The panel row: 19/32 to 1 in
2018 IRC Table R602.3(1) lists wood structural panel subfloor, roof and wall sheathing 19/32 to 1 in thick with an 8d common nail (2½ × 0.131).
A 23/32 in panel is inside that range. The 6d common is too light; the 10d common and 16d box are not this row's fastener.
Spacing: 6 at edges, 12 in the field
The same row sets nail spacing:
- 6 in o.c. at panel edges.
- 12 in o.c. at intermediate supports.
So 19/32 in sheathing on supports at 24 in o.c. gets 6 and 12. The trap: "12 at edges, 6 in the field" reverses the numbers, and 12 everywhere is too wide at the edges.
Footnote c: spans of 48 in or more
Footnote c to Table R602.3(1): nails at not more than 6 in on center at all supports where spans are 48 in or greater, so a 1 in panel spanning 48 in gets 6 in at intermediate supports.
The trap cuts both ways: 12 in intermediate spacing on a 48 in span is the error the footnote prevents, and 6 in everywhere on a 24 in span is wrong, since 24 in is below the trigger. 8 in and 4 in are not footnote c figures.
Georgia amendments: the right document
The amendments that pair with the exam's 2018 IRC are the Georgia State Amendments to the IRC (2018 Edition), revised January 1, 2020. The trap: the DCA file named 2018ircamendments, revised January 1, 2018, is the amendment set to the 2012 IRC despite its name. 2021 IRC amendments do not match the exam's edition.
Georgia R602.10: SR-102 as an alternate
These amendments add an exception to R602.10 (Wall bracing): the APA Simplified Wall Bracing Method, SR-102, may be used as an alternate method, subject to the limits in that document, effective January 1, 2020. It adds an option; it does not delete bracing, require a design professional for every braced wall line, or substitute 2021 IRC provisions.