Why do we chip seal?

“It’s not uncommon for our customers to ask us why we’re chip sealing their ‘perfectly good road’ because there is ‘nothing wrong with it,’” said Deschutes County Road Department Director Chris Doty. “But that’s the point – to treat the roads early so we can keep them in good condition.”

Chip sealing is a process where liquid asphalt is applied to seal the road. Then, a layer of chipped rock coated with asphalt is applied to protect the seal and help improve driver traction. Once it is applied, the chip seal protects the road from becoming brittle and losing its ability to bend and flex.

“We all know that weather in Central Oregon is extreme,” said Doty. “It’s not uncommon to experience a temperature swing of up to 120 degrees in the span of a few months. That constant freeze-thaw cycle is tough on our roads.”

By chip sealing, the county is able to extend the life of our roads in the most affordable way. Chip sealing costs about $25,000 per mile of treated road compared to a traditional 3” overlay of new asphalt that runs more than $200,000 for that same mile.

Each summer, we chip seal about 90 miles of county road, which is about 13% of the paved county road network. In fact, the Road Department schedules chip seal work every work day between Memorial Day and Labor Day weekends.

When chip seal is applied at the right time in the life cycle of pavement, it can double the lifespan of the original asphalt and extend the time between pavement overlay treatments from 15 to 30 years.

Have questions? Feel free to give us a call at 541-388-6581.