It's All in How 

 It Was Built 



Rogers is an old hand at assessing building damage 

 from hurricanes. He's surveyed the structural damage from 

 every hurricane that has struck the East and Gulf coasts 

 during the last 21 years. 



Fran, however, was the first big strike close to home. 

 Sure, there were Diana, Emily and Bertha, but wind and 

 wave conditions during these storms were light in compari- 

 son. Fran was a hurricane of a different category, packing 

 winds, waves and a storm surge like the Tar Heel coast 

 hadn't seen since the 1950s. 



Wind gusts were clocked between 1 10 and 120 mph 

 on the beach during the height of Fran's fury. But North 

 Carolina's building code requires that barrier island struc- 

 tures withstand winds of 130 to 140 mph. Consequently, 

 wind did not directly damage many buildings during Fran, 

 especially those constructed in the last 20 years, Rogers 

 says. However, trees felled by the strong winds did cause 

 damage to buildings. 



The most destructive force came in the storm surge. 

 Along some areas of the southern barrier islands, the surge 

 reached more than 12 feet above sea level — a height at or 

 above the 100-year flood level. 



The surge is also a key factor in erosion, which is 

 affected by the duration of the storm. Fran's arrival on the 

 heels of Bertha caused erosion at a level that occurs only 

 once every hundred years. 



"The worst building damage was caused by water 

 levels, wave action and erosion," Rogers says. 



Damage also depended on topography. 



"If buildings were behind dunes big enough to prevent 

 overwash and were properly elevated on pilings, then they 

 fared better," Rogers says. "That's what happened at 

 Wrightsville and Carolina beaches. The first-row 

 (beachfront) houses took the brunt of the storm." 



In areas with low dunes, the waves and surge knocked 

 out the sandy humps and washed over the island. The 

 hurricane deposited 2 to 3 feet of sand inland, and second- 

 and third-row houses sustained considerable damage. The 

 degree of damage in these areas depended on the elevation 

 of the structure and depth of the foundation, Rogers says. 



And in most cases, those structural elements were 

 contingent upon when the building was constructed. Houses 

 built before the 1 960s fared the worst. Their foundations 

 were often at or only slightly above ground level. 



"On the beachfront, these houses were completely 

 destroyed," Rogers says. "And even as far back as the fourth 

 or fifth row, these houses had significant damage." 



After the hurricanes of the 1950s, the N.C. Building 

 Code Council adopted hurricane-resistant construction 

 standards for barrier island buildings. Beginning in the 



6 JANUARY/FEBRUARY 1997 



