Slurry Seal


These photos depict a street one day after a contractor applied slurry seal to it. As illustrated, streets are typically rough and gritty following application. But the street's new surface will smooth out with time, traffic, weather and three street sweepings, occurring one week, three weeks and three months after initial application.

Kirkland extends the optimal life of neighborhood streets every year by applying a slurry seal to their surfaces.

This quarter-inch layer of water, aggregate and emulsified asphalt--oil--shields the pavement beneath it from weather and replenishes that pavement with new aggregate. 

These functions can extend roads’ good conditions for five to 10 years. And all it costs—in 2023—is $4,900 per city block, compared to the $68,000 per city block it costs to repave a road or the $229,000 per block it costs to rebuild a road.

The cost-effectiveness of slurry seal is why thousands of municipalities throughout the nation use it and why the City of Kirkland has used it in each of its 13 neighborhoods since 2002.  

These benefits, however, can be hard to see in the first few weeks after the streets first receive slurry seal. Initially, the surface is gritty, when it was once smooth. This initial grit is normal. But it is not permanent. 

The first phase of your street’s return to smoothness is the street sweeping, which removes all of the loose gravel. This occurs approximately one week, three weeks and three months after work crews laid down the slurry seal. The second phase of that transition is more subtle. And its main ingredients are time and use. 

Over time, automobile traffic will dislodge the larger, sharper pieces of aggregate that initially give the road its rough, gritty surface. Traffic will also push the remaining aggregate deeper into the surface, replenishing the pavement beneath with a new source of aggregate.  

Within a year or so, the smooth road residents remember before slurry seal will be back—with an extra five to 10 years of high-quality life infused into it.

2012 Streets Levy

The 2012 Streets Levy is doubling the number of lane miles the City of Kirkland can slurry seal each year. Kirkland has a goal of treating every residential street in the City with slurry seal by the year 2032.