6 Types of Asphalt Cracks: Causes and Solutions

Asphalt cracks are more than just unsightly—they can be hazardous and lead to further damage. While asphalt is a durable material, time and wear can cause even the best-installed surfaces to crack. Understanding the different types of cracks, how they form, and, most importantly, their causes can help you determine the best path to repair.

1. Edge Cracking

Edge cracks on asphalt are longitudinal and located near the edges of the pavement. They are caused by the underlying material “settling,” by soil drying, or a lack of lateral support. Trees and shrubs planted nearby can trigger these issues, with the roots lifting the edges of the asphalt. Improper drainage is another possible factor.

2. Reflection Cracking

Reflection cracks occur when an asphalt overlay is improperly installed over existing cracked or jointed pavement. The movement of the underlying pavement causes cracks to reflect up to the surface layer. When reflection cracks occur, it’s best to tear up and replace the asphalt—this requires help from a local asphalt repair company.

3. Slippage Cracking

Slippage cracks are crescent-shaped. There are several potential causes for slippage cracks: water or dirt between layers; poor bonding between the surface layer and underlying material; or an inadequate asphalt mix. 

4. Fatigue Cracking

Sometimes known as “alligator cracking,” these cracks resemble the skin pattern of an alligator or crocodile. Alligator cracks occur because of repetitive heavy loads and asphalt layers that are too thin to accommodate the weight. Usually, you will need to tear out the old, thin asphalt and replace it with thicker, sturdier layers. If you are in need of a full replacement, note that the cost to install an asphalt driveway averages $5,248.

5. Transverse Cracking

Transverse cracks run roughly perpendicular to the centerline of the pavement. These cracks can be caused by low-temperature thermal cracking or a hard asphalt grade unsuitable for the climate you live in. While transverse cracks are not often due to heavy loads, pressure and weight can exacerbate them.

6. Block Cracking

If you notice giant rectangles or squares in your pavement, you have block cracks. These cracks can occur from a lack of moisture or extreme hot-cold temperature cycles, which causes the asphalt binder to contract or expand too slowly or quickly. If the cracks are small, they can usually be sealed; more severe block cracking will require overlay replacement.