Jerold,
I think you could use the NDS pull-out value for nails for a design value in plywood. And how do you hold the roofing material down at that wind load? And the roof framing has to be sized for the uplift minus dead load.
Dave
Dave Gaines, P.E.
Structural Project Engineer
HDR ONE COMPANY | Many Solutions
T: 626.584.4960
F: 626.584.1750
email: david.gaines@hdrinc.com
From: jerold taylor [mailto:jerold_taylor@yahoo.com]
Sent: Wednesday, December 12, 2007 8:45 AM
To: seaint@seaint.org
Subject: Uplift on Roof Sheathing - "Pull Through" Resistance
I would like to ask for feedback on the design / specifying of sheathing for uplift.
For uplift on roof sheathing in HIGH WIND areas, is “Pull-through” a concern for the Plywood or OSB? For Component and Cladding loading at some of the end zones, net uplifts can exceed 100 psf (for example, ASCE 7-02, V=130 mph, Exp. C, Bldg Class. III and Zone 3).
APA provides design data for allowable stresses for spans and thicknesses of material, but for a situation where loading can be concentrated at the nail head “bearing” (kind of a reverse punching shear), are there special precautions I should warrant against? Are there some type of washer that is sometimes typically used at these locations to help “spread out” the load?
I have tried to find specific info on the Internet, without success, so I was hoping for some assistance from those who work with such high uplift pressures more frequently than I.
Thanks
Jerold Taylor PE
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