How do I prep my Ottawa asphalt driveway before sealing?

Proper preparation is absolutely critical for successful driveway sealing in Ottawa — rushing this step will result in poor sealer adhesion, premature peeling, and wasted time and money. The preparation process typically takes a full day before you can even think about applying sealer.

Start with thorough cleaning at least 48 hours before sealing. Remove all loose debris, leaves, and dirt with a stiff broom or leaf blower. Power wash the entire driveway using a pressure washer set to medium pressure (1500-2000 PSI) — too much pressure can damage aged asphalt. Work systematically from the top of the driveway toward the street, allowing dirty water to flow away from cleaned areas. Pay special attention to oil stains, which must be completely removed or the sealer won't adhere. For oil stains, apply a commercial degreaser or sprinkle cat litter on fresh spills, let it absorb for several hours, then scrub with dish soap and hot water before pressure washing.

Crack filling is essential before sealing — this is where many Ottawa homeowners make costly mistakes. Any crack wider than 5mm must be filled with rubberized crack filler before sealing, or water will penetrate through the sealer and cause freeze-thaw damage during Ottawa's brutal winters. Clean cracks with a wire brush or compressed air to remove loose material and vegetation. For cracks wider than 10mm, insert backer rod (foam rope) to the proper depth before applying filler. Use cold-pour crack filler for DIY application, working it into cracks with a putty knife and smoothing flush with the surface. Allow crack filler to cure for 24-48 hours before sealing.

Timing and weather conditions are crucial in Ottawa's climate. The driveway must be completely dry for at least 24 hours before sealing — any moisture trapped beneath the sealer will prevent proper adhesion. Check the weather forecast for at least 48 hours of dry conditions with temperatures consistently above 15°C. Early morning dew or high humidity can ruin a sealing job. The ideal conditions are warm, dry days in late spring through early fall (May through September) with low humidity and no rain forecast.

Address any structural issues before sealing. Small potholes should be patched with cold-mix asphalt and compacted flush with the surface — sealer alone cannot fix structural damage. If you have significant alligator cracking, widespread raveling, or areas where the base is showing through, sealing won't help and may actually trap moisture that accelerates deterioration. These areas need proper asphalt patching or professional repair before sealing makes sense.

Final preparation steps include edge trimming and masking. Trim grass and weeds along driveway edges so they don't interfere with sealer application. Use plastic sheeting or cardboard to protect adjacent concrete, interlock, or painted surfaces — asphalt sealer stains permanently and is nearly impossible to remove from concrete. Have your application tools ready: a long-handled squeegee or specialized sealer brush, stirring paddle, and clean rags for cleanup.

Professional tip for Ottawa driveways: If your asphalt is less than 6 months old, don't seal it yet — new asphalt needs time to cure and oxidize properly. Conversely, if it's been more than 3 years since the last sealing in Ottawa's harsh climate, you may need two coats of sealer applied 24 hours apart to achieve proper protection against our freeze-thaw cycles and road salt exposure.

Need help finding a driveway contractor for repairs before sealing? Ottawa Driveways can match you with local paving professionals through the Ottawa Construction Network.