Wind. Rain. Lightning. Salt water. Humidity. They're the bane of every custom builder who tries to construct a durable, watertight home on an idyllic piece of coastline. After the devastating hurricane seasons of 2004 and 2005, coastal builders are taking a closer look at their techniques, processes and materials.

Dan Buffington of Buffington Homes in Seabrook Island, S.C., has built many island homes off the South Carolina coast. Buffington says many people are surprised to learn that Charleston, S.C., is in an earthquake zone as well as a hurricane zone. "We're right behind Southern California in earthquake risk and have quakes on a continuing basis," Buffington says. "Most are too small to detect without a seismograph, but we had one recently that was kind of a shaker."

Elevated on pilings, this Florida home made it through Hurricane Ivan in 2004 Photo: Federal Emergency Management Agency/Mark Wolfe

That's why a custom builder's construction techniques and materials become even more critical.

To anchor a house and keep the roof from being torn off in a storm, Buffington's crew drives screws, bolts and other fasteners into the footings and extends them all the way up to the roof. Strapping is also used to tie each floor together, says Buffington project manager Charles Arnold: "Wherever there is a joint in the house, we'll strap it together every 2 feet on center just to give it that little bit of extra strength."

Buffington uses wood shear walls and hold-down brackets. Wherever there's a large amount of glass, such as a wall of windows, he'll build what he calls a wind frame: steel columns and beams that run between and along the headers of windows and doors, taking the place of a solid wall.

For greater stability from the ground up, he drives pilings 40 feet deep, cuts them off at grade level and builds a foundation on top of the pilings. Even if heavy wave action causes erosion around the footings, the pilings will keep the house upright, he says.

Plywood sheathing covers the exterior, nailed every 2 inches around the perimeter and 4 inches along the interior stud. The plywood is also glued to the studs for additional holding power.

Although FEMA recommends storm shutters, in Buffington's experience, impact-resistant windows are superior to impact-rated shutters. "If a hurricane is coming, the last thing you want to worry about is making sure the shutters have been drawn and bolted and latched properly." Besides, he notes, impact-resistant window systems are much better than they were a few years ago, when the glass would remain intact but the entire unit would be blown out of its opening.

Brackets, known as wind clips, were used to help protect a coastal home in Gulf Breeze, Fla., against hurricane-force winds and storm surge.  Photo: Federal Emergency Management Agency/Mark Wolfe

Houses are wrapped in 30-pound felt paper rather than housewrap, because the latter material has such a high permeability rating that moisture can travel in and out very quickly. "It's a very effective building wrap in northern or drier climates, but not in the Southeast along the coast, where dewpoints and humidity are very high," he says.

Matt Pappas of Brandywine Developers in Avalon, N.J., builds concrete block foundations to raise houses above the base flood elevation (BFE), which is either 10 or 11 feet depending on a structure's proximity to the beach. The Avalon Township code allows builders to elevate a foot higher than the BFE, "so all of our mechanicals in the crawlspace are within that foot of freeboard," Pappas says. "This ensures that pipes, ductwork and insulation are above the BFE."

Like Buffington, Pappas favors 30-pound felt paper over housewrap, and he doesn't skimp on window and door flashing, roofing underlayment and moisture protection for sidewalls.

Builder Mike Walker of Michael K. Walker & Associates in Sarasota, Fla., has developed his own techniques "to try to keep the water on the wet side of the wall, so to speak. We completely waterproof all masonry window openings, then turn it outside about 4 inches, apply the wood box, install the window, then go back and re-detail it again."

Walker says building sealants and moisture barriers have come a long way in the last five years. In particular, peel-and-stick materials for doors and windows are much more user-friendly and effective.

Also worth considering for coastal homes are spray-on moisture barriers, which are relatively new.

"Fluid-applied products, as opposed to moisture barriers like housewrap that are put up with staples, become part of the substrate, so there's no risk of tearing or the wind blowing them off," says Lisa Petsko, product manager for Atlanta-based Sto Corp., maker of Sto-Guard and other spray-on products. (Other companies, including Grace and a number of EIFS manufacturers, also offer these products.) Once the exterior cladding is applied, Petsko says, a spray-on barrier does a better job of keeping wind-blown moisture out of the wall cavity. While more commercial builders are using spray-on barriers, home builders have been slower to adopt them, likely because of the higher cost, she says. However, Sto's view is that quality-conscious builders — with equally quality-conscious clients — will find the additional expense justifiable; the company has begun to market more aggressively to custom builders.

Construction was about half-finished on a demonstration house in Baton Rouge, La., when Hurricane Katrina pummeled the city. But the house survived. Now builders tour the completed home every week to view examples of building materials and techniques that can withstand nature's worst.

Arch Wood Protection of Smyrna, Ga., provided several types of treated wood for the Louisiana House (LaHouse), an educational venture organized by the Louisiana State University Agricultural Center. LaHouse showcases three different foundation types: a raised-floor system, a slab-on-fill system and a piling system. "All of them bring the first floor up to a minimum of 3 feet above the historic high-water line for floods or tidal surge," says Scott Hoffman, business manager, interior protection for Arch, "but most coastal builders aren't taking the chance that 3 feet's going to be enough; they're going 10, 12 feet up."

