Cracks in cinder block wall - stitch or replace?

[Nozzle]

I'm re-doing the living room, the plaster was quite cracked as the block wall is also cracked and slightly misaligned. I don't think it's about to fall down, (!!) but I do want to do some remedial work to stop the new plaster cracking should the blocks shift some more.

The cracks have been there as long as I have lived here (5 years) and have not worsened. They're on the inner-skin of a cavity wall, which when I moved in was an external wall (gable end) but is now internal as a result of an extension.

There are two vertical cracks, floor to ceiling about 6 feet apart. One goes though a window opening, so the reveal of the window is part of the line. (Though the window is now bricked up, outer skin of cavity only).

I was considering either getting a builder to replace move the cracked blocks and make good the cracked mortar.. (a job I don't want to do myself)

..or use threaded rod as rebar and the two-pack resin stuff in a deep slot I'll cut with angle grinder across the crack. (a job I can do myself)

I suspect replacing the blocks might do more harm than good when he's cutting and chiseling them out leaving a great gaping hole. The joists in this part of the house don't sit atop this skin, though in the new part of the the house the joists are at 90 deg so they do sit on top of the outer skin.

Nozzle

 

[^woody^]

Or do nothing

 

[Nozzle]

Doing nothing is always an option, can't argue with that. Only then once the wall is replastered it will crack up again, and I'll be annoyed that I didn't try anything.

Nozzle

 

[London Mike 49]

If you fix some expanded metal lath (EML) to the block work it will strengthen the the plaster and prevent cracking. It's widely used where plaster and wood have got to be plastered over as cracking is almost certain without the mesh in place.

Mike

 

[tony1851]

It's initial shrinkage cracking which is normal for those blocks. Not a structural issue and highly unlikely to widen, so apply plasterboard and skim.

 

[Nozzle]

tony1851 and London Mike 49 (any relation to "MikefromLondon"?) thanks for the info, and for justification as to how they got there in the first place. I knew they were weren't structural as the cracks aren't getting bigger, though couldn't explain why else they might be there. I'm going for the wet plaster approach (and this EML stuff) rather than plasterboard. (Which is the work of the devil)

Nozzle

 

[London Mike 49]

tony1851 and London Mike 49 (any relation to "MikefromLondon"?) thanks for the info, and for justification as to how they got there in the first place. I knew they were structural as th cracks aren't getting bigger, though couldn't explain why else they might be there. I'm going for the wet plaster approach (and this EML stuff) rather than plasterboard. (Which is the work of the devil)

Nozzle

Mikefromlondon is another forum member and not related to me

 

[^woody^]

What about Mike from Norfolk?

 

[^woody^]

The picture is now up and those are thermalite blocks and not cinder blocks. The cracking is common shrinkage not structural. Mesh across in the bonding.

 

[Nozzle]

I've just seen a typo in my post, and a key one at that doh. Were = weren't! Thanks for the correction in thermalite/cinder. I'll google the difference.

Nozzle

 

[Nozzle]

Mikefromlondon is another forum member and not related to me

Consider yourself blessed!

Nozzle