Proposed Code Provisions for Drifted Snow Loads

Current code provisions for drift snow loads on multilevel roofs are examined in light of recent research results from a statistical study of approximately 350 drift load case histories. New provisions are proposed in which the design drift load is a function of the length of the upper-level roof and the 50-year mean recurrence interval ground snow load. It is felt that these new proposed provisions result in a design draft load with a mean recurrence interval of about 50 years.