Whether your driveway is paved with asphalt, concrete, pavers or another material, sealing the surface is one of the most effective ways to improve the appearance and increase its strength. While most sealers are as simple to apply as paint, there are several pros and cons to consider before using the chemical on your driveway. Sealing a surface is optional, but not doing so leaves the pavement more vulnerable to weather damage, fading and grease stains.
Sealants can improve surface appearance in at least three different ways. They block UV rays and prevent colour fading. Sealants also fill porous surfaces, making them easier to clean the grease and oil stains that driveways are frequently exposed to. For a concrete surface, tinted sealants enhance a plain grey slab with colour, and most varieties add a glossy or matt finish.
Water, snow and harsh weather can wreak havoc on an unsealed driveway. If water seeps through a driveway, it can collect in puddles just below the surface, which can lead to cracks and frost heaves. Sealants fill porous surfaces and repel water, which also preserves the sand joints in brick or paver driveways.
While sealing reduces regular maintenance, it wears off and requires reapplication. Acrylic sealers are used widely on exterior pavements as they allow moisture and air to escape through the surface. While they're non-yellowing, acrylic sealants are also soft so they need to be reapplied every two to three years. Epoxy coatings do not wear away as fast, but their non-permeable nature traps moisture between the surface and sealant, causing bubbling. Wait three weeks, before applying sealer, to avoid trapping efflorescence -- the white substance made of soluble salts that can rise to the surface after the concrete is poured.
There are several safety factors to consider before sealing a driveway. The chemical that gives some sealants a water-resistant glossy finish also makes the surface more slippery, which is especially dangerous if you're already dealing with rain and ice. Some solvent-based sealants, such as acrylic and urethane, pose a health and fire hazard. Water-based alternatives are safer but not as long-lasting.