Asphalt Sealer: When, How and How Often (Quebec Guide)

Sealer is the cheapest and most misunderstood maintenance your asphalt driveway will ever get. Applied at the right time, it keeps the original black and blocks what wears asphalt down: water, salt and sun. Applied too early, too often or on a poorly prepared surface, it does nothing, and it can even do harm. Here is what we explain to our clients before every asphalt sealcoating application.

Why seal: water, salt and UV

Asphalt is a mix of stone and bitumen. Bitumen is the black, flexible binder that holds the stones together. Over time, three things attack it.

The sun. UV rays oxidize the bitumen. It becomes dry and brittle, and the surface goes from black to grey. Small stones come loose: that is the first stage of wear.

Water. It seeps into the pores and micro-cracks. In Quebec, it freezes. As it freezes, it expands and widens every crack, cycle after cycle, all winter long.

Salt and petroleum products. De-icing salt speeds up surface degradation; oil and gasoline dripping from a vehicle literally dissolve the bitumen where they land.

A quality sealer forms a protective layer that slows oxidation, keeps water from getting in and resists petroleum products better than bare asphalt. It repairs nothing: it protects what is still sound. That is also one of the advantages asphalt has over paving stones, whose joints cannot be protected as simply. See our asphalt or paving stones comparison.

When to do the first application on new asphalt

This is the most common mistake: sealing a new driveway too soon. Freshly laid asphalt still contains light oils that need to evaporate while it cures. If you apply a sealer before that process is finished, those oils stay trapped, the surface stays soft longer and the sealer bonds poorly.

Best practice: let new asphalt go through a full season, including a hot summer, before the first application. The simple test: pour a little water on the surface. If it beads, the asphalt is not ready; if it soaks in and darkens the surface, it is ready for a sealer.

If our team paved your driveway, ask us when it is ready for its first sealer.

How often, depending on use

There is no universal schedule. Frequency depends on sun exposure, how much salt the surface gets in winter, traffic and the quality of the previous application. Three signs to watch rather than a date:

• Look at the colour. When the deep black has turned a uniform grey, the protection is gone.
• Look at the water. If it no longer beads after rain and darkens the surface, the sealer is no longer doing its job.
• Look at the texture. If small aggregate comes loose under your finger, it is time.

Sealing too often is no better: the coats build up, the surface becomes smooth and shiny, and the sealer ends up flaking instead of wearing. A residential driveway in Laval or on the North Shore gets sealed far less often than a commercial parking lot that sees dozens of vehicles a day.

The steps of a professional application

A successful application starts with successful preparation. Here is how we proceed.

1. Complete cleaning. Blowing off debris, mechanical brushing, degreasing oil stains. A sealer applied over dust peels off with the dust.
2. Crack filling. Open cracks are filled with a hot-applied crack filler; sealer does not plug a crack, it only covers it.
3. Oil stain treatment. A special primer is applied to contaminated areas so the sealer will bond.
4. Application in one or two coats, by squeegee or sprayer depending on the surface and the product, with a clean edge along the garage, the sidewalk and the curbs.
5. Drying and reopening. No vehicles until the surface is completely dry; the wait depends on temperature and humidity.

For an apartment building or business parking lot, we add zone-by-zone scheduling so all access points are never closed at the same time. See our commercial paving page.

Common mistakes

Sealing too early. See above: new asphalt has to cure first.

Sealing a dirty or damp surface. The product bonds to whatever it touches. If it touches dust or water, it bonds to the dust or the water, not to the asphalt.

Sealing before rain or in cold weather. A sealer needs heat and dry conditions to form its film. A shower in the hours that follow washes the work away; a cool night keeps it from curing.

Sealing without filling cracks. Sealer hides a crack for a few weeks, then the crack reappears. The water, meanwhile, never stopped getting through.

Sealing a driveway at the end of its life. On sunken or alligator-cracked asphalt, sealer is money wasted. The right answer is resurfacing or a rebuild, and we will tell you so before taking your money. Not sure what you are looking at? See the 5 signs it is time to redo or repair a driveway.

Do it yourself or hire a professional

Hardware store products exist and work on a small surface, provided you set aside a full day for preparation and application. What sets a professional application apart is not only the product (more concentrated, applied at a controlled thickness), it is the preparation: hot crack filling, degreasing, mechanical brushing and a clean edge.

Our honest advice: for a single driveway in good condition, doing it yourself is an option if you are meticulous. For a double driveway, a parking lot, or a stained or cracked surface, leave it to a professional: the difference in results shows with the first rain.

Maintaining between applications

• Sweep away debris and rinse off oil or gasoline stains quickly.
• In winter, choose an abrasive (sand, fine gravel) over pure salt when possible, and clear snow with a plastic- or rubber-edged shovel.
• Avoid turning the wheels of a stationary vehicle in extreme heat.
• Fill any new crack before fall: winter is what will make it grow.

More on salt and snow removal in Asphalt driveways and Quebec winters.

Not sure whether your driveway is ready for a sealer, or whether it needs more? The visit is free in Montreal, Laval, Terrebonne and on the North Shore: request your quote and we will tell you honestly what is right for it.