Andy Tullis / The Bulletin file photoEmployees of Deschutes County Road Department, chip seal the surface of NE 17th St near the intersection of NE Wilcox Ave in Terrebonne in June.

Warmer weather couldn’t come any sooner for Deschutes County road crews who have a short window to apply chip seal on area roads and prevent pavement from cracking.

Chip seal consists of spraying hot liquid asphalt on the surface of a road and then covering it with crushed rock. The program is weather-dependent and can only be completed in a three- to four-month period during summer.

Chris Doty, director of the road department, said county crews will apply the treatment to about 125 miles of road in rural and urban areas this year. Cities contract with the county to apply the chip seal.

“They’d have us chip seal more if we could, but our calendar is such that we have to get through our own system,” Doty said about the city of Bend.

The county will apply chip seal to about 95 miles of county roads, as well as up to 20 miles within Bend, 10 miles in Redmond and 2 miles in Sisters.

The process prevents asphalt from deteriorating with the hot and cold weather swings that occur in the High Desert. It’s applied when a road is still in good condition to preempt any deterioration.

Doty said the department starts the program about a month earlier than most road agencies. The department has to stop applying it at the end of August and early September to give it enough time to settle before the cold winter months.

The crews can cover up to 5 miles a day in more rural areas of the county where there is less traffic. Doty said although chip seal is weather-dependent, vehicles can use roads after the process in a relatively short timespan.

“The nice thing about chip seal is it goes down pretty fast and you can get traffic on it right away,” Doty said.

Doty said this year is typical, with volume and workload staying about the same as it has in recent years.

About 70 percent of the money collected from cities for the work goes to the projects and not into the revenue stream for the road department, Doty said.

Road crews will spray chip seal in Redmond through next week. Areas in Bend are expected to have the treatment done during the third week of June.

Deschutes County will also chip seal a 10-mile stretch of Cascade Lakes Highway between Mt. Bachelor and Elk Lake this summer. Nearly $300,000 is being provided by a federal lands program to complete the work.

— Reporter: 541-617-7820, tshorack@bendbulletin.com