Engineered Wood CONSTRUCTION GUIDE
©2011 APA – THE ENGINEERED WOOD ASSOCIATION • ALL RIGHTS RESERVED. • ANY COPYING, MODIFICATION, DISTRIBUTION OR OTHER USE OF THIS PUBLICATION OTHER THAN AS EXPRESSLY AUTHORIZED BY APA IS PROHIBITED BY THE U.S. COPYRIGHT LAWS. Engineered Wood Construction Guide 2 WOOD The Natural Choice Engineered wood products are a good choice for the environment. They are manufactured for years of trouble-free, dependable use. They help reduce waste by decreasing disposal costs and product damage.
Engineered Wood Construction Guide APA engineered wood products are used in a wide range of construction applications. Time-tested panel products are used in traditional wood-frame construction and in combination with other engineered wood products and systems. For low in-place cost, versatility, and superior performance, engineered wood systems are simply hard to beat. This guide from APA is designed as a reference manual for both residential and commercial construction.
WALL CONSTRUCTION Building codes require that walls resist wind pressures caused by the design wind speeds, resist wall-racking forces and provide weather protection. This section provides details on how wood structural panels can be used to meet these fundamental requirements. APA Sturd-I-Wall® The APA Sturd-I-Wall system consists of APA RATED SIDING (panel or lap) applied direct to studs or over nonstruc tural fiberboard, gypsum or rigid foam insulation sheathing*.
Wall Construction TABLE 20 APA RATED LAP SIDING APPLIED DIRECT-TO-STUDS OR OVER NONSTRUCTURAL SHEATHING(a)(b)(c)(d)(e) Minimum Nail(f) Shank Diameter (in.) Penetration in Framing (in.) Minimum Performance Category (in.) Wall Stud Spacing (in. o.c.) 3/8 0.113 1.
Wall Construction A single layer of wood structural panel siding, since it is strong and rack resistant, eliminates the cost of installing separate structural sheathing or diagonal wall bracing. Panel sidings are normally installed vertically, but may also be placed horizontally (long dimension across supports) if horizontal joints are blocked. Maximum stud spacings for both applications are given in Tables 19, 20 and 21.
Wall Construction Siding Fasteners Hot-dip galvanized nails are FIGURE 9 recommended for most siding applications. For best APA STURD-I-WALL (Horizontal Panel Siding Installation) performance, stainless steel Building paper or aluminum nails should or other code-recognized weather-resistive barrier be considered. APA tests also show that electrically or mechanically galvanized Battens at 4' or 8' o.c. to conceal butt joints at steel nails appear satisfacpanel ends.
Wall Construction For other fastener types, refer to Table 22. It provides the withdrawal resistance for a number of different fastener types (smooth-, ring- and screw-shank nails; wood screws and vinyl siding nails). Together with the wind load tables in the 2006 and 2009 International Residential Codes, IRC Tables R301.2(2) and R301.2(3), the attachment schedules for any combination of siding type, continuous wood structural panel sheathing, design wind speed and exposure can be determined.
Wall Construction FIGURE 10 APA STURD-I-WALL (Horizontal Lap Siding Installation)(a) Building paper or other code-recognized weather-resistive barrier required Leave 1/8" spacing and caulk vertical joints unless otherwise recommended by siding manufacturer APA RATED SIDING (lap siding), maximum width 12". Minimum headlap 1".
Wall Construction TABLE 23 APA RATED LAP SIDING APPLIED DIRECT-TO-STUDS OR OVER STRUCTURAL SHEATHING(a)(b)(c) Minimum Maximum Wind Speed (mph) Minimum Nail Performance Wind Exposure Category (d) Shank Diameter Category Fastener Spacing Lap Siding Width (in.) Lap Siding (in.)(e) (in.) B C D 0.113 3/8 6 (a) Table is based on wind pressures acting toward and away from building surfaces, at 30-ft height in wall Zone 5 (corners) with smallest effective area, per Section 6.4.2.2 of ASCE 7-05 and Section R301.
