New interlock driveways and walkways

An interlock driveway lasts thirty years or fifteen depending almost entirely on what happens before a single paver is laid. The stone is durable and the pattern is decoration. The base is the product, and it is the part you cannot inspect once the job is finished, which is why the questions you ask at quote stage matter more here than in most trades.

Step one: the permit question. In Ottawa, constructing, relocating, altering or closing a private approach, which is the part of the driveway crossing the City right of way to the road, requires a Private Approach permit under By-law 2003-447 (City of Ottawa). A permit is only issued where the approach provides access to a legal parking space and complies with the zoning by-law. If you are widening a driveway or adding a second one, start here, because the zoning by-law also governs how much of a front yard can be paved. Your contractor should know this. Confirm it with the City rather than taking their word.

Step two: locates. A locate request through Ontario One Call is legally required, free, and should be submitted at least five business days before digging (Ontario One Call). Private buried services the utilities do not own, an irrigation line or a feed to a shed, are yours to declare.

Step three: excavation. The old surface and the soil beneath come out to the depth the design calls for. This is where corners get cut. On clay, an under-excavated driveway is a driveway that will move, and no amount of quality in the paving above compensates.

Step four: subgrade, geotextile and base. The exposed subgrade is compacted. A geotextile separation fabric over clay is worth insisting on, because its job is to stop clay fines migrating up into your clean base and destroying its drainage. Granular base then goes in and is compacted in lifts. Industry guidance puts a residential driveway at 150 to 200 mm of compacted aggregate base, and explicitly notes the thickness may need to be greater depending on site conditions, freezing temperatures and traffic (CMHA, Application Guide for Interlocking Concrete Pavements). Barrhaven clay and Ottawa winters are exactly the conditions that clause describes, and local practice commonly goes deeper. Ask your contractor what depth they are proposing and why.

Step five: bedding, laying and edges. Bedding sand is screeded to 25 to 40 mm uncompacted and left undisturbed. Pavers are laid to the pattern, cut at the edges, and contained by an edge restraint that is spiked into the base, not into the bedding sand. Every field failure starts at an unrestrained edge.

Step six: jointing and compaction. Joints are filled with sand, the field is compacted with a protective pad, and the joints are topped up. Polymeric jointing sand resists weeds and washout and needs a dry cure. Slope is set throughout so water runs off and away from the house rather than toward the foundation.

How long it takes. A standard two-car Barrhaven driveway is typically five to ten working days from excavation to final sweep, weather permitting. Add the locate week and the permit lead time at the front. Rain stops base compaction and stops polymeric sand curing, so a wet fortnight genuinely moves the finish date.

What it costs in Ottawa in 2026. Indicative ranges, matching this site's price guide. New interlock is priced by the square foot installed: about $25 to $35 per square foot for a driveway built to take vehicle traffic, and about $20 to $30 per square foot for a walkway, which carries lighter loads and needs less base. A typical two-car driveway of roughly 600 square feet therefore often lands somewhere around $15,000 to $21,000. Premium pavers, borders, inlays and complex cutting push higher. What moves it: excavation depth and disposal, whether the existing surface has to come out, paver choice, site access, and any drainage or steps included. A quote noticeably below the range usually means less base.

What makes a Barrhaven driveway different, plus a City rebate. Champlain Sea clay is the governing fact: it holds water, it moves seasonally, and it contaminates a base if there is no separation fabric (NRC). Frost goes deep enough here that the Building Code requires foundations in clay as deep as 1.2 m (OBC 9.12.2.2). Winter salt and plough blades add surface wear that softer materials do not survive. On the useful side, the City runs Rain Ready Ottawa, which offers rebates toward measures that keep rainwater out of the sewer system, permeable paving among them, with stated rebates of up to $5,000 for eligible rain diversion projects (City of Ottawa). Eligibility is geographic and permeable paving is a different build from standard interlock, so raise it before design, not after.

Who should do the work. There is no provincial licence for hardscaping, so check liability insurance and WSIB coverage, ask for three addresses of driveways they built five or more years ago, and go and look at them. Manufacturer or CMHA installer training is a meaningful signal. Where a retaining wall over about a metre forms part of the project, that becomes regulated work needing a permit and an engineer's design.

What to ask before you hire. How deep are you excavating and how deep is the compacted base. Are you using geotextile over the clay. How many lifts and what compactor. What bedding thickness. Which edge restraint and how is it fixed. Which jointing sand. Where does water go, and does the slope carry it away from the house. Are you pulling the Private Approach permit. What is the warranty on settlement, in years, and is it transferable if I sell.