Rochester Sealcoat · Glossary

driveway sealcoating glossary

Plain-English definitions for the technical terms you'll see in quotes, proposals, and inspection reports. Bookmark this when you're comparing bids.

Coal-tar emulsion

A pavement sealer derived from coal-tar pitch. Higher resistance to UV and petroleum solvents than asphalt-emulsion sealer but harder to apply.

Asphalt emulsion

Water-based sealer derived from asphalt. Easier to apply, lower VOCs, slightly less resistant to gas/oil spills than coal-tar.

Crack filling (cold-pour)

Filling cracks with a rubberized, room-temperature compound. Cheaper, faster, and shorter-lived than hot-pour.

Crack filling (hot-pour)

Filling cracks with a rubberized polymer heated to ~380°F. Bonds chemically to the asphalt, lasts 3-7 years.

Cure window

Time after sealer application during which it must stay dry. Typically 24 hours minimum, 48 ideal.

Dilution ratio

How much water is added to concentrated sealer. Industry standard is 25-30%. "Watered down" jobs are 50%+ dilution.

Squeegee coat vs spray coat

Application methods. Squeegee fills cracks better but is slower; spray is faster but penetrates less. Two-coat jobs use both.

Mil thickness

Dry film thickness measured in thousandths of an inch. Quality sealer = 12-16 mils per coat (24-32 total for two coats).

Surface prep

Cleaning + priming the asphalt before sealer. Includes pressure washing, oil-spot primer, and crack fill.

Pavement aging

Oxidation + UV exposure that turns black asphalt gray and brittle. Sealer reverses the gray + slows the brittleness.