Random damp patch in kitchen :-(

[UserThenLotsOfNumbers]

Last night this random damp patch appeared on my kitchen wall.
We are in a first floor flat, there's one above, one below us.
The wall is a north facing wall, 1960s brick built, no insulation. Window is double glazed, but rubbish tbh.
There's no radiator in the kitchen. Wall feels pretty cold.
The damp patch is very inconveniently behind a kitchen cupboard, in a specific place.
The kitchen has been in place for about seven months.
There's a slight gap between the end of the cabinet and the wall.
The wall was replastered and painted a few months ago. This is the first time it's happened.
Measured it this morning and it's not gotten bigger.
After a year or refurbishment and the recent death of my best friend this is the last thing I need, esp before Christmas.
Any help or advice gratefully received, thank you.

I’d check the outside of the wall.

Get a dehumidifier and some heat in there - has the rain been directly on that wall for days?

Hm, my thoughts of possible causes are:

1. Condensation from cooking - do you use an extractor fan or ventilate when you cook?
2. Are there any water pipes/services on that wall?
3. Water ingress from outside - are there any leaking rainwater goods or damaged pointing allowing water to seep inside?

Thank you
Heater and dehumidifier are now running
Not been raining for days on end, but we had the snow and it was raining all day yesterday.
There's just brick outside, no guttering on the other side of the damp.
It's still dark, but I'll take a look when I go out later today just in case.

Thank you

1. Condensation from cooking - do you use an extractor fan or ventilate when you cook?

Yes, however condensation is a problem in the kitchen.

1. Are there any water pipes/services on that wall?

No, but there are heating pipes running horizontally above from my upstairs neighbours flat, but surely then the damp would be on the ceiling?

1. Water ingress from outside - are there any leaking rainwater goods or damaged pointing allowing water to seep inside?

Honestly I have no idea, I am very ignorant about such things, which is why it's stressing m out

I'm just thinking, why is it in that specific place?

I think it sounds like your most likely culprit is condensation then. Damp patches generally form on the walls in the coldest part of the room. Hopefully dehumidifier plus heat will sort it. Many damp issues are caused by everyday build up of condensation, esp at this time of year when we keep our windows and doors shut all day to conserve heat.

I suspect your hob and kettle are nearby this cupboard? Sounds trivial but even small steps like covering saucepans when cooking can help contribute to reducing condensation.

Plus, even though it’s freezing at this time of year (!) open a window/door when cooking to ventilate the kitchen.

Yes the hob and kettle are on the same counter side, kettle probably about a metre away, hob half that. The sink is to the left of the damp, under the window.
Didn't use the oven or hob yesterday though.
Do you think then the damp patch could be a build up? It's the whole why there and why now thing that gets me stumped. It has been cold though.
The heater has helped with the outer ring of damp, but the main dark part is still the same.
It's not damp to touch, just cold.
If I run the hairdryer on it it helps for a while...

The flat is v well ventilated, however I have been slack in opening the kitchen window lately.

Yeah I think it could be a build up of condensation internally, combined with the elements on the exterior wall. Daily steam from your hob/kettle meets cold wall = damp patch. I’m no expert but that’s what I think is the probable cause.

Thanks Ritualunion I really appreciate your help with this!
Funnily enough I noticed it yesterday evening after I was washing up, plenty of steam there.
I will keep an eye on it, but hoping you are correct and it will right itself when the weather 8mproves.
Thanks so much

You’re welcome, hope the damp patch disappears v soon!

Have looked outside and can't see anything drastic, however the brick wall is icy in places, and is icy behind where the damp patch is.
It's very cold and icy today in general.
The heater and dehumidifier have helped, but the damp is still there to a lesser extent.
I guess we'll see what happens when it warms up.

I think a pipe in the wall is the more likely culprit for that, especially with a flat above you. Is there another kitchen or a bathroom above your kitchen?

