Concrete sealers provide a barrier between your concrete and the elements. A properly sealed surface can resist stains and moisture damage, although few sealers are truly waterproof. Don’t wait until the old sealer is peeling up, or until visible staining and weather damage occurs. Plan to seal your concrete regularly as part of the normal maintenance of the surface.
When to Seal
How often you seal your concrete depends on the age of the concrete, your climate, and when it was last sealed.
Newly laid concrete takes approximately four weeks to full cure, so hold off on sealing it for at least one month after installation.
In hot or moist climates, concrete sealer requires replacement every two years. In dry climates, you sealer may last up to three years.
heavy traffic can necessitate more frequent sealer applications. Driveways and heavily used walkways may require sealing every two years, even in a dry climate.
The Best Time to Seal
Early summer or early fall is the best time to seal your concrete. The weather is warm but not too hot, and frost isn’t a concern. Late fall isn’t ideal because falling leaves can damage the sealer as it cures. In mild climates where temperatures don’t rise much above 80 degrees Fahrenheit in summer, you can seal during the long, dry days of midsummer, but in hot climates midsummer sealing may take longer to cure.
Types of Sealer
Several types of sealer are available, and the one you choose depends on the type of concrete work and the sealing history of your concrete. Generally, it’s best to use the same type of sealer each time to avoid discoloration from sealer buildup. The basic choices for sealer include:
Penetrating sealers. These sealers contain silicates that protect exterior concrete. They also penetrate into the surface of the concrete, which provides increased stain and moisture resistance. These sealers are well-suited to driveways or in areas where ice melting chemicals are often used.
Acrylic sealers. Acrylic gives concrete a high sheen, so it’s especially well-suited to decorative or stained concrete work where the luster complements the details. It’s well-suited to both interior and exterior work. Acrylic also dries quickly.
Polyurethanes and epoxies. These high-sheen sealers are best suited to interior concrete floors and countertops. Although exceptionally water repellent, they can trap moisture in wet areas.
The Basic Process
Your contractor will follow a similar process when sealing your concrete. First, he must clean the surface, filling and repairing any cracks or damage. If the old sealer is begin to peel, he may need to remove it. Removal methods depend on the type of sealer. Surface sealers can sometimes be removed chemically, but penetrating sealers usually require grinding to fully remove them from the surface.
Once cleaned and repaired, the sealer is applied in an even coat. It can either be sprayed on or rolled on. After application, it’s left to cure. Curing time depends on weather and sealer type – your concrete contractor will let you know how long to stay of the concrete. Generally, it takes 12 to 24 hours for most sealers to dry.