Failure to maintain a pavement system on a routine basis can erode its lifecycle. Shopping center owners expect their parking lots to last a long time, but most also realize that they have a role in making that happen. The lifecycle of a parking lot generally ranges from 20 to 30 years, according to some experts, who add that within that time frame, there most likely will be at least one complete resurfacing or overlay. Stuckey also emphasizes the importance of the original construction of the lot. How well it is installed, along with the foundation and the specification of materials, play a major role in how long one will last, he says.

“Proper maintenance and sequenced resurfacing can extend lot life beyond 20 years,” says John Stuckey, vice president of property management for The Skinner & Broadbent Co., Indianapolis.

Alan Curtis, president of CHEC Consultants Inc., a Redding, Calif. civil engineering company that specializes in pavements, estimates a lifecycle of 30 to 40 years, with a major rehabilitation of the lot at around 17 to 22 years. “The key to a longer lifecycle is to have a well-built lot with a reasonably good design that is properly maintained through the years.” Curtis works with such shopping center developers as San Diego-based TrizecHahn Centers, Chicago-based Urban Retail Properties Co. and Chattanooga, Tenn. CBL & Associates Properties Inc.

“If there is a problem with the original construction or structure of the lot, it will generally show up in the first four to five years or even sooner,” says Thomas R. Zimmer, principal of Zimmer Consultants Inc., an Oak Brook, Ill. based civil engineering firm that specializes in pavement construction and management. His company works with such shopping center clients as Indianapolis-based Simon DeBartolo Group Inc., Chicago-based General Growth Properties Inc., Atlanta-based ERE Yarmouth and Newton, Mass. based WellsPark Group.

Some of the signs of structural damage, Zimmer says, include depressions in the lot; rutting; and alligatoring, otherwise known as fatigue cracking. Traffic is the primary culprit in these types of problems, which start under the surface and rise to the top.

“Weight [on a pavement] can cause havoc,” adds Lisa Whitney, vice president of property management for West Hartford, Conn. based Konover Management Corp. “As a result developers generally customize their lots to traffic loads in order to avoid some of these problems. High-traffic areas such as truck loading and unloading areas and driving lanes require a thicker asphalt than parking areas do.”

However, traffic load is not the only major cause of parking lot failure. Environment is an equal partner, causing a variety of surface problems. Block cracking, weak edges and water infiltration are all end results of the combination of sunlight and water on a pavement, Zimmer says, adding that these problems start on the surface and work their way to the bottom.

“Water infiltration is the biggest danger,” Whitney adds. “It substantially decreases the lifecycle [of the pavement].” In order to prevent water from entering the system, it is critical that cracks be filled, and edges and drainage be kept in check, she says.

The best way to keep the lot in check and ensure that it remains in tip-top shape is with a planned maintenance program, Curtis says, describing pavement maintenance as taking care of surface problems by crack sealing, filling potholes and seal coating. He distinguishes maintenance from parking lot rehabilitation by saying that pavement maintenance does not add strength back to the pavement system, while rehabilitation work, such as asphalt overlays, does.

Experts emphasize the urgency of sealing cracks and filling potholes in order to prevent further damage. In cold-weather climates, “immediate, temporary repair [should be done] to minimize damage from the winter,” Stuckey adds. Then, once a year, he says, damaged sections should be repaired, or cut and replaced.

Weather does create problems in some cases, but parking lots are usually designed to fit the climate in which they are located. The biggest weather-related concern is freeze/thaw cycles, the experts explain. Pavement problems occur in the lot where water has gotten under the surface, has frozen and then expands. The more freeze/thaw cycles there are, the worse for the lot, Stuckey says.

Regardless of weather conditions, pavement will age. As it ages, the surface of the lot will become rough. Zimmer says this condition, known as raveling, generally happens three to four years after initial construction of the parking lot and every four years after that. When it does occur, he says, it is a good idea to apply a seal coat.

Zimmer estimates that the costs for parking lot preventive maintenance, which includes patching, crack sealing, seal coating and striping, range between 14 cents per sq. ft. to 16 cents per sq. ft. on a four-year preventive maintenance cycle. For more extensive work, in a four-year rehabilitation cycle, he estimates a cost of 60 cents per sq. ft. to 65 cents per sq. ft. for a simple overlay and up to $1 per sq. ft. for a more complex project.

Stuckey, who also talks generally about costs, says his estimates range up to 8 cents per sq. ft. annually to maintain a parking lot in the first eight to 10 years of its life. That cost increases to 12 cents per sq. ft. to 20 cents per sq. ft. after eight to 10 years when the company is beginning to phase in a resurfacing project, he says.

Common-area maintenance charges are expected to cover parking lot maintenance and rehabilitation, Stuckey says, adding that, as a result, overlays and other major repairs oftentimes are phased in.

Additional costs associated with parking lot maintenance come into play depending on who does the work: an in-house staff or an outside contractor.

“Engineering costs generally are 3 percent to 5 percent of the construction cost,” Curtis says, adding that on a project that is expected to cost $100,000, it might make sense to spend $3,000 to $5,000 on a specialist in the field.

There is no fountain of youth for parking lots; time is not on their side. Maintenance is the only hedge owners have against the costly alternative of total parking lot replacement.