Unbalanced Loads

Unlike the partial loads, the unbalanced loads in Section 7.6 of ASCE 7-22 in most cases are drift loads. Except for saw-tooth type roofs, the windward portion of the roof is the snow source, and the leeward portion accumulates a percentage of the drifted snow. This is termed an “unbalanced” condition, because the leeward portion has more snow than the windward portion. This chapter discusses the unbalanced snow loading on hip and gable roofs, curved roofs, saw-tooth roofs, and dome roofs. For hip and gable roofs, the balanced loading condition results from a drifting process in which wind removes snow from the windward side of the ridge line. Unbalanced loads on sawtooth roofs are fundamentally different from unbalanced loads for gable, curved, or even dome roofs. Balanced loads for domes are the same as the corresponding balanced loads for curved roofs.