Concrete lifting
When a slab has sunk but has not broken up, lifting it back is a fraction of the cost of tearing it out and pouring new.
Freeze-thaw does most of the damage to exterior concrete in east central Illinois. Water in the soil expands roughly nine percent when it freezes, heaves the slab up, then the ground thaws and the slab comes down, but not always back to exactly where it started. Repeat that through a Champaign winter, where January averages run to a high near 32 degrees and a low near 16, and the cumulative result is a driveway panel that has walked down an inch and a half and now ponds water against the garage. Slabs poured over backfill that was never fully compacted go first, which is why the panel nearest the house is so often the worst one.
Frost heave is not a single event that reverses cleanly. As soil freezes it lifts the slab and fine material migrates into the gap that opens underneath. When the ground thaws, that material is in the way, so the slab settles onto a slightly different profile than it left. Over five or ten winters the accumulated difference is substantial, and it explains why concrete in this climate tends to move progressively in one direction rather than oscillating around a stable position. It also explains why fixing it once, without addressing the water feeding the cycle, buys you a limited number of years.
Traditional mudjacking pumps a cement and soil slurry through holes roughly an inch and a half to two inches across, filling the void and floating the concrete back to grade. It is heavy, inexpensive per cubic foot, and well suited to thick slabs like driveways where the added weight is not a concern. Polyurethane foam injection uses much smaller holes, typically around five eighths of an inch, cures in minutes, and weighs a tiny fraction of slurry. On weak, saturated clay subgrade the lighter option often makes more sense because it does not add load to soil that already failed. On a wide driveway apron with good subgrade, slurry usually wins on cost.
Holes are drilled through the slab in a pattern determined by its size and how it is settled. Material is injected under pressure while the crew watches the slab with a level or laser, working section by section until it comes back to the target elevation. Holes are patched with mortar, and on a foam job the patches are small enough to be barely visible after a season of weathering. Most residential jobs are done in a day. Foam is typically drivable within an hour or so; slurry needs longer to cure, often a day, and the contractor should tell you specifically rather than leaving you guessing.
If the slab is spidered with cracks, spalling from de-icing salt, or broken into more than a few pieces, lifting it just gives you level rubble. Same if the void was caused by an active leak or an eroding downspout channel that nobody has fixed. Deal with the water first or the slab will be back down inside two seasons. A slab that has cracked into two large pieces can usually still be lifted successfully. One that has crumbled at the edges and lost aggregate at the surface has reached the end of its service life and replacement is the honest recommendation.
Some concrete problems in this climate are not settlement at all. Chloride de-icers accelerate the freeze-thaw cycle at the surface and drive scaling, where the top layer flakes away and exposes aggregate. That is a durability failure in the concrete itself, not a soil problem, and no amount of lifting fixes it. If your driveway is both sunk and scaled, understand that lifting addresses one of those and not the other. Sealing sound concrete before winter and using less aggressive de-icers are the preventive measures worth knowing about.
Square footage of slab to be lifted, how far it has to come up, and which material is used. Depth of lift matters because volume of injected material scales with the void, and a slab that has dropped three inches over a large area takes a lot of fill. Access matters less than with structural work, since equipment can usually reach a driveway or walk without difficulty, though a back patio behind a fenced yard adds time. Compared with removal and replacement, lifting is typically a large saving, which is why it is worth asking about before you accept a tear-out quote.
Look at where the water is coming from before you spend anything. A downspout discharging onto the driveway, a gutter that overflows at a corner, or a grade that channels roof runoff along the garage slab will keep undermining the same panel. Extending the discharge and correcting the fall is inexpensive and it protects the lift. Where the settled slab has itself created the problem, tipping back toward the house and ponding water against the foundation, correcting it is not a cosmetic job at all. It is foundation protection that happens to look like driveway repair.
Garage slabs are the single most common lifting job in this county, and the reason is structural rather than accidental. The garage floor is typically poured over backfill against the foundation wall, it carries vehicle loads, and it is unheated so the ground under it freezes more deeply than under the house. When it settles, a gap opens along the wall where the slab has pulled down and away. That gap is not just cosmetic. It is a direct path for water into the backfill zone against your foundation, which is the last place you want it. Lifting the slab and sealing the joint addresses a foundation risk, not just a trip hazard.
Concrete stoops and porch slabs move earlier and further than almost anything else on a property, because they are shallow, unheated, poured against backfill, and carry very little weight to resist heave. A stoop that has tipped back toward the door is the classic version: water now runs to the threshold instead of away from it, and it works into the joint between the stoop and the house. Many of these can be lifted and re-pitched successfully. Where the stoop is hollow underneath, which is common with formed porch slabs, filling the void and stabilising it is a different scope from lifting a solid slab, so make sure the contractor has looked underneath rather than assuming.
Slabs immediately against the house need a more careful hand than a mid-driveway panel. Injecting material under pressure next to a foundation wall can, if done badly, push laterally against that wall rather than lifting the slab, and on a block wall already under soil pressure that is not a risk worth taking casually. Experienced operators manage this with hole placement, injection sequence and pressure control, working outward from the wall rather than toward it. It is a fair question to ask directly: how are you controlling for pressure against the foundation. A contractor who has thought about it will have a clear answer, and one who has not is the one you want to know about before the drill comes out.
Before you hire anyone in Illinois: there is no statewide general contractor license in this state. Contractor registration is handled by individual municipalities, and the City of Champaign requires contractors to be registered with the city to pull a permit. Ask who is pulling the permit, ask for written proof of liability coverage and workers' compensation, and get the scope in writing.
Measure roughly how far the slab has dropped if you can. It changes which lifting method makes sense. Call (217) 882-0544 or send the form, and an independent foundation contractor working in Champaign County will follow up with you directly.
Call and describe it. It costs nothing to find out whether you are looking at a maintenance item or a structural one.