Stepped cracks in exterior wall

[electrogear]

We're looking at purchasing a house, but there's a 3mm (ish) crack that runs diagonally approx 10ft along the mortar line at the side of the house from towards the middle down to about 4ft up near the front of the house. One of the bricks along this step is cracked down the middle and it looks to have dropped by 1 or 2mm but none of the other bricks seem to have this issue. The crack doesn't appear to open up towards the top, it seems fairly uniform. There's another crack a few feet long (about 2mm or maybe less) at the front of the house under a window that again runs down the mortar line (no cracked brickwork here).

It's difficult to tell looking at google streetview (photo taken Sep 2016) whether the crack existed then, however there's a number of lighter coloured bricks at the front corner. Are these likely to be new bricks? And would that indicate that there's movement at that front corner? Also there seems to be some sort of staple or brace, or gauge(?) just to the right of the drain pipe in this picture from google maps but it's not there now.



I'll go and get some more photos tomorrow which show the cracks. My gut feeling is that it's not serious and looking at other properties in the area they all seem to have had bricks replaced/repointing carried out, but any thoughts would be welcome. Ultimately we'll be getting a structural survey anyway but if there's anything that stands out as obvious right now then we'll leave it and move onto the next one.

 

[electrogear]

Just realised there's a tool on google street view which enables you to see photos from previous years. Going back to 2008, the brickwork looks identical (no evidence of any change to brickwork or mortar). Hopefully if I go and take some pictures from varying distances it will be possible to identify how long the crack has existed by comparing it to the various years.

 

[electrogear]

OK, so in the light of day today it looks way worse than I thought. My unprofessional opinion is that it's historical (and possibly still progressive) subsidence at the front corner of the house, but it's a not-very-well educated guess really from reading various forums so any input from anyone would be appreciated. There appears to be 4 quite long cracks, (both vertical and stepped) and a number of smaller ones. There's actually dozens of cracked bricks, not just one. See the image map and close up images below:-

IMAGE MAP


AREA 1



AREA 2









AREA 3



AREA 4











AREA 5

 

[electrogear]

AREA 6



AREA 7



AREA 8

 

[tony1851]

Subsidence at front corner due to defective drain?

 

[electrogear]

Subsidence at front corner due to defective drain?

It did cross my mind (hence the last photo). Is there any way of knowing without actually inspecting said drain to see if it's defective?

 

[electrogear]

Is it definitely subsidence then? I'm going to ring the agent and cancel if it's not something that can be easily remedied, and judging by the extent of the cracks I'm guessing it's going to be expensive? Shelling out for the work (underpinning?) can be negotiated with the vendor but my main concern is obtaining buildings insurance.

 

[tony1851]

Is it definitely subsidence then?

No-one here can say 100% just on the pics - you would need to have someone to look at it.
But subsidence due to leaking drains is common; and some of those cracks do look relatively recent.

 

[^woody^]

Cracks are typical of thermal movement not subsidence

 

[tony1851]

Cracks are typical of thermal movement not subsidence

So differential settlement would not cause cracking?

 

[electrogear]

Cracks are typical of thermal movement not subsidence

One thing that confuses me is that there doesn't appear to be much cracking near the foundations/DPC but there's some movement of bricks further up, like the photos shown below, the bricks on the left of the crack have dropped by 3 or 4 mm. Looks like I'll need a proper structural survey to come to a conclusion then?

 

[rick68]

Roots from the privets could have cracked the drain.

 

[^woody^]

So differential settlement would not cause cracking?

Not like those

 

[^woody^]

One thing that confuses me is that there doesn't appear to be much cracking near the foundations/DPC but there's some movement of bricks further up, like the photos shown below, the bricks on the left of the crack have dropped by 3 or 4 mm. Looks like I'll need a proper structural survey to come to a conclusion then?

Its possible for there to be a main cause and subsequent action or effect. Those cracks do not appear to have been caused by foundation movement, but that's not to say that there has been some foundation movement. This makes a big difference, as the repair will need to deal with the cause, and not the symptom.

 

[electrogear]

Thanks. Going to have a look tomorrow. I've decided - if there's internal cracks that match the outside then I'm going to leave it. If there aren't, then I'm going to have a structural survey done.