Could this be the cause of all the damp?

[dllive]

We've bought a house and all the walls are damp. We've discovered a well in the garden which is very close to the house. Its a very deep well and when it rains it fills up to about where the house foundations are.

Here is where its located next to the house:

Would the be water under the house or would the water just be contained within the well? If the water is contained within the well then thats ok. But if theres a chance the water table is coming up underneath the house then thats a big concern!

 

[wessex101]

If it is a well then it will be filled from the water table, the height of the water in the well reflecting the rough height of the water table. For the water just to be contained in the "well" then it would be an underground cistern and would need some kind of drain, probably a rainwater drain discharging into it.

As was suggested previously if you were experiencing high levels of damp during the recent hot dry summer there must have been something else happening. A high water table is exactly such a thing. Around here the water table remained largely unchanged during the summer and streams that normally dry up in the summer continued to flow as we had such a wet winter and spring. Hence why we didn't experience the same drought and widespread subsidence damage that we had in 1976 which followed a very dry autumn/winter.

 

[dllive]

The water level in the well rises and falls depending on rain. It fills up quite fast. But the house is built on a slope. And we had the floors dug up (300mm) in February and the ground was dusty. At the moment the well's water level is about 3ft lower than the house.

I dont now how deep the well is. Ive seen it in dryer months and the water level was 20 feet down.

Is there any way I can gauge whats going on with all that water? As you can see from the photos, its not on flat land.

 

[dllive]

If the water level is the level of the water table then I couldnt put a pump in there could I? Theres not much point becuase Im not concerned about the water level in the well, Im concerned about the water level in the ground under the house.

 

[wessex101]

If the water level varies that much and rises quickly after rain I would suspect there is another source filling it other than the water table. I have a well in my kitchen and the water level stays fairly constant, irrespective of what the weather is doing.

On the other hand the sub soil here is a shallow band of silty clay with bands of gravel running through it, overlying deeper gravel beds and sand. When I dug up my floor I tapped in to one of those bands of gravel in the clay, initially it was dry but after overnight rain it was running with water like a small underground stream and my living room was transformed into a swimming pool. The water level in the well was a good 17 feet lower down and doesn't change much. It is also on a sloping site overlooking a river.

 

[dllive]

We are on a valley floor - about 10 feet higher than the river. You can see a steep hill in the photos. I thin the water must be coming off that hill and filling the well up quickly. But theres no other sign of where the water is going to other than the well! The water level is probably about the level of where the bottom step is in the photos.

Could an option be to bore a hole near the well and see if I hit water? I dont know what to do!

 

[wessex101]

I suspect it could be ground water running below the surface rather than the water table. If you are near the valley bottom there could even be a spring near the bottom of that slope.

I put in several things but one that might help you is to put a land drain across the rear garden, approx 3 to 4 feet deep to intercept the ground water running down the hill and drain it around the house to a soakaway at the front.

 

[ivixor]

It's not the well. If the water is in the well, it's also in the ground. Houses are expected to stand on wet ground and not be damp inside.

More likely is a lack of DPC, or the DPC being breached somehow. From the pictures it looks like the ground at the back of the house has been built up or changed since the house was built. It might be worth finding the DPC. IF it's not visible on the wall then you have to dig down against the wall. If you have to dig, then you already know your problem.

That render might also have been slapped on top of the DPC, bridging it.

 

[dllive]

The house was built circa 1860s and I havnt seen a sign of a DPC (I guess it would be slate?)

In the second photo of my first post you can see Ive dug the ground away to reveal the french drain. The ground level was certainly higher than the floor level inside, so I knew that wasnt good.

Now Ive dug away that ground maybe the french drain pipe can be disgarded? Ive been told the house doesnt have foundations (or perhaps very shallow foundations), so I dont want to dig down much further!

The damp tide mark and salts appear on all external and internal partition walls! But liek I say - when they dug the floors out at 300mm the ground was dusty. No sign of water or damp.

 

[ivixor]

No DPC - house will be damp. In the past this wasn't so much of an issue, because all the windows and doors were so leaky that you got enough ventilation to carry away the damp. Now you have double glazing and probably sealed up all random holes in the house, the damp has nowhere to go. Solution- either get a DPC installed (apparently it's possible) or increase ventilation, with either MHVR or positive pressure ventilation.

 

[scbk]

In the first photo, it looks like there's 2 pipes running in to the well?

 

[dllive]

Yes - an old copper pipe and a newer plastic pipe - both now defunct. They were probably used to pump water from the well.