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Why Does Concrete Sink?

When the soils underneath a concrete slab are unable to support its weight, the slab will sink.

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If part of the concrete slab is supported by soils and other sections are not, the unsupported pieces may crack away from the other section and result in unlevel concrete.

AFS Foundation & Waterproofing Specialists can inspect the condition of your concrete slab during an on-site estimate. Call us today to schedule a free quote in Huntsville, Birmingham, Nashville, Chattanooga, Columbus, Biloxi and surrounding areas.

Soil washout can result in empty space beneath your concrete slab, unable to support it. This can lead to cracks and sinking over time.

Primary causes of sinking outdoor concrete

A sinkhole in the yard, showing settling soilsSoil Shrinkage, Compaction & Settling

Different types of soil have different load-bearing capacities. When a soil’s load-bearing capacity is exceeded, the soil will compact and settle.

It’s also possible for the soil beneath a slab to settle and compact of its own accord. Soil that contains large amounts of clay and/or silt will shrink substantially when it gets dry.

As the soil compacts underneath a concrete slab, the unsupported slab will sink as well, usually cracking in one or more spots.


Water washing away mud and sediment in rainy weather.Washout Of Soils

The soil that is underneath your driveway, patio, or concrete steps may not necessarily remain there to provide adequate support for the concrete element.

As water moves underneath your concrete slabs, it can wash away the soil that’s supporting the weight of the concrete. As this happens, it creates a void, or empty space, underneath. Over time, with nothing to support it, your concrete slab can begin to sink or cave in.

Want a permanent solution? Learn more about our SettleStop Concrete Raising installation in Alabama, Tennessee, and Georgia

The good news is that you don’t have to live with sunken concrete anymore!

We would be happy to provide you a free evaluation and cost estimate in Huntsville, Birmingham, Nashville, Chattanooga, Columbus, Biloxi and Surrounding Areas.

CONTACT OUR FOUNDATION EXPERTS TODAY

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Disclaimer: “Concrete leveling” means the process by which cracked, uneven concrete is stabilized, and in many cases lifted, by means of PolyRenewal™ polyurethane foam. AFS does not guarantee that PolyRenewal™ can make your concrete perfectly level.    

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Birmingham AL

130 Interstate Commerce Crt. Bldg. 100 & 200
Alabaster, AL 35007

Chattanooga TN

806 N Holtzclaw Ave.
Chattanooga, TN 37404

Columbus GA

2701 Opelika Road
Phenix City, AL 36870

Dothan AL

1909 Montgomery Hwy, Suite 322,
Dothan, AL 36303

Florence AL

118 E Mobile St
Florence, AL 35630

Gulfport MS

1317 26th Ave, Ste 101
Gulfport, MS 39501

Huntsville AL

2415 Jordan Road
Huntsville, AL 35811

Knoxville TN

3028 E Governor John Sevier Highway
Knoxville, TN 37914

Louisville KY

13105 Middletown Industrial Blvd.
Louisville, KY 40233

Mobile AL / Biloxi MS

3131 Hamilton Blvd.
Theodore, AL 36582

Nashville TN

1519 Heil Quaker Blvd.
LaVergne, TN 37086

Pensacola FL

89 W. Hood Dr.
Pensacola, FL 32534