Section 4.3.7.1, Item 4c. of 2008 SDPWS requires 3 in. nominal lumber for high load shear walls (700 plf nominal = 350 plf for ASD).
Section 4.2.7.2, Item 4 of 2008 SDPWS has the same requirement for “high-load diaphragms”.
Here is an article describing some changes to SDPWS for the 2008 version.
http://www.awc.org/pdf/WDF18-3_SDPWS-08.pdf
Jeffrey D. Linville
Director, Technical Services
American Institute of Timber Construction
(303)792-9559
linville@aitc-glulam.org
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From: Larry Reynolds [mailto:llreyno@yahoo.com]
Sent: Thursday, September 10, 2009 1:33 PM
To: seaint@seaint.org
Subject: 3x Sill Plates and IBC-09
Section 2305.3.11 of IBC-06 requires 3-inch nominal sill plates for shearwalls that resist a load of 350 plf (ASD) or 490 plf (LRFD). This section has been removed in the IBC-09 and Section 2305 now requires use of AF&PA Special Design Provisions for Wind and Seismic 2008 (SDPWS). The SDPWS does not require the 3x sill plate for high demand shearwalls.
Is there a technical reason for this change or is this a case of unintended consequences?
Thanks,
Larry Reynolds