House internal breeze block vertical crack, will helical bars help?

[Person321]

Removed plasterboards to save some space, noticed this crack was covered with undercoat plaster which was also cracked, removed the plaster to reveal breeze blocks cracked the whole way from top to bottom. This is a first floor bedroom on the detached side of a semi-attached house.

I think i can see a very minor crack dowstairs along the same area but its painted over and not opened up for the last 2years ive had this place.
No cracks on the outside brick.

Would helical rods be pointless, given these old breeze blocks are very fragile? I dont want to put another plasterboard on top, my idea was to do secure the rods and plaster with a metal mesh?

Otherwise the other two bedrooms also have some vertical cracks around windows as well. Those were recently just done up with plaster and mesh tape, not been long so not sure if theyll reappear.

 

[mikeey84]

Personally, that meets my definition of a big crack, and I'd seek professional advice.

For me a big crack is one you can get your fingers into

 

[Ollyfp]

Removed plasterboards to save some space, noticed this crack was covered with undercoat plaster which was also cracked, removed the plaster to reveal breeze blocks cracked the whole way from top to bottom. This is a first floor bedroom on the detached side of a semi-attached house.

I think i can see a very minor crack dowstairs along the same area but its painted over and not opened up for the last 2years ive had this place.
No cracks on the outside brick.

Would helical rods be pointless, given these old breeze blocks are very fragile? I dont want to put another plasterboard on top, my idea was to do secure the rods and plaster with a metal mesh?

Otherwise the other two bedrooms also have some vertical cracks around windows as well. Those were recently just done up with plaster and mesh tape, not been long so not sure if theyll reappear.

It looks as though someone has taken the original render/plaster back in order to address the crack, which looks HORRIBLE like this, but may have been relatively small in the first place?
Anyway, you're right in that breeze blocks are fragile (I hate them) and it's good that there are no signs of cracking on the outer leaf. Check to see if a crack follows the mortar line externally. Sometimes it's hard to see from ground level.
Obviously your wall was 'dot and dabbed' in order to disguise the original imperfections, but consider that dot and dab can also serve to make the wall feel less cold!

 

[Person321]

Externally its normal brick and I was looking at that wall for ages and couldnt see any vertical cracks, added pics along the first floor wall where the room is, maybe someone will spot something?
Got a brick wall seperating the gap between mine and neighbours, so have a good view when on it.
Unless externally it was repointed, but dont know how to tell.

FIY because i was using a hammer drill to remove the undercoat and the old plaster that was on there, i busted through the brick in the middle portion where theres a hole going into the cavity. Wasnt very careful with it...
The crack on the actuall blocks isnt that massive that you could put your finger through it. Ive added more pics, including how it was when i took the plasterboard off.

Going back to the main question however, are helical bars appropriate for breeze blocks.

 

[Ollyfp]

I've had a good look at your external brickwork pics. Other than a few very thin/almost non-existent perp joints and a bit of missing mortar here and there, I can't see anything untoward.
I have dealt with cracks like this by cutting a deep groove at about 45 degrees across the crack and embedding a length of galvanized or stainless rod or thread bolt (or even a long coach bolt) with a stiff mortar mix or high resin content exterior filler. No need to spend out on expensive stitching kits!
That's just my take. Anyone else?

 

[Ollyfp]

 

[DAZB]

I have used helical bars and resin many a time and this would certainly benefit from them here. The crack (when zoomed in on) appears small except the hole you made and it is easy enough to set in several bars at intervals up the wall to keep it stable. Follow the recommended usage details on length and number of stitches and you should be all good. Doesn't have to cost a fortune either as there is a large variety in price and this is one of the best deals i have found...

https://www.structuralsupplies.co.uk/product-page/crack-stitching-kits?gad_source=1&gclid=Cj0KCQjw5cOwBhCiARIsAJ5njuYKRn3Y2rYlfTG9Zj6JIGxs2xrtMTFMzOkh3iXbu4k5f-BBxWTLOmgaArgfEALw_wcB

 

[^woody^]

Heli bars would be OK for those blocks, but before carrying out a repair you should have the cause diagnosed and be sure that there is no on-going movement.

That does look like a thermal crack, and it does look like there is injected cavity wall insulation which could alter the internal environment to cause such a crack - which would be a one-off event.

But if you are minded to just crack on, use mesh in the plaster too.

 

[Koolpc]

Doesnt look that serious to me.