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.
ROOF CONSTRUCTION APA Panel Roof Sheathing The recommendations for roof sheathing in Table 30 apply to APA RATED SHEATHING Exposure 1 or Exterior, APA STRUCTURAL I RATED SHEATHING Exposure 1 or Exterior and APA RATED STURD-I-FLOOR Exposure 1 or Exterior.
Roof Construction only. Special conditions, such as heavy concentrated loads, may require constructions in excess of these minimums, or allowable live loads may have to be decreased for dead loads greater than 10 psf, such as tile roofs. Panels are assumed continuous over two or more spans with the long dimension or strength axis across supports.
Roof Construction from Table 30, and minimum fastener requirements are given in Table 32. Increased nail schedules may be required in high wind zones. Recommended nail schedules for high wind zones are described in APA Data File: Roof Sheathing Fastening Schedules for Wind Uplift, Form T325. APA RATED SHEATHING is equally effective under built-up roofing, asphalt or fiberglass shingles, tile roofing, or wood shingles or shakes.
Roof Construction TABLE 33 RECOMMENDED ROOF LOADS (PSF) FOR APA RATED SHEATHING WITH STRENGTH AXIS PARALLEL TO SUPPORTS(a)(b) (OSB and 5-ply/5-layer plywood panels unless otherwise noted) Panel Performance Category Span Rating APA STRUCTURAL I RATED SHEATHING 7/16 15/32, 1/2 19/32, 5/8 23/32, 3/4 APA RATED SHEATHING 7/16 15/32, 1/2 19/32, 5/8 23/32, 3/4 Panel Grade Maximum Span (in.
Roof Construction Long Span Systems Both preframed panel systems and direct application of sheathing to secondary or primary framing are common approaches in long span roof construction. Bay spacing and type of framing govern the choice.
Roof Construction Plywood Under Special Coatings Chemical coatings for roofs have increased the range of design possibilities, particularly in larger commercial structures with contoured or steeply pitched roof surfaces exposed to view.
Roof Construction TABLE 36 APA PANELS FOR OPEN SOFFIT OR FOR COMBINED ROOF DECKING-CEILING(a)(b) (Strength axis across supports. For APA RATED SHEATHING, where appearance is not a major concern, see Table 30.
Roof Construction FIGURE 26 CLOSED SOFFIT FIGURE 25 OPEN SOFFIT APA RATED SHEATHING Shim at each rafter for flush joint, if necessary, at change of panel thickness Strength axis Protect edges of Exposure 1 sheathing against weather Protect edges of Exposure 1 sheathing against weather APA RATED SHEATHING or any appropriate APA Exterior or Exposure 1 panel grade and thickness for desired appearance and load-carrying capacity (see Tables 30 and 36) Strength axis Continuous screened vent or louvered
Roof Construction TABLE 38 ALLOWABLE SHEAR (POUNDS PER FOOT) FOR HORIZONTAL APA PANEL DIAPHRAGMS WITH FRAMING OF DOUGLAS-FIR, LARCH OR SOUTHERN PINE(a) FOR WIND(b)(c) OR SEISMIC LOADING(c) Panel Grade Minimum Nominal Width of Framing Members at Adjoining Minimum Minimum Panel Nail Nominal Edges and Penetration Panel BoundCommon in Framing Thickness aries(g) Nail Size(f) (in.) (in.) (in.) APA STRUCTURAL I grades 4 2-1/2(e) 2(e) Nail Spacing (in.
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.