What's the cost premium for exposed-aggregate over standard concrete in Ottawa?

Exposed aggregate concrete typically costs 20 to 40 percent more than standard broom-finished concrete in Ottawa, translating to roughly $4 to $8 more per square foot depending on aggregate selection, pattern complexity, and site conditions.

For a typical Ottawa driveway of 45 to 55 square metres, that premium works out to roughly $1,800 to $4,800 over a standard concrete pour. Standard 30 MPa broom-finished concrete driveways run $10 to $16 per square foot installed in the Ottawa market. Exposed aggregate on the same driveway runs $14 to $24 per square foot, with the spread driven primarily by the type of decorative aggregate specified and the finishing labour involved.

The premium exists for a few reasons. The exposed aggregate process requires additional labour — the surface paste must be washed or chemically retarded and pressure-washed at precisely the right time during curing to reveal the aggregate without dislodging it. Timing this correctly in Ottawa's variable spring and fall temperatures is genuinely skilled work. Rush it and you wash away too much paste; wait too long and the surface has hardened past the point of proper exposure. The decorative aggregate itself — typically a blend of river stone, granite chips, or coloured quartz — costs more than standard concrete aggregate, and premium blends with consistent colour and size command a further premium.

Ottawa-specific considerations matter significantly here. Exposed aggregate performs exceptionally well in Ottawa's freeze-thaw climate compared to smooth or stamped concrete surfaces, because the textured surface provides natural traction on icy winter mornings without requiring as much sand or salt. The exposed stone surface also hides minor surface wear better than a smooth broom finish. However, exposed aggregate concrete in Ottawa absolutely requires air entrainment in the mix — a minimum 5 to 8 percent air content — to survive 50-plus freeze-thaw cycles per winter. Non-air-entrained concrete will spall and delaminate within 2 to 3 seasons regardless of finish type. Any contractor quoting exposed aggregate work should be specifying 30 MPa minimum compressive strength with air entrainment as a baseline — if they are not mentioning this, ask directly.

On the aggregate selection side, locally available river stone blends (grey and tan tones) sit at the lower end of the premium range. Imported coloured quartz, glass aggregate, or custom blended stone from specialty suppliers pushes costs toward the upper end. Some Ottawa contractors source aggregate from Quebec quarries, which can affect pricing depending on current supply and transport costs.

Sealing is non-negotiable with exposed aggregate in Ottawa. A penetrating silane-siloxane sealer applied after the first winter (once the concrete has fully cured) and reapplied every 2 to 3 years dramatically reduces salt penetration and freeze-thaw spalling. Budget $300 to $600 for professional sealing of an average driveway, and factor this into your long-term maintenance cost comparison. Without sealing, road salt and driveway deicers will attack the cement paste around the exposed aggregate and cause progressive surface deterioration.

Do not apply any deicing chemicals during the first winter after a new exposed aggregate pour — this applies to all concrete but is especially important with exposed aggregate because the surface paste is thinner and the aggregate-paste bond is more vulnerable during the initial curing period. Use sand for traction only during year one.

When getting quotes, ask each contractor to specify the aggregate blend, the concrete mix design (MPa and air content), the curing method, and whether a sealer application is included. These details separate quality exposed aggregate work from a basic pour with decorative stone thrown in.

If you are comparing exposed aggregate against interlock pavers for a similar Ottawa driveway, interlock typically runs $12 to $22 per square foot installed — overlapping with the exposed aggregate range — but carries higher long-term maintenance requirements (polymeric sand, relevelling) compared to concrete's periodic sealing. Both are excellent choices for Ottawa's climate when properly installed on a 300mm Granular B plus 150mm Granular A base.

Need help finding a concrete driveway contractor for your project? Ottawa Driveways can match you with local professionals through the Ottawa Construction Network — free, with no obligation.