Q: We will be closing on a building within a month. It has a parking lot that is beginning to show its age, probably about 20 years old. What sort of preventative maintenance is appropriate for parking lots?

A: The average life of a parking lot is generally from 20 to 30 years, but that depends greatly on its overall maintenance during its lifetime. You did not mention the present condition of your parking lot, but it is common that a parking lot undergoes a major renovation that includes an overlay or complete resurfacing after 17 to 20 years, so yours is probably due.

The original construction of the lot (the quality of the installation, materials, foundation, and drainage), and its continuing maintenance are the major factors influencing its eventual life. If there are problems with the original construction, they will generally show up early in the form of fatigue cracking, depressions or rutting. The original design should take into account high traffic or areas that might bear extra weight, such as loading zones. The environment also causes parking lot failure, particularly water infiltration. Sunlight, water infiltration, and a freezing/thawing cycle all contribute to parking lot failure.

A planned maintenance program is the best way to ensure that your parking lot reaches its peak lifespan. This includes regular sweeping (sand on parking lots works just like sandpaper on wood), crack sealing, filling potholes and seal coating. There should be urgency in sealing cracks and filling potholes. The longer they are unrepaired, the more extensive damage as water infiltrates. Winter repair may be temporary, but it should be done quickly. If necessary, a more permanent repair of cutting and replacing should be done in the spring.

Pavement will age regardless of how it was installed. Within three to four years a parking lot begins to “ravel”, which means the surface is getting rougher. This is the time to seal-coat, and we recommend seal-coating no less than once every four years. This is the time to fill any cracks, which are disastrous to the long-term life of a parking lot because they allow water intrusion into the pavement, as well as any potholes. And obviously, re-striping will be necessary after a complete seal-coating.

There is no magic available to indefinitely extend the life of a parking lot. But with a planned maintenance program, you can extract the maximum life out of your parking lot, probably avoiding a costly total parking lot replacement by at least 10 years. This is truly one of those cases in life where spending a relatively small amount of money upfront will substantially reduce your overall cost.