Slab settling, cracking, or doming? Free on-site inspection: (254) 503-5077
Slab foundation repair lifts and stabilizes a concrete slab-on-grade home by driving piers through moving clay to load-bearing strata. A typical Waco whole-home slab repair costs $4,500-$12,000 using 10-16 piers and finishes in 2-4 days. Pressed concrete pilings run $300-$900 each, steel push piers $700-$1,200. The cause is nearly always Blackland Prairie expansive clay moving under the grade beam.
Written by the Brazos Foundation Repair team – 10 years repairing foundations in Waco & Central Texas.
Last updated: September 2026
Slab foundation repair is the controlled underpinning and lifting of a slab-on-grade foundation. Piers are driven under the perimeter grade beam, and sometimes under interior load lines, until they refuse on load-bearing soil or rock. Jacks then raise the slab toward its original elevation and the voids underneath are filled.
Most Waco homes built after the mid-1960s are slab-on-grade: a 4-inch slab poured monolithically with a reinforced grade beam. The clay carries the slab and the slab carries the house. At full scope this is house leveling.
Three patterns, and they are not interchangeable. Settlement drops a corner or a side. Edge lift raises the perimeter above the middle. Center lift, or doming, raises the middle above the perimeter. Separating them is the point of the survey, because the repair differs.
| Failure pattern | What the clay is doing | What you see inside |
|---|---|---|
| Settlement | Dried, shrank, dropped away from the beam | Floor sloping to a corner, stair-step brick cracks, doors binding at the top |
| Edge lift | Perimeter swelled after rain, covered center stayed dry | Floor high at the walls, baseboard gaps mid-wall, cracks that close in wet season |
| Center lift (doming) | Center swelled from a plumbing leak, removed tree, or trapped moisture | Hallways crowned, tile cracking through the middle, pinched door heads |
Waco sits on the Blackland Prairie: high-plasticity clay with an active zone cycling 8 to 12 feet deep. Near the Brazos and Bosque river terraces it runs deeper; west toward the Balcones Fault zone, shallow limestone stops piers sooner. The USDA NRCS soil survey maps these units county by county.
An elevation survey is a grid of floor-height readings taken with a zip level or manometer, normally every 8 to 10 feet, reported in inches of deflection from the high point of the house. It turns “the floor feels off” into a number you can price, lift to, and warranty.
The shape of those numbers names the failure: a steady fall across the house is settlement, a bowl is edge lift, a dome is center lift. Under roughly 1 inch of deflection across 40 feet, we monitor rather than pier.
Piers carry structural load; foam and mudjacking only lift concrete that is not holding up the house. Confusing the two is the most expensive mistake a homeowner makes.
| Method | Typical depth | Typical cost | Best use case |
|---|---|---|---|
| Pressed concrete piling | 8-15 ft | $300-$900 per pier | Standard perimeter underpinning |
| Steel push / resistance pier | 12-25 ft | $700-$1,200 per pier | Heavy loads, two-story, deep bearing |
| Helical pier | 10-25 ft | $900-$1,600 per pier | Porches, additions, light loads, wet soil |
| Interior slab pier | 8-15 ft | $1,000-$1,800 per pier | Center settlement, interior load lines |
| Void fill / mudjacking | 2-6 ft of slurry | $600-$2,500 per area | Filling the gap under a lifted slab |
| Polyurethane foam injection | Under-slab | $6-$25 per sq ft | Drives, patios, walks, garage floors |
Disclaimer: figures are typical Central Texas market ranges. Your exact price is set after a free on-site inspection.
A pressed concrete piling is a stack of high-strength concrete cylinders driven hydraulically under the grade beam, using the house as the reaction load. A steel push pier is a hollow tube driven deeper the same way; a helical pier screws in to a measured torque and loads immediately. Mudjacking pumps cement-sand slurry through the slab, while foam injection does it with resin at a fraction of the weight – right on a sunken driveway, wrong under a grade beam.
Most Waco slab repairs are perimeter-only. Interior piers are added when the survey shows the middle of the house more than about 1.5 inches below the perimeter, or when a load line under a bearing wall has dropped. They cost two to three times a perimeter pier.
Two ways in. Cutting is faster: flooring comes up, a 24- to 30-inch square is broken out of the slab, the pier is driven, the hole re-poured flush. Tunneling is cleaner – a 3-foot hand-dug tunnel from outside disturbs nothing indoors – but it adds days and cost.
