Can spalling concrete be repaired or does it need to be replaced in NB?

Spalling concrete can often be repaired successfully in New Brunswick if the damage is limited to the surface layer and the underlying concrete is structurally sound — but widespread, deep spalling, or spalling on thin slabs typically means replacement is the more cost-effective long-term choice. The decision hinges on depth of damage, total surface area affected, age of the concrete, and what caused the spalling in the first place.

Repair is appropriate when:

• Spalling is less than 1 inch deep and affects less than a third of the total surface


• The underlying concrete is hard, solid, and produces a clear ring when struck with a hammer (not a hollow thud)


• The concrete is of adequate thickness — a 4-inch slab with 1/2 inch of spalling still has 3.5 inches of sound concrete beneath


• The cause of spalling (de-icing salts, lack of sealer) has been identified and can be corrected going forward


• The feature still has functional integrity — steps that are spalling but still structurally stable and safe to use

For surface spalling in this category, polymer-modified repair mortars with a bonding agent, properly applied and sealed after curing, can last 10-20 years in NB conditions. Expect to pay $300-$1,500 for professional repair of localized spalling on steps or a small patio area, depending on extent and contractor.

Replacement is the better option when:

• Spalling is widespread (more than 40-50% of the surface is delaminating)


• The damage has reached the rebar, which is now corroding and expanding within the slab


• The original concrete was thin (less than 3.5 inches) or improperly mixed — no amount of surface repair fixes a fundamentally weak slab


• The feature is old (30+ years) and the concrete itself has deteriorated throughout, not just at the surface


• Multiple attempts at repair have already failed — some concrete simply will not hold patches because the substrate is too compromised

For NB driveways specifically, widespread spalling across a 400-600 sq ft driveway is almost always a replacement job. Full driveway replacement runs $4,000-$8,000 for a standard two-car concrete driveway in Moncton, Fredericton, or Saint John — expensive, but a properly installed new driveway with air-entrained concrete and a quality sealer should last 30-40 years. Patching a compromised driveway surface repeatedly costs money every 3-5 years and never achieves the same lifespan.

Resurfacing is a middle option for driveways and patios where the structure is sound but the surface is rough or moderately spalled. A professional concrete resurfacer (Quikrete Concrete Resurfacer, Ardex Feather Finish, or similar) applied at 1/4 to 1/2 inch thick over a properly prepared and bonded surface can restore the appearance and function of a slab that is not ideal for repair but not far enough gone to justify full replacement. Cost runs $3-$6 per square foot professionally applied. It is not a permanent fix for deeply compromised concrete, but buys another 10-15 years on a sound slab.

Need help determining whether repair or replacement makes sense for your specific situation? New Brunswick Concrete can match you with local contractors who can give you an honest assessment and competitive quotes.