Potholes Forming: Why They Happen and Who Should Fix Them

How a pothole is born

Almost every pothole starts as a crack. Water finds the crack, runs down through it, and softens the gravel base. Traffic then pumps that wet base with every axle that passes. The asphalt above loses support, breaks into pieces, and those pieces get kicked out by tires. What is left is a hole.

Freeze-thaw speeds all of it up. Trapped water expands when it freezes and lifts the broken pieces loose. When it thaws, the pieces are no longer locked together. One plow pass or one loaded truck is enough to pop them out. That is why potholes seem to appear overnight in April when they were not there in March.

Size is deceiving. What you see on the surface is the small end of the damage. The failed area below the pavement is almost always wider than the hole, which is why a proper repair looks bigger than the pothole did.

Why our elevation makes it worse

Between 5,300 and 6,900 feet we cycle above and below freezing far more often than lower country does. It is not one long freeze. It is hundreds of small ones, sometimes several in a single day in spring and fall. Each cycle works the pavement a little more.

Snow load and snowmelt add to it. Four hundred inches at Donner Summit has to go somewhere when it melts, and a lot of it goes into pavement joints and edges. Pavement that drains well will survive it. Pavement with a low spot or a plugged culvert nearby will not.

Sealcoating does not fix potholes

We want to be clear about this because it comes up on almost every call. Sealer is a wear coat for sound asphalt. Filling a hole with sealer does nothing. Filling it with crack sealant does nothing either, because rubberized sealant is designed to move with a narrow joint, not to carry a wheel load across an open bowl.

A pothole needs the failed material cut out, the hole squared up, the base compacted, and new asphalt placed and rolled. That is patching, and patching is paving work. Robert E. Sutton Co. does not pave, patch, or overlay. If someone tells you they can seal a pothole away, get a second opinion.

What to do next

Get the hole handled by a paving contractor before winter if you can. An open pothole is a water funnel straight into your base. Every storm makes the failure area larger, and a small patch is always cheaper than a large one. Potholes are also a trip and vehicle damage issue on any lot the public uses.

Then get the rest of the surface on a maintenance program so you are not doing this again in three years. Crack sealing the surrounding pavement and keeping sealer on it is what stops the next pothole from forming. Call (530) 587-4161 and we will look at it and tell you honestly what is maintenance and what is repair.

Pay attention to the spots where potholes keep coming back. Repeat failure in one location is a drainage message, not bad luck. Find what is putting water into that spot and deal with it, or you will pay for the same square yard every few years.

Quick answers

More in the pavement guides and the FAQ, or see every pavement problem we get asked about.