Concrete Slab Cracks in a Dwelling

I had an inspection yesterday on a 20 year old frame home built on a slab (Southern Indiana, expansive clay soil). The home is on a slight decline, with the slope toward the home in the rear and away on the sides and in the front. A swale has been installed in the rear yard at some point, and the dirt raised around the perimeter of the home, along the a swale down the left side.

The driveway had no cracks and there were no visible exterior foundation cracks. There are no sticking doors inside the home, or un-level doors. The front porch has settled approximately ½”. I saw a small a crack in the ceramic tile in a closet. When I moved sweepers and trash I found an area that is heaved 3/8” (at an exterior wall on the right rear). Most of the home had new vinyl plank flooring with the kitchen and dining room vinyl installed over the original ceramic tile.

The exterior dining room sliding door (exterior) was little tight, and after seeing the cracked ceramic in the closet I put a small level in front of the dining room door. The floor slopes downward ½” in the first ten inches from the wall. Suspicious I checked the entire interior perimeter of the home and all the flooring slopes downward ½” in the first 10 inches from the wall. 10 inches away from the wall the floor is level. While doing this I found a section of vinyl plank that had cam apart and was clearly un-level. One living room window won’t stay in the track or lock.

My question for the forum is (1) do you recommend an engineer or a foundation contractor/home builder. (2) Is there any way to fix the floor if the problem isn’t current or ongoing.















I had a similar finding yesterday. I recommended a licensed building contractor follow up.

My thought is both your condition and my condition are going to have to be exposed by removing the floor covering. Is there a significant crack in the slab present under your tile? Is the condition stable? If stable, floor leveler can be used, and the high areas can be ground down in order to create a flat floor for replacement tile. The contractor can decide if an engineer is needed. A good/experienced contractor can solve this. It’s what they are paid to do. The engineer is needed only if there are ongoing structural issues that the contractor doesn’t have the expertise to solve.

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Thanks for reply Michael. I agree, floor covering needs removed.

Was it a SOG foundation or something different? What did the garage floor to driveway transition look like?

Possibly from street creep?

It was slab on grade, garage floor had zero cracks. Garage floor to drive transition was good. Drive had no cracks and drive to road transition was good. The plumbing and gas lines come into the home in the area of the ceramic tile crack in the closet. I think there has been a previous problem due to the swale in the rear doesn’t have good grass like the rest of the yard and dirt has clearly been added against the home on the sides but that is instinct, so not in the report. One of the big problems on a conditions like these is was it a previous problem or ongoing. Has it been remedied or an attempt made at remediation? It would be helpful if sellers disclosed what they knew but they don’t around here. Most answers on the disclosure form or “do not know”.

There is no street creep involved. The street is below the home.

Or it could have been built this way. Just a bad pour that the builder did not catch or ignored. Regardless, that was a nice catch. An inspector in a hurry might have breezed right by.

Mike, I’ve seen plenty of the type of thing your picture shows because of poor site prep before the pour of the slab, too.

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It’s in that fuzzy subjective area, imo.

  1. 20 year-old home. Break and displacement likely many years old and may be stabilized.
  2. Walls not showing corresponding cracking.
  3. But out-of-track window and exterior vinyl planking might indicate structural settling.
  4. And sloping slab at perimeter edges is not consistent with a post tension slab which would be expected for a 20 year-old slab.

I would recommend evaluation by a structural engineer.

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Here’s what I see.
Suspect, gutter/downspout arrangement. Not enough downspouts.
Roof water dispersed below grade.
Poor veneer clearance.
Plantings/bushes too close to the building.
Porous material, not backfill grade soil, Suspect: Water being distributed under the slab creating conditions for hydrostatic pressure.
Floor slab cracks. Various locations.

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I suspect its a soil moisture issue where the soil has dried out under the middle combined with swelling along the outer edge due to poor water management. Inspectors from Houston TX could be a good source of information. Email me the address of the house and I will look up the USDA soil information for that building site.

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For those that do not have it the Foundation Performance Association of Texas has many very good publications on their WEB site for structures on expansive soils. These can be had for free here https://foundationperformance.org/ .

Also for those that may not be aware of it the USDA WEB Soil Survey site can be found here Web Soil Survey - Home . This site has a very good soil mapping system with a large amount of information for soils around the country. The mapping program is not completely intuitive but easy to figure out.

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Thanks Randy, I emailed you the address

I came across one like this before. They magically had a dog crate covering large cracks in the laundry room tile and then a few cracks in the master on the other side of the home. I recommended a structural inspection. Structural inspection acted like its normal. After they moved in realized the yard is extremely wet all the time, like a mini underground spring. They weren’t happy with there $10k estimate to fix. Seller definitely knew it was an issue and did not disclose.

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