Snow Drift on Existing Building
Snow Drift on Existing Building
(OP)
I'm working on a project where a new building is adjacent to an existing building and is approximately 13' higher than the existing. I'm in the process of analyzing the existing roof structure for the potential snow drifting introduced by the new building. The issue I'm having is determining the correct "lu" (length of roof upwind of the drift) to use. I've attached a sketch showing the new and existing roof profiles. Should I be using 500' as my length or does the 3' step justify using 180' as the length? Typically, I would just go with the worst case scenario, but, if I do this, the snow drift load on the existing roof structure becomes extremely large and will require very costly reinforcements. Has anyone come across this type of situation before? Any help or guidance would be very much appreciated. Thanks in advance!






RE: Snow Drift on Existing Building
RE: Snow Drift on Existing Building
RE: Snow Drift on Existing Building
bigmig - I believe that is only for checking leeward snow drift. When checking for windward drifting you substitute the length of the lower roof and use 75% of the drift height determined from Figure 7-9 of ASCE 7-05.
RE: Snow Drift on Existing Building
RE: Snow Drift on Existing Building
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RE: Snow Drift on Existing Building
RE: Snow Drift on Existing Building
http://books.google.com/books?id=z1hUx7-iHv8C&...
I don't have it with me, but I'll see if I can find it.
EIT
www.HowToEngineer.com