Garden soil and moisture

Hello

In the middle of a bit of a dry spell at the moment, and the bottom of my garden wall is wet, and if i dig down, the soil is quite damp.

Seems to be one side of the garden, have had my drains inspected and fixed last year for this reason. Now wondering if it is "normal" in areas with heavy soil/clay soil? The bottom course of bricks is literally wet to touch for most of the length. The other possibility i've been wondering about is that my neighbours garden is huge, and a sort of allotment. It is mostly brick driveway/paving, and concreted apart from growing areas. Half of these are covered in tarpaulin at the moment. Could the run off from this area cause general increased damp subsoil?

Might be worrying about nothing, or chasing a wild goose, but there are symptoms elsewhere i am trying to solve (minor damp in house) and am currently looking at drainage around my house.

Any opinions appreciated.

Thanks
Mike

Just to perhaps put a bit more context to my question with a picture. The dark patches on this wall are wet to touch, even after no rain for what seems like quite a while. The ground is dry, yet the base of this wall is wet along the majority of its 30m odd run.


Does this look like it is coming "through" the wall from the neighbours side? Neighbours side shows no obvious wet ground though most of it is paved, and is a very large area.

Reason i'm asking is i actually had some of my own drainage replaced last year (broken gully and underground soil pipe replaced) due to this wetness. The pipes were broken, confirmed by CCTV. However i am now wondering where this moisture is coming from..

Thanks
Mike

Was this noticeable and the reason for having the pipes checked in the first place last year?
I would be inclined to get the camera back down there and just establish all's well. Also if the neighbours concreted garden run off is the problem, you would notice it only after some heavy rain, is this the case??
If your garden abutting the wall is dry and the superstructure bricks wet, I would be inclined to look in the solum area for water/leaks...pinenot

pinenot said:

Was this noticeable and the reason for having the pipes checked in the first place last year?

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Yes, that's right - a broken gully and internal soil pipe were found to be broken, and have since been replaced in plastic. The rest of the run was fine.

pinenot said:

I would be inclined to get the camera back down there and just establish all's well. Also if the neighbours concreted garden run off is the problem, you would notice it only after some heavy rain, is this the case??

Click to expand...

This "patch" of garden is not really used and always seems to be a bit wet (in part why i'm trying to solve this). It is actually south facing but is between two buildings, so doesn't get a huge amount of sun. Reason i'm pointing that out is because its difficult to determine if its worse after rain as its always generally "damp". Since this dry spell, and with rain due on weekend, i'll be watching it closely

CCTV - not keen on this, i saw the builders putting it back together and its hard to see how it could go wrong, plus the ground nearest the repairs is now dry (and was wet last year).

pinenot said:

If your garden abutting the wall is dry and the superstructure bricks wet, I would be inclined to look in the solum area for water/leaks...pinenot

Click to expand...

Sorry, can you confrim what you mean? I did look up what solum meant do you mean dig until i find it wettest? I did try that but there are wet bricks for pretty much the stretch of the wall. The wall is pretty long, and the ground rises gradually to the back of the garden. Mid way along the length of the wall (though i am not clear / sure how close TO the wall) is a soakaway and potentially one on the neighbours side, which was apparently build under the garage (find that hard to believe). As the ground gently falls toward the front of my house (est 1.5m drop over 40m or so?) and with clay ground, perhaps the soakaways are not working too well and water is congregating/pooling at the bottom of the boundary wall?

I've not raised this with the neighbour yet, but having ruled out (in my mind at least) drainage on my plot, and incoming water supplies being sound (tested by water company ) I am wondering if they have an irrigation system for their garden with pipes buried along wall, perhaps leaking. They are very old and one is sick, so reluctant to worry them too much. Their garden is basically an allotment, so it is possible as i've wondered how they keep their plants watered in dry spells (son does most of tending these days but is not around much).

Thanks

Edit, here is a pic showing the layout, my garden on left. The X marks where the picture was taken, and the red line is the boundary wall, most of which is as shown in the picture (wet bricks at bottom).

Oh sorry, the solum is the infill between the foundation walls forming your building footprint. My point was that if the external ground surrounding these damp bricks, best check the inside under the floor for signs of dampness. That is if there is a void under the flooring? ...pinenot

Ah I see. Sorry, this is a garden wall. House or rather bungalow has solid concrete floors, edges of which are damp in places, which is ultimately something I'm trying to sort though it is very minor.

Does this still look like a leak somewhere?

Ah concrete floors, I presume the floors are unaffected? ...pinenot

Penetrating damp at the wall/floor junction.. nothing major, but is the reason I am chasing unusual wet patches in the garden!

As the concrete flooring seals any moisture below the effect is it pushes the moisture aside, like all water movement, it will find the easiest route and as your foundations are deeper than the concrete floors a dam is effectively formed. Water will find its way through the most minute crack and I wonder if that's what's happening here! where concrete is laid to form a floor a dpm is laid bellow it, this in turn is dressed up the inside of the foundation walls and should be dressed over the foundation walls dpm or sealed to them, if this breaks then any water would soak through the bricks. Perhaps this is what's happening here? ...pinenot

See what your saying, except this is the bottom of a garden wall, not the house. there is no DPM or even DPC.

Oops forget everything I've said, my mistake sorry...pinenot

No probs. Any ideas on garden walls then?

Yes, the lower bricks are in touch with water, cure the water problem and the wet bricks will go. If no one else has the same problem and your level is much the same as theirs, then there may be a leak further from your house...pinenot

Thanks - given that the wall is pretty similar for almost its entire length, where do i start looking for the leak?

Good point about levels - neighbours garden is slightly raised compared to ours. Ours rises up as i said earlier. X is at low point compared to both gardens. This is not the water table btw, as I dug several 750cm deep holes last year and they did not fill with water. Ground is clay though.

Given that the soil is clay it can hold a lot of moisture and presuming you won't want to improve the whole garden, you could form a pebble border down the length to improve drainage. But given that there's the opposite side to the wall, I presume in the neighbours garden, there may be little point unless that side can be done as well. Beyond there are expensive options like wall drainage mats, but I doubt you would want to go to this length.
As I stated before, remove/cure the moisture contact to the wall and the problem will go, how far you wish to go is entirely up to you, good luck...pinenot