What are foundation conditions like in Norman, Oklahoma?

Reviewed by Preston · Updated 2026-11-11

In short: Norman is a city of two kinds of ground: sandy soils over soft Permian sandstone, which rate low on shrink-swell and cover about 41% of the land, and clay on old terraces and shale prairie, which accounts for most of the 20% rated high ¹. Knowing which kind a house sits on explains most of what it does.

How much of Norman has expansive soil?

Norman is the third-largest area compared here at about 179 square miles ², mostly in the Cleveland County soil survey ¹. About 5% of the land inside city limits is open water ¹. Poorly drained soils cover only about 5% ¹.

Which Norman soils matter most for houses?

• Stephenville, the most common soil, is moderately deep and well drained, formed from Permian sandstone, with soft sandstone typically 20 to 40 inches down ³.
• Harrah is very deep to sandstone and well drained, on backslopes and foot slopes of low hills ⁴. Darnell is shallow and sandy, with sandstone 10 to 20 inches down ⁵.
• Kirkland is very deep, on old stream terraces, with a dense clay subsoil of 35 to 60 percent clay and slickensides ⁶.
• Renfrow formed from clayey Permian shale and is clay below about 13 inches, with seasonal cracks and slickensides ⁷.
• Newalla has an upper part formed from sandstone and a lower part from shale, and is very slowly permeable ⁸.

Why do neighbors in Norman see different problems?

Sandy, well drained soils swell little, so on Stephenville, Harrah and Darnell ground, movement more often comes from fill, slopes, erosion or leaks. On Kirkland and Renfrow clay, the familiar pattern is edge heave after wet spells and edge drop in drought ⁶⁷; see perimeter drying settlement.

What does Norman's permit data show?

Norman's monthly permit reports list "Foundation" permit categories for multi-family and commercial work, and no single-family residential foundation category appears ⁹. Ask the city's Development Services Division what a specific repair needs. See permits and licensing by city.

Which soils cover Norman?

ZIP codes in Norman

ZIP 73026, ZIP 73069, ZIP 73071, ZIP 73072

Looking for a foundation company near Norman?

Companies that serve Norman can appear on the company map in the Homeowner Hub. Paid listings there are marked Sponsored; the library and the AI guide don't rank or recommend any of them.

Buying or selling a house in Norman? Realtors who serve the area can be on the same map, also marked Sponsored, and for realtors covers the seller disclosure form, inspections and the sale timeline. Seeing cracks at home? Start with for homeowners.

How were these numbers measured?

We overlaid the city's current limits from the Census Bureau ² on the USDA soil survey's map units ¹ and added up the area of each soil. Where a map unit is a mix of soils, its area was split by the percentages the survey lists for its major soils, so the shares above leave out minor inclusions and do not add to 100%. A soil counts as high, moderate or low shrink-swell by the linear extensibility of its most expansive layer, the survey's measure of how much a soil changes length between wet and dry (6% or more is rated high). Water table, bedrock and flooding come from the survey's map-unit summaries: the shallowest water table in any month, the shallowest bedrock, and the most common flooding frequency. Bedrock here includes soft, weathered sandstone and shale that a pier can push through, so it is not the depth where piers stop. These are mapped averages for the whole city, not a test of any one lot. Fill, grading and the soil actually under a house can differ, which is why a site visit or soil boring still decides a repair.

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