One of the most common questions Minneapolis St. Paul homeowners ask us at Richfield Blacktop is how thick the layer of the asphalt on their driveway should be. That’s a natural question, but the answer may surprise you. Unlike with concrete, where thickness means strength and weight-resistance, thicker is not necessarily better when it comes to asphalt paving. Far more important is the thickness and compaction of the underlying sub-base. The asphalt paving itself retains flexibility over time, and serves mainly as a waterproof coating over the sub-base, which is actually what bears the weight. Without a properly constructed sub-base, asphalt driveway can quickly lose its integrity and as a result, cracks and sunken spots may appear.