Georgia-Pacific APA Engineered Wood Construction Guide - Walls - Manual (Page 19)

Wall Construction
ENGINEERED WOOD CONSTRUCTION GUIDE ■ FORM NO. B360P ■ © 2011 APA – THE ENGINEERED WOOD ASSOCIATION ■ WWW.APAWOOD.ORG 60
Wall Bracing
Wall bracing is typically a part of conventional prescriptive construction as found in 2009 International Building Code
(IBC) Section 2308 or the International Residential Code (IRC) Chapter 6 . Wall bracing is prescribed in a how-to format,
and braced walls generally do not require hold down devices or have significant nailing requirements. Usually, there is no
engineering required when using wall bracing since the “solution” is prescribed. For structures or portions of them that do
not meet the prescribed construction parameters in the IBC or IRC, engineered design is required.
Meeting the bracing requirements is easy when using wood structural panel wall sheathing because of its inherent
strength. More information is available at www.wallbracing.org and in the following APA publications:
■
Introduction to Wall Bracing, Form F430
■
Brace Walls with Wood, Form G440
Shear Walls
The engineered version of wall bracing is a shear wall. Shear walls are designed by an engineer to resist the specific
forces determined by engineering analysis. Shear walls have specific design values depending on their construction, fas-
tener spacing, fastener size, sheathing thickness and framing species.
Table 29 shows the Allowable Stress Design values
for single-sided sheathed wood structural panel shear walls. Shear walls are also permitted to be designed to account
for openings and with both sides of the wall sheathed. They usually require hold downs to resist overturning of wall
segments, as shown in Figure 20. More information on designing with shear walls is available in the APA publication
Design/Construction Guide: Diaphragms and Shear Walls, Form L350 .
Either APA RATED SHEATHING or all-veneer plywood APA RATED SIDING (and other APA RATED SIDING panels
that qualify on a proprietary basis) can be used in shear wall design. The data presented here give maximum shears for
walls with APA RATED SHEATHING, with plywood APA RATED SIDING installed directly to studs (APA Sturd-I-Wall),
and with panels applied over gypsum sheathing for walls required to be fire-rated from the outside.
Shear wall overturning moments may be transferred by a fabricated
steel bracket such as this. Regular foundation bolts may be all that is
required in some cases depending on engineering analysis.
APA RATED SHEATHING or
APA RATED SIDING 303
Studs
Fasteners to framing,
size as required
Hold-down anchor
Treated sill plate
Flashing to separate
siding from concrete
Bolt to foundation
Concrete foundation
FIGURE 20
SHEAR WALL HOLD-DOWN ANCHOR