Exterior vertical hairline crack. Reason to worry?

[JonnyP_7]

Hello,
We brought this house around a year ago. Built in 1990’s. The other week I noticed a rather long hairline crack running up the corner of the house. Runs from the bottom, through DPM and through around 12 bricks… The previous owner has planted a decent sized shrub that has a fairly thick trunk and also our guttering down pipe is close to the crack. Wondering if this could be main cause. Hoping it not to be subsidence. Also would it be worth re-pointing, epoxying / waterproofing for the time being to give it a chance of not escalating quickly and needing significant repair work

Thanks

 

[jeds]

Settlement cracking would normally be a wider crack at top or bottom - indicating rotation. What you have there looks more like thermal cracking. Is it a particularly long extension?

 

[JonnyP_7]

Settlement cracking would normally be a wider crack at top or bottom - indicating rotation. What you have there looks more like thermal cracking. Is it a particularly long extension?

It’s around 3/4 feet in length running from the bottom brick up on the original exposed wall

 

[Ivor Windybottom]

Dig down at the corner, see what the foundation looks like and how deep.

If it's a small DIY extension then it may be sitting on topsoil, many are. If so then it's not fit for purpose and will move and crack. Either live with it and don't worry about it or knock it down.

Definitely check the drain too, underground. If it's leaking then it may be rinsing soil from under the wall.

 

[JonnyP_7]

Dig down at the corner, see what the foundation looks like and how deep.

If it's a small DIY extension then it may be sitting on topsoil, many are. If so then it's not fit for purpose and will move and crack. Either live with it and don't worry about it or knock it down.

Definitely check the drain too, underground. If it's leaking then it may be rinsing soil from under the wall.

Thanks. This is part of the main house, we have no extensions built onto it. The crack does go down to the foundation, but can’t see a crack in it

 

[jeds]

It’s around 3/4 feet in length running from the bottom brick up on the original exposed wall

Sorry, I assumed it was an extension. I mean how long/wide is the house? Are there any expansion joints? A photo of the main elevation would be useful.

 

[JonnyP_7]

Sorry, I assumed it was an extension. I mean how long/wide is the house? Are there any expansion joints? A photo of the main elevation would be useful.

Photo of the main wall added. Not too sure if we’d have expansion joints being built circa 1990. Would this be a fairly inexpensive way to stop future cracks?

 

[Ivor Windybottom]

Looking again, it doesn't look like anything's moving downwards, if so there'd be a step change in the brickwork courses across the crack. It's probably just shrinkage, in which case what you have is just a natural movement joint.

Don't fill it, otherwise if it's opening and closing you'll cause it to ratchet wider. It won't be able to close up if the building expands, so it will push outwards then you'll end up with a 2x width crack when it next shrinks. If you fill this you'll get a 3x crack etc etc. People tear their house apart by filling cracks.

Just keep an eye on it, perhaps make a mark at the top of it and you've already got photos of the bottom. If nothing changes then don't worry about it. You may find it breathes open and closed depending on temperature and wetness, if so that's nothing to worry about.

We've got several similar cracks in ours. It looks like it's been there a good few decades so if it was going to fall down it probably would have by now. I wouldn't worry unless it's growing.

 

[Ivor Windybottom]

Photo of the main wall added. Not too sure if we’d have expansion joints being built circa 1990. Would this be a fairly inexpensive way to stop future cracks?

It's quite a long front wall including your neighbours. The shiny engineering brick is continuous under the doors.

It was going to crack somewhere, it's just decided to crack on the corner.

If you had a staircase in the brick courses then you'd have an issue. I wouldn't worry.

A good video from a sensible bloke...

 

[JonnyP_7]

Top bloke, thank you. Put my mind at ease a bit

 

[jeds]

Would this be a fairly inexpensive way to stop future cracks?

It looks very much like a thermal crack caused by racking of the corner. I've come across this quite often in surveys of commercial buildings but much less often in houses. The difference being the length of the building. What happens is the front of the building expands, pushing the corner outwards, but the side elevation is unable to flex sufficiently to allow for the movement. The result is a vertical crack.

You could just leave it, keeping an eye on it. I don't think it will change much. If you really want to do something with it, the best alternative is to grind an 8mm chase up the crack - carrying on up the entire elevation - and seal with a high quality polysulphide adhesive. That will allow future movement and look less alarming than an obvious crack.

 

[^woody^]

That's got all the hallmarks of a thermal crack. The only anomaly is the continuation down into the different engineering bricks - typically the brickwork would slide on the DPC if it wanted to, so only the one type of brick would crack. But it's not unknown.

Anyway, these tend to be single occurances related to random and specific hot/wet weather events. That brick and gable size are common and require no specific design precautions, so it's just a phenomenon.

Clear silicone into the crack would be less obtrusive than any other repair. And just monitor it to check its not progressive - it may well extend vertically, but you are looking for it widening, and if so then involve a structural engineer. If it does not change significantly, forget it