Low-cost slurry coating gives residential streets a second life

It sounds like a new way to make chocolate-dipped ice cream cones.

But slurry coating is actually Spokane County’s latest method to fix residential streets for a fraction of the cost and in a fraction of the time it would take to repave them.

Fairwood Neighborhood residents, north of Spokane, are this week experiencing slurry coating firsthand.

By the end of the week, the streets there will look like new. Cracks, pits and bumps will be gone, replaced with a smooth black coating.

“It’s not brand-new, but it’s hard to tell the difference when it’s down,” said Spokane County engineer Ross Kelley.

The process involves applying a thin coating of emulsified asphalt mixed with a latex compound.

Crews on Tuesday closed one side of many of the streets in the subdivision and some cul-de-sacs, but the process was a lot less painful for residents than a full-scale repaving project would have been.

The Fairwood Crest and Brentwood neighborhoods will get the same treatment in the coming days and weeks.

“The inconvenience to rebuild these roads would be a lot longer,” said Spokane County pavement engineer Howard Hamby.

Repaving the streets in Fairwood and the other subdivisions would have meant months of torn-up pavement, dust and noise.

Slurry coating takes just a few days.

And while repaving the subdivisions would have cost the county close to $1 million, the slurry coating tab is expected to be about $200,000.

Residents can’t drive on the pavement when the coating is wet, and they are advised to keep pets and children inside during the process. It takes about four to six hours to dry.

Bend an ear toward the ground and you can hear the coating harden as it crackles and wheezes like a piece of bacon in a frying pan.

Using this technique is especially good for older neighborhoods where sewers were installed when the homes were built, Kelley said. Those roads have remained largely untouched over the years, even as other subdivision streets have been totally rebuilt when sewer lines were installed.

The slurry coating repair process is a little more complicated than just applying the coating. Crews must first seal any cracks and repair curbs damaged over the years by utility work.

The streets also have to be swept before the slurry coating.

In the case of Fairwood, major chip-seal repairs were performed to resurface the road a couple of years ago, but other neighborhood streets will be fixed this year with just the slurry coating.

In the coming years, Camelot, Gleneden, Northwood and Shenandoah Forest subdivision streets will be repaired using the slurry coating process.