asce 7-05 drifting and sliding snow
asce 7-05 drifting and sliding snow
(OP)
I have a long (40' per side)shallow pitched (4:12) gable roof that drops down (8 ft) to a 30' long flat roof. I am developing a truss loading diagram for the flat roof area. The question is do you combine balanced snow + drifting snow + sliding snow or do you treat balanced + drifting as one case and balanced + sliding as another and take the worse case?





RE: asce 7-05 drifting and sliding snow
I would not consider balanced + drifting + sliding as one total combination. The last sentence of ASCE 7-07 section 7.9 states "Sliding loads shall be superimposed on the balanced snow load." It does not mention superimposing the sliding snow on the snow drift.
In this case, I would look at windward drift + balance snow, leeward drift + balance snow and sliding snow + balance snow. I would also not consider a mineral surfaced roof slippery (if you have one).
This is how I interpret this section you need to do the same.
RE: asce 7-05 drifting and sliding snow
RE: asce 7-05 drifting and sliding snow