How do I repair spalling on my concrete porch in Moncton?

Repairing spalling on a concrete porch in Moncton requires cleaning off all loose and delaminated material, profiling the surface for bonding, applying a polymer-modified patching compound or overlay, and sealing the repaired surface before the next freeze-thaw season. Done properly, a spalling repair can last 10–15 years; done poorly (wrong product, inadequate prep, wrong timing), it delaminates by spring.

Moncton's location in the Petitcodiac River valley gives it a classic Maritime climate with significant freeze-thaw cycling — typically 100–150 cycles per year — plus exposure to salt-laden snowmelt from surrounding roads. Porches face the worst of it: horizontal surfaces that hold water, exposed to full weather, and often sprinkled with de-icing salt by homeowners trying to keep the entry safe in winter.

Assess the damage first. Tap the porch surface systematically with a hammer or metal rod. A hollow sound indicates delamination — the concrete beneath is already separating from the layer above. All hollow areas must be removed before patching; applying a repair mortar over delaminated concrete traps the problem and the new patch will come off with the old layer.

Use a cold chisel and hammer (or rotary hammer with chisel bit) to remove all spalled, delaminated, and hollow concrete back to solid, sound material. The patch needs minimum 1/4-inch depth to hold; ideally 1/2 inch or deeper for better bonding area. Feathered edges (tapered thin at the perimeter) don't work for concrete repairs — chip the edges square or slightly undercut for mechanical interlock.

Surface preparation is everything. Pressure wash the repair area thoroughly to remove dust, laitance, and any remaining loose material. Allow to dry completely — apply a concrete bonding agent (acrylic or epoxy-based) and let it become tacky before applying the patch.

Choose the right repair product for Moncton's climate:

• Polymer-modified mortar (like Quikrete Sand Mix with acrylic fortifier, or Sika MonoTop) — best for repairs 1/4 inch to 2 inches deep. Bonds well, flexible enough to handle freeze-thaw cycling, widely available at Moncton building supply stores.
• Rapid-setting concrete — good if you need to return the porch to use quickly, but has less bond strength than polymer-modified systems.
• Avoid standard Portland cement mixed with water only — it will delaminate quickly in Moncton's climate without a polymer fortifier.

Apply the repair mortar in layers no thicker than 1/2 inch per lift for deep repairs. Feather the edges to blend with the surrounding surface. Broom-finish the repaired area to match the existing texture and ensure safe traction in NB winters.

Cure and seal. Cover with plastic sheeting for 3–7 days to retain moisture during curing. After 28 days, apply a penetrating silane/siloxane sealer over the entire porch surface — not just the patched area. This is essential for Moncton porches and should be reapplied every 2–3 years.

For large-scale spalling that covers more than 30–40% of the porch surface, a full resurfacing overlay or replacement may be more cost-effective than patching individual spots. New Brunswick Concrete can match you with experienced local contractors for an honest assessment and repair quotes.