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snow drift on lower roof
ground snow = 35 psf
roof snow = 30 psf.
the lower roof, above an entrance, extends 10' beyond the building. the upper roof,(lu>150')which is 13' above the lower roof, extends 8' beyond the building. thus, the lower roof extends 2' further from face of building. with the 8' overhang above the lower roof, will a drift occur?
thank you!
i wouldn't count on an upper roof overhang to reduce a lower roof drift. while there is some logic in saying that blown snow will drop mostly beyond the lower roof, with swirling winds, complex behavior, and silence on this matter in the codes, i'd take the conservative route here.
if you leave your car window open one quarter inch, even with one of the popular aftermarket wind/rain deflector installed, snow will blow in under the right conditions. be conservative, do not count on a shadow effect.

2009-09-15, 11:58 PM	#1
huangyhg 超级版主注册日期: 04-03 帖子: 18592 精华: 36 现金: 249466 标准币资产: 1080358888 标准币	snow drift on lower roof snow drift on lower roof ground snow = 35 psf roof snow = 30 psf. the lower roof, above an entrance, extends 10' beyond the building. the upper roof,(lu>150')which is 13' above the lower roof, extends 8' beyond the building. thus, the lower roof extends 2' further from face of building. with the 8' overhang above the lower roof, will a drift occur? thank you! i wouldn't count on an upper roof overhang to reduce a lower roof drift. while there is some logic in saying that blown snow will drop mostly beyond the lower roof, with swirling winds, complex behavior, and silence on this matter in the codes, i'd take the conservative route here. if you leave your car window open one quarter inch, even with one of the popular aftermarket wind/rain deflector installed, snow will blow in under the right conditions. be conservative, do not count on a shadow effect. __________________ 借用达朗贝尔的名言：前进吧，你会得到信心! [url="http://www.dimcax.com"]几何尺寸与公差标准[/url]