What causes asphalt to crack?
1) The weight of a vehicle may be too great, or the application of the asphalt was too thin. 2) The substrate was not prepared properly. The substrate is not solid it will give way under what should otherwise be acceptable vehicle weight. 3) Tree Roots or Mushrooms penetrating through the asphalt. (Yes, mushrooms can grow through asphalt pavement!) 4) The effects of expansion and contraction on the asphalt surface. Items 1&2 create what we refer to as “Alligator Cracks” (many cracks in a localized area). Items 3&4 create what we refer to as “Linear Cracks” (long running cracks) Or in the case of Mushrooms, a single nodule.
There are many reasons that explain this. In many cases cracks occur due to movement of the base the asphalt sits on. It is important to ensure that your base is level and solid. When we pave our driveways we typically remove any grass or topsoil and then lay down a level of gravel to produce a solid base thus increasing the durability of the asphalt.There are other uncontrollable factors such as frost, weather conditions, excess weight/heavy traffic, and age of the asphalt (as it ages it becomes more brittle which can lead to cracks).
