Hi there, another 'what's up with my paint' thread and I really hope someone out there can help.
I have an upstairs room which we had skimmed a couple of years ago. Since then, we've had bubbling paint on two of the walls - mostly beneath a window (and above and behind the radiator) but also a patch above the window too, and a very small amount on the other external wall too.
The first paint on the new plaster was a coat or two of Dulux Supermatt followed by regular Dulux emulsion. When the bubbles first appeared I scraped, sanded, filled and repainted.
We then discovered damp / water ingress issues and had some extra flashing added to a nook in the roof (which is basically at the corner of the room) last year which seems to have sorted that, and there's no sign of damp now, besides the paint bubbling. In any case, the paint issues are mostly ~5ft away from where the damp patches were.
Once the flashing had been sorted (last summer) I scraped again and this time primed with some Zinsser 1-2-3 (standard, not plus) because I had some of that lying around, filled and finished with the same Dulux emulsion.
Now a few months later the bubbles are back. Just as before, they are hard and crusty (not 'fluffy' like efflorescence seems to be) and scrape right off back to the plaster.
I wasn't very happy with the plastering at the time (there were a few patches that didn't look good, albeit I think those were elsewhere in the room) but with the history of damp I wouldn't like to say that's definitely the culprit.
Any ideas?
Ps - it's a solid brick wall (1912 built house), the room in question is rendered on the outside and that seems to be in decent enough condition.

I have an upstairs room which we had skimmed a couple of years ago. Since then, we've had bubbling paint on two of the walls - mostly beneath a window (and above and behind the radiator) but also a patch above the window too, and a very small amount on the other external wall too.
The first paint on the new plaster was a coat or two of Dulux Supermatt followed by regular Dulux emulsion. When the bubbles first appeared I scraped, sanded, filled and repainted.
We then discovered damp / water ingress issues and had some extra flashing added to a nook in the roof (which is basically at the corner of the room) last year which seems to have sorted that, and there's no sign of damp now, besides the paint bubbling. In any case, the paint issues are mostly ~5ft away from where the damp patches were.
Once the flashing had been sorted (last summer) I scraped again and this time primed with some Zinsser 1-2-3 (standard, not plus) because I had some of that lying around, filled and finished with the same Dulux emulsion.
Now a few months later the bubbles are back. Just as before, they are hard and crusty (not 'fluffy' like efflorescence seems to be) and scrape right off back to the plaster.
I wasn't very happy with the plastering at the time (there were a few patches that didn't look good, albeit I think those were elsewhere in the room) but with the history of damp I wouldn't like to say that's definitely the culprit.
Any ideas?
Ps - it's a solid brick wall (1912 built house), the room in question is rendered on the outside and that seems to be in decent enough condition.

