Codification of Wind‐Pressure Coefficients for Multispan Gable Roofs

Abstract

A wind‐tunnel study has been carried out to assess wind loads on multispan gable roofs with roof slopes of 4:12 and 12:12. Local and area‐averaged pressure coefficients were measured on models with one, two, and four spans. Critical suctions were significantly larger than those specified for single‐span roofs in wind standards. Discrepancies between single‐span design pressures and the multispan results were largest for the high‐pitch roof, for which local suctions obtained in the present study exceed the wind‐standard values by a factor of two. Suctions measured on the 4:12 single‐span and multispan roofs were 20–50% higher than design values specified in wind standards for single‐span buildings. Critical values of positive pressures measured on the 4:12 and 12:12 multispan gable roofs agree well with design pressures specified in wind standards for single‐span gable roofs. The largest positive pressures occurred on the high‐pitch roof along the low edge of the windward span and in the trough regions. The present paper proposes design pressure coefficients for multispan gable roofs.