Mysteriois damp patch - leak or something coming through the floor?

[Diplobrat]

Hi all - I recently took off a bit of skirting and a kickboard in my tiny kitchen to hunt for moths (whole other story) and discovered that it is very damp under the kitchen cupboards and behind the skirting - there are no water pipes on that side of the kitchen.

I have put some of those moisture things under there to dry things out a bit and as far as I can tell, the damp seems to be coming through the wall (floor feels reasonably dry). The wall in the next room is dry so my suspicion is that water may be coming through the wall from the outdoor tap. Does this seem likely? The only complicating thing is that the house has no DPC (victorian) so I guess one of those chemical DPC injections might be needed. Thrilling pictures attached.

Mysterious - sorry folks!

No idea I’m afraid but we had a chap round from preserva to sort a damp wall and when he quoted he also looked at another bit i was worried about and said he thought it was condensation from cold water pipes and to just remove the ply boxing them in, lag them like mad, and try another winter before we paid for anything done there - so they seem good about not just trying to make money off everything and he was helpful.

Is the other side of the wall on the outside of your house?
I'd look there first.

You need @PigletJohn

kitchen, eh?

is it a concrete floor?

what's the floor covering?

Can you draw a floorplan?

include the damp patch, and the kitchen sink, and the outdoor tap, and the route you think the water pipe takes.

A photo of the outdoor tap and adjacent drain would be interesting.

How old is the house?

Depending on the materials, buried waterpipes are liable to start leaking between 50 and 80 years old.

Do not allow anyone who sells silicone injections anywhere near your house.

@PigletJohn

Do not allow anyone who sells silicone injections anywhere near your house.

What's wrong with silicone injections?

www.heritage-house.org/damp-and-condensation/managing-damp-in-old-buildings.html

Agree with PigletJohn, see link for more info on why injections are a con

Piglet John is right an injection damp course is a bad idea.
Does the outside tap splash the wall or is the ground outside higher. I had this problem with an outside tap. I stopped using the tap unless 5ere was a bucket underneath and the problem was solved. Took a while for the wall to dry though

@bravotango

https://www.heritage-house.org/damp-and-condensation/managing-damp-in-old-buildings.html

Agree with PigletJohn, see link for more info on why injections are a con

That was really interesting, thanks!

Oh my gosh @PigletJohn is here! Answers as follows:

1. Yes a concrete floor
2. Tiles on the concrete, but they don't extend under the cupboards
3. Dodgy floor plan below with some markings - the water for the kitchen and bathroom is on the opposite side of the kitchen
4. See also picture of the outdoor tap (the ground outside is lower than the floor) - drain is further back by the small bedroom. Next to what I think is the soil stack for both me and upstairs
5. House is c.1890 but converted to flats in the 80s
6. I do have a drain in the side return which is original but in good condition (according to some guys who stuck a camera down it when I was buying)

@mayblossominapril I don't *think I'm splashing the wall with the tap (and haven't been watering from the hose any time recently!) But good point!

The ferns indicate long-term continuous clean water.

I think it's either a leak in the pipe you can see supplying the tap, or in the drain that the soil pipe goes to. The leak is quite likely in the ground or in the concrete floor.

Stand back and take a wider pic of the outside.

Pull back the growth round the pipe. Look for any signs of repair, cracking or sinking in the concrete or paving.

Have you ever seen wild tomato plants growing?

Peel back the kitchen flooring and see how much if it is damp.

Have you got a water meter?

It's useful to note that silicone injections do not repair leaking pipes.

now I've blown up the pics, have another look at the corner behind the kitchen unit. Is the damp patch higher? It may be simply lack of ventilation to dry it out, but it could also indicate the water is from a higher leak.

Wnen you see a mountain-shaped damp patch, the source may be around the middle of the mountain.

If it is rounded, the source may be below the centre of the round patch.

Look also at the wall in the corner of the bedroom behind. Wallpaper may have lifted. There may be woodlice in the skirting.

Hi @PigletJohn, thabk you so much for your detailed replies!

The fern is actually in a pot (brightening up the depressing side return) and some pictures with it pulled out are attached.

I can't see anything obvious going on with the pipes but I can take a closer look at the weekend and pull out the shed too just in case (as I notice that the grub around my pots suggests rain water might be settling between the wall and the shed).

Nothing but the odd garden weed grows around the pipes and the wall in the next room is dry. I do have a meter, which I haven't noticed ticking up while the water isn't running (bills are about what I would expect) but I suppose if there is a smallish leak I might not have noticed.

I hear you loud and clear on the injections! The previous owners had some condensation in other rooms which I have solved by putting in vents and not drying laundry indoors.

Also - I can't get in to the side of the kitchen unit but the damp patch doesn't appear to extend above the tiling - but the paint on the end of the wall is a bit bubbly up to about the level of my hand in this picture.

The more I think about it the more I think the outdoor tap could be the culprit!

some water meters have a glass window, and you can see a small air bubble in it. While water is flowing, the bubble turns. This is a much more sensitive indicator than the numbers on the meter.

If you have a leak in a mains-pressure pipe, you may be able to hear it by pressing the tip of an engineers stethoscope to the pipe. I haven't tried it on a plastic pipe, which might not transmit vibrations. They are quite cheap.

Small update on this - I have moved the shed and cleared the relevant bit of the side return - turns out there's a hole in the wall! Quite low down and previously blocked with cobwebs so hard to see. I can't think what it's for (any bright ideas welcome) and it's about 20cm or so deep. I think it might have been being flooded when a puddle builds up by the back door (moving the shed should help prevent that) so will keep it clear and dry then consider blocking it off if that helps.

ot looks very much like a hole that was drilled for a pipe. perhaps there was formerly another pipe that has been removed, or perhaps it was drilled for your existing pipe but found to be in the wrong place.

if the garden tap splashes, water will tend to go into it.

Poke it and see how deep it is, and if a snake or spider runs out and bites you.

Unless there is some reason not to, you can fill it with sand and cement mortar, rammed well in. You can use silicon sealant round the other pipe.

Cor, another kitchen floor thread!
Just to add, it might not necessarily be a big amount of water you're looking for - it doesn't take much, if it's consistent. My most recent kitchen moisture was literally one drip every 30 seconds coming from right down at the back of the sink on the washing machine hose, that we hadn't noticed because it's in a cupboard.
Six months or so of that, and the cement under our slate tiles was saturated.
It now is not!!!

Poke it and see how deep it is, and if a snake or spider runs out and bites you.

have poked with a bamboo pole - nothing lunges out but it might be biding its time!

Thanks so much all for the advice - I can't see the harm in filling it (other than the snake bashing through the floor in the other direction) so hopefully that deals with the issue.

an older brick wall is usually 9 inches thick, so less than that might mean it was not drilled right through, or was filled from the inside.

more than that means you have poked right through.

I have found the comments on this thread so helpful! Thank you for imparting knowledge/experience.