Cracks In Single Skin Brick Wall

[NorthBristol]

I am applying for planning permission to extend my garage. It has single skin brick walls, and my plan was to keep two walls, and substantially extend in the other directions. However, one of the walls has cracks in it.

They have been there for years, and never bothered me that much, but this is one of the walls that’s supposed to stay. Is the builder going to tell me it’s easier just to knock the whole thing down and start again? If so, I would take the opportunity to move this wall about 80cm, but that would mean more foundations and would add thousands to the cost.

If I wanted to close up the cracks, what would be the approach? I wondered if I could inject something, but the cracks are so narrow.

Thanks for your help.

 

[Notch7]

Others on here have more knowledge interpreting wall cracks, however, this would appear to be a crack which opens up as it gets nearer to the corner: that can indicate subsidence of the foundation on that corner.

Do you have any trees or hedges growing nearby that might cause movement?

 

[^woody^]

If these have been there for years and have not got any worse, and are not affected by the proposed works, then they are not a problem - just ignore them or have them pointed up.

Your other option is to have them investigated, go through all the "it might be this or that" and then have expensive/extensive repairs for what may be no reason.

And don't let the builder talk you into what he thinks needs to be done and will charge you accordingly for doing it.

 

[Harry Bloomfield]

Might a photo of the brickwork just round the corner, over the other side of that fence offer a few more clues?

 

[NorthBristol]

The crack stops at the corner. There is a similar crack in the opposite wall, 3m away, and another in the diagonally opposite corner, 7m away.
There is foliage not far behind the corner you can see, but nothing thicker than 1/2" stems, and nothing that's obviously attacking the garage. The diagoanally opposite corner which has a not-too-different crack is adjacent to a tarmac path and a driveway.
Thanks for your replies so far.

 

[martygturner]

Is the roof tied to the walls ? Ie does it have galvanised straps in each corner tie the roof wall plate and the first rafterto the walls. Normally there is a pier in the middle of the gable that keeps that end from moving, but the force of the wind load transfers to the corners then giving them a nudge outwoods if they are not connected to the roof. Its only a guess without photos but I would say those cracks go back to the pier in the middle of the gable wall which is acting as a fulcrum.

 

[Notch7]

Is the roof tied to the walls ? Ie does it have galvanised straps in each corner tie the roof wall plate and the first rafterto the walls. Normally there is a pier in the middle of the gable that keeps that end from moving, but the force of the wind load transfers to the corners then giving them a nudge outwoods if they are not connected to the roof. Its only a guess without photos but I would say those cracks go back to the pier in the middle of the gable wall which is acting as a fulcrum.

It’s a good point, gable ends can experience significant wind load

 

[Harry Bloomfield]

The crack stops at the corner. There is a similar crack in the opposite wall, 3m away, and another in the diagonally opposite corner, 7m away.
There is foliage not far behind the corner you can see, but nothing thicker than 1/2" stems, and nothing that's obviously attacking the garage. The diagoanally opposite corner which has a not-too-different crack is adjacent to a tarmac path and a driveway.
Thanks for your replies so far.

My unqualified guess would be that the weight of the roof is pushing the tops of the walls out.

 

[^woody^]

It's indicative of foundation movement, not roof movement.