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Re: ASCE7-98 Wind Loads for Cladding

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Bill Polhemus wrote:
> 
> Look under 6.5.12.4. The equations and definitions given there will, I believe,
> clear all this up for you.
> 
> Basically, the distinction is that you MAY simply (and conservatively) use qh,
> based on the mean roof height, for calculating the wind pressure for components
> and cladding when the building is 60 feet or less in height,


Actually, it says you MUST use qh for buildings 60 feet or less. Using
qz, which would be based on lower elevations than qh, would give lower
pressures and is not permitted.





> but you MUST use qz evaluated at the level of the component you are
> loading, when the building height is greater than 60 feet, and when the
> component is on the "windward" side.


And you MAY use qz for the windward side of buildings greater than 60
feet. In this case, using qz which gives lower pressures than qh is
permitted. I say MAY, since of course you could use the higher pressures
based on qh.  However, you MUST use qh for the leeward and side walls of
buildings greater than 60 feet.

Just my interpretation.
Rick Burch