Reliability of Light-Frame Roofs in High-Wind Regions. I: Wind Loads

In this first part of a two-part paper, the statistics of wind loads acting on roof structural components in light-frame structures are evaluated for use in a reliability analysis. Particular attention is paid to typical wood-frame residential construction and to an analysis of wind speeds at locations along the coast of the southeastern United States. The nominal wind loads on the roof sheathing panels and roof-to-wall connections are calculated using available load standards and other design specifications. A statistical description of the wind load acting on the roof system is then determined using the nominal wind loads and information from a selection of coastal North Carolina/South Carolina sites for which significantly long wind-speed records were available. A composite set of statistics for wind load (as a function of code-specified nominal values) is determined based on an analysis of the coastal sites. These statistics are shown to be valid for different roof zones and different exposures. In a companion paper, the reliability of light-frame roof components subject to wind uplift is investigated and results are presented for three baseline coastal residential structures.