2007 CBC/2006 IBC Section 2304.9.5 states that “fasteners” for PT & fire-retardant wood shall be galvanized, stainless, silicon bronze, or copper. 2001 CBC/2000 UBC Section 2304.3 also stipulated this requirement. On a wood-frame job currently in construction, we have pressure-treated sill plates and the inspector is saying that galvanized anchor bolts (sill bolts and hold-down bolts) are a “code requirement”.
I understand the new preservatives can be much more corrosive than the old stuff, but was of the impression that bolts are of a large-enough diameter to not pose a concern. I had thought I read that somewhere but I cannot find any published code language, commentary, or interpretations to support this position. Also, I started thinking, what about the washer? Is that a “fastener”? It’s in contact with the PT wood - does that mean it needs to be galvanized too? I could not find a definition of “fastener” in the CBC/IBC.
I’ve been away from wood design for awhile and am feeling a little rusty, so I’m hoping someone can give me some guidance on this.
Thanks in advance,
Diane C. Gould, S.E.
Senior Structural Engineer
DGS-RESD-PSB
Design Services Section
(916) 375-4219 phone
(916) 375-4916 fax
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