Diagonal Crack in External Wall

[tonyhg395]

I have recently noticed a diagonal crack in an external wall, underneath a window, near the drainage pipes.
The bungalow was built circa 1965 and had a loft conversion done approximately 8-9 years ago. (done prior to me moving in).
I have checked internally and there is no visible signs of water ingress or internal cracking in this area.

My concern is that this could be due to subsidence? Has anyone else encountered this issue and can provide any guidance on how best to resolve it, or who best to contact (builder, or structural engineer), or could it be attributable to 'natural shrinkage'?
Many thanks and kind regards, Tony

 

[Ivor Windybottom]

Can you show the context of where it is, showing more or all of the wall?

It's probably shrinkage. It will be a weak point, where the wall is much less tall due to the window. Imagine the whole wall as a piece of wood, if you bent it, is it where it would snap? Our bungalow is similar, I have a few under windows in various places. Houses are less wide so suffer less from shrinkage but are also stronger due to the upper storey giving the wall more strength.

I was at a friend's newbuild house the other day, I noticed that just along a block of 3 small houses there were two movement joints. They build to allow movement now, put the cracks in deliberately from day one.

I did see a bungalow where each corner had detached itself and dropped downwards. It's hard to tell from the photo, it doesn't look like there's a huge amount of horizontal gap. Check whether there's another similar crack around the corner.

 

[tonyhg395]

Hi, unfortunately, I can't get nuch more of the wall in a picture due to the neighbours property and the fence!
There is one small area similar to this, but is inside a porch that has been added and, again, is under a window but doesn't go as far as the ground level. The wall that is affected is the largest of the walls of the property, so seems that those 2 windows may be the cause?
Apart from that, the rest of the wall doesn't have any cracking from the ground.

 

[^woody^]

Check for a leak in that adjacent drain. CCTV.

 

[tonyhg395]

Can you show the context of where it is, showing more or all of the wall?

It's probably shrinkage. It will be a weak point, where the wall is much less tall due to the window. Imagine the whole wall as a piece of wood, if you bent it, is it where it would snap? Our bungalow is similar, I have a few under windows in various places. Houses are less wide so suffer less from shrinkage but are also stronger due to the upper storey giving the wall more strength.

I was at a friend's newbuild house the other day, I noticed that just along a block of 3 small houses there were two movement joints. They build to allow movement now, put the cracks in deliberately from day one.

I did see a bungalow where each corner had detached itself and dropped downwards. It's hard to tell from the photo, it doesn't look like there's a huge amount of horizontal gap. Check whether there's another similar crack around the corner.

Hello - thanks for the reply. Would you recommend filling the gaps, or wait a while to see if it creeps/opens up any more?
Thanks, Tony

 

[HERTS P&D]

Gully/drain line will be leaking.

Andy

 

[tonyhg395]

Gully/drain line will be leaking.

Andy

Hello Andy. What trade will I need to call out to do the investigation? Is it a plumbers job, or a builders? Never had a problem like this before so any help will be gratefully appreciated.
Many thanks, Tony

 

[HERTS P&D]

Drainage engineer.

Andy

 

[tonyhg395]

Drainage engineer.

Andy

Hello Andy. Thanks.

 

[Ivor Windybottom]

It's probably nothing to worry about, hopefully this will set your mind at ease...