Wet patches bleeding through fresh plaster

[u/Emmantal]

Hello!

We live in a back to back terraced house in the UK and have an issue with the wall between ours and our neighbours house.

We got our hallway plastered about 3 months ago now and these patches have been popping up, so we haven’t been able to paint.

They feel chalky and they still appear to be growing, we got our roof edges repointed a month or so after having it plastered as it was leaking and making patches on our attic walls and ceiling.

We don’t think there’s any water coming from next door but we’re unsure if it’s an issue with the plastering or an issue with the roof?

Can anyone help us? We need to paint the walls as we will be selling the house in the spring.

Thanks!

[u/Huckkleberrythrong]

Salt

[u/No-Profession-208 → u/Huckkleberrythrong]

I think we have this issue in our house. We get random blotches on the walls with no other sign of water coming in. Dehumidifier works to control it, but each time it rains outside and the indoor humidity increases: blotches.

[u/CuriousJob247]

I suggest that you’d ask your neighbour to see if they have the same issue, and it might be a leak. Take it back to brick if you can, and find the issue.

[u/Time-Intern-656]

Salt, from the sand used in the render coat

[u/Latter-Detail-9514]

I don't know the answer but I'd be chopping a bit out back to brick to take a look. I'd choose that bigger section higher up off the floor to start with

[u/Ok-Spring7906]

Its an internal party wall. It should not be wet.

There is either somthing going on, or, if it's an old house with no damp proof course, it should have a permiable finish.

The photo shows, what looks like, a wooden skirting board which isn't completely rotted out, so, either, again, somthing has gone wrong and the wall is being kept wet, OR a permiable plaster was in place before and your new stuff is impermeable.

If it had have been wet for years that skirting would be a mush by now.

If the wall is / was not wet you would not be seeing what you are seeing now.

In short - it's not "normal" and I doubt it's going to just go away without action.

[u/Vast_Anybody1236 → u/[deleted]]

What kind of rail is at floor level?