Wall Construction APA Panel Wall Sheathing APA RATED SHEATHING meets building code wall sheathing require ments for wind pressures and wall bracing. Even when foam or other nonstructural sheathing is used, APA RATED SHEATHING corner bracing panels (Figure 14) of the same thickness meet code wall bracing requirements. Installation recommendations are given in Figure 13 and Table 24. Recommended wall sheathing spans with brick veneer or masonry are the same as those for panel sheathing (see Table 24).
Wall Construction APA Sheathing Under Stucco Greater stiffness is recommended for wall sheathing when stucco is to be applied. To increase stiffness, apply the long panel dimension or strength axis across studs. Blocking or a plywood cleat is recommended at horizontal joints. Blocking is required for shear wall and wall bracing applications. For panel recommendations applied horizontally or vertically, see Table 25.
Wall Construction FIGURE 17 TYPICAL PANEL SIDING JOINT DETAILS (Note: Water-resistive barrier [building paper or house wrap] is required behind siding.) VERTICAL WALL JOINTS Butt Shiplap Reverse Board and Batten Siding Vertical Batten Batten T1-11 & Channel Groove Treat panel edges with water repellent Use ring-shank nails for the battens, applied near the edges in two staggered rows Note: Nailing of both panel edges along shiplap joint is recommended.
Wall Construction APA Rated Siding Patterns and Grades APA RATED SIDING, including 303 plywood siding, is available in a wide variety of surface textures and patterns. For descriptions of siding surface patterns and thicknesses, refer to APA Product Guide: APA Performance Rated Sidings, Form E300. Actual dimensions of groove spacing, width and depth may vary with the manufacturer. Where the characteristics of a particular wood species are desired, specify by grade and species preference.
Wall Construction Finishing APA RATED SIDING may be finished with a variety of products such as semi transparent stains, solid-color stains or paint systems. The recommended finishes depend on the type of siding product, and whether it has an overlaid surface. Oil-based, semitransparent stains may be used on certain veneer-faced siding products as detailed in Table 27. Solid-color stains may be used on most APA RATED SIDING products and usually provide better protection.
Wall Construction Paints (all-acrylic latex) Top-quality acrylic latex house paint systems are recommended for all APA Rated Sidings, except brushed plywood. If house paint is used on plywood siding, an all-acrylic latex paint system consisting of at least one stain-blocking prime coat and an all-acrylic latex topcoat is recommended. For extractive staining woods, some house paint systems utilize an oil-alkyd primer. Others use up to two coats of a stain-blocking acrylic latex primer.
Wall Construction FIGURE 18 FIGURE 19 PANELING NEW INTERIOR WALLS PANELING EXISTING INTERIOR WALLS Block all unsupported edges Leave 1/32" spacing at panel edges Install 1x2 furring strips horizontal and/or vertical with nails into studs, expansion bolts, concrete nails, powder-actuated fasteners, or adhesive as necessary. Use treated furring strips if in contact with concrete or block walls.
Wall Construction TABLE 29 ALLOWABLE SHEAR (POUNDS PER FOOT) FOR APA PANEL SHEAR WALLS WITH FRAMING OF DOUGLAS-FIR, LARCH, OR SOUTHERN PINE(a) FOR WIND(b)(c)(d)(e)(f) OR SEISMIC(c)(d)(e)(g) LOADING Panels Applied Over 1/2" or 5/8" Gypsum Sheathing Panels Applied Direct to Framing Panel Grade Minimum Minimum Nominal Nail Nail Size Panel Penetration (common or Thickness in Framing galvanized (in.) (in.
Wall Construction 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.
Additional Information ADDITIONAL INFOR M ATION About APA – The Engineered Wood Association APA – The Engineered Wood Association is a nonprofit trade association of and for structural wood panel, glulam timber, wood I-joist, structural composite lumber, and other engineered wood product manufacturers. Based in Tacoma, Washington, APA represents approximately 150 mills throughout North America, ranging from small, independently owned and operated companies to large integrated corporations.
Engineered Wood Construction Guide APA offers a comprehensive set of services and tools for design and construction professionals specifying and using engineered wood products and building systems. If you’re looking for detailed product information, training material, or technical assistance, APA can help. ➠ www.apawood.org, APA’s website, is your link to in-depth design and building support, including a library of more than 400 publications available for instant pdf download or hard-copy purchase.