Slab lifting — sunken driveways, paths and garage slabs lifted back to level

Slab lifting raises a sunken concrete slab back to level from underneath. It goes by a few names — slab jacking, concrete lifting, mudjacking in the old days — and covers anything poured on the ground outside the house: driveways, paths, pool surrounds, patios, garage and shed floors.

Here's what 15,000+ jobs have taught us: the concrete is almost never the problem. The ground underneath is. The soil has settled, compacted, or washed away — and the slab has simply followed it down. Fix the ground, and the slab goes back where it belongs.

Expanding resin is injected through coin-sized holes drilled in the slab. It fills the voids, compacts the soil and lifts the concrete back to level while a laser tracks every millimetre. Done in hours. Drive on it the same day. A sunken floor inside the house is a different job — that's floor levelling.

A trip edge where two path slabs used to meet flush. A section of driveway that holds a puddle after rain. A gap under the garage door you can see daylight through. Pool coping pulling away from the shell. A crack across the slab with one side sitting lower than the other.

Outside, a dropped slab is usually water. A downpipe discharging beside it, a leaking irrigation line, a garden bed built after the concrete was poured. The soil under one edge softens or washes out, and that edge drops first — which is why a sunken slab almost always tilts rather than sinks flat. Outside, a dropped slab is rarely only a trip hazard. The movement that let it drop also breaks the drainage and the underground services running beneath it, so the water that caused the sinking has more ways in.

The other common one is the ground the slab was poured on. Compacting the soil first drives the air out from between the grains and makes it dense enough to carry concrete. Sometimes that step was rushed, half done, or skipped altogether — and soil that's still full of air can only go one way once a slab is sitting on it.

A slab that has dropped and cracked can still be lifted. The crack becomes a hinge, and the engineer sets the injection points either side of it so both halves come up together. Not sure whether yours can be lifted or has to come out? That's what the free assessment answers — the levels are measured on the spot.