Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Wood on Steel Studs -Reply

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Los Angeles is currently working on revising its requirements for use of
plywood shear walls on steel stud framing. You may now design them
according to the requirements of the 1997 UBC Tables 22-VIII-A,B,C. 
These tables limit you to 18 and 20 gage studs. Fasteners are #8 x 1 inch
with flat heads. Compass International has COLA RR on the approved
screws. A new memo will be issued soon. Contact Stuart Tom @
213-580-1154.

Side note: Design the framing at 24 inch o.c. to reduce the effects of
heat loss if you're in a residential building. Otherwise you may cost the
owner extra money on thicker rigid insulation on the exterior walls due to
CA State energy code limits. Because tracks are not structural (unless
you design them to be),  all members in the vertical load path must stack.

Common mistakes also include the omission of stiffeners at supports and
bracing on both sides of the walls to match axial load assumptions by the
manufacturer. This latter condition occurs in attics. You must also
specify the steel framing manufacturer because allowable values can
vary and there are no "code tables" like wood for framing members.

Lateral load path design, particularly at diaphragm to shear wall
connections requires special detailing.  Site inspections show common
errors and omissions on these elements (like wood). Plan on long
structural observations.

Tim McCormick, P.E.
Training Officer
City of Los Angeles, Building & Safety