Improper Drainage

      Drainage is the key to a parking lot's success. Water is the number one cause of pavement failure. Proper drainage is obtained by documenting certain elevations on a given property. For the least amount of ponding water, the elevation throughout the property should have a minimum of a 1% slope. When water "ponds" on a pavement, the asphalt is weakened. When a vehicle passes over the weak spot, the asphalt starts to crack. Soon the crack becomes several cracks, several cracks become potholes, and the area continues to expand and deteriorate.

Poor Subgrade

      A poor subgrade is also a leading cause of pavement failure. A subgrade problem can be seen if mud or soil is coming up through the cracks in the pavement, or there is surface deflection or "waves" in the pavement. Sometimes a subgrade problem can't be seen from the surface, and a sample of the subgrade needs to be taken. Subgrade problems may be fixed with several different methods. Depending on your needs and problem at hand , we may recomend a geotextile fabric , removal of some of the subgrade, drain tile, or several other rehibilitation options.

Oxidation

      The sun's ultra violet rays combined with the oxygen in the air, also contribute to pavement deterioration. You may have noticed a road or parking lot that has a light gray appearance and a lot of loose stone, this is called "oxidation" and "raveling" and is caused mostly by the sunlight and the air. The atmosphere's effect on a parking lot or roadway can be greatly reduced by sealcoating.

Original Design Strength

      One of the most common reasons for an asphalt pavement to fail is poor design. Many failing asphalt pavements tend to lack a sufficiant amount of Hot Mix Asphalt (HMA) and/or stone base. Requirements for design strength can be found in the table below. Note the data represents an average. We can help determine what specifications are right for your individual need.