Plan on flooring. Carpet rolls back and goes down again; tile over a pier hole breaks and cannot be reused; hardwood is cut and patched. We restore the concrete flush. Finished flooring is a separate trade and belongs on the quote as an exclusion.
Wet weather adds a day: saturated Blackland clay slumps into open holes and will not compact.
Honest answer: worked-on for about a month, not wrecked. Expect bare soil mounds at the pier holes, plywood-path marks across the lawn, and re-set shrubs that sulk for a few weeks.
Backfilled clay settles, so top off each hole once or twice in the first six months, then seed or sod. Grass covers the scars in 4 to 8 weeks in growing season. Cut sprinkler lines are repaired before we leave; heads need re-aiming.
No, and any contractor promising dead level is selling you something. The realistic target is maximum practical recovery, typically 80 to 95 percent of the measured deflection – doors closing, gaps shut, movement stopped.
Slabs are rarely poured dead level: a 1978 Waco slab can sit half an inch out across a room from the day it cured. A slab is also a rigid, already-cracked plate – push it past where it wants to return and you break plumbing, open new cracks, and pop brick mortar. We lift to maximum recovery and stop, and the final survey records what was recovered.
Wait 30 to 60 days. The house needs a few moisture cycles to settle into its new position, and patching too early means patching twice.
Then, in order: re-hang and plane doors, tape and float drywall cracks, caulk trim gaps, tuckpoint brick mortar, and seal slab cracks by epoxy or polyurethane injection – see foundation crack repair. Cosmetic work is a separate line item, not buried in the pier price.
Scope and pier count set your number, and both come off the survey.
| Scope | Typical pier count | Typical Central TX range |
|---|---|---|
| One settled corner | 4-8 | $1,800-$6,500 |
| One settled side | 8-14 | $3,500-$11,000 |
| Full-perimeter underpinning | 22-40 | $10,000-$30,000 |
| Perimeter plus interior piers | 30-50 | $18,000-$40,000 |
Disclaimer: figures are typical Central Texas market ranges. Your exact price is set after a free on-site inspection.
Full pricing logic sits on the foundation repair cost page. Qualifying pier work carries a tiered, transferable lifetime warranty – terms on the warranty page. Texas policies commonly exclude earth movement, so clay-driven settlement is rarely covered; read your policy. Texas does not license foundation repair contractors, which is why a written, pier-counted quote is your protection.
Get your pier count in writing – call (254) 503-5077.
We repair slab-on-grade foundations across McLennan and Bell counties: Waco, Woodway, Hewitt, Robinson, Bellmead, McGregor, China Spring, Lorena, and Temple. Piers stop settlement at the pier, so we also grade for roughly 6 inches of fall in the first 10 feet and add a root barrier or soil stabilization where a thirsty tree sits close. Whole-structure re-leveling falls under foundation leveling; the full overview starts at foundation repair in Waco, TX. Local soils are documented by the USDA NRCS soil survey and Texas A&M AgriLife Extension:
Can a slab foundation be repaired, or does it have to be replaced? Nearly every settling slab in Waco is repaired with piers. Replacement means lifting or demolishing the house and is reserved for rare structural failures.
What is the difference between edge lift and center lift? Edge lift means the perimeter has risen above the middle after rain swells the outer clay. Center lift, or doming, means the middle has risen, often from an under-slab plumbing leak.
How deep do slab piers go in Waco? Pressed concrete pilings usually refuse between 8 and 15 feet; steel push piers run 12 to 25 feet. The active clay zone cycles 8 to 12 feet deep, so a pier must pass through it.
Do interior piers mean my tile gets destroyed? Tile over a pier location is broken out and cannot be reused. Carpet rolls back and hardwood is cut and patched. We restore the concrete flush; flooring is a separate trade.
Can foam injection lift my house instead of piers? No. Polyurethane foam lifts non-structural concrete such as drives, patios, and garage floors. A load-bearing grade beam needs piers driven to load-bearing strata.
Will the cracks come back after the slab is lifted? Piering stops the settlement that opened them, and cosmetic repair after 30 to 60 days keeps them closed. Cracks that reopen point to ongoing moisture swings, so drainage is part of the plan.
The inspection is free, the elevation survey comes with it, and the quote names pier count, pier type, and target depth.
Call Brazos Foundation Repair at (254) 503-5077 or email info@brazosfoundationrepair.com.
Disclaimer: figures are typical Central Texas market ranges. Your exact price is set after a free on-site inspection.