Many fire resistance-rated wood stud wall assembles are constructed and tested with cross-bracing of the stud cavity. Cross bracing is a construction method used to stabilize the building structure against lateral forces. In basic terms, cross-bracing refers to the practice of bracing stud to stud to reduce the effective length of the stud, increasing its load capacity.
Frequently Asked Questions
- How is cross bracing installed in a wood stud wall assembly when the UL Design on Product iQ specifies “Cross braced at mid-height”?
In most cases, the bracing is done at the mid-height of the wall as that is the most effective location of the bracing. This may not be the only method specified by the National Design Specification, but contractors typically use 2 x 4 (or 2 x 6) members spanning stud-to-stud, located at essentially the mid-height of the wall, orientated with the 1.5 in. dimension vertically, offset vertically 1.5 in. between cavities to allow for nailing. The cross bracing is not intended as backing for horizontal joints of the gypsum board.
Additional details on cross-bracing can be found in the “National Design Specification for Wood Construction.” The PDF is available for purchase from AWC here. Most structural engineers are aware of the practice.
- Is “cross bracing” mandatory when it is referenced in the design?
Yes. It is mandatory as specified for the assembly construction, such as “Where Necessary for Clip Attachment”.