Volume 4, Issue 10 (November 2007)
Understanding Low-Sloped Roofs Under Hurricane Charley From Field to Practice
Natural wind hazard damages have been dramatic in recent years, incurring losses of life and property around the world. Wind-induced failure is one of the major contributors to insurance claims, and it is rising. To address these growing concerns, RICOWI (Roofing Industry Committee on Weather Issues) started a Wind Investigation Program (WIP) to investigate the field performance of roofing assemblies after major windstorm events and to factually describe roof assembly performance and modes of damage. As part of this program, Hurricane Charley, which hit Punta Gorda, FL, with winds exceeding 140 mph (63 m/s), was investigated. This paper mainly focuses on the field performance of the low-sloped roofs with three important parameters that were found critical in the failure of the roofing systems, namely, • Effect of corner wind suction, • Effect of parapet, • Effect of internal pressure. For each scenario, first scientific documentation was presented, and then how the field observation reflects the fundamental principles were discussed. Based on this exercise, correlations are developed for roof wind design. In addition, wind design data from the North American codes of practice are also calculated and compared to show the impact of science and field observation on durable roof design. With these illustrations, this paper offers recommendations to advance the roof system design for hurricane-prone regions.