Professional Concrete Sealing Services

Concrete sealing is one of the most important maintenance investments you can make for your driveway, patio, or walkway. While concrete is incredibly durable, it's also porous meaning water, oil, salt, and other contaminants can penetrate the surface and cause damage from within. In Ontario's harsh climate, this is particularly problematic because water that seeps into concrete will freeze and expand during winter, causing cracks, spalling, and surface deterioration. Professional sealing creates a protective barrier that dramatically extends the life of your concrete while enhancing its appearance.

The science behind concrete sealing is straightforward but critical to understand. Concrete is made of cement, aggregate, and water when cured, it contains millions of tiny pores and capillaries. These microscopic channels allow moisture to wick into the slab through capillary action. Once inside, water carries dissolved salts (especially road salt and de-icers) deep into the concrete matrix. When temperatures drop, this water freezes and expands by approximately 9%, creating internal pressure that eventually causes the surface to pop off in flakes a process called spalling. Sealer fills these pores and creates a hydrophobic surface that causes water to bead up and run off rather than absorbing.

There are several types of concrete sealers, each with specific advantages. Acrylic sealers are the most popular for decorative concrete because they enhance color and provide either a wet-look or matte finish. They're breathable, allowing moisture vapor to escape while preventing liquid water intrusion. Penetrating sealers (silane/siloxane) soak into the concrete and react chemically to create water-repellent properties without changing the surface appearance ideal for those who want protection without added sheen. Polyurethane and epoxy sealers provide the most durable protection but are typically used for interior or garage floors rather than exterior applications.

Timing matters significantly when sealing concrete. New concrete should cure for at least 28 days before sealing this allows the hydration process to complete and excess moisture to evaporate. Sealing too early traps moisture and can cause the sealer to fail or the concrete to remain weak. For existing concrete, the ideal sealing window in Ontario runs from late April through October when temperatures are consistently above 10°C and no rain is forecast for 24-48 hours. The surface must be completely dry even morning dew can interfere with sealer adhesion.

Surface preparation is arguably the most critical step in the sealing process. Any contaminants left on the surface will be sealed in permanently and may prevent proper adhesion. We begin with thorough power washing to remove dirt, mold, mildew, and debris. Oil stains require special degreasers and sometimes multiple treatments. If previous sealer exists and is peeling or flaking, it must be removed we cannot simply apply new sealer over failed coatings. After cleaning, the concrete must dry completely, which typically takes 24-48 hours depending on weather conditions and concrete porosity.

Application technique affects both appearance and durability. We apply sealer using professional sprayers for even coverage, followed by back-rolling to work the product into the surface and eliminate puddles. Two thin coats are always better than one thick coat thick applications can bubble, peel, or turn cloudy. We wait for the first coat to dry completely before applying the second, typically 2-4 hours depending on temperature and humidity. The result is a uniform, properly bonded seal that will protect your concrete for years.