Thanks austim.
I also picked the brains of our senior structural guru this afternoon. His explanation was basically the same, so I am feeling slightly more confident with the application of the Aerodynamic Shape Factor now.
If you would like a copy of the final code post your email and I can...
Can anyone help me to understand the application of the Aerodynamic Shape Factor (Cfig) as used in calculation of design wind actions on a structure. I am looking at a purlin design for a monoslope free roof (carport)structure and am having trouble interpreting Table D4(A) as depicted in AS/NZS...