How do I prep my Ottawa driveway crack before filling?

Proper crack preparation is critical for lasting repairs in Ottawa's freeze-thaw climate. Clean preparation determines whether your crack filler lasts one winter or several years.

Start by thoroughly cleaning the crack using a wire brush, putty knife, or pressure washer to remove all loose asphalt, vegetation, dirt, and debris. For cracks filled with old, failed filler material, dig out all the loose stuff — it won't bond to new filler and creates a weak point. Use a shop vacuum or leaf blower to remove all loose particles from inside the crack.

Assess the crack width and depth to choose the right repair approach. Cracks narrower than 5mm can be filled directly with liquid crack filler or sealcoat. Cracks 5mm to 20mm wide need rubberized crack filler — either cold-pour from a caulk tube for DIY or hot-pour applied by professionals. For cracks wider than 20mm, you'll need backer rod (foam rope) inserted into the crack before filling to prevent the filler from sinking too deep and wasting material.

Timing matters significantly in Ottawa. Clean and fill cracks on a warm, dry day when temperatures are above 15°C with no rain forecast for 24 hours. The crack and surrounding asphalt should be completely dry — moisture trapped under crack filler prevents proper adhesion and causes the repair to pop out during the first freeze-thaw cycle. If you're using cold-pour crack filler, warm the tube in sunlight or indoors before application for better flow and penetration.

For deeper cracks or small potholes, remove loose material down to solid asphalt, then fill in layers rather than trying to fill the entire depth at once. Pack the first layer firmly, let it cure, then add subsequent layers until slightly above the surrounding surface level. The filler will settle and compress over time.

Apply crack filler slightly proud of the surface — about 2-3mm above the surrounding asphalt. This accounts for settling and compression from traffic and thermal movement. Smooth with a putty knife for a neat appearance, but don't worry about making it perfectly flush initially.

Professional hot-pour crack filling costs $2 to $5 per linear foot in Ottawa but lasts significantly longer than DIY cold-pour products. Hot-pour filler remains flexible through Ottawa's extreme temperature swings and bonds better to the asphalt. If you have extensive cracking (more than 50 linear feet), professional application often provides better value and durability.

Complete crack filling before sealcoating your driveway. Sealcoat applied over unfilled cracks will bridge the gap temporarily but won't prevent water infiltration, and the crack will telegraph through the sealer within one winter season.

Need help finding a driveway contractor for extensive crack repair? Ottawa Driveways can match you with local paving professionals who use professional-grade hot-pour crack filling equipment.