High Wind Screens Effects on Building C&C Forces 1

[UtahAggiePE]

For C&C wind pressures generally the taller the building the higher the net pressures. Here's my question, when I have a 16 foot tall screen surrounding an area about 1/3 of roof with huge mechanical equipment behind it, is it fair to use the actual roof height for determining my C&C pressures, or should I consider the building height to be the top of the screen? The roof height is 56.5 ft, but the top of the screens go to 73 ft. (See attached for visual)

There has to be some effect to the overall pressures as you have a generally larger obstruction that is the building and its accessories despite where the roof happens to be. That is if the general behavior of the code design pressures is any indication.

We have large lites of glass in some areas and the resulting change of 10psf is no small matter.

 

[jayrod12]

Is the screen fully solid or does it have some openings that may allow some wind to go through it?

 

[UtahAggiePE]

Basically solid.

 

[jayrod12]

Ugh, then I'm probably more for being conservative, but I could be persuaded.

I might be game for designing the screen for the higher pressure and the building for slightly more than the lower pressure, but not as if the entire building was 73 ft. Maybe just rounding up on the 56.5 ft wind pressure.