Snow Drift Loads for flat roofs
Snow Drift Loads for flat roofs
(OP)
I am sizing these long spanning (53') roof trusses for a building in Chicago. The building code says to to follow ANSI A58.1-1982 for snow drift calculation, but I understand that standard has been replaced by ASCE 7-05.
Does someone have experience in calculating the portion of a flat roof that may experience snow drifting from the aerodynamic shade effect on the lower potion of a building. I understand that some of the trusses will be affected by higher snow loads caused by the drifts, but I am interested in determining how many of the trusses will be affected. And yes, I do not own a copy of ASCE 7-05. Thanks!
Does someone have experience in calculating the portion of a flat roof that may experience snow drifting from the aerodynamic shade effect on the lower potion of a building. I understand that some of the trusses will be affected by higher snow loads caused by the drifts, but I am interested in determining how many of the trusses will be affected. And yes, I do not own a copy of ASCE 7-05. Thanks!





RE: Snow Drift Loads for flat roofs
RE: Snow Drift Loads for flat roofs
RE: Snow Drift Loads for flat roofs
Mike McCann
MMC Engineering
RE: Snow Drift Loads for flat roofs
RE: Snow Drift Loads for flat roofs
Unless specifically dictated to use something this old by an AHJ, most engineers would consider its use to be a deviation from the accepted standard of care.
I get a sense from your query that you are perhaps not licensed as an SE in Illinois. They are picky about that and require specific SE licensing.
I would suggest that you buy a copy of ASCE 7-05 to be reasonably current. Some codes have not yet adopted ASCE 7-05 and are still using ASCE 7-02, but change will likely occur with the next code change cycle. Most model codes are revised on a 3-year cycle.
RE: Snow Drift Loads for flat roofs