Is this rising damp?

[Plump82]

We live in an old converted Georgian building and we have noticed a damp patch in the back of the close on the ground. I'll attach a photo.
Sometimes it's around the size it is in the picture, other times slightly larger. At one point there was a full puddle of water.

There's an outside wall to the left of it and directly behind it is my down stairs neighbours bathroom. Above it, we think is my upstairs neighbours kitchen (we've never been in either property) Neither of them are taking any responsibility for it and saying they don't have a leak. They're both quite difficult characters so it's like pulling teeth trying to get information from them. We've asked my upstairs neighbour if it could be his washing machine and he immediately blamed the downstairs neighbours shower!! We get the feeling the don't like each other so are blaming one another. Upstairs also has some health issues and lots going on so seems to avoid anything else that might be a problem. It's not directly impacting my property but I'd still like to get it sorted. We don't have any factors so its up to all of us to get this fixed.
Does anyone have any ideas?

Are you on the ground floor? Any chance you could do a diagram please? It's really difficult to imagine exactly where everything is. I am guessing the building was converted into flats?

It's not clear from your OP where this is? Is it a basement?

You said the left wall that's right next to it is an external wall. What's on the other side? Any leaky gutters or mortar cracks? Anything that could be bridging the DPC?

Is there anything on the ceiling directly above that would indicate it's a drop from there? If not I'd rule out the upstairs kitchen.

It doesn't look close enough to the back wall to be coming from the neighbors bathroom (unless I've misunderstood the locations from your OP)

Hello, sorry for only getting back to this.

I live in a small block of flats. The damp patch is, where communal area (I'm in Scotland so we call it the close) and the back door. This is on the ground floor.

I've attached a diagram of the ground floor. Where is says walk, this wall also runs under the stairs. The stairs go up my flat and my upstairs neighbours flat. His flat is directly above downstairs but a slight different lay out. As it's an old building, each flat is different.

Forgot to add picture.

So the bit between the back and front door is internal and not some sort of ginnel?

If so then then the first thing to check is the external ground level. How high is it compared with the internal floor level? If it's too high then it might need lowering and a french drain putting in.
There probably won't be a damp proof course in a Georgian house so rising damp is kept at bay by good underfloor ventilation and lime plaster on the internal walls. What are the internal walls covered in? Is it pink modern plaster or white/grey lime?

If it's modern plaster then replacing it with lime will definitely help the moisture get out of the wall, although without working out where it is coming from, it might not totally fix it.

To do this, you need to take the plaster off that wall back to brick and replaster in lime. All ground floor walls in a Georgian property should be done in like plaster to help stop damp issues.

If you're sure it's not a leak from your bathroom and it's in a communal area, I'd refer it to the management company. Does the wall feel damp at any time?

@Geneticsbunny thanks for all this information. That's correct, it's internal. I'm not sure how we'd check to see if the ground outside is higher or lower? The whole area is very uneven. If it was higher, do you reckon water could be coming through the walls that amount? I couldn't tell you what the internal walls are covered in as they're painted. My home report said there had been a damp proof course done
There's holes drilled along the bottom of the wall where the carried that work out. My neighbour also confirmed it had been done. Would you reckon it's a brickie that might be able to help us?

@Sunnyside4 it's definitely not a leak from my bathroom as it's on the other side of the building. We don't have a management company/factor. The wall never feels wet/damp, just the ground. There's no smell of damp either.

You can't retrofit a damp proof course. The drilling into the wall thing just traps moisture in the wall and potentially covers up the problem.
You can check the outside floor level by working out what height the internal floor level is by looking at the floor level neat a door and then you can usually just follow that course of bricks around the building. The external ground level should be a couple of courses below the internal level all the way round.

Aa it's an internal wall though, the cheapest, quickest fix is to remove all the existing plaster on the damp wall and let it dry out for a few months, then. replaster in lime plaster.

That is reasonably likely to fix the issue. If not, then you. Can look at external ground level.

The thing is, the wall isn't damp at all. Its just on the ground.

It's incredibly unlikely to be rising damp.

Georgian buildings don't need damp proof courses although this doesn't stop people paying to retro fit them.

It will either be a leak, use of cement plaster or use of cement too high next to the house.

As the house has had someone try to add a damp proof course it's very likely that someone hasn't used appropriate materials maintaining it and so it's one of the last two options.

So what is the floor made of?

The floor looks to be made of concrete.

We had similar issue and eventually we traced it to leakage from gutter which was going into main wall cavity. Check from that angle as well.

Funny you should say that. My upstairs neighbours gutter was leaking a few months back. I'll have a look tomorrow and see what it's doing.

So the house is old enough that a concrete floor is probably not original. If there is water coming up through it then something has gone wrong as it would probably have had a plastic dpc installed then it was laid. Very weird.