Parking lot Crack Sealing which is one of the most important maintenance events for asphalt parking lots and all pavement surfaces. Hot rubber or liquefied rubber is used to seal the cracks in the pavement and prevents and slows water from destroying the stone base and sub base of your parking lot or roadway. The goal is to seal the cracks so that the water runs off the pavement and does not erode the base or foundation of pavement.