A city of Kirkland began street maintenance on Aug. 27 on more than 40 sections of neighborhood roads and cul de sacs in the Kingsgate and Rose Hill neighborhoods.

Intermountain Slurry Seal will apply a thin layer of emulsified asphalt, water and fine gravel known as slurry seal.

The four- to six-hour process requires full road-closures on these streets. Any form of interference — foot traffic, automotive traffic or an errant sprinkler system — can undermine the new surface’s integrity.

“Fortunately, our residents care a lot about the condition of their streets and they do what they can to help us take care of their streets,” Kirkland streets engineer George Minassian said in a press release. “The most important thing they do is to remove their cars from the streets we are slurry sealing.”

When it dries after roughly six hours, the slurry seal provides a quarter-inch layer of pavement that seals out weather and moisture and, as a result, extends the functional lives of roads by five to 10 years. Slurry seal also replenishes years of aggregate-loss in the pavement beneath it.

And it does all this at an estimated cost of $3,400 per city block, the release states.

Residents doubled Kirkland’s capacity to preserve their neighborhood roads in 2012 when they approved the streets levy. Since then, Kirkland has used slurry seal to extend the functional lives of more than 126 lane-miles of neighborhood roads, according to the release.

Without slurry seal, traffic and weather would continue to hammer the streets’ asphalt until chunks of pavement begin breaking loose and webs of cracks morphed into potholes that would undermine the road’s basic structure. At that point, the only comprehensive, long-term solution available to those residential roads would be reconstruction, the release states. And reconstruction is prohibitively expensive, costing on average $165,000 per block. These high costs are what have made reconstruction a once-in-a-decade solution in Kirkland.

“This is what makes slurry seal such a great choice for our more proactive strategy of maintaining a network of functioning residential streets,” Minassian said in the release.

For more information on the city’s slurry seal program visit www.kirklandwa.gov/slurryseal.