How does mudjacking work and is it a good option in NB?

Mudjacking — also called slabjacking — is a process of pumping a slurry mixture of water, soil, and Portland cement under a sunken concrete slab to lift it back to its original level. It is a legitimate, cost-effective repair option in New Brunswick for sunken driveways, sidewalks, patio slabs, and garage aprons — but its suitability depends on why the slab sank and what the soil conditions are beneath it.

The process works by drilling 1.5 to 2-inch holes through the sunken slab at strategic locations, then injecting a pressurized slurry through these holes. The slurry fills voids beneath the slab and builds pressure until it lifts the slab to the target elevation. Once lifted and confirmed level, the injection holes are patched. A crew can typically complete a residential mudjacking job in a few hours, and the slab is usable within 24-48 hours — compared to weeks of curing time for a full replacement.

Mudjacking costs in NB run $3-$6 per square foot, making it significantly cheaper than replacement ($8-$15 per square foot). For a 400 sq ft sunken garage apron in Moncton, mudjacking might run $1,200-$2,400 versus $3,200-$6,000 for full removal and replacement. When it works, it is an excellent value.

Mudjacking works well in NB when:

• The slab itself is structurally sound (no major cracking or delamination)


• The slab sank due to void development or gradual soil consolidation beneath it


• The soil beneath is stable enough to support the re-lifted slab


• The slab edges have not broken or separated significantly

Mudjacking is not a good option in NB when:

• The soil beneath is poorly compacted organic material that continues to consolidate — the slab will sink again within a few years


• The void beneath the slab is too large for the slurry to fill effectively without massive injection volume


• The slab itself is cracked, broken into pieces, or delaminated — you would be lifting a compromised structure


• Frost heave is the cause of the unevenness — if the slab heaved up in winter and has not fully settled, lifting it further makes things worse

In NB specifically, the cause of sinking is important context. Slabs in Fredericton, Moncton, and Riverview that settled due to poor compaction of fill soil when the home was built are good mudjacking candidates. Slabs that have been repeatedly heaving and settling due to frost on inadequate base material are better candidates for removal, proper base preparation, and replacement.

The mudjacking slurry also adds permanent weight to the soil, which is a consideration in areas with soft or wet subgrade. On properties near waterways in Miramichi, the Saint John River valley, or low-lying coastal areas, a professional assessment of soil conditions before mudjacking is worthwhile.

New Brunswick Concrete can connect you with concrete lifting and repair specialists in Moncton, Fredericton, Saint John, Dieppe, and across New Brunswick for a free estimate.