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Foundation Crack 1

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Anks12

Computer
Feb 14, 2023
3
Hi all,

As I am new to this wanted your expertise/suggestions to see if this is something serious that needs to be taken care of.
Seeing a horizontal crack below the screen porched foundation, please see attached picture. Just a bit of history not sure if its related , four years back my sump pump failed and I had water in crawlspace but then after replacing the sump pump never had any water issues in crawlspace since then.

Please share your thoughts.

Thanks
 
 https://files.engineering.com/getfile.aspx?folder=7b01c5b2-e67d-45e9-8c89-8bb37472443a&file=Crack1.jpg
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Might be some shrinkage of the soil below as its slowly drying out. If the soil is clay, it could take several years to dry.

Off hand the crack doesn't look serious at this point assuming the photo shows the entire crack. I'd just repair the surface with some flex grout and call it a day. If it continues to open, give us a callback.

Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."
 
is this a concrete block wall with parging? Cracks often develop in that type of construction due to thermal movement. Unless there is some settlement, or bulging it's probably not serious. I would seal the crack as a maintenance precaution. If it's what we call a "working crack" ie opening and closing use a flexible sealant. If it's "non=working" mortar is fine. There are crack gauges you could install to observe movement but it's probably easier to mark some points along the crack and measure the width over a period of time to see what's going on.
 
This is likely due to the footing settling but the slab-on-fill not. I would not worry about it unless it enlarges a bit. At that point, you could underpin it with helicals.
 
XR250, based on your response, I assume you think the horizontal crack in the photo is between a concrete slab and a concrete or CMU stem wall below? I thought the crack we are seeing is a cracked bed joint between CMU courses?

To the OP, can you clarify whether the foundation stem wall is concrete or CMU. Also, I assume there is a concrete slab floor? If so, is it poured on fill soil or is it elevated (i.e., with crawl space underneath? If it is poured on fill soil, does it overlap the top of the foundation wall, or is it poured inside of the foundation wall?

Anyway, the crack does not look significant. I would monitor for changes, then make structural repairs only if needed if conditions worsen. You can make non-structural repairs (e.g., seal the crack or reapply the parge coat) to seal out water. Water intrusion into the crack will tend to result in the crack becoming more noticeable over time due to freeze thaw damage, etc.
 
gte447f said:
XR250, based on your response, I assume you think the horizontal crack in the photo is between a concrete slab and a concrete or CMU stem wall below? I thought the crack we are seeing is a cracked bed joint between CMU courses?

The upper CMU blocks stick to the slab. I have seen this many times in my practice and it is the only hypothesis I can come up with.
 
XR250, interesting hypothesis. You may be right.

I saw a crack like this just yesterday, and I have seen it on other projects in the past. I don't have a great hypothesis for what causes it. Because of the horizontal orientation of the crack, I have been inclined to think it is caused by lateral pressure on the wall, possibly from backfilling or maybe from soil consolidation after backfilling. Admittedly, if the crack appears after the slab is cast, then backfilling as the cause doesn't seem to fit. Another hypothesis that recently occurred to me is shrinkage of the concrete slab pulling on the top of the wall and causing the crack.
 
I would say that IF it is an issue of settlement THEN you will see some sort of diagonal (or stair step) cracking somewhere along the crack line as you get away from the corner. So... look for that and it might confirm some things.

The downspout line right there at the corner is a suspect for causing water to be flushed into the soil at that location and settlement is a strong candidate.

As XR wrote, it doesn't look too serious but just keep an eye on it.
 
Thanks all for your responses, appreciate it. Foundation stem wall is concrete. As this doesn't seem to be a serious issue, I will keep an eye .
For a second opinion spoke to few local guys and they say since the house is 14 years old and that's just a horizontal crack it might be due to soil and nothing serious to worry about
 
I suggest that you glue on a few crack monitors somewhere behind you bushes and record the position seasonally for a couple years. If you observe movement, you'll know the direction and location. If there's no movement, then you have a record to show the next buyer.
 
Anks12, thanks for clarifying that the foundation stem wall is concrete and not CMU. If that is the case, then the crack you see may simply be the cold joint between the stem wall and the concrete slab telegraphing through the parge coat. Nothing to worry about. Like I said before, the crack will probably continue to degrade and become more noticeable over time due to water infiltration and freeze thaw action. Eventually, if it starts to look bad, you can reapply the parge coat.
 
Thanks once again for valuable suggesions.
 
If you redo it, forget parging. Find a contractor that will do a proper stucco finish. It'll be more expensive, but will be much more resilient and resistant to this sort of cracking.
 
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