Vertical crack in internal wall

[James1979]

Hi - I’ve just started bricking out the internal skin of a wall under a window to convert the window to french doors.

I’ve had a SE visit to check the lintel is ok and have also notified Building Control and got the go ahead to begin.

There was no indication of any cracks on the internal plaster or on the outside wall.

however, as I’ve started taking plaster / bricks off, you can see a vertical crack under the window that has cracked all the bricks in half (as photos below).

It was there before I started any work as I could see it as soon as plaster came off. Is that a concern and what could causes of that be? No other visible cracks anywhere in house.
Thanks in advance.

 

[KenGMac]

James1979, good evening.

Given the section of brick is being removed, no problems.

As to what caused the crack? the bricks are [obviously] a lot more recent than the outer leaf, not sure what type of bricks have the crack, possibly a sand lime / Concrete type??

Given the cracked brick section is an infill and may not be secured at each side?? worth looking for? it is possible that an impact on an almost free standing section of brickwork has cracked centrally.

Ken.

 

[^woody^]

They look like calcium silicate bricks, and if so are prone to cracking like that mostly from shrinkage.

 

[James1979]

Many thanks for the reply - really useful and reassuring! I’ll carry on and take the rest out.
Thanks again.

 

[James1979]

*replies

 

[stuart45]

They look like calcium silicate bricks, and if so are prone to cracking like that mostly from shrinkage.

Very much like Midhurst whites.

 

[JohnD]

was that brickwork built off the floor?

the crack looks to me like the result of hogging.

 

[James1979]

The bricks weren't on the floor and extend down into the ground but can't see the bottom of the wall. I've finished the job now and there weren't any other cracks so not sure what it was but fingers crossed nothing else 'moves' now the doors are in!

Just not sure what to put in the cavity at the bottom of the door now (I posted separate thread https://www.diynot.com/diy/threads/cavity-insulation-round-new-french-door.553271/) but otherwise all done.

 

[^woody^]

Very much like Midhurst whites.

You are surely the Brick Meister.