Simpson Strong-Tie offers many products which can be used in construction of the braced wall panels to meet the provisions of the building code. The information contained within this site is intended to offer a general overview of the braced wall provisions and highlight Simpson product solutions which meet the building code requirements.
What Are Braced Walls and Why Are They Needed?
Each of the model building codes (UBC 1997 2320.11.3, IRC 2000/2003 R602.10 and IBC 2000/2003 2308.9.3) require all exterior walls of a non-engineered or conventionally designed single family residences to be braced against lateral loads from wind or earthquakes. Depending on the configuration of the home, wall bracing may also be required for some interior walls. Each wall brace, called a braced wall panel, has specific prescriptive construction requirements which must be followed and several bracing options are offered in the codes. The building codes define eight prescribed ways to build a braced wall ranging from 4' to 8' in length. A few examples are let-in bracing (like Simpson RCWB or WB/WBC), wood structural panel sheathing and gypsum board. For areas where window or door openings do not provide enough space to put a standard panel, the building codes also allow for alternate braced wall panels to be site built to a minimum dimension of 2'-8". The IRC also provides separate bracing requirements for homes which are continuously sheathed with OSB or Plywood. The IRC also provides additional alternate braced wall panel designs which can be site built to a minimum dimension of 1'-4".
The braced wall panels are required to be strategically located in a given wall line to provide an effective system. The codes mandate that the braced wall panels be located near each end of a wall and at least 25 feet on center (see Figure 1 below). Designated wall bracing must also make up a certain percentage of overall wall length based on several factors including wind requirements, seismic category and method used. In a given wall line, the walls may be offset out of plane and still be considered part of the wall line provided that no single offset is over 4 ft or the total offset is no more than 8 ft (see Figure 2 below).