UV ray damage and water penetration are primary reasons why you should seal your asphalt parking lot. UV rays react with asphalt binder and cause it to break down and be washed away exposing the remaining sand and stones. Over time sand will also be washed away leaving space for water to enter. As water freezes it expands and this leads to cracks, dips, and pot holes.
Sealing your asphalt prevents oil, gasoline, and other fluid spill/leak damage as well as prevents asphalt breakdown, potholes, and water penetration.
Not Sealed Vs. Sealed