Should I patch cracks before sealing my Ottawa driveway?

Yes, you should absolutely patch cracks before sealing your Ottawa driveway. Applying sealer over unrepaired cracks is like painting over rust — it looks better temporarily but doesn't address the underlying problem, and the cracks will telegraph through the sealer within months.

Why crack repair comes first is critical to understand in Ottawa's brutal freeze-thaw climate. Even hairline cracks allow water penetration, and when that water freezes and expands by 9 percent during our 50+ annual freeze-thaw cycles, it widens the crack progressively. Sealer alone cannot bridge structural cracks or prevent this expansion force. The crack will continue growing beneath the sealer, eventually breaking through and creating an even larger problem.

For cracks wider than 5mm, use hot-pour rubberized crack filler applied by a professional contractor. This material remains flexible through temperature swings and provides a proper structural repair. Professional crack filling costs $2 to $5 per linear foot in Ottawa but is essential for cracks you can fit a coin into. For smaller cracks (hairline to 5mm), you can use cold-pour crack filler from a caulk tube as a DIY project — clean the crack thoroughly, apply the filler slightly proud of the surface, and smooth with a putty knife.

Timing matters significantly in Ottawa's short paving season. Do crack repairs on a warm, dry day (above 15°C) when the asphalt has expanded and the cracks are at their narrowest. Allow crack filler to cure for 24 to 48 hours before applying sealer. Never attempt crack repair or sealing when rain is forecast within 24 hours or when temperatures will drop below 10°C overnight.

The proper sequence is: clean the driveway thoroughly (pressure wash if needed), fill all cracks, allow curing time, then apply sealer in two thin coats. This approach extends your driveway's life significantly — properly sealed asphalt with repaired cracks can last 20 to 25 years in Ottawa with maintenance every 2 to 3 years. Sealing over unrepaired cracks typically fails within one winter season.

For extensive cracking (alligator cracking, multiple interconnected cracks, or cracks wider than 25mm), crack filling may be a temporary solution. These conditions often indicate base failure beneath the asphalt, and full replacement may be more cost-effective than repeated patching.

Need help finding a driveway contractor for professional crack repair? Ottawa Driveways can match you with local paving professionals who understand Ottawa's climate challenges.