Engineered Wood Components

The scope of Engineered Wood Products is immense. Engineered wood products are a high-performance, consistent, reliable and environmentally responsible choice for everything from construction to materials handling applications to home projects.  New building systems and high-tech products are changing the way builders build and homeowners live. Leading the change into tomorrow are high performance glued engineered wood products and systems that provide builders with cost-effective and labor-saving alternatives in construction applications behind the walls.

Glued engineered wood is manufactured by bonding together wood strands, veneers, lumber or other forms of wood fiber to produce a larger and integral composite unit that is stronger and stiffer than the sum of its parts. The phenomenal growth in the use and acceptance of engineered wood is proof that a new era is dawning in residential building.

We spoke with Tom Williamson, Executive Vice President of Engineered Wood Systems, a Tacoma, Washington-based affiliate of the APA.

Williamson explained why these products have become so popular: "Glued engineered wood products provide designers with greater flexibility to create the open spans desired by today's home owners. And they result in stronger and more durable floors, walls and roofs. They are carpenter-friendly and lightweight, making them easier to use by the builder."

Williamson brought up the benefits to the environment: "Manufactured wood products use less wood fiber than traditional wood products to achieve the same or better performance. They make use of wood elements that might otherwise not be suitable for use as a structural product. In addition, these products make efficient use of faster-growing trees from managed forests and farms and previously under-utilized species which helps preserve old-growth forests. Also, engineered wood compares very favorably to non-wood products with regard to pollutants and emissions during manufacturing."

To promote high quality building practices using engineered wood products, the APA instituted the Code Plus Program. It requires participating builders to go one step above minimum code requirements. For example, most areas require some sort of let-in bracing or corner bracing using OSB or plywood on the corners. A Code-Plus home would have fully sheathed walls using OSB or plywood. The APA provides materials such as brochures, window decals and a certificate suitable for framing for builders to promote the fact that their homes are built according to Code Plus criteria.

Overview of APA Engineered Wood Products

Sheathing
Structural wood panel wall sheathing, whether plywood or oriented strand board (OSB), is a major element in a high-quality, engineered wood home.

OSB consists of wood strands bonded with waterproof adhesives to form a mat which is then pressed under high pressure and temperature to create the finished product. Like the veneers in plywood, these mats are layered and cross-oriented for maximum strength, stiffness and stability.

OSB is widely used as construction sheathing and as the web material for wood I-joists. A house with walls sheathed with OSB or plywood will provide much greater resistance to high wind and seismic conditions and will be four times stronger than one with only foam sheathing - providing a shear capacity of 350 lbs/foot.

Laminated Veneer Lumber
Laminated Veneer Lumber (LVL) is the most widely used of the structural composite lumber products.  It is produced by bonding thin wood veneers together in a large billet with the grain of all veneers parallel to the long direction.  It is then sawn to the desired dimensions depending on the construction application.  Some of the product's many uses are headers and beams, hip and valley rafters, and a flange material for prefabricated wood I-joists.