Crack routing is the act of machine routing cracks to a uniform width and depth before sealant is poured into the cracks. Routing machines cut a 1.5 x 2 cm channel into the crack of the pavement. It is cleaned then sealed.
These cuts allow a more uniform application of sealer however they are not always reccomended.As soon as cracks are noticed and larger than 3 mm in width they should be sealed. As far as time of the year goes, cracks should be sealed before the rainy weather hits. The idea is to keep water from penetrating into your sub grade layer of your asphalt.
Most cracks are completely sealed after a single application of crack sealer, however some may require a second application of sealer should product settling occur.
