Dealing with recurring hairline cracks

[markjg123]

Bit of history on the problem wall...

Is a 1930s house with both lathe and plaster and plaster on brick walls.

In this case it's the latter causing me grief. The original plaster is about 12-15mm thick. The wall was in poor condition and was professionally skimmed. Cracks appeared before I even painted it and it was skimmed again. The wall was painted but cracks reappeared. It was left like that for quite some time and no new cracks appeared. I filled the hairline cracks just about 3 weeks ago and repainted. All looked great but the cracks have reappeared.

I suspect that filling and painting is pointless and the problem might only be fixed by the extreme process of taking off all the old plaster, boarding and skimming. I really don't want to go to those lengths, so I'd love to hear your other suggestions on fixing this annoying problem.

I'm sure you know what a hairline crack looks like but I've posted a photo anyway.

 

[JohnD]

Stand back and take a wider pic of the whole wall, floor to ceiling, and indicate where the crack is, and how long.

Especially if it is near a doorframe.

Is it an external (nine inch) wall?

 

[Deleted member 292770]

is there any tiny movement when you press anywhere along the crack?

 

[markjg123]

Stand back and take a wider pic of the whole wall, floor to ceiling, and indicate where the crack is, and how long.

Especially if it is near a doorframe.

Is it an external (nine inch) wall?

It's an internal brick wall. The crack is possibly floor to picture rail. About 7 foot long with a branch off it. There's no visible crack above the picture rail. I say possibly from the floor because it's behind a radiator if it is. It's central to the wall and not near the door frame. I'll try to show it on a wider photo.

 

[markjg123]

is there any tiny movement when you press anywhere along the crack?

No movement. It feels solid all the way along the crack.

 

[JohnD]

has there been any building work, such as "knocking through" and removing a supporting wall below?

or building in the loft above?

 

[Deleted member 292770]

The brick wall may be a timber frame wall with brick infills. Does it sound completely solid or more hollow in parts?

 

[markjg123]

has there been any building work, such as "knocking through" and removing a supporting wall below?

or building in the loft above?

Yes, extensive work in the room behind and in the loft above, but this was carried out almost 8 years ago.

 

[JohnD]

do you know when the crack started?

 

[markjg123]

The brick wall may be a timber frame wall with brick infills. Does it sound completely solid or more hollow in parts?

I believe it's solid and it certainly sounds it. The only section that isn't solid is on the far right hand side where I believe a door used to be, but this was removed and plastered over before we moved in over 14 years ago.

 

[markjg123]

do you know when the crack started?

About 5 years ago and has repeatedly come back after multiple repairs.

 

[JohnD]

so, after the building work.

 

[Deleted member 292770]

sounds like solid brick. I’d gouge it out and fill it with this :
https://www.halfords.com/motoring/p...MI1ez1t9CW9QIVGKd3Ch0pjQRyEAQYAyABEgKqk_D_BwE

 

[Harry Bloomfield]

Might the radiator have been put back on too soon after the wall was skimmed?

 

[markjg123]

so, after the building work.

Correct