Why is this happening?

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We've had a problem with paint flaking in our ibgoenook for a while. I posted on here ages ago, and everyone e concluded we needed to sort the damp issue. We have since consulted damp experts who have said it's a condensation issue and related to it being a cold corner. On their advice, we used the fire frequently over winter and have installed a background heater in that corner. We left it until the weather had been dry and warm for some time to paint. Before doing so, we spent hours removing all the lose paint, then used a primer recommended to go under mineral paint. This was all advised by the damp expert, and the primer was sold specifically for this paint.

Roll on a week since painting and the pictures show the state of the new paintwork!

Can anyone shed any light on why this is happening, and what we could do about it?

What's the other side of the wall? Has the chimney flashing been checked?

Have you used a dehumidifier to dry it out?

I had something similar happen to me and it was a leaking pipe directly above. It could be worth cutting a hole in the celling to see if something similar is happening. Sorry I know that is drastic but in my case nothing else would have sorted it.

Have you checked the substrate with a moisture meter?

If it's damp, you have wayer getting in somewhere.

Condensation from heaters and burners tends to just cause surface mold on the paint. Peeling paint usually means damp.

The brick is the inside of an external wall. The smooth is the chimney breast. We had a new cowl fitted on the chimney last year, and the flashing was all okay then. The cowl is supposed to reduce the amount of rain coming down the chimney. There are no pipes near this, and the guttering etc was all done recently.

I suspect damp, but not sure what we can do. It's an old house with no damp coarse. It was all okay until we repainted last year. We repainted it as part of doing the whole room, and it was fine at that point, but ever since it's been a nightmare.

Yes, we had a dehumidifier in the corner for a while. We also have a background heater which we were told should help.

Have you tried the special damp proof paint, I am in an old house with some areas of damp bubbling paint and it has worked well.

We had much the same. DH initially thought that it was a problem with our chimney.

In the end, I lifted a floor board upstairs and found a teeny leak in a pipe.

We had similar and turned out our shower has a leak. You'll need to find why it's getting damp. Our wall never felt very damp so it doesn't take much water to cause the paint to do that.

I think that the paint needs to be stripped off, so that the material can dry out and 'breathe'.
The Society for the Protection of Ancient Buildings (SPAB) has great advice on this and other topics. They wrote 'The need for old buildings to breathe'.

This is unlikely, but it is a thought. We had a very old cottage and had a similar problem in the inglenook. We tried everything and eventually lifted the hearth stones - there was a uncapped culvert running under it. We capped it off and the problem stopped.

Damp in walls can take absolute ages to dry out.

Sounds like when you originally redecorated you might have used paint which isn't permmiable to moisture and that has meant that water has built up in the wall. You will probably need to strip all the paint off right back to the plaster and try again with water permiable paint.

What is on the outside if the external wall? Is the ground level low enough? Is there leaky guttering?

Looks like salting issue.

Plaster that has been wet draws up salts from the ground through the mortar tracks, even once its dried those salts will continue returning to the surface and crystalizing causing paint to bubble and flake every time the wall gets a little bit moist.

its unsightly but not really dangerous, only way to fix it is to hack off all the salted plaster up to 1m and re-plaster with new plaster (often they will advise some kind of salting barrier paint on the wall too) which can be quite a messy job.

This can come with its own issues though, our previous owner did that and all its done is move the issue which has traveled along the mortar further and popped up again just past the barrier/new plaster.

It could possibly be a paint issue too like mentions, if you do a 2nd coat before the first cures paint can bubble and flake but the pictures look a bit granular and rough textured which would like be salt crystals rather than just 'flaky' paint from it not adhering properly.