Treated wood was used during the construction of the first floor to prevent decay, termite infestation and exposure to water. The preserved wood decking is highly resistant to termites and fungal decay and has a built-in water repellent.

Since water from a storm surge can float a home off its foundation if it isn't built properly, LaHouse has flood control vents that allow water to flow through the home, keeping the structure anchored to its foundation and letting the water drain when the storm subsides. Different types of hardware were used to help hold the home together through high-impact, Cat-5 storms.

Thanks to mold-resistant framing, "Even if the wood gets wet due to a storm or something as simple as a bathtub leak, once it dries out it will still be mold-free," Hoffman says.

Vapor barriers were reversed in the home's heated and air-conditioned crawlspaces because research has shown that the traditional way of applying vapor barriers in coastal areas may actually be detrimental to the effectiveness of insulation and the resistance of a structure to mold.

In March 2007, Royal Concrete Concepts of Tampa, Fla., became the first manufacturer of single-family homes to earn the Fortified ... for safer living designation from the Institute for Business and Home Safety. The Fortified program specifies construction and design guidelines to increase a home's resistance to disasters such as hurricane winds, wildfires and flooding. To meet or exceed the High Velocity Wind Zone requirements of the Florida Building Code, it's using patented, steel-reinforced concrete modules.

The idea for the modular homes originated with Wally Sanger — who patented the Royal Wall system, a combination of concrete, polystyrene and reinforced steel — in 1989. In 1997, Sanger found a way to integrate the floor, walls and roof into a single structure, and launched RCC. Until recently most of the company's business came from educational facilities, but interest from the residential sector is growing, says John Albert, director of business and project development.

Due to spikes in concrete and steel prices, an RCC home costs a little more than stick-built, but "we're probably neck and neck with block, which consumes a huge portion of concrete construction in the state," Albert says. Custom builders tend to prefer the Royall Wall System because it allows more design flexibility than the modulars while still offering durability and sound insulation.

RCC claims its homes can withstand up to 186 mph winds because of the home's engineering. Six-inch-thick walls are built on tilting tables and individually joined. Then concrete is poured into a frame to create an 8-inch-thick ribbed floor. After the roof structure is set in place, concrete is poured to form the roof. There's little likelihood of uplift even when hurricane-force winds batter the roof, says Albert.

Tarpon Coast Builders of Venice, Fla., also has earned the Fortified ... for safer living designation for its homes. Tarpon Coast exceeds state code as well as the most stringent code for the barrier islands and the Florida Keys.

The company typically builds a mono-pad foundation (pouring the pad and footer together, then reinforcing the footer). The only utilities run through the slab are drains, says Tarpon Coast President Mike Romig.

Tarpon Coast uses precast concrete walls guaranteed to test a minimum 5,000 pounds per square inch compared to a typical foundation slab, which is poured using 3,000 to 3,200 psi concrete. The walls have been large-projectile wind-tested to 235 mph. At 5,000 psi, concrete is impermeable, so once the wall system goes up, even if left unpainted, no water will penetrate — and therefore, mold won't grow. For additional strength, the wall system is expansion-bolted to the foundation.

Roof truss systems are engineered to 150 mph — the maximum wind zone in the state — and sheathed in 5/8-inch plywood that is both ring-shank-nailed and glued. The roof itself is strapped to the wall system with hurricane ties.

"Over the plywood we do a complete secondary moisture barrier, which is basically a peel-and-stick membrane," says Romig. "It's not only adhesive but also a sealant. We use Miami-Dade rated shingles over that, and when you put nails through the moisture barrier, it actually locks around the nail and seals that, too."

Homes are fitted with Miami-Dade pressure-rated windows, doors and shutters. Windows have double-pane, Low-E glass.

Romig says his building techniques and materials have evolved significantly over the last three years. For example, he has started sealing attics with open-cell foam on the underside of the roof deck, eliminating soffit vents and ridge vents. "When we had hurricanes come through here a couple of years ago, one of the big problems was rain being blown into the attic insulation and creating a mold environment. The only way to prevent that is to seal the attic and include it in the conditioned space."

Roof shingles rated for 150 mph winds are standard, and Tarpon Coast offers metal roofing as an upgrade. The metal roof has been a hard sell, Romig admits, because it means the home buyer has to spend an extra $10,000 to $12,000.

Tile roofs are definitely not an option: "There's a big demand for tile roofs because they look nice, but you're going to have a high degree of flying debris damage in any major storm."

Romig stresses that his construction techniques are not unique. "Everything we do is available in the market," he says. "It's just that no one else is using the particular combination of technologies we use, probably because it costs a little more."

No portion of the Eastern Seaboard and Gulf Coast is safe from hurricanes, yet these areas aren't the windiest in the United States, as the map shows. Source: Federal Emergency Management Agency