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.
FLOOR CONSTRUCTION Engineered wood floor systems give builders and designers strength, dependable performance and design flexibility. A variety of floor framing and wood structural panel products can be used in floor construction. To select the appropriate products and floor design, it is essential to define the predicted loads and to consider both the structural requirements and compatibility with the finish floor requirements.
Floor Construction Product Standard PS 1 or PS 2. Plywood APA STURD-I-FLOOR meets PS 1 Underlayment specifications, but in addition to qualifying as underlayment, STURD-I-FLOOR carries a Span Rating (thin underlayment carries no Span Rating). STURDI-FLOOR is easy to use and specify because the maximum recommended spacing of floor joists – or Span Rating – is stamped on each panel. Panels are manufactured with Span Ratings of 16, 20, 24, 32 and 48 inches.
Floor Construction TABLE 12 RECOMMENDED UNIFORM FLOOR LIVE LOADS FOR APA RATED STURD-I-FLOOR AND APA RATED SHEATHING WITH STRENGTH AXIS PERPENDICULAR TO SUPPORTS(a) Sturd-I-Floor Span Rating Sheathing Span Rating Minimum Panel Performance Category Maximum Span (in.) 16 oc 20 oc(e) 24 oc 32 oc 48 oc 24/16, 32/16 40/20 48/24 60/32(f) NA 7/16(d) 19/32, 5/8 23/32, 3/4 7/8 1-3/32, 1-1/8 16 19.2 24 32 48 (a) Panels 24" or wider applied over two spans or more, dry; normal load duration assumed.
Floor Construction Sturd-I-Floor 32 oc and 48 oc FIGURE 2 Install APA RATED STURD-IFLOOR 48 oc or 32 oc panels over 2x joists or I-joists spaced 32 inches on center (Figure 2). Install APA RATED STURD-IFLOOR 48 oc over 4x girders 48 inches on center (Figure 3). For the 48 oc method, supports may be 2x joists spiked together, 4x lumber, glued laminated timber (glulams), lightweight steel beams, or wood I-joists or floor trusses.
Floor Construction APA Performance Rated Rim Board® A Rim Board is the wood component that fills the space between the sill plate and bottom plate of a wall or, in second floor construction, between the top plate and bottom plate of two wall sections. The Rim Board must match the depth of the framing members between floors or between the floor and foundation to function properly. In addition to supporting the wall loads, the Rim Board ties the floor joists together.
Floor Construction The glue bond is so strong that floor and joists behave like integral T-beam units. Floor stiffness is increased appreciably over conventional construction, particularly when tongue-and-groove joints are glued. Gluing also helps eliminate squeaks, floor vibration, bounce and nail-popping. Field-glued floors go down quickly, even in cold weather, using ordinary construction materials and techniques.
Floor Construction 8. Stagger end joints in each succeeding row, where possible. A 1/8-inch space between all end joints and edges, including tongue-and-groove, is recommended. Use a spacer tool to assure accurate and consistent spacing. 9. Complete all nailing of each panel before glue sets. (See Table 11.) Check the glue manufacturer’s recommendations for allowable time. Warm weather accelerates glue setting.
Floor Construction FIGURE 5 APA PANEL SUBFLOORING Stagger end joints (optional) APA RATED SHEATHING Wood strip, wood blocks, or lightweight concrete flooring 2x rim joist or APA Rim Board gth en Str 2x treated sill is ax Panel edges T&G or supported on blocking (shown) unless covered with underlayment, light-weight concrete or wood strip flooring perpendicular to panel edges. Notes: 1. Provide adequate moisture control and use ground cover vapor retarder in crawl space.
Floor Construction Underlayment grades of plywood have a solid, touch-sanded surface for direct application of carpet and pad. For areas to be covered with resilient floor covering, specify panels with “sanded face,” or certain other grades as noted in Table 14. Special inner-ply construction of Underlayment resists dents and punctures from concentrated loads.
Floor Construction Always protect plywood Underlayment against physical damage or water prior to application. Panels should, however, be allowed to equalize to atmospheric conditions by standing individual panels on edge for several days before installation. Install plywood Underlayment, smooth side up, immediately before laying the finish floor. For maximum stiffness, place face grain across supports. Edge joints of underlayment panels should be offset by at least 2 inches from joints of subfloor panels.
Floor Construction TABLE 15 APA FLOOR SYSTEMS FOR CERAMIC TILE FLOORING BASED ON THE TILE COUNCIL OF NORTH AMERICA HANDBOOK FOR CERAMIC TILE INSTALLATION TCNA No. Service Classification(a)(b) Max. Joist Spacing (in. o.c.
Floor Construction TABLE 15 continued TCNA No. Service Classification(a)(b) Max. Joist Spacing (in. o.c.
Floor Construction APA Panel Stair Treads and Risers A growing number of builders and manufacturers are using APA panels for treads and risers of both site-fabricated and prefabricated stairs in closed-riser stairways. Risers support the front and back of the tread, creating a very short effective span. TABLE 16 APA PANEL STAIR TREADS Minimum Performance Category APA panel stair treads may be used interchangeably with boards when NailNailedthe system is to include closed risers.
Floor Construction TABLE 17 PS 1 PLYWOOD SPAN RATING OR PERFORMANCE CATEGORY RECOMMENDATIONS FOR UNIFORMLY LOADED HEAVY DUTY FLOORS(a) (Deflection limited to 1/240 of span.) Uniform Live Load (psf) Center-to-Center Support Spacing (inches) (Nominal 2-Inch-Wide Supports Unless Noted) 12(b) 16(b) 19.
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.
