ASCE 7 Wind Loads on Open Structures

[callawaygolfer]

I have a question regarding ASCE 7-02 wind loads on open structures. ASCE 7 seems to sidestep wind loads on open structures except for monoslope roofs.

Question: Can I just calculate the wind loads based on the enclosed/partially enclosed figures & equations and exclude the internal pressure coefficients? Also, same question for the components and cladding winds loads. I'm designing a wood structure that only has a gable style roof and open walls.

Thanks in advance

Kirk

 

[ajh1]

The new ASCE7-05 has a much enhanced section on open coefficients, both MWFRS and components and cladding. The new charts cover monoslope, gable with ridge, and inverted gable with valley. They are still rather silent on what to do with elements of the building other than the roof surface that might be exposed to horizontal wind forces.

For low rise stuff, the coefficients for enclosed and partially enclosed are based on a wide range of wind tunnel tests and are more properly viewed as "envelope" conditions, i.e., they provide an upper bound for "all" possible arrangements. Not sure how accurate they would be for open structures. In some fashion you need to apply wind pressures to surfaces that would be impacted by horizontal loads and deal with the potential of multiple surfaces seeing the wind, not just the first surface the wind comes to. There are times when the horizontal wind on an open building structure could be as high or higher than the equivalent enclosed structure fully sheeted.