Structural engineered wood products are "engineered" by virtue of possessing structural properties that are confirmed by methods other than simple visual grading. Glued engineered wood products are manufactured by bonding together wood strands, veneers, lumber or other forms of wood fiber to produce a larger and integral composite unit with structuralperformance characteristics.
These high performance building components achieve predictable and reliable performance characteristics and meet rigorous quality standards.
APA - The Engineered Wood Association divides structural glued engineered wood products into four general categories: 1) wood structural panels, including plywood, oriented strand board, and composite panels; 2) gluedlaminated timber (glulam); 3) structural composite lumber (SCL), including primarily laminated veneer lumber (LVL); and 4) wood I-joists.
These wood products are further "engineered" for the structural applications in which they are used. The highly predictable performance characteristics of engineered wood products is important to design professionals, building officials and the end user.
APA'strademarked plywood, OSB and composite panels and APA-EWS trademarked glulam, I-joists, and LVL are all part of this family of engineered wood products.
RECOMMENDED PDF RESOURCES
GUIDE TO ENGINEERED WOOD PRODUCTS ( K)
Comprehensive guide to engineered wood construction systems for both residential and commercial/industrial buildings. Includes information on plywood and oriented strandboard (wood structural panels), glulam, I-joists, structural composite lumber, typical specifications, and design recommendations for floor, wall, and roof systems, diaphragms, shear walls, fire-rated systems, and methods of finishing. (84 pages)
Lesson 2: Common Characteristics of Engineered Wood Products
All glued engineered wood products are made by combining wood strands,veneers, lumber, or other wood fiber with glue to form a larger, more efficient composite structural unit. In other words, the sum is greater than the individual parts.
These products are extremely resource-efficient because they use more of the available resource with minimal waste. In most cases, engineered wood products are produced using faster growing and often underutilized wood species frommanaged forests and tree farms, thus reducing the industry's reliance on so-called "old growth" forests. A variety of tree species are used to produce the products, as explained in Unit 2. Because engineered wood products are manufactured using dry — not green — lumber, the resulting products have superior dimensional stability.
The adhesives used to make engineered wood are stronger than thewood itself. Phenol-formaldehyde glues are used to make all APA-trademarked Exposure 1 and Exterior panels. This type of glue emits very small amounts of formaldehyde that does not present a danger to humans or animals. Because formaldehyde emissions associated with phenolic resin bonded products are so low, HUD exempted these products from all testing and certification requirements of theManufactured Home Construction and Safety Standards.
Non-APA wood-based panels may or may not contain phenolic resin glues; emissions of these products should be addressed by the manufacturer or appropriate trade association.
Engineered wood products are designed and manufactured to maximize the natural strength and stiffness characteristics of wood through (a) orientation of woodveneers, strands, or laminations and, (b) by combining wood with adhesives.
APA panel products possess inherent strength and durability. Because of their stiffness, they can often be used with less framing or bracing than other materials require for the same application. They resist bending, or deflection; racking, or shape distortion; and impact damage. Because of their split resistance, wood...