Interlock Driveways in Ottawa: What to Know Before You Build

Why the base matters more than the stones

Interlock stones look the same on day one. What separates a driveway that stays level from one that sinks or heaves is the base under them. Ottawa’s freeze and thaw cycles lift and drop poorly prepared ground every year, so a shallow or loosely compacted base shows up as dips, gaps and uneven stones within a few seasons.

What a proper installation includes

• Excavating the old surface and soft ground to the depth the job needs
• A compacted granular base built up in layers
• A bedding layer set to the right slope so water drains away from the house
• Edge restraints that hold the stones in place
• Stones laid in the agreed pattern and compacted
• Joint sand to lock the stones together
• Cleanup and disposal of the excavated material

Drainage and winter

Slope the driveway so rain and melting snow run away from the foundation and not toward it. Water pooling next to the house can lead to leaks in the basement, so ask where the water goes. Plan the work for the months when the ground is not frozen, and expect the weather to affect the schedule.

Interlock compared with asphalt and concrete

HomeStars’ Ottawa paving cost guide reports an average of about $4,443 for paving projects based on homeowner reviews, ranging from $100 to $38,420. It covers all paving types, so it is not an interlock price. HomeStars notes that interlocking stone is an option for a natural look on a driveway or pavement.

Because every driveway has a different size, shape and base, the reliable way to compare options is to get written quotes for the same area from each contractor.

Check with the City before widening or moving a driveway

Rules for driveway width, location and where a driveway meets the road are set by the City of Ottawa, and they have changed recently. A simple replacement in the same footprint is different from widening, adding a second entrance or moving the driveway. Contact the City before you start, and ask your contractor to confirm what applies to your property.

How to compare quotes

Ask each contractor to put in writing:

• The area to be done, and the price per square foot or per job
• The excavation depth and the base materials
• How the driveway will drain, and what slope is planned
• The stone type, colour and pattern, and who supplies it
• What is included for removal and disposal of the old surface
• The warranty and what it covers
• Who checks with the City if the layout is changing

Get a quote for your driveway

The most reliable price comes from a site visit. Aelia Construction and Design offers free estimates across Ottawa, Kanata, Barrhaven, Nepean and Orleans.