All contractors have encountered the client who was unhappy with the finished job because he and the contractor weren't on the same page when discussing the actual work. This happens less often in pavement marking or sealcoating, but it can easily happen when contractors begin bidding pothole repair work. That's because repairing a pothole is somewhat of an inexact science. Factors to be considered include not only the client's budget but the size of the defect, the need to get the pothole repaired quickly, the quality of the surrounding pavement, and the expectation of how long the repair is going to last.

But make no mistake about it: Pothole repair is a staple of many pavement maintenance contractors' services. Pothole repair is a great way to introduce your firm to new customers, gives you an opportunity to showcase yourself by performing well on a small job, gives you an "in" to return, and in many cases enables you to sell future pavement restoration work right on the spot. Plus, pothole repair can help you keep your crew busy and keep some cash flowing throughout the slow winter months and give you early season work to do in the spring when weather is not conducive to other types of projects.

In fact, research conducted for the Federal Highway Administration (FHWA) has determined that even though potholes need to be repaired during the winter, "better climatic conditions increase the life expectancy for patches placed in the spring."

"The goal of spring patching operations should be to place patches that last as long as the surrounding pavement," according to FHWA's Materials and Procedures for Repair of Potholes in Asphalt Surfaced Pavements. "Patches surviving as long as the surrounding pavement reduce the cost of the overall operation by reducing the amount of labor, equipment, and material needed."

Anatomy of a pothole

Potholes result when the pavement or the base or subbase beneath it cannot support the weight of the traffic. This is true whether the pavement is a parking lot or a roadway. And while traffic always has an impact on a weakened pavement, the main culprit in creating potholes is moisture. Any time there are cracks in the surface, moisture has access to the subbase.

As the material beneath the pavement becomes moist, it loses its strength and can shift when traffic drives over the surface. This weakening of wet material beneath the surface has a greater impact as temperatures drop because the wet material expands when it freezes, pushing the pavement surface up, then thawing and contracting when the temperature rises.

After enough of these freeze-thaw cycles occur a gap is created between the asphalt pavement and the base, and traffic driving over the surface breaks the pavement into the depression, creating the beginnings of a pothole. The longer this pothole is left untreated, the more extensive is damage to the surrounding pavement and the faster the overall pavement deteriorates. So it is cost-effective to repair potholes as soon as they occur.

While potholes are probably unavoidable it's important to realize that potholes can be minimized through proper pavement design and proper pavement construction. A regular maintenance program that involves crack repair and repair of other defects, sealcoating, and timely overlays, can help hold the number of potholes to a minimum.

Select appropriate repair

Over the years the paving and pavement maintenance industry has developed a number of methods to repair potholes, and matching the method to the client's expectations is essential, whether the client is a property manager or a municipality.

"It's important to recognize the difference between a pothole patch and restoration. The important thing is to make a distinction between pothole repair, which is temporary, and restoration, which is permanent," says Michael Groh, president of Pavement Consulting Inc. "Frequently the client just needs to get it fixed and the quickest way is to throw some mix in the hole."