metalchair
Structural
- Oct 25, 2022
- 13
Hello All,
Quick question for you all regarding components and cladding pressures regarding a roof with overhangs. I have been doing a bit of digging and the way ASCE 7 presents the information appears conflicting, or at least misleading.
I am speaking of components and cladding figure 30.3-2A through 30.3-2D; tables which show the C+C pressures for gable roofs of varying pitches. As printed, there is one GCp graph labeled "roof" and one labeled "overhang". This is where my confusion starts. For years, I have taken this to mean, use the first graph for the main interior portion of the roof, and the second graph for only the overhang portion.
Digging around in the printed commentary for this section, the tables providing the graphs' line equations divide the two sections as "negative without overhang" and "negative with overhang". This naming convention has me thinking that I have been using the graphs wrong and the graphs should probably be labeled "roof without overhang" and "roof with overhang". This is what is causing my confusion. The fact that the graphs' labels and the table titles presented in the provisions and commentary do not line up.
Ultimately, my question is this: do I continue with my original assumption of how to use these graphs, being that you use the "roof" graph for the interior, and the "overhang" graph for the overhangs? Or is my second interpretation correct, in that the graphs should be labeled "roof without overhang" and "roof with overhang"?
Any advice would be greatly appreciated. Thank you.
Quick question for you all regarding components and cladding pressures regarding a roof with overhangs. I have been doing a bit of digging and the way ASCE 7 presents the information appears conflicting, or at least misleading.
I am speaking of components and cladding figure 30.3-2A through 30.3-2D; tables which show the C+C pressures for gable roofs of varying pitches. As printed, there is one GCp graph labeled "roof" and one labeled "overhang". This is where my confusion starts. For years, I have taken this to mean, use the first graph for the main interior portion of the roof, and the second graph for only the overhang portion.
Digging around in the printed commentary for this section, the tables providing the graphs' line equations divide the two sections as "negative without overhang" and "negative with overhang". This naming convention has me thinking that I have been using the graphs wrong and the graphs should probably be labeled "roof without overhang" and "roof with overhang". This is what is causing my confusion. The fact that the graphs' labels and the table titles presented in the provisions and commentary do not line up.
Ultimately, my question is this: do I continue with my original assumption of how to use these graphs, being that you use the "roof" graph for the interior, and the "overhang" graph for the overhangs? Or is my second interpretation correct, in that the graphs should be labeled "roof without overhang" and "roof with overhang"?
Any advice would be greatly appreciated. Thank you.