Asphalt is not just "black tar and rocks." It is a highly engineered chemical composite, and the specific recipe matters immensely based on your geography.
Understanding Performance Grades (PG)
The liquid asphalt binder holding the rocks together is rated by a PG system. The numbers represent the extreme temperatures the asphalt can survive. For example, PG 64-22 can withstand 64°C (147°F) surface heat and -22°C (-7°F) winter cold.
The Appalachian Upgrade
For steep driveways and commercial lots in the Virginia Highlands, standard mixes are prone to rutting under heavy summer heat. We upgrade to PG 70-22 polymer-modified asphalt. The addition of elastomeric polymers makes the asphalt significantly stiffer in the scorching summer heat (preventing downhill creep and tire ruts) while remaining highly elastic in sub-zero winter temperatures to prevent thermal cracking.