The primary reason to sealcoat pavement is to protect it from the deteriorating effects of sun and water. Sealcoat combats deterioration by providing a waterproof membrane which not only slows down the oxidation process, but also helps the pavement shed water, preventing it from entering the base. City streets are placed in a scheduled rotation for sealcoating.
The secondary benefit of sealcoating is to increase surface friction. This is accomplished by the additional texture the cover aggregate adds to the pavement. Sealcoats are affected greatly by weather conditions, especially during construction. The ideal conditions for applying a seal coat are a warm, sunny day with low humidity.
Steps in the process
Apply seal coat to ensure the street is prepared by making minor repairs and cleaning the surface.
Spray asphalt cement on the existing pavement surface using an oil distributor.
Apply cover aggregate using a chip spreader.
Roll cover aggregate into the asphalt cement as soon as possible.