What is a Chip Seal?

The County Public Works Department Maintenance crews perform two types of chip seal:

  • A single chip seal involves spraying liquid asphalt on the pavement followed by the spreading of a layer of small aggregate (chips) that is embedded into the oil.
  • A double-chip seal is a single chip seal with a second application (layer) of liquid asphalt and small aggregate.

Single and double-chip seals are typically used on arterial and collector roads that have a significant amount of wear and high traffic volume. Schedule information regarding the chip seal application can be obtained by calling the Public Works Department Maintenance Division at (925) 313-7000, visiting our Pavement Management Program webpage or email us.


Show All Answers

1. What is a cape seal?
2. What is a Chip Seal?
3. What is a micro-surface seal?
4. What is a slurry seal?
5. What is the construction work occurring on a County Road or Flood Control Facility?
6. When does the County perform its surface treatment work?
7. Who do I contact if I have questions about the road surface treatment work?
8. Why do I not see construction activity associated with the road surface treatment when I drive by?
9. Why do they spray oil on the road before they place the asphalt during a road surface treatment?
10. There is construction work occurring on a County Road or Flood Control Facility. What is going on?
11. Where can I find the current and future county road projects?
12. What can I do to help make the road surface treatment work successful?
13. When will roadwork associated with the road surface treatment be finished?
14. Why are road surface treatments necessary?
15. Will I still have access to my driveway during the road surface treatment work?
16. Will traffic be severely disrupted due to the road surface treatment work?