Concrete leveling: lift sunken slabs instead of replacing them
Free estimate. Most lifts take a few hours, and foam-lifted slabs can be used the same day.
- Polyurethane foam or cement slurry
- Small injection holes, patched afterward
- Joints sealed so it doesn't sink again
How concrete leveling works
A sunken slab is usually a sound slab sitting on a hole. Water washed out the base, or the fill under it was never compacted, and the concrete dropped. If it's still in one piece, we can lift it back into place for a fraction of what replacement costs.
We drill small holes, inject polyurethane foam or a cement slurry under the slab, and raise it in controlled steps. Then we seal the joints and look at why it sank, because a downspout or an open joint will undo the work.
- Polyurethane foam
- Holes about 5/8 in.; lightweight, waterproof foam lifts and fills voids; usable within the hour
- Slurry (mudjacking)
- Larger holes; a cement-based slurry pumped under the slab; economical on big voids
- Control
- Lifted in small increments and checked with a level as it rises
- Patching
- Injection holes filled with cement grout
- Joints
- Joints and cracks sealed afterward so water stays out
- Floor leveling
- Self-leveling underlayment over sound interior slabs before new flooring
- A
- Void where water washed the base out
- B
- Injection holes about 5/8 in. across
- C
- Foam fills the void and lifts the slab
- D
- Joint sealed so water stays out
How the job goes
Assess
We check whether the slab is whole, how far it dropped and why.
Drill
A pattern of small holes through the slab.
Inject and lift
Foam or slurry injected and the slab raised to grade in controlled steps.
Patch and seal
Holes patched, joints and cracks sealed.
Fix the cause
Downspouts extended, grading corrected, gaps sealed.
Planning prices
| Work | Planning range | What drives it |
|---|---|---|
| Lift 1–3 sidewalk or walkway panels | $600–$1,500 | Polyurethane foam or slurry, depending on the slab |
| Driveway or garage apron, 2–4 panels | $1,200–$3,000 | Joints sealed after the lift |
| Patio or pool deck | $1,500–$4,500 | Bigger areas cost less per square foot |
| Front stoop that settled as one piece | $700–$2,000 | If it's cracked through, replacing is usually better |
| Self-leveling underlayment for new flooring | $4–$8 / sq ft | Basements and garages, over a sound slab |
Planning ranges for Connecticut in 2026, not quotes. Ledge, tight access, long pump or wheelbarrow runs and very small pours push a job up. Your price comes in writing after we've seen the site.
What we lift and level
- Sidewalks and walkways
- Trip hazards lifted flush. See sidewalks.
- Driveways and garage aprons
- Panels that sank at the garage door or the street.
- Patios and pool decks
- Slabs that tipped toward the house or the pool.
- Front stoops
- Steps that settled as one piece.
- Garage and basement floors
- Voids filled, and self-leveling underlayment for new flooring.
- When to replace instead
- Slabs broken into pieces, heaved by roots or frost, or badly scaled aren't good candidates.
Why slabs sink in Connecticut
Washout. Roof water dumped at the edge of a slab carries the base away a little with every storm. It's one of the most common causes of sinking.
Poor fill. Backfill around a foundation keeps settling for years, and slabs poured on it follow it down.
Frost. Water trapped under a slab freezes and lifts it, then leaves a void when it thaws. Sealed joints keep that water out.
Timing. We lift from spring through fall. The ground has to be thawed for the material to fill voids properly.
Questions we hear about concrete leveling
Foam or mudjacking: which is better?
Polyurethane foam uses smaller holes, weighs less, so it doesn't load weak soil, and cures fast, but costs more per pound. Slurry costs less on large voids. We use whichever fits the slab and the soil.
How long does concrete leveling last?
Years, if the cause is fixed. Lifting without extending a downspout or sealing the joints just resets the clock.
Is leveling cheaper than replacing?
Usually much cheaper, often half or less, and done in hours instead of days.
Can you level a cracked slab?
If it's cracked into two or three large pieces that are still intact, often yes. If it's shattered or the surface is badly scaled, replace it.
How soon can I use the slab?
Foam-lifted slabs can usually take foot traffic and cars the same day. Slurry needs a day or so.
Can you level a concrete floor for new flooring?
Yes. We grind high spots and pour a self-leveling underlayment over a sound slab, which is what most flooring manufacturers want.
Concrete leveling by town
We build concrete leveling in 67 Connecticut towns. Pick yours for local conditions, permit notes and nearby towns.
Every dot is a town we serve.
Free concrete leveling estimates
Call or send the estimate ticket. We set a time to see the site and put the price in writing.