Surface Coatings & Seals
Surface coatings keep structurally sound pavement from wearing out — they are preventive maintenance, not structural repair.
The treatments, lightest to heaviest
Crack seal (fill cracks first) → fog seal (light diluted emulsion, no aggregate) → sand seal (emulsion + fine sand) → slurry seal (emulsion + fine aggregate + water + filler) → micro-surfacing (polymer slurry; fills minor ruts, opens in ~1 hour) → chip seal (emulsion + aggregate chips). Sealcoat protects asphalt lots but adds no strength.
Preventive vs. rehabilitation
All of the above seal and protect pavement that is still structurally sound. Once the base has failed — for example, a pothole that keeps returning — a seal won’t fix it; the job needs an overlay or reconstruction. Choosing the right treatment for the pavement’s condition is the heart of this section.
Practice: Surface Coatings & Seals
Frequently asked
What is the difference between a slurry seal and a chip seal?
Does a sealcoat make pavement stronger?
More C-32 Parking & Highway topics
Planning & Estimating
C-32 study guide on planning and estimating parking and paving work: parking-stall layout and angles, drive-aisle widths, wheel stops, drainage slope, and estimating striping and asphalt.
Read & practice →Striping, Markings & Markers
C-32 study guide on pavement markings: white vs yellow line meanings, solid vs broken lines, paint vs thermoplastic, glass beads, raised pavement markers, and California curb colors.
Read & practice →ADA Parking & Accessibility
C-32 study guide on ADA accessible parking: how many accessible spaces a lot needs, the van-accessible ratio, car vs van access-aisle widths, the 2% slope limit, and signage.
Read & practice →Special Applications
C-32 study guide on special paving applications: tennis and basketball court surfacing, running tracks, and FAA airfield marking colors.
Read & practice →Incidental Pavement Repair
C-32 study guide on incidental pavement repair: durable pothole patching, crack sealing, mill-and-overlay, and recognizing when a base failure requires a full-depth repair.
Read & practice →Safety & Traffic Control
C-32 study guide on work-zone safety: orange signs, tapers, the flagger's paddle, channelizing-device spacing, high-visibility apparel, struck-by and silica hazards, Dig Alert, and stormwater.
Read & practice →