Breakage on corners of slab, report?

I have a brick house sitting on a slab with no basement. The house is about 10 years old and 2 corners of the slab have some concrete that has been broken off with some minor cracking. It doesn’t look to me like there is any structural integrity issue, though some of the mortar between the slab and first layer of bricks could possibly fall out in the future. I was thinking one might report it as something to monitor. I’m not sure a repair is in order here. Thoughts? Thx!

Mike, welcome to our forum!..Enjoy! :smile:

This is what is happening with your breakage:


Welcome to the forum, Mike. Enjoy!! :+1:

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Interesting. Appreciate the explanation and picture is awesome, as I’ve never seen this illustrated or explained. So the question is: is this a common problem?
Would you report it as Needing repair or Monitor or maybe not report it at all?

Thanks for the welcome :slight_smile:

After looking more at the diagram, I have to know some things.
Why is thermal expansion causing an inward force between the 2 adjacent brick walls?
Is it more prevalent in the summer (thus thermal) because of the heat outside, causing a slight expansion of the brick? I was thinking that brick/mortar has little to no thermal expansion/contraction properties unlike other more malleable materials.
And why would the slab force be going in the opposite direction, or is it more that the slab force is stable i.e. its just resisting but has no force in the opposite direction?

Hi, Mike, I don’t know if you are in a cold-weather climate, but the damage was done by frost heaving in this pic. The footing is not below the frost line.

Thanks Scott. In my situation the house is in Oklahoma. I found a good article explaining this a little more: Foundation Corner Cracks | Foundation Check

And in your situation above, did you report that as a defect? Because it can’t really be fixed, right?

Yes it is a defect. We do not care how hard it is to fix. Not our problem. Report and elevate.

I would be more interested in writing up masonry defects.
More images of masonry course please.

When ever you see downspout terminations, look at the foundation and any material in close proximity! That includes the lot!

Observation: Poured concrete slab.
Minor spalling/chipping/scaling.
Masonry: Degraded bed, but and head mortar joints.
Recommend: Licensed professional masonry contractor repair degraded, missing bed, but and head mortar.

Mike, Brick walls will expand and contract with changes in temperature similar to concrete. The issue is the concrete foundation is mostly protected from the thermal effects of the sun by being buried in the soil. As the brick starts to expand stress builds up from the center of the brick wall and pushed outward in both directions. The south and west facing brick walls typically receive the most sunlight and expand more than walls on the shady sides. I performed a finite element analysis verifying the stress in the concrete foundation builds up at the corners where these wedge cracks develop. The damage is typically cosmetic unless the wedge breaks off and more than 50% of any individual brick is left unsupported. I estimate 90% of brick houses in my area will have one or more corners broke or cracked. If a large repair is needed usually short pieces of rebar are anchored into the concrete to hold the repair in place.


I appreciate all the great responses. Thanks!! Mike

Here is a graphical printout of the finite element stress build up at the top corner of a concrete foundation due to brick expansion. (The brick was not shown for clarity.) The red represents the highest stress level, which is concentrated at the corner where the wedge cracks occur.