Do I dare fix a crack showing daylight between cinderblocks?

[Zamboni]

Ok, long story short, there is a skinny crack showing daylight along the grout lines about half way down a cinderblock wall. The crack is mostly straight down and then becomes a "ladder crack" near the ground. It's on a room that was clearly an addition to the back of the house, which is built on the side of a hill, and it also appears to have been repaired before. I'm guessing the ground has just sunk a tiny bit under that corner of the addition room. The rest of the house seems amazingly structurally sound.

The area where I live has clay soil that is prone to causing this, and I've seen much, much bigger cracks in the walls of other homes. So, honestly I'm just not that worried about it to the level of paying an engineer or anything like that at this point. But obviously I'd like to patch it up.

Does anyone have experience with just mixing up something and injecting it in the crack? Anything I should watch out for? It looks like some people on youtube are using 2 part structural adhesives with mixing tips that go to a needle for injection, and some other guys are using quikrete with a mixing tub and a trowel.

Thanks for any advice or experience that you can offer.

[Jon Bon]

Ok, long story short, there is a skinny crack showing daylight along the grout lines about half way down a cinderblock wall. The crack is mostly straight down and then becomes a "ladder crack" near the ground. It's on a room that was clearly an addition to the back of the house, which is built on the side of a hill, and it also appears to have been repaired before. I'm guessing the ground has just sunk a tiny bit under that corner of the addition room. The rest of the house seems amazingly structurally sound.

The area where I live has clay soil that is prone to causing this, and I've seen much, much bigger cracks in the walls of other homes. So, honestly I'm just not that worried about it to the level of paying an engineer or anything like that at this point. But obviously I'd like to patch it up.

Does anyone have experience with just mixing up something and injecting it in the crack? Anything I should watch out for? It looks like some people on youtube are using 2 part structural adhesives with mixing tips that go to a needle for injection, and some other guys are using quikrete with a mixing tub and a trowel.

Thanks for any advice or experience that you can offer.

Foundation problems are almost always drainage problems.

So how is your grading away from the house? How are your gutters and downspouts. How much overhang do you have at the eves. Stand outside when it rains, when it rains hard. Does water flow over your gutters or pool anywhere? Assuming this is all good, go to step 2 of addressing the crack itself.

So with the crack, what is the concern? Letting water in? Looks ugly? How big are we talking? 1/2 inch or 1/16?

In terms of patching sure you can either jam some mason mix in there that will make it no longer a crack. You could also chip an loose motar out of there if you wanted to be ambitious. but if you don't address any issues you have above it will return. Your house will not fall down if you go after this. FYI your work will probably look like crap compared to what is already there, but structurally it should be fine either way.

[Papa bear]

I’ve filled mortar joints with hydraulic cement with no issues.  If you’re seeing daylight, then I would for sure patch it up. It’s letting in unconditioned air, insects, etc. 

Agree with jon bon.  It’s typically water issues.  I don’t worry much about steps cracks, but maybe put a straight edge on there and see if the wall is still plumb.   If it is, go ahead and patch up the cracks.  If it’s not, come up with solutions to fix water issues and then to shore up your wall.


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[Zamboni]

Thank you for these replies! It is a very small opening, but seems to be growing slowly. It's also clear that it has been patched up before.

Drainage is definitely away from the house and seems to be well set up, but this crack is right in the middle of a wall on the downhill side of a home on a decent front-to-back slope.

I'll check that the walls are still plumb, then figure out how to go from there. Your advice is highly appreciated!