What Is Slurry Seal?

A thin layer of asphalt emulsion and fine sands/aggregates applied over the surface of the street. This seal fills in small spaces and fine cracks protecting the street from water damage and improves the ability for cars to grip the roadway.

Why Use Slurry Seal?

Each year between July and September we apply slurry seals to select neighborhood roads throughout Hillsboro. This type of maintenance is applied to roads that are in good condition to keep them in good condition.

Similar to repainting a home to extend the life of its siding, applying a slurry seal extends the life of an asphalt roadway, is quicker to complete than repaving, and saves the City money in the long run.

What Happens After Slurry Seal is Applied?

A slurry seal is different from a traditional repaving project. Remember these four things after the project is complete:

On a hot day, the slurry seal may seem sticky. This is because the oils in the slurry seal soften with heat. Although this occurs on old and new slurry seals, it is more noticeable when the slurry seal is new and the oil is fresh. This will be less noticeable when the weather cools and the oil ages.

You may see some sand or gravel on the roadway. For this reason, the roadway will not look smooth for a while. This is completely normal and happens mostly because vehicle tires dislodge materials not needed for filling voids in the underlying asphalt. It is also more common in areas where cars are turning. These loose particles should be picked up as part of the City’s routine sweeping maintenance.

Scuffing is common in the first few weeks following a slurry seal. This is totally normal and scuffs may reappear during periods of hot weather. Scuffing happens when vehicles turn at slow speeds or when drivers turn the wheels when they are not moving, such as backing out of a driveway. It does not affect the quality of the finished product. To minimize this occurring, drivers can turn the wheel and move slowly rather than turning the wheel while stopped.

The oils from the seal may produce a foam when mixed with rain. This is also normal and is more common when a slurry seal is new.

Advance Notices