What is poly levelling and how does it compare to mudjacking in New Brunswick?

Poly levelling (also called polyurethane foam lifting or foam jacking) uses expanding polyurethane foam injected through small holes to lift sunken concrete slabs. It is the modern alternative to traditional mudjacking, and in New Brunswick's climate, it has several advantages — but it also costs more and is not always the right choice for every situation.

The process is similar to mudjacking at a high level: technicians drill small holes through the sunken slab (typically 5/8 inch diameter, much smaller than mudjacking's 1.5-2 inch holes), inject material through the holes under pressure, and the expanding material lifts the slab. The critical difference is the material. Instead of a heavy cement slurry, poly levelling uses a two-component polyurethane that expands 20-30 times its liquid volume into a rigid, lightweight, waterproof foam that fills voids and exerts controlled lifting pressure.

Advantages of poly levelling over mudjacking in NB:

Weight: The polyurethane foam adds very little weight — roughly 2-4 lbs per cubic foot versus 100+ lbs per cubic foot for mudjacking slurry. In areas with weak or soft subgrade (common in low-lying NB communities), adding hundreds of pounds of grout is a problem. Foam is essentially weightless in comparison.

Water resistance: The cured foam is waterproof and does not erode, dissolve, or wash out. Mudjacking slurry is cement-based but can be eroded by water movement beneath the slab over years. In NB where spring snowmelt creates significant water movement under slabs, this matters.

Smaller holes: The 5/8-inch injection holes are patched nearly invisibly versus the 1.5-2 inch holes from mudjacking, which is aesthetically relevant for stamped or decorative concrete.

Speed: The foam cures in minutes, not hours. Slabs are fully loadable within 15-30 minutes of completion versus 24-48 hours for mudjacking.

Disadvantages of poly levelling:

Cost: Poly levelling runs $5-$10 per square foot in NB — roughly 50-75% more expensive than mudjacking at $3-$6 per square foot. For a large garage floor or driveway, the cost difference is significant.

Material sensitivity: Polyurethane foam does not perform well in certain soil conditions, particularly very loose or organic soils where the foam may not find adequate resistance and can create irregular lifts.

Both methods are appropriate for NB applications — sunken garage aprons, settled sidewalk sections, tilted driveway slabs, and sunken patio sections that are structurally sound. The choice often comes down to budget, substrate conditions, and the proximity of the project to water or drainage concerns.

For most standard residential concrete lifting in Moncton, Fredericton, Saint John, Dieppe, and Riverview, both options outperform full removal and replacement from a cost-benefit perspective when the slab itself is sound. New Brunswick Concrete can match you with lifting and levelling specialists serving your area for a free site assessment.