What did an engineer specify when old piers stopped holding in south Tulsa?

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

south Tulsa20251-story wood frame, stone veneer, attached 2-car garageSlab-on-grade (floating slab) with continuous perimeter footings

In short: A south Tulsa slab home that had been piered before, including its garage wall, showed reopening veneer cracks and new floor cracks. The engineer attributed this to active clay and to the old garage piers no longer holding, and specified repressurizing (or replacing) those piers, 3 new piers at the southeast corner, slab piers or foam for the floor, and plumbing tests before and after ¹.

What did the house show?

• Stone veneer separations at the southeast corners of both the house and the garage ¹.
• Hairline to 1/8 in. cracks on the south, east and west walls and on the chimney ¹.
• Hairline to 1/4 in. interior cracks throughout, and floor cracks in the entry, kitchen, living room and hall bath ¹.
• Evidence of earlier piering, including along the garage's south wall, where cracks had reopened ¹.

What did the engineer find was causing it?

Shrink-swell movement of active clay soil, together with loss of support from the existing piers along the garage's south wall, which were no longer holding ¹.

What repair was specified?

1. 3 new piers at the southeast corner, shown at about 3 ft spacing near the corner, at least 10 ft below the bottom of the foundation ¹.
2. Repressurize the existing piers on the garage's south wall (about 9 ft spacing on the plan); if they would not repressurize, replace them with new piers ¹.
3. For the slab, steel slab piers about 6 ft on center, or foam injection on about a 6 ft grid with a warranty, or a combination, after consulting the engineer. Floor cracks to be stitched with #3 rebar or carbon fiber staples at 18 in. ¹.
4. A plumbing test before and after the repair ¹.

The engineer's standard pier specification applied: steel piers only unless the engineer approved another system; refusal on firm strata, with the detail showing bedrock (blue shale); a log for each pier listing depth, type, diameter, driving pressure and lift; mortar removed from patched cracks before lifting; a 6 x 6 x 1/2 in. angle iron under the footing where a pier lands near a crack; and a call to the engineer if old shallow concrete piers turned up ¹.

What happened on the job?

The record shows the repair contractor's proposal was checked against the engineer's requirements, a plumbing leak test was provided, and an updated scope was sent in early 2026 ¹.

What does this case show about Oklahoma foundations?

This house had already been piered, yet it was moving again. The old piers were along one garage wall, and the new distress appeared at an unpiered corner, in reopened cracks along the old pier line, and in the interior slab ¹. Clay soils shrink when they dry and swell when they wet, the uplift is usually uneven, and floor slabs often show the distress ², which matches the floor cracks recorded throughout this house ¹.

The engineer's answer to the old piers was graded: first try to restore load by repressurizing them, and replace only if that fails. The engineer also required plumbing tests both before and after the work ¹.

Related

• Pier Uplift or Movement After Repair
• Steel Push Piers
• Slabjacking and Polyurethane
• Interior Piers (Tunnel or Core)
• Plumbing Leak Detection and Repair
• Visible Slab Cracks