Sliding Snow Loads
Sliding Snow Loads
(OP)
ASCE 07-05 section 7.9 discusses sliding snow requirements for any roof above another roof.
I'm curious if this load should apply for dormers, where the roof above is not very high above the roof below?
Secondly, does sliding snow or drift loads apply to roofs at a pitch change?
Any comments? I've attached a picture for your review.
I'm curious if this load should apply for dormers, where the roof above is not very high above the roof below?
Secondly, does sliding snow or drift loads apply to roofs at a pitch change?
Any comments? I've attached a picture for your review.






RE: Sliding Snow Loads
Question 2--the answer is no.
DaveAtkins
RE: Sliding Snow Loads
RE: Sliding Snow Loads
DaveAtkins
RE: Sliding Snow Loads
I suppose one area of discussion could be in ASCE 07-05, section 7.9, is the defintion for W as "eave to ridge." I'd say that this defintions would more clearly read "overhange to ridge." If it truly is eave to ridge, this would reduce my total load a bit.
Am I missing something?
RE: Sliding Snow Loads
I missed the part about per unit length "OF EAVE." I thought the 0.4*pf*W was per unit lenght over the 15 feet, so I interpreted the total load as a uniform load over 15 feet, not the total load / 15ft.
I think what you were getting at was this:
0.4 * 25.2 * 8 = 80psf / 15ft = 5.3psf
Ps = 20psf + sliding snow = 5.3psf = 25.3psf over 15 feet.
Is this what you were trying to say?
RE: Sliding Snow Loads
DaveAtkins