Unit Shear Capacities for Wood-Frame Diaphragms

[swooneyWOODSTRUCT]

Hi all,

I have a project on an existing building where the diaphragm sheathing is 3/4" Tongue & groove Plywood with 8d nails. In the Special Design Provisions for Wind and Seismic the largest size with 8d nails is 15/32". I am trying to find come extra capacity in this diaphragm.

Is there any way to account for the larger panel thickness and/or the tongue and groove?

References to relevant codes would be much appreciated.

Thanks

 

[Aesur]

I have typically used 19/32" with 10d nails for the capacities, I use this because based on what I can tell the fasteners start controlling at this thickness and therefore thicker sheathing is pointless (for shear) without additional rows of fasteners. If you need additional loading I would suggest looking at high load diaphragms with multiple rows of fasteners and 23/32" sheathing.