foot home at Carolina Beach, builder Michael 

 Hogan glued down the roof, screwed it, and then 

 used self-adhering tape on the roof deck seams 

 for a secondary water barrier. 



"It cost about $500 extra to do this," says 

 Hogan. "It makes the roof a lot stronger." 



Below the roof, windows and doors are 

 also important to maintaining the integrity of the 

 building envelope — they need to be strong and 

 well attached. French and sliding-glass doors — 

 with wide spans and poor connections in the 

 middle — can be vulnerable to strong wind. And 

 large picture windows are often not strong 

 enough to survive fierce storms. 



Another troublesome spot is the garage. 



It is important to use garage doors with 

 extra bracing and heavier tracks designed for 

 high wind resistance. "The garage is one of the 

 weakest points in the house for lateral wind 

 forces," says Rogers. "The consequences of a 

 door failure can be even more of a structural 

 threat than a loss of a window elsewhere in the 

 house." 



Last summer, Clemson researchers used 

 everything from high-tech crowbars to a huge 

 crane to "test to destruction" houses that were 

 outfitted with hurricane-resistant retrofits. They 

 first tested houses as they were built without any 

 hurricane-resistant features and then retrofitted 

 the houses with hurricane-resistant features. 



The homes in Horry County, S.C., all had 

 been damaged by floods in Hurricane Floyd and 



were slated for destruction. South Carolina and 

 North Carolina Sea Grant programs were 

 involved in the project. 



Retrofits for connecting the sheathing to 

 the roof framing made a "significant improve- 

 ment in the roof connection uplift performance," 

 says Reinhold. 



However, there were a few surprises. 

 In two cases, the rafters split before the roof 

 connection failed, according to a report. "This is 

 an indicator that building code standards have 

 been improving, with lessons learned from 

 building performance in previous storms," 

 he adds. 



The researchers also tested the homes' 

 resistance to flying debris by shooting wooden 

 two-by-fours from an air cannon. 



Flood Damage 



Buildings most often are destroyed by 

 waves and erosion that accompany storm- 

 induced floods. Erosion causes structures to 

 collapse, and the power of even small waves can 

 pound a home into pieces. Research has shown 

 that a 1 .5-foot or higher breaking wave can 

 easily destroy a well-built house designed for 

 120-mph winds, Rogers says. 



The remedies are an open piling founda- 

 tion and a high floor elevation. Piling founda- 

 tions on oceanfront homes must extend to at 

 least 5 feet below sea level so that waves can go 

 through them unimpeded. 



North Carolina has the second-oldest 

 hurricane construction codes in the country, 

 first implemented in the 1960s and improved 

 over time. 



The first test of the latest foundation 

 standards came with Hurricane Fran in 1996, 

 which brought storm surges up to 1 1 feet and 

 coastal winds of more than 100 mph. 



Of the 205 new Topsail Island structures 

 built after the piling foundation standards set in 

 1986, 200 buildings survived — while 180 

 oceanfront buildings on the island that were built 

 on shallower pilings were destroyed by erosion, 

 Rogers notes. It is suspected that the five newer 

 buildings lost were not in compliance with the 

 1986 code. 



At Carolina Beach, oceanfront structures are 

 required to have 26-foot pilings — 16 feet in the 

 ground and 10 feet out of the ground. Waterfront 

 structures require 20-foot pilings — 10 feet in the 

 ground and 10 feet out of the ground. 



To go beyond code and make a stronger 

 foundation, Hogan installed the pilings six feet 

 deeper than required — to 16 feet in the ground 

 — in one waterfront home. 



"It costs about $10 a foot for piling 

 installation," says Hogan. 



Existing buildings also can be retrofitted to 

 prevent flood damage. After Hurricane Emily in 

 1993, more than 50 Outer Banks homeowners 

 raised their houses by 2 to 10 feet, Rogers says. 



Continued 



Hurricane clips or metal straps help strengthen the connections between the wall and roof in new or existing homes. 



Photos bs Scon D Taylor 



COASTWATCH 15 



