What Is Concrete Lifting?
Concrete lifting raises a sunken slab back to its original level without removing it. Small ports are drilled through the concrete, expanding polyurethane foam is injected underneath, and the slab rises in controlled stages while we watch it against a laser level. The ports are patched, the joints are resealed, and the surface goes straight back into use.
The insight that makes this work is simple: in most cases the concrete is fine. It sank because the ground under it moved, not because the slab failed. Toronto clay shrinks as it dries and leaves voids. Trench backfill over a service line settles. Water from a downspout washes fines out from underneath. Engineered fill in newer subdivisions keeps consolidating for years. In every one of those situations you have perfectly good concrete sitting on nothing.
Replacing that concrete costs $10 to $16 per square foot, takes days, and involves demolition, disposal, curing and disruption. Lifting it costs $6 to $12 per square foot and is done in hours.
We use polyurethane foam rather than traditional mudjacking for most GTA work. Mudjacking pumps a heavy cement slurry into the void, which is effective but adds considerable weight to a subgrade that has already proven it cannot carry what is on it. Foam weighs a small fraction of that, expands to fill irregular voids completely, cures in minutes, and needs ports about the diameter of a pen rather than the large holes slurry requires.
What’s Included
- Void mapping and cause diagnosis
- Port drilling on an engineered pattern
- Polyurethane foam injection, or mudjacking where preferred
- Laser-level monitoring throughout the lift
- Controlled staged raising to avoid over-lifting
- Sub-base stabilisation where soils are weak
- Port patching flush with the surface
- Joint cleaning and resealing
- Post-lift drainage check
Common Problems We Solve
Sunken Driveways at the Garage or Sidewalk
The two places driveways drop most, because both are transitions where compaction is hardest to achieve. Lifting restores grade and stops meltwater running toward the garage or the house.
Trip Hazards on Walkways
A walkway panel that has dropped an inch is a genuine liability. Lifting it is faster and cheaper than replacement, and does not leave a new panel that does not match the weathered ones beside it.
Settled Garage and Basement Floors
Interior slabs are the strongest case for lifting, because the alternative is breaking out and repouring inside a finished building. Higher-density foam handles the load.
Pool Deck and Patio Settlement
Backfill around a pool is rarely compacted as well as the rest of the yard, so deck sections settle. Lifting avoids running a jackhammer next to a vinyl liner.
How Much Does Lifting Cost in Toronto?
Lifting runs $6 to $12 per square foot. Drivers:
- Area. Mobilisation is a fixed cost, so small isolated lifts cost more per square foot than large ones.
- Lift height. Raising a slab three inches uses considerably more material than raising it half an inch.
- Void volume. Large voids under a slab take more foam than tight ones.
- Slab type. Load-bearing interior and garage slabs need higher-density foam.
- Access. Interior work needs more protection and clean-up than an open driveway.
Against replacement at $10 to $16 per square foot plus demolition, disposal and a week of curing, the arithmetic usually favours lifting comfortably.
When Lifting Is Not the Answer
Lifting restores level. It does not repair concrete. If the slab has broken into multiple pieces, if the surface has scaled deeply enough to expose aggregate across most of its area, or if cracking runs through with vertical displacement in several places, then raising it simply gives you level bad concrete. In those cases replacement is the honest recommendation and we will say so, and the job moves to a new concrete driveway, concrete walkway or concrete patio depending on the surface. Isolated cracks in an otherwise sound slab are handled separately under concrete crack repair, and a lifted slab with a tired surface can be finished with concrete resurfacing.
We also look for the cause. A slab that sank because a downspout has been discharging against the foundation for five years will sink again if the downspout is not addressed. Fixing the symptom without mentioning the cause is not a service we are interested in providing.
Send us a photo showing the drop, ideally with a straight edge across the joint, and we will come back with a written published-rate quote inside two hours.
