How to fix a sinking concrete patio in Dieppe NB?

A sinking concrete patio in Dieppe NB most commonly means either the gravel base beneath the slab has washed or compacted away, or the soil below has settled — and you have two main repair options: slab lifting (mudjacking or poly levelling) or full replacement.

Dieppe sits in the greater Moncton area where the soil is predominantly a mix of clay and glacial till that can be slow to drain and prone to movement during freeze-thaw cycles. When a patio slab was originally poured over a base that was not adequately compacted, or when water has been allowed to drain under the slab and erode the substrate, voids form beneath the concrete and the slab settles. You might see one corner drop, a slope toward the house, or a panel that tilts and rocks when you step on it.

Mudjacking (sometimes called slabjacking) involves drilling holes in the settled slab and pumping a cement-sand-water slurry under pressure into the void beneath. The pressure fills the void and lifts the slab back toward its original position. In Dieppe, mudjacking typically runs $3 to $6 per square foot. It works well when the slab itself is in reasonable condition and the void is modest. Limitations: the slurry adds significant weight to the substrate (which is partly why it sank in the first place), and in areas with soft or wet soil it can resurface over time.

Poly levelling (polyurethane foam injection) uses the same principle but with expanding polyurethane foam injected through smaller holes. The foam expands to fill voids and lifts the slab. It costs $5 to $10 per square foot, weighs almost nothing compared to the mudjacking slurry, cures in minutes rather than days, and the smaller injection holes are less visible after patching. For a residential patio in Dieppe where aesthetics matter and the slab is otherwise in decent shape, poly levelling is often the preferred approach.

When lifting is not the right answer: if the slab has widespread cracking, is breaking into multiple pieces, shows significant delamination or scaling, or is more than 15 to 20 years old, lifting it may just delay an inevitable replacement. A lifted slab that continues to settle repeatedly — which happens when the underlying drainage problem is not addressed — will cost more in repeated levelling treatments than a fresh pour would have.

Before any repair, address the reason the slab sank. Is there a downspout draining adjacent to the patio? Is the grading sloping toward the slab? Is a tree root nearby? Fixing the drainage and grading issues before lifting the slab dramatically improves the longevity of the repair.

For a patio assessment and levelling quote in Dieppe or the greater Moncton area, New Brunswick Concrete can match you with concrete professionals who offer both mudjacking and poly levelling services.