Wind loading on gable and multi-span roof buildings: Comparison between field monitoring, wind tunnel experiments, and design code provisions

Abstract

The wind loading provisions in the National Building Code of Canada (NBCC) have not been updated for decades despite developments in wind tunnel methods since the original source data. This study aims to review the Nbcc 2020 provisions compared to wind tunnel experiments, field measurements, and the ASCE 7–22 provisions for single and multi-span gable roof buildings. Field measurements and wind tunnel tests are used to collect data for an isolated building and later for a multi-span gable. The pressure coefficients from the field measurements were mostly higher than the wind tunnel, which is consistent with previous studies. The results provided evidence that NBCC provisions for single-gabled roofs (with slope $7^{\circ }<\alpha \le {27}^{\circ }$) and multi-span gabled roofs (with slope ${10}^{\circ }<\alpha \le {30}^{\circ }$) are currently underestimated. New provisions are suggested for the corner (c), edge (s), and field (r) zones of the single-span gabled roof and for gable-end-edge (s’) zone of the multi-span. It is suggested to merge Zone s into Zone c to form a new perimeter Zone p for the single gabled roof and to merge Zone s’ into Zone c for the multi-span gabled roof. The proposed changes correct the current provision underestimation and add simplicity for easier construction.