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Another Canopy Wind Question

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This small canopy project has turned into a study of the ASCE wind provisions.  The next question is sort of a little more general in nature.


One of the canopies is about 18’ long x 9’ wide and is double pitched at a 4:12 pitch.  Disregarding my question yesterday about the Load Case A (or B) thing I came up with wind loads that were fairly low.  So low that I referred back to section and used the 10 psf on a vertical projected plane.  Actually, I used more because I did another footing a couple of weeks ago and wanted to stay consistent.  Yea, I know, fight through the numbers and use something else, but like I said this has turned into sort of a study, and then I also have to be able to say that what I did use is conservative.


The canopy is supported on two posts at each end that are very close together, so for the sake of discussion, assume a single post each end.  For this example the canopy roof will be attached to the post using a moment resisting connection.


O.K. here goes….I figure that the moment that will be produced is due to the wind loads perpendicular to the roof surface.  A larger load into the roof on one side (load is perp. to the roof surface) and a smaller load away from the surface on the other side.  But, what loads to use?  Should I use the original calculated loads, take the minimum load and using trig and the “C” factors from the original calculations to produce the loads perpendicular to the surfaces based on the minimum wind load, or I could also use C&C loads.


Any suggestions?


Any of the three would probably work, with the C&C loading probably the most conservative, but maybe not the most proper.  I know this is not a major project, but the questions will certainly pertain to larger canopies.  And again I think the wind provisions are difficult to use. 


But, thanks anyway,



Joseph R. Grill, P.E. (Structural)

Shephard - Wesnitzer, Inc.

Civil Engineering and Surveying