ASCE 7-10 Wind loads on MWFRS low rising building. Figure 28.4-1

[ENGINEER92]

I am calculating the wind loads for an enclosed low-rise building. I am using the method in table 28.2-1 in ASCE 7-10. In figure 28.4-1, note 7, it says "For flat roofs, use slope=0 and locate the zone 2/3 and zone 2E/3E boundary at the mid-width of the building." I am not sure what it means by locate the boundary at the midwith. Any help would be greatly appreciative.

 

[KootK]

They're just saying to define the transition boundary from the 2 & 3 zones as a line down the middle of the building rather than at the ridge-line because, obviously, there is no ridge-line.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[ENGINEER92]

Thank you. That answers my question.