Cracks I've Never Seen Before

[randynavarro]

First time I've seen something like this.

Home is single story. 1981. Standard poured footing and 20" or so stem wall.

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The cracks runs horizontally across most of the front section of the home.

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This is the biggest the crack gets.

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Every so often, there's this cross-cracking phenomenon. There were three of them.

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The cracking continues and ends.

Crazy I say!!

Any thoughts?

[AHI in AR]

Poured concrete foundations are extremely rare in my neck of the woods so I don't have much experience with them, but without any other info, my first inclination is to guess that it's due to lateral soil pressure. Where was the soil level outside this wall?

[Darren]

Kevin,

Looking at the pictures, the exterior grade can't be much higher than the location of the crack.

I noticed there's little to no cracking at the inside corner (which is acting as a shear wall).

I'm wondering if there put something in the pour to act like rebar that's has a different expansion rate.

Whatever it is, call for a structural review (hopefully they tell you what they find so you can tell us).

Darren

www.aboutthehouseinspection.com

[AHI in AR]

Originally posted by Darren

Kevin,

Looking at the pictures, the exterior grade can't be much higher than the location of the crack.

Whatever it is, call for a structural review (hopefully they tell you what they find so you can tell us).

Darren

www.aboutthehouseinspection.com

That's why I asked about the soil line. I can only speculate that there was soil placed against the concrete prior to a full enough cure. That might set up tiny stress cracks that could later grow, right? Especially if heavy equipment got too close to the wall. If the soil line is essentially at the same level as the crack that would be my guess as to the cause. However, there are too many unknowns to say for sure.

Do let us know what the cause is.

[Chad Fabry]

It looks like the concrete was placed too wet and the aggregate is all #1 and smaller. Hardly an ideal mix for a foundation. I'd bet it's easily crumbled with little resistance to impact. It has the distinctive look of a cement starved mix.

[hausdok]

Hi Randy,

Call for a structural and insist it be a guy who's intimately familiar with residential foundations 'cuz they're a different animal than commercial jobs. You could call Dave Pioli at Criterium in Bothell, or, I've heard that Bodine has an engineer on staff. Either way, hHorizontal cracking should always be called, and, in this case, I bet you've got a stemwall that's fractured because of liquifaction movement - probably during the 1996 or 2001 quakes.

ONE TEAM - ONE FIGHT!!!

Mike

[randynavarro]

...my first inclination is to guess that it's due to lateral soil pressure

There's not a lot of soil outside, maybe 18" or so. I'm hard pressed to think it's soil pressure.

I'm wondering if there put something in the pour to act like rebar that's has a different expansion rate.

I like that idea.

It looks like the concrete was placed too wet and the aggregate is all #1 and smaller. Hardly an ideal mix for a foundation. I'd bet it's easily crumbled with little resistance to impact. It has the distinctive look of a cement starved mix.

Well, being totally blindsided with this one and not really having many other theories, I might buy into that for a buck.

Call for a structural and insist it be a guy who's intimately familiar with residential foundations 'cuz they're a different animal than commercial jobs

Done

I probably won't hear a thing about any engineer or additional evaluations. The client is a single lady with some kids; the house has a Stab-Lok panel and mold / mildew in the attic. She didn't look so well when we were done, unfortunately.

[Eric B]

"She didn't look so well when we were done, unfortunately. "

Actually that's probably a good thing. That foundation alone is more than she may want to deal with. I always dread having clients want to continue with purchasing a home with such problems. A buyer who moves in and then begins to realize the mess that they've gotten into is never good.

[randynavarro]

I only say that because the home was actually renovated very nicely. I was actually impressed. I'm rarely impressed because I see so many poorly executed flips and do-it-yourself work with materails supplied by the big box.

It was a rental for years, got thrashed, and the owner renovated to sell. The choices and materials used were much better than the average. He went way above and beyond what we expected. He obviously cared about the place. He just wasn't aware of these larger issues.

[Brandon Chew]

Dang! I wrote a nice long reply. After I previewed it and proofed it, I hit the wrong button and lost it all. I'm too bummed to write it again.

The gist of what I wrote:

Any thoughts?

The concrete looks funky. Mix looks wet to me. If so, concrete is weak. (Agree with Chad)

Was the wall still in the same plane above and below the horizontal cracks, or was it bowed and hinging along the cracks?

If it was due to hydrostatic pressure, expansive soils, or frost heave, I'd expect the cracking to be further below grade than you are showing in the pics, and I'd expect to also see bowing. It looks to me like someone grabbed the house by the footings, shook it, and the foundation tried to shear off where it came out of the ground. (Agree with Mike)

If this is seismic damage and the concrete is weak (Chad and Mike are both right), the fix could be as extensive as having to jack the house up and replace the foundation. So on that note, and based on your description of the buyer, it might be fortunate that she's nervous (Agree with Eric). The house could still be a good deal for a buyer with deep pockets if the price is right. By the way, I don't try to sway my client either way regarding the purchase. I try to give my client good, clear information so they can make a decision about what is right for them.

I'd call for evaluation by a PE that has experience with residential foundations. (Agree with Mike and You) If an evaluation is done I'd be interested in hearing about the findings and the recommended fix.

[Jim Katen]

Wet mix.

Bad juju.

-Jim Katen, Oregon