Street Maintenance staff are chip sealing many streets in Greenwood and Crown Hill this month. Chip sealing is a preventative treatment to maintain residential streets so they don’t deteriorate into expensive reconstruction projects.
You’ve got to appreciate the term “chip seal” because it pretty much tells you what’s involved:
- Chips: Rock chips, a.k.a. bits of rock about ¼” wide. The chips become embedded into the pavement surface, protecting the emulsion and providing some additional traction.
- Sealant: an emulsion that seals the pavement to keep out water. It also glues those chips to the street.
Chip sealing has three main steps:
- Emulsion is applied to the street surface.
- A thin layer of rock chips is spread over the emulsion.
- Chips are pressed into the emulsion with a vehicle similar to a steamroller.
Of course not all of those millions of rock chips stick to the emulsion, so loose rocks are inevitably part of the chip seal process.
Because of those loose rock chips, we ask folks to take extra care on these streets – especially cyclists. SDOT sweeps up loose chips, but we still advise that you pay extra attention both before and after we sweep.
Cyclists in particular should also be aware that the street surface will be a bit rougher than usual until the chips get further imbedded into the pavement over the next several weeks.
Handy tip: we only chip seal residential streets, so you can avoid the chip seal streets by simply staying on arterials. Of course that’s not always possible, so here’s a map showing which streets we are chip sealing this year. By August 19, the sealant and chips will be applied to all the streets marked on the map.
For more info on how chip seal works, check out the project website. Questions? Call Project Manager Susan Almachar at 206-684-5303.