Crack in bricks 4

[Craig_1988]

Hello all,
I wonder if someone would be kind enough to take a look at these pictures and either put my mind at rest or let me know I need a structural engineer.

I was up adjusting the CCTV today and noticed a vertical crack that spans 3 bricks. It isn't wide (less than 2mm) and there is no cracks on the inside wall. House was built around 1960. I happened to find a picture from June 2018 (taken of the window for the fitter) and the crack is there too. It doesn't look to have got any worse in the 2.5 years that have passed since then.

What do you think? Does it just look cosmetic or does it warrant further investigation? I feared subsidence but everything I have read says it would be diagonal, wider at the top than the bottom and noticeable inside too. None of those apply

Appreciate any thoughts, thanks in advance, Craig

 

[dik]

Keep an eye on it... looks like a normal shrinkage crack... not bad for a home of that age. I don't think an engineer would help... and repair would likely be a lot uglier than the crack

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[MIStructE_IRE]

Agreed. Doesn’t appear to be of any structural significance. If that’s all its moved in 60 years then that’s nothing. Looks like shrinkage to me but as said above, keep an eye on it. Record its width as best you can every 3-4 months. Any immediate significant changes then get an engineer - but I’d be surprised if you see anything at all.

 

[EdStainless]

Easy way to measure. In the two mortar joints scratch lines on either side of the crack 10mm apart.
Measuring the distance between the lines will be easier than trying to measure the crack.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[hokie66]

Clay bricks don't shrink. They expand with time. So I wouldn't call it a shrinkage crack. When I see a crack in the vicinity of an opening, the first thing I look for is corrosion of the lintel. When steel corrodes, it expands to occupy additional space.

 

[dik]

Agree... Hokie and that sometimes causes problems with concrete framed structures... Should have noted that it was temperature related change, and not material shrinkage.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Tomfh]

Why is the mortar below these cracks a different colour? Was there an addition to the house?

Are there any cracks at all in the lower section with the darker mortar?


As the crack is close to the opening it is likely related to that. It's not major cracking and I too would be keeping an eye on it. Buy a crack width gauge. They are cheap on ebay.

 

[dik]

Done that numerous times, except using hardened PAF pins and digital caliper...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Craig_1988]

Thanks all for looking.

Was there an addition to the house?

I'm not sure why the mortar is darker - there is no cracks in that area, the only cracks are the ones in the photos. No additions. I checked with the neighbour who has lived here since the house was built and she can't recall any work/repointing being done in that area.

I'll get a gauge and keep an eye on it over the next few months - I am reassured though that no one is shouting subsidence at me...!

Many thanks, Craig

 

[bones206]

Is this a south facing wall? Could be thermal expansion that is making the wall slightly bulge out and crack. The window opening perforates that vertical wall section making it more prone to cracking in this scenario.

Another possibility could be frost-induced cracking, if moisture is getting into the bricks or in the cavity behind the bricks. Window sill may be a source of water intrusion...

 

[Craig_1988]

I should have mentioned, yes that wall is South facing. The windows and sills had seen better days and have since been replaced.

Would you bother patching it up or just leave it and monitor for a while - will it get any worse if not repaired?

 

[bones206]

Would you bother patching it up or just leave it and monitor for a while - will it get any worse if not repaired?

I would say yes to repairing. If moisture is getting into the cracks and freezing, it could become a cyclical and destructive process. The more the cracks open up, the more room for water to accumulate, the more frost damage you get. Not sure if that's you're issue or not, but repairing the cracks couldn't hurt.

It may also be frost-induced cracking from moisture penetrating the pores of the bricks themselves if they aren't adequately sealed. You could try to have the wall sealed if that's the case.

I would have a local mason take a look, since they will have insights and experience specific to homes in your area that nobody on this forum can provide. This may be a common issue that's readily diagnosed.

 

[oldestguy]

Filling the cracks will show. Then more movement. Then fill, etc. Better off leaving AS IS. A common situation in masonry, to be expected now and then.

 

[dik]

You said a mouthful...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[bones206]

If it's a thermal expansion crack, it may be self-relieving and not get much worse. If it's a freeze-thaw issue, it may progress. Hard to say... But if that crack has been like that for decades, I agree that it's probably ok to leave as-is.

 

[liam1369]

Not sure what the 'shrinkage' comments are referring to? Clay bricks don't shrink much at all unlike concrete or blocks.

It's most likely a thermal crack and the wall relieving itself a bit.

Does the wall face the south? Therefore, does it get hit by the Sun all day long in the summer?

Also, where is the closest expansion joint? For a wall on this face, you would expect one within 3-6m of the corners. If there is any at all.

It is likely a thermal crack due to the flank return walls acting as edge restraints. Do you have any other pictures?