How far apart are foundation piers in Oklahoma?

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

In short: Pier spacing comes from three numbers: how much weight each foot of wall puts on the foundation, how much each pier can safely carry, and how far the concrete beam can bridge between piers. Oklahoma steel push piers are commonly set about 7 feet apart and driven to at least 6,000 psi ¹. Final spacing on any house is an engineering decision: Oklahoma's engineering board expects a professional engineer to be in responsible charge of a foundation repair plan and to sign and seal it ².

Where does the load come from?

A house's weight reaches the soil through its perimeter beam or footing. Engineers express this as a line load: pounds per linear foot of wall. It adds up from the roof, the walls, the floors and the concrete itself. Brick veneer adds a large share. Oklahoma's engineering board illustrated this with a back-calculation: 10-inch piers spaced 7 feet apart on soil allowing 3,000 pounds per square foot would carry only about 5 feet 10 inches of brick veneer wall height, before any roof, floor or other loads were added ².

How is pier spacing worked out?

In plain terms, spacing is limited by whichever of these runs out first:

• Pier capacity. The load one pier can carry, divided by the line load, gives the longest spacing the pier allows.
• Beam span. The concrete beam between two piers has to carry the wall like a bridge. A beam with little reinforcing may need closer piers than the pier capacity alone would allow.
• Bracket capacity. The steel bracket that connects the pier to the beam has its own rating.

On Oklahoma steel push pier jobs, exterior piers are placed about every 7 feet in the affected areas ¹. Oklahoma's statewide residential code now requires two #4 reinforcing bars in all new footings ⁵, so newer foundations generally have more reinforcing to span between supports than many older ones.

How is pressure read on a pier log?

A steel push pier is driven by a hydraulic ram that pushes against the weight of the house. The gauge pressure when the pier stops, multiplied by the ram piston's area, equals the force applied to the pier. That is why the ram size has to be recorded to convert psi into pounds or kips (thousands of pounds).

Oklahoma installation data ¹:

How does frost depth affect shallow systems?

Oklahoma's engineering board described common "pier and grade beam" systems: grade beams about 8 to 10 inches wide and 14 to 18 inches deep, on piers 8 to 10 inches in diameter, no more than about 36 inches deep and 6 to 8 feet apart ². The board noted that grade beam bottoms were often only 1 to 8 inches below finished grade, and that codes require the bottom to be below frost depth unless perimeter insulation is used. It cited about 18 inches as the Oklahoma City frost depth ². More on this: freeze-thaw and frost depth.

How does expansive clay cause uplift?

The active zone is the depth of soil whose moisture changes with the seasons ³. In that zone, swelling clay can grip a pier shaft and pull up on it. Building codes require foundations placed on or within the active zone to be designed to resist differential volume changes ³, and residential foundations on expansive soil must be designed under the building code's expansive-soil provisions ⁴. Resistance to uplift has to come from below the active zone, through depth, a bell or a helix. See shrink-swell and the active zone and pier uplift after repair.

What drives the number of piers?

• Length of wall that has settled
• Weight of the structure (one or two stories, brick or siding)
• Condition and reinforcing of the existing beam
• Depth to load-bearing soil or rock, which affects capacity

Related

• Steel push piers
• Helical piers
• Drilled bell-bottom piers
• Working with engineers
• Bedrock in the Tulsa metro