What Causes Potholes in Virginia Driveways and Parking Lots?

Potholes seem to appear overnight, but they are the end result of a slow, predictable process. Once you understand how they form, it becomes clear why crack filling and sealcoating matter so much in the New River Valley.

Step 1: Water Gets In

It always starts with water. Through cracks, faded surfaces, or poor drainage, water works its way past the asphalt surface and into the base layers beneath. A sealed, well-maintained surface keeps water out; a cracked or worn one lets it in.

Step 2: Freeze, Thaw, Repeat

This is the Virginia winter problem in a nutshell. Water trapped under the surface freezes and expands, pushing the asphalt up and apart. When it thaws, it leaves a gap and weakens the base. Our region runs through this cycle many times each winter, and each round does a little more damage.

Step 3: Traffic Breaks It Open

Once the base is weakened and the surface is undermined, the weight of vehicles does the rest. The unsupported asphalt cracks, caves in, and pieces break loose — leaving the hole we recognize as a pothole. From there it only grows as more water and traffic hit the exposed edges.

Common Contributing Factors

• Unsealed cracks that let water reach the base.
• Faded, porous surfaces that have lost their protective sealcoat.
• Poor drainage and standing water.
• Heavy or constant traffic on a weakened surface.
• Aging asphalt that has become brittle over the years.

How to Prevent Potholes

Prevention is far cheaper than repair. Fill cracks as soon as they appear, sealcoat every 2 to 3 years, keep water draining away from the surface, and address small repairs promptly. For surfaces that already have potholes, prompt patching stops the damage from spreading to the surrounding asphalt.