Trellis Wind Load

I have a 30 ft. x 30 ft. trellis with perimeter HSS beams and two intermediate HSS or I-beams to break the 2x10 rafters into 10 ft. spans. For wind perp. to the rafters, does anyone have any info on the wind shading from rafter to rafter? I found an old post from 2006 in Eng Tips that states anything within 4d spacing is considered shaded. Not references were cited, however.


(This is cross posted to Eng Tips)

@XR250…generally, shading is not considered. Some codes specifically precluded use of shading.

Always tricky when designing the top floor of a parking garage…