Agree with wowfudge. .i would be surprised if that type of damp patch was condensation and would suggest either pipes from upstairs flat or perhaps guttering faulty outside making rain sit on that wall. My guess is more with pipes though and it could be coming down in corner where cupboard is then spreading to where you can see it on wall.

I'm no expert but I am currently dealing with leaking pipe/tank in bathroom causing water damage to kitchen ceiling and wall below so maybe that's why my guess is more on pipes!

ice on the wall in not usual.

I'd suspect a water leak because it is so localised.

Is there any green algae or white limescale on the wall outside? Is there an overflow or vent pipe? Is there any sign it has been dripping?

Photos of the outside would be helpful, also of the ceiling and the indoor wall above the mark.

If you get condensation, run your extractor more often (a recirculating hood is useless)

Thanks so much for your replies, pictures attached as requested:

There is no pipe going down the corner of the cupboard, and there is not a pipe going down inside the wall.
Upstairs there is a kitchen, same set up as ours (used to live there too!)
However, there are heating pipes in the upstairs flat that run along their floor through the kitchen into the bedroom on the right.
The "ice" could be white limescale, and it appears over some of the building as a whole.
The overflow pipe is not next to the kitchen, and is not overflowing.
Our water meter is not ticking over constantly so if it's a leak, it's not ours.
It's weird how it suddenly seemed to appear, however it's not gotten any worse...yet!
Really don't have the mental energy for this!

for some reason I can't enlarge your photos

can't see anything relevant in them.

If you tap your wall, does it sound hollow (like plasterboard with a gap behind it) or hard like brick?

The plumbing duct usually runs down a corner of the kitchen and/or bathroom, and the sink and bath wastes run into it. Do you know where yours is?

If you tape a piece of clear plastic or clingfilm tightly to the wall, you will see if water forms on the room side (condensation) or the wall side (wet wall).

Thank you PigletJohn.
It sounds hard like brick imo.
The wall was recently replastered and painted, a few months ago, if that's relevant at all.
The soil stack is in a cupboard in the hallway (nowhere near the damp) into which the sink, bath and kitchen pipes drain. The cold water feed is in the next cupboard along, again, not near the damp.
I will try your suggestion with the cling film, thanks.
If it is not a leak, but water is coming through the wall, what might it be, and what can be done about it?
I am keeping a close eye on it to see if it gets worse at a certain time - perhaps when my neighbours heating comes on in the evening.
Thanks again for your advice.

water coming from the wall is quite rare. In your case the building looks less than 50 years old so is pretty sure to have cavity walls. These discourage water from the outside reaching the internal leaf, even if there is a crack or other defect allowing the outer bricks to become wet. You are not near the roof so a roof or gutter leak is unlikely to be so localised.

if your damp patch has a "centre" the the source of the water is probably close. It might possibly be water dripping down the cavity and migrating across a wall tie or plaster snot, but not very likely.

If you don't think there is a boiler, sink, waterpipe or drain above, it might be coming from a radiator leak, but I expect the block has concrete floors so I'd have expected a damp patch to show on the ceiling. Maybe an old pipe has been plastered over.

It's possible the flat upstairs had a washing machine leak or a bad spill of water and, as the floors are probably concrete, the water has come down the wall.

Thanks for your replies.
Yes it's a cavity wall (with no insulation) as far as were aware. Flat is exactly 50 years old.
It's gotten better so now, I think what we're left with is a stain from the water?
It's a mystery. It's either a leak from the heating pipes upstairs (why not on the ceiling tho?) or condensation.

I am thinking whatever it was it was a one off wowfudge so your explanation makes sense.
If it was a leak I would imagine it would be getting worse?

Doesn’t look like condensation to me tbh
The floors in flats can be solid concrete I think which is why leak from upstairs may not come through ceiling

I see, yes the floors are concrete. I think it has to be a leak from above then. Will have a chat with neighbour when I get a chance!