How do I prep my old Ottawa driveway for a fresh top coat?

Proper surface preparation is absolutely critical for a successful asphalt overlay in Ottawa — rushing this step will cause your new topcoat to fail within 1-2 winters, wasting your investment entirely.

Start with a thorough structural assessment of your existing driveway. Walk the entire surface looking for areas of base failure — soft spots that flex underfoot, large cracks with vertical displacement, areas where the asphalt has broken into loose chunks, or sections that have settled more than 25mm below the surrounding surface. These indicate base problems that an overlay cannot fix. In Ottawa's freeze-thaw climate, overlaying failed base locks the movement and cracking beneath a thin new surface that will reflect every problem within the first winter.

Clean the existing surface completely using a pressure washer or stiff-bristled broom to remove all loose debris, vegetation, oil stains, and dirt. Pay special attention to the edges where grass clippings and soil accumulate — these prevent proper bonding of the new asphalt. Oil stains must be treated with a commercial degreaser and scrubbed thoroughly, as petroleum products prevent asphalt adhesion. Any moss or weeds growing in cracks should be killed with herbicide and removed completely.

Address all cracks and surface defects before the overlay. Cracks wider than 5mm must be filled with hot-pour rubberized crack filler — this remains flexible through Ottawa's extreme temperature swings and prevents water infiltration that would cause the overlay to fail. Clean each crack with a wire brush or compressed air, then fill slightly above surface level as the filler will settle. Potholes and large damaged areas need to be cut out square with a concrete saw and patched with hot-mix asphalt, compacted flush with the surrounding surface.

Ensure proper drainage and edge support before paving. The existing driveway must slope at least 2% toward the street or drainage area — standing water will destroy your overlay through freeze-thaw cycling. If the edges are unsupported or crumbling, they need to be rebuilt with compacted granular material or the overlay will break away within months of Ottawa's first snowplow season.

Prime oil-stained areas and severely oxidized asphalt with tack coat (asphalt emulsion) to ensure proper bonding between old and new surfaces. This is especially important on driveways over 15 years old where the existing asphalt has become brittle and oxidized from Ottawa's UV exposure and temperature cycling.

When to Hire a Pro: Surface preparation might seem straightforward, but assessing base stability, properly filling cracks with hot-pour material, and applying tack coat requires experience and specialized equipment. Most importantly, if your assessment reveals significant base failure, soft spots, or drainage problems, you need full removal and reconstruction rather than an overlay — a decision that can save you thousands in premature failure costs. Professional contractors can determine whether your existing driveway is a good candidate for overlay or needs complete replacement.

Need help finding a driveway contractor? Ottawa Driveways can match you with local paving professionals who understand Ottawa's challenging climate conditions.