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As a code compliance officer for Miami-Dade County, Kenny Everett is the watchdog and teacher for roofing inspectors in 30 municipal building departments. In a conference room at a county office, Everett leaned as far as possible across the table without leaving his chair, jabbing the formica with his forefinger. He was describing sloppy construction practices in the years before Andrew. "Workmanship was down the tubes," he said. "And building inspectors were in the dark, blind to the problems." Roofers routinely ignored important details and fundamentals, Everett said. They even neglected to read installation instructions for construction materials. To illustrate this problem, Everett hurried off to a storeroom and brought back an asphalt shingle. "Instructions on shingle packages always said that roofers should attach each shingle with six nails in high wind areas," he said, jabbing to show their placement. "But roofers used only four nails; it was just the way things were done." Inspectors also didn't read installation instructions, and the local building code did not spell out requirements. "We were in the dark, too," Everett said, shaking his head.

In recent decades, some South Florida contractors—and inspectors paid by taxpayers to regulate them—went far beyond "blindness" to a calculated negligence. Charles Danger, Everett's boss, became director of the Dade County Building Code Compliance Office just months before Andrew struck. Danger is the county's top construction regulator, enforcing proper building practices, materials, and inspections. "Contractors and inspectors were just going through the motions before Andrew," Danger said. "If the code said that you need 45 nails in a section of roof, a contractor could put in 10 nails, and inspectors didn't care, even though a roof could fly away in a hurricane and somebody could get killed." All told, Andrew caused $25-30 billion in damage, killing 28 in Dade County and in Louisiana. "We were extremely lucky that we lost only 28 people," Danger said.

Andrew totally destroyed 63,000 homes and partly damaged another 110,000, making 250,000 people homeless. With roofs damaged or blown off, rain following the hurricane poured inside structures, soaking and collapsing Sheetrock and destroying billions of dollars worth of furniture, carpeting, televisions, and other items. The insurance industry estimates that 25–40% of insured losses were due to slipshod construction practices.

Most homeowners do not give a second thought to their roofs—until they leak or disappear. Yet roofs are the Achilles heel of homes in hurricane-prone areas from Maine to Texas.

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As strong winds strike a building, their flow is diverted, swirling over and around the structure. Think of a mountain stream roaring against a giant boulder, which deflects the current. The stream flow accelerates around the obstacle, resulting in rapids. In the same way, hurricane winds speed up around corners and edges, creating suction that pulls on building materials like a super-powerful vacuum hose. Fierce gusts and suction pressure make a dangerous combination, especially for roofs. They yank off tiles and shingles, first at the roof edge and then along its slope as you'd peel an orange. During Andrew, huge numbers of tiles were stripped from roofs this way, and carried off by high winds, they crashed through windows by tens of thousands.

If you lose a window or door during a hurricane, you're in big trouble. Extreme winds push through an opening in a building, increasing air pressure inside like blowing up a balloon beyond its capacity. If you force enough air pressure inside a house, it can break at its weakest point, usually the roof.

As roofs are being pushed off from within, they are being pried loose from the outside. Peel away tiles or shingles and you'll find a covering of roofing paper, under which is plywood attached to rafters. But a roof won't stand much of a chance in hurricane-force winds if builders haphazardly tie down plywood to rafters—if they use too few nails or miss the rafters altogether with their nail "guns." After Andrew, engineers reported that many contractors had routinely missed their marks. "With the use of automatic nail guns, the workman lost his feel for the nailing process," said Saffir. "The result was that many nails went through the sheathing into thin air, not into the truss or rafter below. This was a common occurrence."

If your plywood sheeting flies away in the wind, you've lost more than just a roof covering. You've also lost a portion of the house's structural integrity. That is, plywood sheets are often the sole lateral bracing for the rafters, actually holding the roof together. So with the plywood gone, the rafters are loosely tethered in the wind.

To compound the problem, many contractors fail to tightly fasten wood gable ends—the flat ends of a pitched roof—to walls. So when a powerful gust hits an unbraced gable, the gable end can be pulled loose at the wall, allowing wind to enter the building. If the roof sheathing is pulled off at the gable end, the rafters can fall over.

During Hurricane Andrew, tens of thousands of homes were damaged due to such failures in roofs.

Alex Major was the owner of a frame house in Country Walk, a development of more than 1,100 homes in unincorporated Dade County. Country Walk gained notoriety because virtually every building there was destroyed or damaged during Andrew due to inferior construction, and later property owners won a class-action suit against the developer. "Devastation was amazing—some houses were totally flattened," said Major, who won a separate lawsuit against the developer. "There were 52 code violations in my house, most of them in the roof." Major's roof gables had not been tightly attached to the frame walls, which had not been tied down to the slab. So when the roof gable was blown off, some of the walls collapsed. Fortunately, Major and his family were not at home during Andrew.

To be sure, jerry-built structures are not unique to South Florida, experts said. "In many coastal areas, the housing industry is almost unregulated, either because counties don't have codes or they lack enforcement," said Tim Reinhold, Clemson University civil engineer. Damage surveys by engineers after Hugo, for example, showed that many roofing materials were poorly attached, causing widespread insured losses. After hurricanes Fran and Bertha hit North Carolina in 1996, engineers found widespread cases of shoddy workmanship in construction.