Photos by Scon D Taylor 



closet under the stairs in the center of the house. 

 Rogers added three layers of plywood to the 

 walls and ceiling and two layers to the door. He 

 also reinforced the door hinges and latches. 



"During the worst winds of the five most 

 recent hurricanes that hit Wilmington, my family 

 huddled in a central hallway of my home," says 

 Rogers. "Although I never felt that our lives 

 were threatened or that we should have 

 evacuated to another building, it became 

 apparent that the added assurance of a strong 

 room would add peace of mind should we get hit 

 again." 



Wilmington's wind risk from hurricanes 

 is significantly lower than the extreme tornado 

 winds — more than 200 mph — used for 

 national "safe" standards. Thus, Rogers chose 

 a strong room design developed and tested at 

 Clemson. The room has an estimated capacity 

 of about 60 percent of the national standard for 

 safe rooms designed for the worst tornados. 



Rogers emphasizes that no single 

 technique is right for making everyone's home 

 safer during a hurricane. 



"The hurricane resistance of many homes 

 can be substantially improved using a variety of 

 techniques to reduce the chance of structural 

 damage and damage from wind-blown water or 

 flood water," says Rogers. "Each house is 

 different. What matters is finding the weakest 

 components and looking for the most cost- 

 effective priorities for each house." 



The best — and least expensive — way to 

 make a building storm-resistant is to modify it 

 while it is under construction, says Rogers. 



"It is much easier and more reliable to do a 

 brand new house if you want a higher standard 

 for wind resistance than retrofitting an old 

 house," he says. 



Wind-Resistant Materials 



Decades of experience support Rogers' 

 advice. Over the last 27 years, he's surveyed the 

 structural damage from major hurricanes that 

 have hit the East and Gulf coasts. 



He says the key to preventing structural 

 wind damage from hurricanes is connections. 



To prevent structural damage, strengthen 

 each separate connection between the top of the 

 roof and the foundation. It is critical to prevent 

 water from penetrating through exterior siding, 

 roof coverings, wall sheathing, windows, vents 

 and doors. 



"It is not the board that breaks in a 

 hurricane," says Rogers. "It's what holds the 

 boards together — usually a nail or a screw. It's 

 critically important that everything be strongly 

 tied together." 



Likewise, buildings don't simply blow over 

 in the wind, he says. Inadequate connections and 

 the wind's forces of uplift often cause the 

 damage. 



Wind-uplift forces cause airplanes to fly, 

 and the same principle applies to roofs. When a 



high-speed wind blows across a low- to 

 moderately sloped roof, it creates a lift. The roof 

 pulls off when the lift force exceeds the roof s 

 weight plus the capacity of its connections to the 

 walls. Without the roof, the walls collapse. 



Homeowners can counter the problem by 

 working from the top down, making sure the 

 roofing is well-attached to the sheathing, the 

 sheathing to the roof framing, framing to the 

 walls, and the walls to the floors — all the way 

 down to the foundation. 



Rogers advises using metal straps or 

 hurricane clips rather than nails alone to secure 

 the roof. 



"Straps change the direction that nails are 

 pulled and make any nail used 10 times stronger 

 than typical toenailing," he says. "You also need 

 to make sure each connection is tied to something 

 lower. The higher the elevation of the connection 

 in the building generally, the more important it 

 becomes. The lower you go in the building with 

 the connections, the heavier the sum of the parts 

 for the connection." 



One way to strengthen connections between 

 the wall and roof in existing homes is to use a 

 retrofit bracket developed by Clemson researchers 

 Tim Reinhold and Ed Sutt. 



The structural bracket can be installed from 

 the inside of the room without removing 

 sheetrock. Once installed, the system is hidden by 

 molding. 



To install the roof on a new 2,400-square 



14 EARLY SUMMER 2002 



