What preparation do Ottawa contractors do before applying driveway sealer?

Proper preparation is arguably more important than the sealer itself, and in Ottawa's climate, skipping steps leads to early failure. Here is what a thorough preparation process looks like from a reputable Ottawa sealing contractor.

Step 1: Cleaning the Surface

The driveway must be completely clean before any sealer is applied. Professional contractors start with a thorough sweep to remove loose debris, gravel, and leaves — particularly important in Ottawa where sand from winter road treatment accumulates in driveway edges and expansion joints. This is followed by commercial power washing at 2,500-3,000 PSI to remove embedded dirt, moss, and surface contaminants. In shaded driveways common in older neighbourhoods like Westboro, Alta Vista, and the Glebe, moss and algae growth is significant and requires focused attention.

Step 2: Oil and Stain Treatment

Ottawa driveways develop oil stains from vehicles idling during winter warm-ups. Petroleum-based stains prevent sealer from bonding to the asphalt. Professional contractors apply a specialized oil-spot primer that encapsulates the stain and provides a surface the sealer can grip. This step is often skipped by discount operators, and the result is sealer that peels off those spots within weeks. A driveway with multiple oil stains may need treatment applied 24 hours before sealing.

Step 3: Crack Filling

This is the most critical preparation step for Ottawa driveways. After a winter with temperatures reaching -25°C to -30°C and dozens of freeze-thaw cycles, most asphalt driveways develop new cracks or see existing ones widen. Professional contractors use hot-pour rubberized crack filler heated to approximately 190°C, which flows into cracks and bonds to the crack walls. This material remains flexible at Ottawa's winter lows and expands and contracts with the asphalt.

Cracks wider than 20mm may need to be routed (widened with a mechanical router) to create a reservoir that holds enough filler to remain effective. Cracks showing vegetation growth need to be cleaned with a heat lance or wire brush before filling. Contractors typically fill cracks and allow 24-48 hours of curing before applying sealer over top.

Step 4: Edge and Joint Work

The edges where your driveway meets the garage floor, walkways, garden borders, and the street apron are vulnerable points. Ottawa contractors use a detail brush or edging tool to ensure sealer coverage extends fully to these boundaries. The joint between the driveway and the garage floor is particularly important — water entering here can undermine the driveway base through freeze-thaw action.

Step 5: Surface Must Be Dry

The driveway needs to be completely dry for sealer adhesion. In Ottawa, this means monitoring the weather forecast carefully. Overnight dew can leave enough moisture on the surface to compromise adhesion, so most professional applications begin mid-morning after the sun has dried the surface. If rain fell within the previous 24 hours, a good contractor will reschedule rather than risk a poor result.

What to Expect on Sealing Day

A properly prepared driveway takes 2-4 hours of prep work before the first drop of sealer goes down. When a contractor arrives and starts spraying within 20 minutes, the preparation was not adequate for Ottawa conditions.

Find contractors who take preparation seriously through Ottawa Driveways — proper prep is what separates a one-winter seal job from a three-year result.

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Looking for experienced contractors? The Ottawa Construction Network connects Ottawa homeowners with qualified professionals:

• 613Bins
• RenoMotion Inc.
• Grunt Work 4 Grunts
• M.O.T. CONSTRUCTION INC.
• JMY Renovations