Sealcoating in Antioch, CA

Sealcoating is a thin protective coat spread over asphalt pavement. It does not add strength, but it shields the binder in the asphalt from sunlight, oxygen, oil drips and water. In Antioch, where the average July high is above 91 degrees and summers run long and dry, ultraviolet light oxidizes unsealed asphalt and turns it gray, brittle and prone to raveling. A sealcoat every few years keeps the surface flexible and black and keeps winter rain from soaking in through fine cracks.

When to seal

New asphalt needs time to cure before it is sealed: HomeGuide says to wait three to six months. After that, it suggests resealing every 2 to 10 years depending on the sealer and the climate; lots and heavily used driveways are at the shorter end. Sealing needs dry weather between about 50 and 95 degrees, so in Antioch the season runs roughly spring through fall, avoiding winter storms and the hottest afternoons.

Preparing the surface

Sealer only bonds to clean pavement. We blow off and sweep the surface, scrape away dirt and weeds along the edges, treat oil spots so the coat will stick, and fill cracks first. Sealcoat over open cracks just hides them for a season.

Sealer choices

HomeGuide describes two common types. Coal tar emulsion resists fuel and oil well but has been banned in many areas because of health and runoff concerns. Asphalt polymer emulsion is considered more environmentally friendly but can stain from gas and oil. For homes we generally use asphalt emulsion, and for lots we match the product to traffic and spills.

Curing and reopening

Most sealers can be walked on after one to three hours and driven on after 12 to 72 hours, depending on temperature and humidity. We schedule lots in sections and tell you when each area can reopen.

Seal and stripe together

For parking lots, sealcoat covers the existing lines, so restriping follows. Doing both on one visit means one closure, and gives you a chance to update the layout, including accessible spaces under the 2010 ADA Standards.

Signs it is time to reseal

• The surface has turned from black to gray
• Fine cracks and loose stones appear, especially in the wheel paths
• Water soaks in instead of beading on the surface
• Oil and fuel stains have softened spots on the pavement

If several of these show up, sealing soon is far cheaper than repairs later. We will tell you honestly if the pavement is already past the point where sealcoat helps.