parapet wind loads

huangyhg

parapet wind loads
it is my understanding that when calculating wind load (low rise structures) for mfwrs as well as components and cladding, we must use significantly higher wind loads applied to the parapet versus the much lower wind loads used on zones 4 and 5.  asce05
i have been reviewing calculations (and texts) where the zone 4 and 5 wind loads are used at the parapet as well as the walls.
am i missing something?  the use of parapet wind loads produce significantly larger shear wall loads.
you are correct.  the parapet provisions of 6.5.12.2.4 apply to both low rise and the provisions for buildings of all heights.  using zones 4 or 5 is far underconservative since those assume that one side of the wall has external pressure and the other has a much smaller internal pressure.  parapets have very high pressures on both faces, causing their loads to approximately double.
thank you - always good to have back up.