How much does exposed aggregate concrete cost per square foot in NB?

Exposed aggregate concrete costs $10–$16 per square foot fully installed in New Brunswick, compared to $8–$15 per square foot for standard broom-finish concrete. The premium reflects the extra labour involved in washing and exposing the aggregate surface before the concrete fully cures.

For a 400-square-foot driveway, exposed aggregate runs $4,000–$6,400 versus $3,200–$6,000 for broom finish — a difference of $400–$1,500 for the same area depending on aggregate choice and the complexity of the finish. A 300-square-foot patio with a seeded aggregate finish and a coloured border runs $3,500–$5,500 with most NB contractors.

How it's done: The freshest-poured surface concrete is retarded (a chemical retarder is applied or used in the top layer) to slow the surface cure while the bulk of the slab cures normally. At the right time — typically 6–24 hours later — the contractor pressure washes the surface to remove the thin cement paste layer and expose the decorative aggregate below. The aggregate itself can be standard crushed granite (grey tones), river stone (rounded, multi-colour), or specialty coloured stone for premium finishes.

Exposed aggregate performs very well in NB's climate when properly executed. The textured surface provides excellent traction on wet and icy surfaces — better than smooth broom finish — making it popular for Moncton and Fredericton driveways and front walks. The critical requirement is the same as all exterior NB concrete: air-entrained mix is mandatory. The aggregate layer itself is well-bonded when properly done, but if the concrete matrix beneath doesn't have adequate air entrainment (4–7%), the surface will still scale under NB's freeze-thaw cycles and aggregate will pop loose.

A quality penetrating sealer is also important for exposed aggregate — it protects the stone and cement matrix from salt and water infiltration. Seal within 28–30 days of the pour and reapply every 2–3 years. New Brunswick Concrete can match you with decorative concrete specialists in your area through the New Brunswick Construction Network.