Foundation Settlement Repair

What settlement is

Settlement is the foundation sinking into the soil below it. In Central Texas the usual culprit is expansive clay shrinking during dry spells: the soil contracts and pulls away from beneath the footing, leaving the foundation unsupported until it drops. You see it as diagonal cracks above doors and windows, separating brick, and floors that slope toward the settled area.

What is foundation underpinning?

Underpinning is any method that strengthens or extends a foundation’s support below its original footing depth, transferring the structure’s weight onto more stable ground. The term covers two distinct approaches. The older, traditional method — digging under an existing footing in stages and pouring a new, deeper concrete footing beneath it — is common for basement additions and historic masonry buildings on firm, stable soil, and it’s what most generic underpinning explainers describe. It’s a poor fit for Central Texas: our expansive clay sits close to the surface and keeps moving, so a shallow poured footing settles again the same way the original one did. The residential standard here is pier-based underpinning — driving or drilling piers (pressed concrete, steel, or helical) past the active clay layer down to load-bearing soil or rock, then transferring the foundation’s weight onto them. That’s the process this page describes.

How the repair works

Settlement is corrected by underpinning — transferring the foundation’s weight onto piers that reach stable soil. The five steps above (survey → excavate → install piers → lift → backfill) are the standard sequence. The choice of pier matters:

• Pressed-concrete pilings — most common, cost-effective for typical residential loads.
• Steel push piers — driven deeper for heavier loads or deeper instability.
• Helical piers — screwed in; excellent where soil is inconsistent or for lighter structures.

How many piers you need — and why that drives the bid more than pier type

Two quotes for the “same” settlement repair can differ by thousands of dollars, and it’s rarely because one installer is padding the price. It’s pier count. Using the per-pier costs each method actually runs in Austin (see the pier comparison):

Scope of settlement	Typical pier count	Pier type most often used	What it does to the bid
One corner or short section	4–8 piers	Pressed concrete ($300–$800/pier)	Toward the low end of $4,000–$14,000
One full side of the house	8–14 piers	Pressed concrete or steel push	Mid-range, plus more excavation labor
Whole-house perimeter	14–24+ piers	Mix, by load and depth	Toward the high end, or above it on larger homes

That’s why an honest quote starts with an elevation survey to map exactly how much of the foundation moved — not a flat per-house price.

How you know the piers actually reached stable soil

A pier that stops short of load-bearing strata will settle again, no matter how good the paperwork looks. IBC Chapter 18 (Soils and Foundations) requires deep foundation elements — piers included — to be verified against adequate bearing capacity during installation, using driving resistance, torque readings, or load-test records, not just installed and backfilled on faith. It’s the code basis for the same point made on the pier comparison guide: “torque readings are your proof” for helical piers, and “verify it reached refusal, not just resistance” for pressed concrete. Ask any installer for those per-pier records before you sign off.

Cost and what makes it last

Most Austin settlement repairs land at $4,000–$14,000, driven by pier count (see the cost guide). The repair lasts when it’s paired with water control — drainage plus steady summer watering — so the clay’s moisture stays even and new settlement doesn’t start next door to the fix. If your home is slab-on-grade, settlement is the most common repair you’ll face here.