I am working on a project with an existing building that is 50'-0" wide, is a gable roof with a 6:12 roof slope. At the center of the roof there is an additional gable roof that extends 6'-0" tall. Essentially this is a 12'-0" wide gable roof over the peak of the lower roof. We are adding a new taller structure adjacent to this existing building creating a valley to trap snow between the new building and existing double gable roof. I calculated the roof drift for the windward and leeward snow drifts but am worried this does not properly account for the valley being created. Are there additional provisions to be taken when a structure is essentially trapped on all sides by taller structures?
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Christopher Volk P.E., S.E., M.ASCE
Structural Engineer
Venetia PA
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