Reputable company to design a better drainage system to manage water ingress in to cellar

[Jane]

Hi I have nearly removed all the tanking render from my cellar to expose the stone but there are high levels of water ingress. I have had a drain survey and a surveyor to see if a cause of the ingress can be found but nothing has been identified and it looks like it is water coming off the fields. My cellar is totally underground so I am limited in terms of what to do and so I want to get somebody to design the drainage system in the cellar so that the water can be managed. All the companies I can see where I am don't appear to have experience of old stone cottages . Does anybody have experience of this or know of reputable companies that might cover our area- County Durham
Thank you
Jane

 

[88v8]

Our cellar was lined for the PO about twenty years ago. Membrane on stand-offs, special plaster, the damp trickles down behind the membrane and evaporates through a gap at the bottom. This sort of thing, found on a random Google.
Not particularly dry, you wouldn't want to live down there, but not mouldy. We keep books down there, and a freezer and our wine, and with a full-time dehumidifier running it's OK.

The back of the cellar is underground, at the front more like the bottom three feet - we are on a steep slope.

That membrane system deals with three sides of the cellar, but it probably wasn't all that wet, depends how much you have coming in.

However on one side behind the stone staircase a lot of water comes in when it rains, or rather it starts some hours afterwards. That originates from land drains, and fetches in a lot of water, literally gallons per minute after heavy rain, as we discovered when we took the staircase out for repair.

That was dealt with by running a perforated plastic pipe around the bottom of the stairwell, leading to a sump with a submersible pump and float switch, and the water is pumped out through the wall onto the down slope in the front garden. The collection pipe is 3" dia iirc, wrapped in two layers of Terram so it doesn't clog up with fines, it's around 12' long.

So, in general if you can't stop the water coming in, it needs to be collected and pumped out. In your case, you might use a membrane to send the water to the base of the wall and collect it in a perimeter pipe leading to a sump + pump.

Co Durham does not seem to be replete with sump pump installers, all I can find is this collective.

I think I would start by talking to people who do basement conversions, and try to find one that doesn't want to reinstate your failed tanking.