Mudsill Plate Washers

[yellerwhale]

We've got a two story building under construction that was designed under the 2001 CBC. We specified Simpson BP-58 (2"x2") plate washers on each shear wall anchor bolt. The permit was issued under the 2007 CBC, but we and the plan checkers didn't catch one Code upgrade -that the 2007 Code specifies 3"x3" plate washers on shear wall anchor bolts. Of course, rather than check for conformance with the approved documents, now the inspector wants the washers changed to 3"x3". Any Ideas?? I'm considering proposing only changing the washers on shear walls stressed over 2/3 their design capacity.

http://www.Qengineers.com

 

[BAretired]

I am not familiar with the CBC. Why would you change any of the washers if the 2" x 2" washers are adequate by engineering calculation? If they are, tell the inspector to get lost.

BA

 

[woodman88]

BAretired, The CDC 2001 is California's revision of the UBC 1997, the CBC 2007 is their revision of the IBC 2006.
yellerwhale, The ANSI/AF&PA SDPWS-08 (which is referenced in the IBC 2009) Section 4.3.6.4.3 offers the following
“Exception: Standard cut washers shall be permitted to be used where anchor bolts are designed to resist shear only and the following requirements are meet:
a. The shear wall is designed in accordance with provisions of 4.3.5.1 with required uplift anchorage at shear wall ends sized to resist overturning neglecting dead load stabilizing moment.
b. Shear wall aspect ratio, h:b, does not exceed 2:1.
c. The nominal unit shear capacity of the shear wall does not exceed 980 plf for seismic or 1370 plf for wind”
If you meet these requirements you might be able to talk the inspector into them. Referencing new codes for this type of situation have work about half the time for me.

Garth Dreger PE
AZ Phoenix area

 

[yellerwhale]

Thank you for the input.