Why did a Tulsa slab home get wall piers but no slab repair?

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

Tulsa20251-story wood frame, painted brick veneer, attached 2-car garageSlab-on-grade (floating slab) with continuous perimeter spread footing and stem walls

In short: A Tulsa slab-on-grade home had brick cracks on its east wall and cracking under the east bedroom windows. The engineer attributed it to active clay moving the perimeter footing under that wall, found the slab itself within 1 in. of level, and specified 7 steel piers along the east wall, at least 12 ft below the footing, plus a plumbing test ¹.

What did the house show?

• Brick cracks on the east wall. The veneer had been painted, and the engineer noted that paint may hide additional cracks ¹.
• Inside: uneven floors, cracks at ceilings and windows, and cracks under the windows of the east bedroom ¹.
• Ceiling cracks in the garage, which the engineer traced to over-loading of the attic above it rather than to the foundation ¹.
• An elevation survey of the floor showed less than 1 in. of differential, with about 1 in. of settlement noted ¹.

What did the engineer find was causing it?

Shrink-swell movement of active clay soil under the east wall's perimeter footing. A plumbing leak was not confirmed, and the engineer asked for one to be ruled out ¹.

What repair was specified?

• A plumbing test of the supply and drain lines ¹.
• 7 piers along the east wall at 8 ft spacing on the plan ¹.
• Steel piers only; any other system needed the engineer's approval ¹.
• Each pier to penetrate at least 12 ft below the bottom of the foundation to firm, stable strata; the typical detail reads "drive to refusal — bedrock (blue shale)" ¹.
• A pier log for every pier: depth, type, diameter, driving pressure and amount of lift ¹.
• Mortar to be removed from previously patched cracks near piers before lifting ¹.
• A 6 x 6 x 1/2 in. angle iron under the footing wherever a pier fell close to a crack ¹.
• The engineer to be called if old shallow concrete piers were found; locations and count could change with footing conditions ¹.
• No slab repair, because the floor movement was judged minor ¹.

What happened on the job?

The repair contractor installed the piers in spring 2025, shortly after the report was issued ¹.

What does this case show about Oklahoma foundations?

On a floating slab, the perimeter footing and the interior slab are separate pieces and can move by different amounts. In this house the brick and the east-side rooms showed the footing had dropped, while the survey showed the slab itself was within 1 in. of level, so the engineer treated only the footing ¹.

The engineer's spec ties the piers to depth and bearing material, not just to pressure: a 12 ft minimum below the footing and refusal on shale ¹. Seasonal moisture change is greatest in roughly the upper 1.5 to 2 m (about 5 to 6.5 ft) of soil and can reach about 5 m in some settings ², so a 12 ft minimum below a shallow footing places the pier tip below the zone where clay moisture swings are largest.

The garage ceiling cracks are a reminder that not every crack is a foundation problem. The engineer assigned them to attic loading and left them out of the foundation scope ¹.

Related

• Steel Push Piers
• Elevation Surveys
• Slab on Grade
• Shrink-Swell and Active Zone
• Plumbing Leak Detection and Repair
• Diagonal Drywall Cracks at Openings