Concrete Leveling: Raising a Slab Instead of Replacing It

A settled slab is usually a support problem, not a concrete problem. The slab was poured on ground that has since moved, washed out or compressed, so the slab followed it down. Concrete leveling addresses the space that opened up: material is injected through the slab, the void beneath is filled, and controlled pressure raises the slab toward its original elevation.

You will see the same work described as concrete lifting, slab lifting, slab leveling and slabjacking. Those terms overlap heavily in everyday use; the meaningful distinction is which material gets injected, not which word a company prefers.

What leveling does not do is repair concrete. If a slab has broken into pieces or the surface has deteriorated badly, restoring its elevation does not restore the slab.

• A measurable vertical difference at a joint that used to be flush.
• Water standing in one part of a slab after rain, or draining the wrong way.
• An open gap along the garage line, or joints that keep widening.
• A slab that rocks slightly or sounds different underfoot in one area.
• Cracking concentrated along the low area rather than spread across the surface.

None of these confirms what is happening beneath the slab. A hollow-sounding area is a reason to have someone look, not proof of a void — sound alone is not a reliable test.

The usual contributors are loss of soil support, incomplete compaction of backfill, concentrated water from roof drainage or grading, erosion beneath slab edges, and repeated freeze-thaw cycling acting on saturated ground. In many Central Indiana yards more than one of those is in play at the same time, which is why fixing the elevation without looking at the water tends to disappoint.

Sometimes the goal is not lifting at all. Where a slab is still at an acceptable elevation but has lost support beneath it, filling the void can be the objective on its own — the slab is supported rather than moved. Void filling and lifting frequently happen in the same visit, because you cannot raise a slab without first filling what is under it.

Not every void calls for polyurethane. What gets used depends on the void, the slab and what the provider is trying to achieve.

• Surface type — a garage floor, a driveway apron and a public-facing sidewalk are not the same job.
• Square footage and the number of separate slabs involved.
• How far the slab has settled, and whether the drop is even or tilted.
• The size of the void beneath the slab — voids consume material.
• Access for equipment, hoses and material.
• Method: polyurethane injection versus a cement-based slurry.
• Number of injection locations needed to control the lift.
• Drainage or grading conditions that contributed to the settlement.
• Joint sealing, patching of injection ports and site cleanup.
• Commercial scope items such as phasing, off-hours work or traffic control.

For planning context, one current consumer dataset reports $4.50 – $7.50 per square foot for mudjacking projects reported for the Indianapolis area, with an average project of about $1,240. Treat that as a budgeting starting point, not a price. Last reviewed: September 2026.

1. You describe the surface, the problem and the rough dimensions, ideally with photos.
2. A provider evaluates the slab on site — condition, elevation difference, drainage.
3. You get a scope: method, injection locations, expected lift, restoration details.
4. Work typically takes hours rather than days for a residential slab.
5. Ports are patched and joints are addressed as agreed in the scope.

Contractor licensing, registration, insurance, permitting and project requirements may vary by local jurisdiction. Homeowners should verify applicable requirements for their project and location with the relevant city or county authority. Among construction trades, plumbers are licensed at the state level in Indiana; there is no single statewide concrete contractor license to point to.

Practically, that means asking a provider directly about insurance and any local registration that applies where you live, rather than relying on a badge on a website.

• What do you think caused this slab to settle?
• Which method are you proposing here, and why this one for my slab?
• How many injection locations, and where will the ports be?
• What lift are you expecting, and what happens if the slab does not respond?
• Does anything about my drainage need to change for this to hold?
• What is included in restoration — port patching, joint sealing, cleanup?
• What is in writing about the result, and what is excluded?