Snow Load on sloped Sawtooth Roof

[cgstrucg]

Hello Everyone,

Please see the attached image. I have a project in NYC for which I have varying weird slopes on the roof. I need to design snow load for this roof and I wanted to know if my approach is right or not or if there is anything someone would consider which I might have missed.

When Wind is in the X direction, I considered this roof to be the gable roof which would have varying unbalanced snow roof loads as the eave to ridge distance changes (In some cases it is less than 20ft.)
When Wind is in the Z direction, I think I should consider the sawtooth roof and design snow load considering that. The issue is if I do consider it a sawtooth roof, it would be sloped sawtooth and I can't find anything as to how I can reduce the snow load in that case. Can someone tell me if the approach is right and how I can resolve this issue in the Z direction.

Thanks.

 

[BAretired]

Except for the area abcdef, treat the roof as normal sloping roof. Use ground snow load in area abcdef.

BA

 

[r13]

This thread may help in calculating snow load in the roof valley. Pay direct attention to the last two responses. Link

 

[BAretired]

The following is published by the National Research Council of Canada. It deals briefly with sawtooth roofs, starting on page 12:

https://nrc-publications.canada.ca/eng/view/ft/?id=b9b6e9bd-8cbb-4c2c-85c2-3ceace78cfdb

Another Canadian reference National Building Code of Canada - 2015:

https://cssbi.ca/assets/resources/Design_Manuals/CSSBI-B15-17-lr.pdf

BA

 

[JLNJ]

It doesn't look like a classic 1940's era sawtooth roof, where there were vertical portions to let the light in with sloping roofs opposing. ---> \|\|\|\|\|\|
It looks like a folded plate/gabled roof. I would consider using the unbalanced snow load and apply it to both sides instead of just one side (and substitute this for the lesser-loaded "balanced" condition called for in ASCE 7).