Snow Load 7-02, 7-05, Cold Roof Cs Questions
Snow Load 7-02, 7-05, Cold Roof Cs Questions
(OP)
I have a cold roof with Ct = 1.1. Roof slope is 6:12 or 26.6 degrees. It's an unobstructed slippery surface.
Using Figure 7-2b, it looks like Cs = about 0.8.
Using equation C7.4 2(a), Cs = 1.0 - (slope - 10°)/60° = 1 - (26.6 - 10)/60 = 1 - 16.6/60 = 0.72.
Which is it: 0.8 or 0.72?
Are there some notes I'm missing? Are my eyes playing tricks on my concerning using the graphical solution rather than the equation?
Any assitance is most appreciated, etc.
Using Figure 7-2b, it looks like Cs = about 0.8.
Using equation C7.4 2(a), Cs = 1.0 - (slope - 10°)/60° = 1 - (26.6 - 10)/60 = 1 - 16.6/60 = 0.72.
Which is it: 0.8 or 0.72?
Are there some notes I'm missing? Are my eyes playing tricks on my concerning using the graphical solution rather than the equation?
Any assitance is most appreciated, etc.





RE: Snow Load 7-02, 7-05, Cold Roof Cs Questions
I don't think you missed anything. I compared the graph to the equation in ASCE 7-0052. Note on the graph in Fig. 7-2, at the top end of the inclined portion of the dashed line. It's marked 10 degrees, but that's not where its located. I'd say they drew that line wrong in the graph. If you pencil in a line that goes from (0,70) to (1.0, 10) it looks like your case reads about 0.72 on the graph, just like the equation.
In ASCE 7-02, the graph looks like it is correct.
regards,
chichuck
RE: Snow Load 7-02, 7-05, Cold Roof Cs Questions
Alert to ASCE: REVISE THE FIGURE!!!
RE: Snow Load 7-02, 7-05, Cold Roof Cs Questions
RE: Snow Load 7-02, 7-05, Cold Roof Cs Questions
http://www.seinstitute.org/publications/errata.cfm
RE: Snow Load 7-02, 7-05, Cold Roof Cs Questions
regards,
chichuck
RE: Snow Load 7-02, 7-05, Cold Roof Cs Questions