For the same reasons as for seal coating, sealing the cracks is a very important tool to extend the life of pavement. Usually, crack sealing is done before each seal coating process to establish a good, clean environment for the finished coating. However, crack sealing is also done between seal coating applications when obvious cracks are apparent.
As with seal coating, the process seals the top of the asphalt preventing water from penetrating the surface of the pavement and protecting the top layer of asphalt from oxidation and wear caused by exposure to the elements.