Cracks from .2 to .7 inch in width should be sealed with rubberized asphalt. Open cracks allow water to get into the sub base and subgrade. The expansion and contraction of the water breaks up the pavement. Cracks are ideally sealed in moderate temperatures, 30-50 degrees Fahrenheit, to minimize the amount of expansion (thaw) and contraction (freeze) the seal must tolerate. Cracks must be properly cleaned before sealing. Larger cracks should be filled with sand before crack filling and routed as needed.
Seal coating is used to extend the life of performing asphalt and enhance the appearance of the surface. It does so by improving surface drainage and reducing the impact of ultraviolet radiation (oxidation), fuel, and oils. Because the seal coat fills minor voids in the surface, it also helps prevent raveling (the loss of aggregate). Property owners and managers that get on a regular cycle of crack filling, pot holing and seal coating will go a long way to lowering their long term spend on asphalt infrastructure.