Shear walls using metal studs as framing

New in current Uniform Building Code is a section providing values for shear walls using metal studs in place of wood framing. Look at pages 2-266 and 2-267 in the 1997 UBC. A caution: the values listed are ultimate strength values that must be divided by a safety factor before they may be used in design.  The following tables should help:

Shear Values for Shear Walls Framed with Cold-Formed Steel - Combined & Modified Table
(Framing spaced at 24" centers maximum)
Assembly Description Force Type

Fastener Spacing at Panel Edges
(Inches)

    6 4 3 2
15/32-inch Structural I sheathing (4-ply) one side Wind 355 n/a n/a n/a
7/16-inch rated sheathing (OSB) one side Wind 303 470 578 636
15/32-inch Structural I sheathing (4-ply) one side Seismic 312 396 586 650
7/16-inch (OSB) one side Seismic 280 366 510 650
           
Assembly Description Orientation Screw Spacing at Edges & Field (Inches) Nominal Shear Value (Lbs./ft.)
1/2-inch gypsum board on both sides of wall with studs 24 inches o.c. Gypsum board applied perpendicular to framing with strap blocking behind the horizontal joint and with solid blocking between the first two end studs. 7/7 195
4/4 283

Restrictions

  1. Wide flange cee studs (1 5/8" wide) are required.
  2. Studs must be at least 20 gage material.
  3. Fasteners must be at least #8 diameter x 1" in length.

Compare the allowable shear values below with those of 8d and 10d nails. This type of system could reasonably be limited by the strength of the plywood.

Allowable Shear Values for Self-Drilling Fasteners - ITW Buildex
(Fastener Factor of Safety = 4.0)
 
Screw Size TEKS Point

Gauge of Stud Material

    20 18 16 14

#8-18

#3 182 272 302 303

#10-16

#3 182 316 385 388

#10-24

#3 187 302 388 423

#12-14

#3 192 339 405 492



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