which then slopes up to the house. There is a supposed to be a ditch where the lawn meets the patio, which runs to a soakaway. I suspect this is now under the shed ;-) The lawn does appear to be particularly soggy in this region, which is certainly above the level of the sub-floor.

The front drive slopes away from the house and there is a surface water drain at its low point. I had imagined that a sump pump could simply discharge onto the drive. Arguably, draining the rear garden onto the front drive by way of my sub-floor is not the most elegant solution, but until I have gauged the severity and frequency of the pooling, I will reserve judgement.

Now that I have been paying more attention to the locality, I have noticed that the road verges often hold pools of water by the kerbside, even in dry spells. I wonder if this could be indicative of a high water table ? (Or it could be leaky supply pipes.)

Of course.

I will have a word with my neighbour who lives in a much older house which will almost certainly have cellars, and see if he has any relevant information to impart.

[Stanley]

Somebody wrote....

Could you not dig a small sump to collect a depth of water and pump it to a drain outside? It could have a float switch to cut out when the sump is empty.