Water found under suspended floor, please help!

RoseGeorgia

Sorry for the long post, trying to get all the detail in! Appreciate any advice as we really weren’t expecting this issue and it’s been a real struggle up to this point.

We recently purchased a small terraced house, we started gutting the property in order to refurbish it, taking up the floors to discover standing water under the floors. About 6 inches of clear water.

I’ve been in touch with our building control Officer who had no reports of a water table issue on my street or in the surrounding area. I then got in touch with united utilities who ran a dye test, they put green dye on the flagstones at the rear of the property, red in the domestic drains and blue in the rainwater gulley. A couple of days later it rained and the water turned green suggesting that the water is rainwater possibly from broken flagstones at the rear of the property.

Since then we have been pumping the water out of the sub floor, we dug a small hole in the sub floor to redirect any existing water. We also laid a tarp over the yard to temporarily hold off the rain. Since then there is less water, however we think simply replacing the flagstones won’t improve drainage enough. We have noticed the level of the sub floor is significantly lower than outside, so we’ve thought about raising it an inch or two. We’ve also thought about a French drain in the rear, but we’re not sure whether this will attract more water than deflect.

Does anyone have any idea of a solution? Or had a similar issue? Thanks!

RedFraggle

It's not uncommon here to have that kind of problem as the water table is high. Friends of mine have either tanked or fitted pumps.

RoseGeorgia

Thanks RedFraggle for your response, the building officer has said the water table in the area isn!!!8217;t high so we don!!!8217;t think it!!!8217;s a water table issue, we!!!8217;re just a bit mystified.

that

speak to the neighbours, and see what they know. Surprised it is not mouldy and wood rot in the subfloor area? think you may have to vent the floor?

fit a permanent auto triggering sump pump in that hole.

a lot depends on soil type and the slope of the land.

unsure how big your garden is but tarp it fully as a temporary measure. if it is still coming in months after and not reducing then you either have a spring or a bust pipe.

remove a flagstone 2 m away from your wall of the house and dig a hole below subfloor level hole and cover it. Does it fill with water? if you pump out hole no2, does hole no1 eventually dry up?

if the ground is porous, i'd put it a sloping french drain that starts below sub floor level and continue to flow downwards to the end of the garden and putting a waterproof membrane under the sloping away flags or concrete

wazza99

Our old house permanently had water under the floor, about 5 feet drop to the ground and water, odd at first but seems it was normal for that area, lived there many years without issue.

sevenhills

RoseGeorgia wrote: »

Thanks RedFraggle for your response, the building officer has said the water table in the area isn!!!8217;t high so we don!!!8217;t think it!!!8217;s a water table issue, we!!!8217;re just a bit mystified.

A friend has a terraced house which has had issues with water in the cellar, due to a nearby underground culvert.

Mojisola

We had this problem when we first moved into this house - a combination of outside levels being raised and water flowing in through the airbricks (missed by the surveyor - we got a payout from them in compensation to recify this) and the water level rising after rainfall.

We lived with it for a long time by pumping out when necessary but the subfloor was always damp to some extent.

We eventually put in insulated solid floors and that's made a massive difference to the house - warmer and drier throughout and cheaper heating bills.