SDOT street maintenance crews are in the thick of crack seal season. Crack sealing is exactly what it sounds like – filling cracks on city streets. Each summer SDOT crews help keep our streets in good condition by filling cracks in our arterial streets with a flexible sealant.
Cracks allow water to penetrate into the pavement. When the water freezes, it expands and creates potholes and other damage. By keeping out that water, crack sealing extends the life of our streets. It’s a classic case of preventive maintenance, where we invest a relatively small of money today to save a lot of money in the future.
Let’s take a look at the actual process. In the first step, crews clean the pavement so the sealant can stick to the sides of the cracks and create a tight seal. We sweep the street to remove dirt and debris, then we bring out the hot air lance which incinerates and removes material inside the cracks.
Here’s a short video of an SDOT crew working to seal cracks along 35th Ave NE near NE 125th Street, in north Seattle:
The second and final step is the actual sealing of the cracks. A crewmember applies the hot sealant to the cracks using a crack seal wand. Another member of team immediately smooths the material with a squeegee, then a third team member sprays a solution to prevent the sealant from sticking to tires. The solution allows vehicles to drive over the newly sealed street immediately, so vehicles can travel on a street just minutes after the crack seal process is complete.
Before (upper left) and after crew repairs (bottom)
SDOT has a substantial crack seal program in 2015. We will fill cracks on ten sections of arterials throughout the City. If you add up all the cracks SDOT will fill this summer, they would stretch over 51 miles – about as far as downtown Seattle to Snoqualmie Pass.