THE ROOFING INDUSTRY COMMITTEE
on Weather Issues (RICOWI) is a nonprofit organization formed in 1989 in response to concerns regarding the performance of roofing, particularly in high-wind areas, and to address important technical issues related to the cause of wind damage. There is an essential link between product research, performance and the model building codes. The model code groups have moved toward "performance-based codes" versus "prescriptive codes." There was a need to improve the understanding of roof/weather concepts and issues within the building community in general. Specifically, more research and new or improved industry consensus practices for weather design and testing was needed. RICOWI responded and developed the Wind Investigation Program (WIP) in 1996. WIP is facilitated by Oak Ridge National Laboratory (ORNL), Oak Ridge, Tenn., and the and the U.S. Department of Energy (DOE).
Under the auspices of DOE and ORNL, RICOWI investigators consisting of wind engineers, roofing material specialists, insurance analysts, structural engineers and roofing consultants were trained in wind issues by a number of the country's leading scientists and others qualified in examining wind
damage to roof systems. Training workshops were held in 1996, 2000, 2005 and March 2006.
Those who attended the training seminars were educated about the specifics of forming the WIP teams and traveling to hard-hit areas in the hours directly following a hurricane that has wind speeds of at least 95 mph (one minute sustained) and makes landfall in a populated area. Team members were educated about lifesafety procedures; wind characteristics; evaluations of building interactions with wind; improved methods of factually documenting their findings; and specific techniques to use when writing evaluations that accurately and factually report roof damage.
The 2004 season brought hurricanes that met the criteria, and RICOWI dispatched seven teams to investigate damage after Hurricane Charley and five teams after Hurricane Ivan. These were the most comprehensive roofing investigations of hurricane-stricken areas. Charley made landfall near the Punta Gorda-Port Charlotte area of Florida as a Category 4 hurricane on Aug. 13, 2004. And Ivan hit on Sept. 16, 2004, west of Pensacola, Fla., as a Category 2 hurricane.
The teams were helped by members of the Federal Emergency Management Agency (FEMA). Each four-member team included representatives of academia, insurance, contractors, manufacturing and consulting interests. This was done to guard against bias. Each team was comprised of four members delegated to the tasks of report writer, data recorder, photographer and sample collector.
RICOWI teams involving 51 experts investigated a combined total of 93 low-slope roofs and 91 steep-slope roofs in Florida in the immediate aftermath of hurricanes Charley and Ivan. Investigators examined roof shape; materials; edge conditions; installation details; and degree of deterioration, if any. The teams found a wide range of roof performance from no damage to complete displacement, or blow-off.
A roof system's ability to withstand the high winds of hurricanes Charley and Ivan in 2004 depended on installation of the entire system according to specifications more than selection of roof covering materials, according to an investigation by RICOWI.
Among steep-slope roofs, damage ensued in some cases because the roof covering was not installed according to the governing code or standard practice at the time. In addition, the failure of one component of a roof structure often influenced the performance of other materials. Roofs that best survived the hurricane winds featured systems with the required materials installed according to specifications.
For low-slope roofs, investigators found certain conditions most often associated with damage-corroded fasteners, deteriorated wood substrates and mechanically attached base sheets, and lack of compliance with fastening recommendations for high-wind zones. They also found increased damage when roof systems included openings that allowed winds to penetrate between the roof membrane and deck.
Rick Olson, RICOWI chair, states: "In general, RICOWI investigators determined far less damage occurred when contractors installed roofs according to the manufacturers' specifications and latest building codes, particularly in regard to fastener type, frequency and placement pattern."
Investigators noted that "fastening requirements specified in later versions of the building code were an improvement" over earlier code requirements. Based on their findings, the report writers drafted a report, and each of the teams' members critiqued it for accuracy. Following the first draft, peer-review input provided a better formatting layout and, though it delayed the release of the report, it improved the report. RICOWI's board of directors approved the final report at its March 23 meeting in Phoenix. In mid-April, the 243-page report was made available on CD. It also can be downloaded from the RICOWI Web site, www.ricowi.com.
The report has an Executive Summary, Code Commentary, Conclusion and Future Research section up front allowing for a quick perusal. Detailed reports and images for each hurricane are separated into low-slope and steep-slope roofing. Appendices include storm swath and wind-speed maps.
The failure of one component of a roof structure often influenced the performance of other materials.
With this report finished, RICOWI is working on a Hurricane Katrina report, which will be released later this year. RICOWI deployed six teams to investigate Katrina damage. The Oct. 19 RICOWI seminar in Houston will include Katrina presentations.
The RICOWI investigations provide valuable information about the performance of roofing exposed to hurricane-force winds. The investigation teams were able to discern the effectiveness of materials and methods of construction in resisting these winds.
When speaking about the hurricanes Charley and Ivan report, André Desjarlais, program manager for Building Envelope Research at ORNL, states: "Data from these investigations will lead to more energy-efficient and durable roof systems and a reduction in insured losses, which may lead to lower overall costs to the public."
As those in coastal areas prepare for the 2006 hurricane season, it may be somewhat comforting to know that RICOWI is doing its part to ensure roof systems perform as expected.
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