Managers who rely on their shopping center's maintenance crew to handle routine roofing upkeep may live to regret the decision, says Danny Stokes, vice president of Advanced Roofing Inc., Fort Lauderdale, Fla.

"While the monthly maintenance - such as cleaning the rooftops and gutters - can be done by the center's maintenance crew, a professional crew is trained to spot more pervasive problems," he says.

And he should know. For the past 16 years, Advanced Roofing has done much of its business in the hurricane-prone Caribbean islands and the southern Florida counties of Dade, Broward and Palm Beach, where preventive maintenance is essential to avoid vulnerability in a surprise storm.

When a roof's condition deteriorates, major repairs can be quite expensive, costing some centers up to $5,000 per month, Stokes estimates. Yet, until they can afford to re-roof, some centers will bear this cost. A preventive maintenance program, by contrast, can cost from $2,500 to $5,000 per year. Roofing repairs and maintenance, though not re-roofing, are tax deductible business expenses. By contrast, re-roofing for a 100,000 sq. ft. center can cost an average of $400,000.

Climate often determines preventive maintenance schedules, says Stokes, who explains that in the Florida area, the company's twice-yearly preventive maintenance is usually done before hurricane season, in March or April, and then afterwards, from November to January. For other parts of the country, Stokes suggests preventive maintenance be scheduled before and after the rainy season in temperate climates, or before and after winter in the Northeast and Midwest.

"In the Midwest, there can be significant damage to roofs from ice and from shoveling snow, which can really tear up the roof, so these are problems that should be checked," Stokes says.

A center's own maintenance staff should check the roof monthly, primarily to clean it of trash that may have accumulated, such as bottles or cans, and to keep gutters clean, advises Rob Kornahrens, Advanced Roofing's president.

Then, twice yearly, a qualified roofing contractor should service the center with a formal preventive maintenance program that would spot and repair leaks and water damage. This would include caulking and sealing leaks around projections such as pipes, electrical conduits, air conditioning units, exhaust fans, soil stacks, roof drains and the stands that hold mechanical equipment.

"Objects that come through the roof are constantly moving, as there is expansion and contraction of the deck under the roofing," says Stokes. "This deck, usually made of metal, concrete or wood, is always moving, and the caulking or sealant around some of the more stationary items, like pipes, gets broken away and needs repair."

"The roofs on centers have 2- to 4-foot-high parapet walls around their edge. In the front of the center, the parapet wall might be as high as 8 to 15 feet, creating a facade. We put base flashings on the vertical parapet walls at the angle where they intersect with the horizontal roof," he says.

Flashings are made of the roofing material and are often further protected by counter flashings of metal (such as copper, galvanized metal, stainless steel or aluminum). Ninety percent of roofing leaks occur at the flashings, Stokes says.

Detecting moisture damage is also an important part of a preventive maintenance program. One of the most advanced ways to accomplish this is through infrared technology, which utilizes an infrared camera that takes the equivalent of an X-ray of the roof. Areas that have moisture will appear as bright red or pink in this X-ray. The technology works by detecting areas that have retained heat - a symptom that moisture has penetrated into those areas, since objects retain heat longer when they're wet.

"Often, detecting these areas allows us to stop problems before they become widespread," Stokes says.

Infrared moisture surveys are recommended for insulated roofs that are five to 10 years old, Stokes says, adding, "We have these surveys included in our maintenance programs for certain customers."

Kornahrens emphasizes that it is often important to go the extra step of upgrading minimum building code standards. "We always make the customer aware that sometimes these rules are not good enough," particularly for withstanding hurricanes and other severe weather conditions, he says. Extra precautions might range from applying more asphalt than required or using more fasteners, as Advanced Roofing does in its work as exclusive contractor for Publix, Florida's largest supermarket chain.

How does a shopping center owner or manager know when repairs and even preventive maintenance are not enough, and it is time to re-roof? One measure is to keep track of how much the center might be spending to repair leaks. "At some point, the membranes of the roof become too brittle to take sealant and caulking," Stokes notes. Widespread moisture problems could be another indication that re-roofing is indicated.

In selecting a roofing maintenance provider, Kornahrens recommends that center owners and managers investigate a contractor's history and reputation, review their industry experience and familiarity in applying a particular roofing system, and ask for a resume of completed projects similar in size and complexity to the one being considered.

Since the roofing industry represents more than 70% of all construction litigation, careful checks of contractors make sense. A good roofing contractor will also understand the nature of a center's business, pacing the work so that the occupied building is not left exposed to the elements.

With today's improved roofing systems (synthetic systems offer 10- to 20-year warranties) and technology that can detect moisture before it does significant damage, shopping centers should be able to keep the same roof over their heads for many years to come.

"There was a time when no one went up on the roof unless there was a leak," Stokes says. "Now developers are becoming aware of how cost-efficient a preventive maintenance program for their roofs can be."