How thick should a concrete driveway be in New Brunswick?

A residential concrete driveway in New Brunswick should be a minimum of 5 inches (125 mm) thick for passenger vehicles, and 6 inches (150 mm) if you park a truck, SUV, or RV on it regularly. Given NB's aggressive freeze-thaw climate and the frost heave forces that act on your driveway slab every winter, thicker is not a luxury — it is genuine protection for a significant investment.

The often-quoted 4-inch minimum is technically achievable for very light use, but experienced NB concrete contractors rarely pour residential driveways at less than 5 inches. Here is why: NB experiences 150+ freeze-thaw cycles annually. Each cycle imparts stress on the slab through differential movement between the slab and the gravel base beneath it. A thinner slab cracks sooner under these repeated thermal and moisture stresses. At 5-6 inches, the slab has the mass and strength to absorb these stresses over a 30-40 year lifespan with proper care.

Thickness alone is not the whole story. A 5-inch concrete slab poured over an inadequate base or with the wrong mix will fail faster than a 4-inch slab poured with proper preparation. The critical package for a long-lived NB concrete driveway is: 6-8 inches of well-compacted granular base + 5-6 inches of air-entrained concrete (25-30 MPa) + proper reinforcement (rebar or wire mesh on chairs at mid-slab height) + control joints every 8-12 feet + a quality penetrating sealer applied within the first year.

Heavier loads require more. If you routinely park a pickup truck, cube van, delivery vehicle, or RV in your driveway, or if heavy concrete trucks or oil delivery trucks regularly drive on it, specify 6 inches minimum. For a commercial driveway apron where heavy trucks make frequent turns, 7-8 inches with additional rebar may be warranted. Discuss your actual usage with your contractor before the pour — changing the thickness spec is easy before forming, impossible after.

The cost difference is modest. Going from 4 inches to 5 inches adds roughly 25% more concrete. On a typical two-car NB driveway of 450 square feet, that is approximately 1.5-2 additional cubic yards of concrete — adding $300-$480 in material cost on a project that already costs $4,000-$8,000. For the added durability in NB conditions, this is money very well spent.

Get matched with a local driveway contractor through New Brunswick Concrete for a free estimate on your project.