What soils cause foundation problems in the Oklahoma City metro?

Reviewed by Preston, Oklahoma foundation repair consultant · Updated 2026-10-14

In short: The Oklahoma City metro sits on two very different grounds. Much of the area has deep red clays weathered from Permian shale — such as Renfrow and Kirkland — that crack, shrink and swell with the seasons ¹². Other parts have shallower sandy soils over Permian sandstone, such as Stephenville and Darnell ⁴⁵. Drought and wet cycles drive most movement on the clays.

Cities covered: Oklahoma City, Edmond, Moore, Norman, Midwest City, Del City, Yukon, Mustang and Choctaw.

What is the Oklahoma City climate like?

USDA descriptions of the metro's main soils list mean annual precipitation of roughly 26 to 40 inches and mean annual temperatures around 56 to 64 °F ²³⁴⁵. Statewide, rainfall ranges from about 17 inches in the far western Panhandle to about 56 inches in the far southeast, with Oklahoma's climate shifting from humid subtropical in the east to semi-arid in the west ⁸. Central Oklahoma sits in the middle of that range, so long dry spells and wet springs both occur. See drought and wet cycles.

What ground lies under the metro?

Red shale clays (west, south and central metro)

Clay soils formed from Permian-age shale — the Hennessey Shale and related red beds — cover large parts of the metro.

• Renfrow soils are very deep and well drained, formed from Permian clayey shale. USDA describes them as having vertic properties: cracks at least 5 mm wide open in most years, and linear extensibility (a measure of shrink-swell) is 6 cm or more in the upper 100 cm ¹.
• Kirkland soils are very deep with slow permeability, 40 to 60 percent clay in the subsoil, and intersecting slickensides — polished, grooved surfaces formed when clay swells and shears ². The type location is in Logan County ².
• Bethany soils are very deep, formed in loess or alluvium over Permian shale, with type location in Oklahoma County ³.

An Oklahoma State University study measured cumulative linear extensibility of about 11 cm for Bethany and 12 cm for Kirkland profiles and described the Kirkland soil as "inherently unstable" for engineering uses ⁶.

Sandstone soils (east metro)

The east side includes soils formed from Permian sandstone, associated with the Garber Sandstone:

• Stephenville — moderately deep, with weakly cemented sandstone at 20 to 40 inches; type location in Oklahoma County ⁴.
• Darnell — shallow, with sandstone at 10 to 20 inches; well to somewhat excessively drained ⁵.

Neither description lists vertic properties ⁴⁵. On these sites, water, erosion and fill are often bigger factors than swelling clay, though shale and mudstone layers within the sandstone and the Wellington Formation can produce clay pockets that need site-by-site checking.

Which soils are common in the metro?

More series are listed in soil series in the OKC metro.

What foundation problems are common?

• Perimeter drying settlement and tree-root desiccation settlement on the shrink-swell clays during drought.
• Center heave and leak-related heave when water collects under slabs on the same clays.
• Framing and support problems in older crawl-space homes.

Oklahoma research using Mesonet data put statewide active zone depths — where soil moisture changes seasonally — at about 0.5 to 4 meters ⁸. Repairs such as steel push piers aim to bear below that zone.

Do earthquakes affect OKC foundations?

The Oklahoma Geological Survey lists El Reno–Mustang and central Oklahoma among the state's principal seismic areas ⁷. Telling earthquake damage from soil movement is covered in seismic damage vs soil movement and induced seismicity in Oklahoma.

Related

• Soil Series - OKC Metro
• Bedrock - OKC Metro
• Hennessey Shale (Group)
• Shrink-Swell and Active Zone
• Tulsa Metro