1930s bungalow subfloor

[CJ66]

My wife and I are Renovating a 1930s bungalow with a 3ft void from floor joist to sub floor. Our issue is pooling water. We've been told its the water table as we're in a flood zone and the bungalow is designed to flood. However we've removed loads of visqueen as we thought this was trapping water above the membrane and not draining giving the bungalow a damp issue.
What we'd like to know is do we leave as is or put a membrane back in??. And let nature take it's course.

 

[a twig]

I’m not sure what you mean by “designed to flood”? The only buildings I’ve seen that would fit my understanding of that would be on stilts

 

[Cubist]

You say you've removed 'loads of Visqueen' and this I find rather worrying.

Was this membrane attached to and beneath the joists and floorboards or was it merely resting on the sub-soil below?

Is it fair to assume the pools of water you are seeing are sitting on the surface of the membrane or is it lying on the sub-soil?

The poor weather and the exceptional rainfall we have all seen has led to a general rise in ground-water levels across the country and many owners of homes with basements and cellars have experienced serious flooding of these spaces. As your home is near the coast and has a major river running nearby it's not unreasonable to assume it was constructed in an old flood plain. Despite the claims of some the only 'flood proof' home ever constructed is a house-boat, so if someone claimed otherwise maybe you can sue.

The only sensible reasons for Visqueen to have been used under your bungalow would be to either prevent damp getting to the wooden floors and brickwork OR to prevent gases exuded from the wet earth below being exuded into the atmosphere of the structure. Hence my worry - is the area known for radon gas emissions and/or have you tested for this?

 

[CJ66]

I’m not sure what you mean by “designed to flood”? The only buildings I’ve seen that would fit my understanding of that would be on stilts

Only what the neighbours have all said.

 

[CJ66]

You say you've removed 'loads of Visqueen' and this I find rather worrying.

Was this membrane attached to and beneath the joists and floorboards or was it merely resting on the sub-soil below?

Is it fair to assume the pools of water you are seeing are sitting on the surface of the membrane or is it lying on the sub-soil?

The poor weather and the exceptional rainfall we have all seen has led to a general rise in ground-water levels across the country and many owners of homes with basements and cellars have experienced serious flooding of these spaces. As your home is near the coast and has a major river running nearby it's not unreasonable to assume it was constructed in an old flood plain. Despite the claims of some the only 'flood proof' home ever constructed is a house-boat, so if someone claimed otherwise maybe you can sue.

The only sensible reasons for Visqueen to have been used under your bungalow would be to either prevent damp getting to the wooden floors and brickwork OR to prevent gases exuded from the wet earth below being exuded into the atmosphere of the structure. Hence my worry - is the area known for radon gas emissions and/or have you tested for this?

The visqueen and many plastic bags where just laid on the wet subfloor. these have all been removed and i now have cleared all the debri that was left. many vacuums of water sucked out too!!

Have been told many many years ago the area built on use to be a old sand quarry, we also back onto Barmston Drain. My only theory is the water is coming up through the soil thats not been constructed on. My air bricks are also level with the floor joists as in side by side so any air coming in would hit the joist and bounce back, it won't flow.

Not tested or heard about any rising gases either.

 

[Cubist]

Rising groundwater levels are the most likely root cause of the puddles you have been seeing and, until the surrounding terrain drains sufficiently, significant observable improvement is unlikely. You would be wise to check for gases, particularly radon, accumulating in the void to determine whether work is needed to enhance ventilation of that space. Equally you should perhaps consider alternate approaches to protect the underside of the wooden floor from the wet sub floor as that can be the only reason for the presence of the Visqueen.

Hopefully others here will be able to offer some alternate solutions for this.