From: John Rose <jrose36(--nospam--at)earthlink.net>
Date: Sat, 29 Jan 2000 22:18:35 -0800
True T1-11 plywood siding is now 19/32" thick, grooves 1/4" deep. If you nail in
the full-thick portion of panel (including edges), full allowable design shear
values apply since panels are thicker (where nailed) than minimum nom. thickness
specified in Table 23-II-I-1. Regularly, T1-11 plywood is nailed with 8d hot-galv.
box nails (same shear values as 8d common nails). But if the panel is nailed along
thinner shiplap edge, then use allowable design shear values for 5/16" panels
since thickness of panel at point of nailing governs shear values. The "link"
between UBC shear wall table and T1-11 plywood siding is in ICBO ES Report 1952.
John Rose/APA, Tacoma, WA
Roger Turk wrote:
> *True* T1-11 is 5/8 inches thick and the grooves are 1/4-inch deep, leaving
> you with effectively a 3/8-inch panel that has good face material on only one
> side. Where does most of plywood's strength come from? (Rhetorical
> question.) You make the call!
> A. Roger Turk, P.E.(Structural)
> Tucson, Arizona
> Mark Baker wrote:
> >>Does anyone know if T-111 siding has an ICBO approval for use as shear panel
> sheathing? I have a non-conforming structure which has to be brought up to 97
> UBC and it is sheathed with T-111.<<