Concrete Lifting & Foam Injection in Waco, TX

Call Brazos Foundation Repair for a free on-site inspection – (254) 503-5077

Polyurethane foam concrete lifting – polyjacking – raises sunken concrete flatwork by drilling 5/8-inch ports, injecting expanding foam into the void underneath, and watching the slab rise on a laser. In Waco it runs $5-$25 per square foot, most jobs finish in 2 to 6 hours, and the surface takes vehicle traffic the same day. Foam lifts flatwork and fills voids. It is not underpinning, and it does not replace piers under a house foundation that has moved.

Written by the Brazos Foundation Repair team – 10 years repairing foundations in Waco & Central Texas.

Last updated: September 2026

Quick answers

Cost: $5-$25 per sq ft, about $500-$1,300 per area – see foundation repair cost.
Timeline: 2-6 hours; the foam is firm in 15-30 minutes and you drive on it the same day.
Cause: Blackland Prairie clay shrinking away from the slab, then storm water washing the soil out.
Warranty: written workmanship coverage on lifting; pier work carries the tiered transferable lifetime terms – see our warranty.
Limit: foam lifts flatwork only. A settled house foundation needs piers – see slab foundation repair.

What is polyurethane foam concrete lifting?

Polyurethane foam concrete lifting raises a settled slab by injecting a two-part expanding polymer through small holes drilled in the surface. The foam fills the void under the slab first, then keeps expanding until the concrete lifts. It cures into a closed-cell plastic that does not absorb water or wash away.

What does foam lifting actually fix?

Foam lifting is for concrete flatwork that is still sound but has dropped. The concrete has to come up as a slab, not as gravel.

Sunken driveway sections and aprons that dropped below the garage
Sidewalks and walkways with a trip lip at the joint
Patios that slope back toward the house
Garage floors with a settled corner or hollow spot
Pool decks that pulled away from the coping
Settled interior slab sections under tile, wood, or carpet
Void filling under a slab after piering

That last one is part of foundation leveling: when a grade beam is raised on piers, the soil under the slab does not follow, and the cavity has to be filled.

Polyurethane foam vs mudjacking – how do they compare?

Foam wins on hole size, weight, and speed; mudjacking wins on material cost. Mudjacking pumps a cement-and-soil slurry under the slab through large holes; foam pumps a light polymer through small ones. Head to head:

Factor	Polyurethane foam (polyjacking)	Traditional mudjacking
Hole size	5/8 in, about the size of a dime	1-5/8 to 2 in, about the size of a golf ball
Weight added to the soil	About 2-4 lb per cubic foot	About 100-110 lb per cubic foot
Cure / return to use	Firm in 15-30 minutes, drive the same day	24-72 hours before vehicle traffic
Lift precision	1/8-inch increments, read live on a laser	Coarser – slurry takes the path of least resistance
Longevity	Inert closed-cell plastic; will not absorb water, shrink, or erode	Slurry can shrink, wash out, and settle under its own weight
Typical cost	$5-$25 per sq ft	$3-$10 per sq ft
Best use case	Most residential flatwork; washed-out clay	Large, thick, low-traffic slabs on firm soil

The weight row decides most Waco jobs. The soil under a settled slab already failed once. Adding 100-plus pounds per cubic foot of wet slurry is how a mudjacked driveway ends up back where it started.

What does foam lifting NOT do?

Foam lifts concrete flatwork and fills voids under it. It is not a structural underpinning system.

It does not underpin a house. Foam bears on the same shallow clay that moved and transfers nothing to load-bearing strata. A settled foundation needs pressed concrete pilings or steel push piers – see foundation repair in Waco.
It does not stop expansive clay moving. Shrink-swell continues under the foam as before.
It does not fix the water. Foam seals the cavity; it will not redirect the runoff that dug it.
It does not repair bad concrete. Spalled, crumbling, or badly broken slabs should be replaced.
It does not repair a plumbing leak. A leaking line under the slab must be found and fixed first.
It does not hide cracks. A cracked panel lifts as pieces, so hairlines can open slightly. We flag those first.

Anyone selling foam as a substitute for piers under a moving house is selling the wrong repair.

How does foam injection work, step by step?

