Repointing/repairing loose brick work

[600rob]

Ive got got some areas of a wall that i first thought would only need repointing (see pics)

DSC_2626

• 600rob
• 13 Apr 2020

DSC_2625

• 600rob
• 13 Apr 2020

however on closer inspection the four rows of brick on the left hand stack below the cracked
horizontal mortar line are all loose.

The stack of four bricks is intact but loose from the wall.....
I could probably pull them out as a single block with a bit of force.

How would you guys go about repairing this?

edit sorry about the typo in the title..... cant edit it now i've posted
Thanks

 

[bobasd]

I'm not a brickie so bear with me,

You have a two brick jog-out so it seems - the vertical open slot is an expansion joint.
Is this the only one in the wall?
How long is that wall?

Will you post a pic showing the jog-out from the other side of the wall.
Is there anything applying pressure against the wall from the other side of the wall?
Did there used to be say a tree there?

Perhaps the loose brickwork is because the Expansion slot finishes below the tile creasing & all the pressure is happening up there?

 

[^woody^]

The top bricks should be relayed if loose, although they could be just repointed if not loose

You may find that there is a steel ties across that expansion joint and this could have rusted and lifted the bricks. If so it needs to come out and be replaced.

 

[600rob]

You have a two brick jog-out so it seems - the vertical open slot is an expansion joint.
Is this the only one in the wall?
How long is that wall?

The wall encircles a garden.... Probably about 40m perimeter.
The secion of wall in question is about 15 meters in a straight line before it turns off to one side.
That is the only expansion slot on this straight section.

The other side is a neighbouring property

Is there anything applying pressure against the wall from the other side of the wall?
Did there used to be say a tree there?

On the other side almost directly behind the expansion slot is some sort of evergreen conifer tree,probably about a few inches taller than the wall

On my side about 3 metres away is another conifer tree, probably about 5-6 metres. The trunk is about 25 cm in diameter.

I guess both of these could be part of the issue?

 

[bobasd]

I guess the jog and slot were built into that 50ft straight run during the original build. A good precaution esp given the now proximity of the neighbour's tree.
Trees and walls are bad news esp as garden walls are often on shallow foundations.
Its possible that its merely the length of wall brickwork, and its expansion causing the movement - nothing to do with any trees?
Or, as above, the left hand side seems to have been lifted not shunted?

 

[JohnD]

it looks to me like the top has been rebuilt at some time, without the expansion joint. Might that be the cause?