Asphalt sealant is an elastic polymer mixture used to seal coat asphalt surfaces. It is used to protect and preserve asphalt from oxidation due to sunlight exposure. It also fills structural voids, prevents ice and water damage, and creates a more uniform appearance.
Often referred to as driveway sealant, the concentrate's most common use is in asphalt driveway repair. Though normally made of viscous asphalt, asphalt sealer can also contain coal tar. Coal tar sealants are sometimes preferred to asphalt sealants, but asphalt-based products are considered more environmentally friendly. They also present less of a health risk during use.
Before applying asphalt sealant, surfaces should be cleaned. Dirt, oil, sand or grease residues will inhibit the product's adhesion if not removed prior to application. Spots of grease may need to be scrubbed or scraped off as well. If the grease or oil saturation is heavy, the asphalt should be removed and replaced rather than sealed.
Cracks smaller than a quarter of an inch can be sealed with asphalt sealant. Any larger voids should be repaired prior to the sealing process. Rough surfaces can often be treated by adding clean silica sand to some types of asphalt sealants.
To begin seal coating the asphalt, the instructions on the asphalt sealant container should be followed. The waterproof sealant is usually poured directly onto the surface in wide horizontal lines. Application is generally performed twice with a squeegee or broom to ensure a clean, continuous result. The first coating should be dry before beginning the second coating.
If ridges occur during the application process, they should be smoothed out. Though drying time typically ranges from three to four hours, the area should remain untouched for a full day before its general use resumes. Applications should be avoided entirely during cold or rainy conditions.
During application, mishaps can happen. Should sealant be spilled on a non-asphalt surface, it can be washed off with clean water. If the product has already dried, it is possible to remove it with a petroleum solution.
Many experts and manufacturers recommend seal coating asphalt structures every three years to foster durability and longevity. Most sealants come with a limited warranty that ensure effectiveness during this, or a similar time period. Asphalt sealant can often be purchased in a five-gallon bucket from a hardware or home improvement store. Professional grade sealers can be purchased in larger amounts.