Concrete Levelling near you

Concrete rarely sinks on its own; the ground beneath it gives way. The pattern of the drop usually points to the cause.

Lifting a slab without dealing with the water that undermined it only resets the clock. Downspouts and sump discharge should empty well away from slabs and the foundation, onto ground that carries water off, and gaps along slab edges and against the house should be sealed so meltwater can't run underneath. Where a patio or walkway now slopes toward the house, restoring its fall away from the wall is often the main reason to lift it.

The Government of Canada's property grading guidance calls for soil beside the foundation to sit about 8 cm (3 in.) higher than the soil 1.5 m (5 ft.) away, and notes that paved areas might need a different slope, which a professional should confirm. A careful levelling contractor states the fall they're aiming for on each slab and checks it afterwards, rather than simply lifting the concrete back to flat.

The contractor first maps the job: where the slab has dropped, which way it should drain, where joints and cracks run and where voids are likely. Holes are drilled in a planned pattern through the sunken section, material is pumped in while the crew watches levels or string lines, and injection stops once the slab reaches its target height and slope. Neighbouring panels sometimes need a small lift too, so the joints line up again.

The holes are then filled with a cement-based patch, which stays visible as a row of small circles, and joints and cracks get a flexible sealant to shed water. An already weakened slab, or one pinned against a wall or step, can crack as it rises, so experienced crews free binding edges and lift gradually. Before work starts, point out any buried drains, sprinkler lines or cables near the slab, since injected material can travel into gaps and pipes.

Lifting is far less disruptive than tearing out concrete, but it only makes sense for a slab worth saving.