Sound the slab – tap and probe every panel, map the hollow areas, and confirm the concrete will lift as a unit rather than fragment.
Set the target – a rotary laser is set on the elevation we are lifting to, with a receiver on the slab so the lift is measured, not guessed.
Drill the ports – 5/8-inch holes on a rough 4 to 6 foot grid, tightened at corners, joints, and the deepest part of the void.
Fill the void – foam goes in through the low ports first in short shots, making contact with the soil. Nothing moves yet.
Lift – once the cavity is packed, continued injection raises the slab, port by port, 1/8 inch at a time.
Monitor – the laser receiver and the joint lines are watched on every shot, and injection stops at the target reading.
Check the edges – joints, thresholds, garage door tracks, and adjoining panels are checked so nothing is pushed past its neighbor.
Patch the ports – the holes are filled with mortar mixed for color and troweled flush.

Call Brazos Foundation Repair – (254) 503-5077 – and we will sound your slab for free.

How long does a concrete lifting job take?

Most residential foam jobs run 2 to 6 hours. A few sidewalk panels take under two hours; a two-car driveway and apron takes most of a day. Multiple areas on one property usually finish in a single visit.

The foam reaches most of its strength within 15 to 30 minutes, so driveways take a vehicle before the crew leaves.

How much does concrete lifting cost in Waco?

Typical Waco foam lifting runs $5-$25 per square foot, with most single-area repairs between $500 and $1,300. Price follows square footage, how far the slab dropped, and how much void must be filled.

Job	Typical range
Sidewalk or walkway, 1-3 panels	$500-$1,300
Patio or porch	$800-$2,200
Garage floor section	$900-$2,500
Two-car driveway	$1,500-$4,000
Pool deck	$1,200-$3,500
Void fill under a slab after piering	$600-$2,000

Disclaimer: figures are typical Central Texas market ranges. Your exact price is set after a free on-site inspection.

Why do Waco slabs sink in the first place?

Blackland Prairie clay shrinks in drought and pulls away from the underside of concrete, leaving an air gap nobody sees. The next Central Texas storm pushes water into that gap and carries the loose soil out. The slab is then spanning open air, and it drops.

Downspouts dumping at a driveway edge, lawns graded back toward the house, and poorly compacted backfill around an apron all speed it up. The USDA NRCS soil survey maps how that clay varies across McLennan County and the Brazos and Bosque river bottoms.

When will the settlement just come back?

Foam does not shrink, rot, or wash out, so when lifted concrete drops again the foam is rarely the reason. The slab comes back down when the water problem was never fixed.

Unaddressed washout – a downspout, gutter, or driveway edge still dumping concentrated runoff on the same spot.
A plumbing leak under the slab – a leaking supply or sewer line carries soil away continuously. Static and hydrostatic testing finds it; foam only hides it.
Poor drainage and negative grade – ground sloping toward the concrete keeps the soil saturated and soft.

Fix the water and the lift holds. That is why we quote lifting and drainage solutions together when grade is the real cause.

Frequently asked questions

Is foam injection better than mudjacking? For most residential flatwork, yes. Foam uses 5/8-inch holes instead of 2-inch holes, adds about 2-4 lb per cubic foot instead of over 100, and takes traffic the same day. Mudjacking still wins on price for large, thick slabs on firm soil.

Can foam lift my house foundation? No. Foam lifts flatwork and fills voids under it. A house foundation that has settled needs piers driven to load-bearing strata, which is a different repair with a different warranty.

How soon can I drive on the concrete? Usually the same day. The foam is firm within 15 to 30 minutes of injection, so walkways open as soon as the ports are patched and driveways take vehicle weight before the crew leaves.

Will the drill holes show? Slightly. The ports are 5/8 inch and get patched with mortar mixed for color, so they read as small dots rather than as repairs. Broomed and stamped surfaces hide them best.

Will my concrete sink again? Foam does not shrink or wash out, but new voids form if the water problem stays. Unaddressed downspouts, negative grade, or a leaking line under the slab will drop the same concrete again.

Do you fill voids left after piering? Yes. When a slab is raised on piers, a gap opens between the concrete and the soil that dropped away. Foam fills it without loading ground that already proved it could not carry weight.

Call Brazos Foundation Repair – (254) 503-5077 – for a free on-site inspection in Waco, Woodway, Hewitt, Robinson, Bellmead, and Temple.

Disclaimer: figures are typical Central Texas market ranges. Your exact price is set after a free on-site inspection.