Slab-on-grade · San Antonio & the I-35 corridor · Lifetime transferable warranty

Slab foundation repair, sized by the elevation survey — not the sales pitch.

Most San Antonio homes built since the 1950s sit on a slab, and most of what looks like “foundation failure” is one edge that settled when the clay underneath dried out. We measure your floor, support the settled section on piers driven to load-bearing soil, and lift it back toward plane in stages you can watch on the readings.

SETTLED EDGEACTIVE CLAYSTABLE STRATA

What’s actually happening

A slab doesn’t sink. The clay under one edge leaves.

A slab-on-grade foundation is a single poured plane resting directly on the soil. In Central Texas that soil is expansive clay — it swells when it’s wet and shrinks when it’s dry, and it almost never does both evenly across a whole house. A perimeter edge dries faster than the protected center, drops, and takes the corner of the slab with it. That’s settlement. When a wet spot — a leak, a downspout, a flower bed on a soaker — pushes one area up instead, that’s heave. Same clay, opposite directions, and the elevation map is how we tell which one your house is doing.

This is why honest slab repair starts with a measurement, not a crack. A stair-step crack in the brick tells you something moved; it doesn’t tell you how far, in which direction, or whether it’s still moving. The free survey answers all three — and about half the time it ends with “monitor it, don’t repair it,” which is an answer you should be able to get for free.

What homeowners notice first

The signs a slab edge has moved.

Stair-step brick cracks

Diagonal cracks climbing the mortar joints near a corner — the brick veneer reporting that the slab behind it tilted. How to read the wedge →

Doors and windows racking

One sticky door is weather. A cluster — front door, hall door, a window that won’t latch, all on the same side — is geometry. Why doors stick →

Sloping or bouncing floors

A marble that rolls the same way in every room, or a floor that dips toward one corner, points to a plane that’s no longer flat. Cosmetic or structural? →

Cracks at wall-ceiling corners

Diagonal cracks fanning from door and window corners, or separation where the wall meets the ceiling, as the frame racks with the slab.

Gaps under baseboards & trim

Daylight under a baseboard, or trim pulling away from the slab at an exterior door, where the edge dropped out from under the finish.

Cracks that move with the seasons

A hairline that opens every August and tightens after fall rain is the clay cycle talking — sometimes monitoring, sometimes the early signal worth catching.

How the repair runs

Excavate, support, lift — and measure between every step.

01

Elevation survey

A grid of floor readings establishes how far each area sits from the original plane. This is the quote and the plan — pier count comes from the map, not a guess.

02

Excavate at the settled edge

Compact pits open at the marked pier locations along the affected run — typically about every 6 feet, with corners getting priority.

03

Install piers to load-bearing soil

Steel, concrete-and-rebar, or hybrid piers go in beneath the grade beam, driven or pressed until the soil proves it carries the load.

04

Stage the lift

Hydraulic rams raise the settled section in small increments, re-shooting elevations between stages so we lift to the map, not the eye.

05

Backfill and document

Pits are closed, the site is cleaned, and you get the before-and-after elevation maps, the pier log, and the warranty paperwork.

Hydraulic pier-driving ram set in an excavated pit at a brick corner during slab foundation repair
A compact pit at the settled corner — support goes in, then the lift brings the edge back toward plane.

What goes under the slab

Three pier methods. The soil and the readings pick the one.

There is no single “best” pier — there’s the right one for your soil, your structure, and your budget. Here’s how to compare them honestly, and the table lays out the trade-offs.

COMPARESteel piersConcrete + rebarHybrid piers
DepthDriven to verified refusal — deepestPressed to practical refusal in suitable soilsSteel starter depth + concrete stack
Proof of bearingHydraulic pressure readings at every pierPress resistance during installPressure readings on the steel starter
Relative cost$$$$
Best suited forHeavy structures, deep active clay, prior failed repairsLighter slabs, favorable soil, budget-conscious repairsMiddle ground — depth where soil demands it
Install speedFast — no curingFast — no curingFast — no curing
WarrantyLifetime, transferableLifetime, transferableLifetime, transferable

Make sure it’s actually a slab problem

Slab-on-grade and pier-and-beam are different repairs.

If your house was built after about 1960, it’s almost certainly slab-on-grade, and the work above is the work. But San Antonio’s pre-war neighborhoods — Monte Vista, Beacon Hill, King William — are largely pier-and-beam, leveled from underneath in the crawlspace for a fraction of slab-pier money. A bid that quotes perimeter piers for a crawlspace house is the most expensive mistake in this trade. Our inspection checks which foundation you actually have before anyone talks price — and if you already hold a quote that feels off, a free second opinion is the cheapest insurance there is.

Money, plainly

What slab foundation repair costs.

Slab repair is priced by the piers it takes to make the fix permanent. A settled corner (4–6 piers) typically runs $3,000–$9,000; a full side (8–12 piers) runs $6,000–$22,000; and severe, multi-side movement — usually the result of years of deferral — climbs from there. Method, access, and whether plumbing or drainage work is needed move the number. Catching it early is the biggest lever you control: a two-pier corner today beats a ten-pier side after three more droughts. The slab repair cost breakdown walks every scope and range, the cost guide covers the full method math, the San Antonio cost guide covers local multipliers, and the calculator gives you a defensible number tonight.

Slab specifics

Slab foundation repair questions, answered straight.

The honest answer is measurements, not symptoms. Stair-step brick cracks, doors that rack in a cluster, a hairline that re-opens every summer, or a floor that slopes toward one corner all raise the odds — but plenty of those are cosmetic or moisture-driven. A free floor elevation survey settles it: if one slab edge sits more than about an inch below the rest, that's a structural conversation; a quarter-inch of drift across the house usually isn't.

From real jobs and inspections

Slab repair, documented end to end.

Exterior slab-edge crack and separation documented during a foundation inspection
The exterior tell: a slab edge cracked and separated where the clay dried out beneath it.
Crew member shoveling spoil from a hand-dug interior pier hole during slab foundation repair
Excavating a pier pit at the settled run — piers go where the elevation map calls for them.
Concrete pier cap set in an excavated pit beneath a slab grade beam
A pier capped beneath the grade beam, bearing on soil that proved it can carry the load.
Inspector holding a tablet showing a color-coded floor elevation map during a slab foundation assessment
The instrument that sizes the job: the floor elevation map, shot before and after the lift.

Find out what your slab is actually doing — for free.

A free elevation survey, written readings, and a straight answer: repair it, monitor it, or leave it alone.

Now booking free inspections in Central Texas.