Wind pressure on a 45-degree gabled roof: verifying code provisions with field measurements and wind tunnel data

Abstract

The wind load provisions for gabled roofs with a slope of 27o< α < 45o in NBC were derived from wind tunnel studies conducted in the 1970s. The paper presents the results of full-scale measurements and wind tunnel experiments to verify the necessity to update the current NBC provisions. A full-scale building with a gabled roof of 45o was instrumented with pressure taps, and the wind load was monitored for 15 months. The building and surroundings were replicated at a wind tunnel scale and investigated by Concordia and Western. Based on these three sources of data, the study concluded that the corner and edge provisions for both cases –a roof with and without overhang– need to be increased. It is suggested to merge the corner and edge into a single "perimeter" load provision.