Polymeric sand and sealing

Sealing is the most oversold service in this trade and also a genuinely useful one, depending on what you expect from it. It will stabilize your joints, deepen the colour and make oil and rust easier to lift off. It will not stop your driveway settling, it will not fix heaving, and it is not structural in any way. A contractor who offers sealing as the answer to a sinking driveway is selling the wrong product.

Step one: assess whether the surface is ready. New pavers should weather before sealing, commonly a full season, so that efflorescence, the whitish salt bloom that rises out of new concrete, has run its course. Sealing over efflorescence locks it in and you get a permanent milky haze. Existing pavers need their stains, weeds and old failed sealer dealt with first.

Step two: clean thoroughly. Weeds and moss are removed from joints, organic staining is treated, and the field is washed, usually with a pressure washer at a controlled pressure and a fan tip. Too much pressure strips the surface of the paver and blasts out the joints. Oil and rust stains need specific treatments rather than more pressure. Old sealer that is peeling has to be stripped, which is a job in itself.

Step three: rejoint. Joints are refilled with sand, usually polymeric, swept in and consolidated. This step matters more than the sealing. Joint sand is what transfers load between pavers and keeps the field acting as one surface, and washed-out joints are how a driveway begins to come apart.

Step four: dry, then seal. The surface has to be properly dry, commonly 24 to 48 hours after washing, or the sealer traps moisture and turns cloudy. Sealer is applied evenly by sprayer or roller in thin coats, typically two, with pooling avoided. A film-forming sealer sits on top and gives a wet look or a gloss. A penetrating sealer soaks in, changes appearance very little and lets the surface breathe. Both have their place, and the wet-look finish is a matter of taste that is hard to undo.

Step five: cure. Keep off for the stated period, typically 24 hours for foot traffic and two to three days for vehicles. Polymeric sand and sealer both need dry weather to cure, so a forecast with rain in it is a reason to postpone rather than proceed.

How long it takes. A standard driveway is one to two days including drying time between cleaning and sealing. A larger property with patios and walks is two to three. The work is weather-bound at both ends, which is why sealing contractors in Ottawa are booked solid in the dry weeks of July and August.

What it costs in Ottawa in 2026. Indicative ranges, matching this site's price guide. Cleaning out failed joints and refilling with polymeric sand runs about $3 to $5 per square foot. Sealing on top of that is about $2 to $4 per square foot. On a typical two-car driveway of roughly 600 square feet, that puts a clean and re-sand around $1,800 to $3,000 and sealing around $1,200 to $2,400, which is why many owners do the re-sanding and skip the sealer. What moves it: how much cleaning and stain treatment is needed, whether old sealer has to be stripped, the product chosen, and how much joint sand the surface swallows. Stripping failed sealer can cost as much as the sealing itself.

How often, and what makes Ottawa different. Sealers are generally reapplied every three to five years, and Ottawa is at the harsher end of that range. Freeze-thaw cycling works at the surface repeatedly through the winter and again during the melt, road salt and driveway de-icer attack joint sand, and snow ploughing abrades the finish. The spring melt is also when washed-out joints show up most clearly, which makes late spring a sensible time to assess and mid-summer the right time to do the work. One local caution about permeable paving: if your driveway was built as a permeable system, perhaps under the City's Rain Ready Ottawa rebates, a film-forming sealer would defeat the point of it by closing the joints. Permeable installations are cleaned and maintained differently, so tell the contractor what you have.

Who should do the work. No licence applies. Sealing is one of the more common doorstep-sales services in Ottawa summers, so check liability insurance and WSIB coverage, ask which specific product they use and look up its data sheet, and be cautious of anyone offering to seal today at a discount because they happen to have material left over. A capable homeowner can do this work, and the products are sold retail. The parts that go wrong are pressure washing too aggressively, sealing a damp surface, and sealing too soon after installation.

What to ask before you hire. Is my driveway ready to seal, and how do you know. Which product, film-forming or penetrating, and what finish will it leave. How many coats. Are you rejointing with polymeric sand, and is that in the price. What pressure are you washing at. How long do I stay off it. How long before it needs doing again. What happens if it rains the day after. If a contractor cannot answer why penetrating differs from film-forming, keep looking.