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RE: Wind load on sloped roof with parapet

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Thanks, Harold and Conrad,
I am a bit embarrassed not to know this, I have not done an ASCE 7-05 wind analysis for a building yet.
For this building the B and D zones are zero. So do I take the pressure on the parapet from and add that to zones A and C to get the force for the MWFRS in the transverse direction or would I take the A and C zones to the top of the parapet for the MWFRS and design the parapet separately per
On another note, The 2006 IBC seismic design manual on page 202 only takes the minimum 10 psf check up to zones A & C, is that correct?

From: Harold Sprague [mailto:spraguehope(--nospam--at)]
Sent: Monday, December 01, 2008 8:22 AM
To: seaint(--nospam--at)
Subject: RE: Wind load on sloped roof with parapet

The conditions to design the MWFRS according to the simplified procedure are listed in ASCE 7-05, Section OR  I am not sure which of the 8 provisions of Section are in question. 
You can not use the parapets to shield roofing elements.  You must assume the parapets are not there for the design of the roof.  You then design the parapet under
Regards, Harold Sprague

> From: jeffsmith7(--nospam--at)
> To: seaint(--nospam--at)
> Subject: Wind load on sloped roof with parapet
> Date: Sun, 30 Nov 2008 13:21:22 -0800
> Say you have a small existing victorian wood building, 30' x 22', 12'
> ceiling with a 22.5 degree roof pitch, 5' ridge height, gable ends, but 2
> orthoganal walls have a 4' parapet (1 foot lower than the ridge.) The front
> gable end and one side have parapets. The front parapet perpendicular to the
> ridge is part of the victorian look and the side is essentially a dutch
> gutter against the property line.
> Can this be analyzed using the simplified procedure? For the MWFRS, how do
> you apply the B and D zones to a pitched roof that has a tall wall parapet?
> Seismic will probably govern in both directions for the MWFRS.
> Thanks
> Jeff
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