Lawton Foundation Repair Guide: Clay Soil & Piers (2026)

Updated October 19, 2026. This guide is general information, not legal or engineering advice. Rules change, so confirm with the agency listed before you start work.

Quick reference

Topic	What to know	Source
Swelling clay	Montmorillonite can swell to 1.5 to 2 times its dry volume when wet	Oklahoma Geological Survey
How common	Over 75% of Oklahoma has bedrock that can produce expansive soils	Oklahoma Geological Survey
Local soils	Lawton series (type location in Comanche County) mapped with Hollister, Foard and Tillman clays	USDA NRCS soil series
Bedrock	Permian Garber Sandstone with some Hennessey Group shale in the south of the county	Comanche County (Wikipedia)
Climate	About 27.5 in. of precipitation a year; July highs average about 97°F	NOAA 1991–2020 normals (via Wikipedia)
State license	Oklahoma doesn't license general contractors	State of Oklahoma
City permits	License & Permits Division, 212 SW 9th St., 580-581-3360	City of Lawton
Before digging	Call OKIE811 before any excavation, including piering	City of Lawton; OKIE811

Why do Lawton foundations move?

The short answer is expansive clay plus a climate that swings between wet and dry. In a 2008 summary of Oklahoma's geologic hazards, the Oklahoma Geological Survey noted that clay-rich shales and the soils weathered from them can contain clay minerals such as montmorillonite that swell to 1.5 to 2.0 times their original dry volume when wetted, and that more than 75 percent of Oklahoma has bedrock that can serve as a source of expansive soils. The same summary warns that saturation from rainfall, lawn watering or sewer leakage can cause major damage when soils expand beneath sidewalks, utility lines and foundations.

Comanche County's soils fit that picture. The USDA's official description of the Lawton soil series puts its type location in Comanche County near Faxon and lists Foard, Hollister and Tillman among the soils mapped alongside it. USDA classifies Hollister as a fine, smectitic Vertisol, a clay soil that cracks more than 30 inches deep and stays cracked for 150 or more days in most years. Foard is described as fine and smectitic with vertic (shrink-swell) features, and Tillman's description notes cracks more than 48 inches deep. Smectite is the mineral group that includes montmorillonite. In the southern part of the county, the bedrock includes Permian Garber Sandstone with some Hennessey Group shale.

The weather does the rest. Lawton averages about 27.5 inches of precipitation a year, and July's average high is about 97°F. Long hot spells dry the clay and shrink it away from the foundation; heavy storms swell it again. Houses rarely move evenly, because one side gets more sun, more roof runoff, or more tree roots than another.

Settlement, heave or seasonal movement?

These three look similar from inside the house but call for different fixes:

Settlement is a part of the foundation dropping, usually at a corner or edge where the soil has dried and shrunk or was poorly compacted. Piers are the usual repair.
Heave is part of the foundation rising, often in the middle of a slab, when soil gets wetter than it used to be, such as from a plumbing leak or poor drainage. Piers at the edges don't fix heave; finding and stopping the water does.
Seasonal movement is the house rising and falling with wet and dry periods. Steadier moisture around the foundation can reduce it.

An elevation survey, ideally compared with a second survey taken in a different season, is the best way to tell them apart.

Which warning signs matter most?

Stair-step cracks in brick that are wider at one end
Doors and windows that start sticking or won't latch
Sloping or bouncy floors
Gaps at baseboards, crown molding or the garage door
Cracks that keep coming back after patching

Write down when each sign appeared and photograph cracks with a scale. A record over a few months tells a contractor much more than a single visit.

What are the repair options?

Slab foundations that have settled are usually supported with piers under the perimeter beam: steel push piers, helical piers or pressed concrete piers. Pier-and-beam houses are often leveled from the crawl space by re-shimming, adding or resetting interior piers, and repairing beams and sills, with perimeter piers only where the outside beam has dropped. In both cases, drainage and moisture control around the house are part of a lasting repair. Our pier comparison covers the differences between pier types.

How should I compare foundation repair bids?

Bids for the same house can differ a lot in the number of piers, the pier type and the warranty. Ask every contractor for the same things in writing:

A floor elevation map and their explanation of what's causing the movement
A drawing showing where each pier goes and why
The pier type, and the typical depth reached on nearby homes
Whether you'll get a pier log with depth and pressure or torque for each pier
What drainage work is included or recommended
Who handles utility locates and any city permit
Warranty length, what it covers (piers only, or readjustment and cosmetic damage), and whether it transfers to a buyer

If bids disagree sharply, or the repair is large, an independent evaluation by a licensed professional engineer can be worth the cost. You can look up an engineer with the Oklahoma State Board of Licensure for Professional Engineers and Surveyors.

What licenses and permits apply?

The State of Oklahoma states that general contractors are not required to hold state licenses for their construction services, so there's no state foundation-repair license number to check. Locally, the City of Lawton issues contractor's licenses, including building contractor licenses, and notes that a city license doesn't replace any required state or county license or permit. The city's License & Permits Division (212 SW 9th Street, 580-581-3360) can tell you whether your repair needs a permit. Cache, Elgin and other towns run their own permits.

Piering and drainage work involve digging. The City of Lawton reminds residents to call OKIE811 before they dig, and your contractor should request locates before excavating.

What can I do myself?

Keep gutters clean and extend downspouts well away from the foundation
Make sure soil slopes away from the house on every side
In long dry spells, water evenly around the foundation instead of soaking one spot
Watch your water bill for unexplained increases that could signal a leak
Keep a dated log of cracks and sticking doors

Buying or selling a house?

Ask for any previous repair records, pier logs and the warranty paperwork, and whether the warranty transfers. A home inspector may flag foundation signs and recommend a specialist; a structural evaluation can tell you whether they matter. If the house was repaired before, a new elevation survey shows whether it has stayed put.

Common questions

Why is foundation damage so common in Lawton?

Comanche County has clay soils with high shrink-swell potential, and the Oklahoma Geological Survey notes swelling clays can expand to 1.5 to 2 times their dry volume when wet. Hot, dry summers and heavy rains make the soil shrink and swell under houses.

Does a foundation repair company need a license in Oklahoma?

The state doesn't license general contractors. Ask the City of Lawton License & Permits Division (580-581-3360) what city license or permit applies, and confirm your contractor has it.

Should I hire an engineer before a foundation repair?

It's worth considering for a large repair, a home sale, or when bids disagree. Verify the engineer's license with the Oklahoma State Board of Licensure for Professional Engineers and Surveyors.

Lawton foundation repair guide (2026)