The fabrication, uses, performance and sustainability of plywood.
What is plywood?
Plywood is one of the most widely recognized multi-purpose engineered wood-based panel products used in Canadian construction projects. Plywood binds resin and wood fibre sheets to form a composite material sold in panels. A typical plywood panel has face veneers of a higher grade than the core veneers. The function of the core layers is to increase the separation between the outer layers where the bending stresses are highest, improving resistance to bending forces.
How is plywood made?
Plywood panels are fabricated from multiple layers or plys of softwood veneer glued together with the grain direction of each layer of veneer perpendicular to that of the adjacent layers. These cross-laminated sheets of wood veneers are fastened together with a waterproof phenol-formaldehyde resin adhesive and cured under heat and pressure. In BC, plywood is made from softwood species, usually Douglas-fir or spruce, pine and fir (collectively known as Canadian softwood plywood—or CSP). The most common dimension is 4 feet × 8 feet. Plywood varies in thickness, the most common being ½-inch. There is a wide variety of choices when it comes to plywood, ranging from smooth, natural surfaces suitable for finish work to more economical unsanded grades used for sheathing. This includes a dozen common thicknesses and over twenty different grades. In Canada, Graded Douglas-fir Plywood (DFP) is manufactured to meet the requirements of the Canadian Standards Association (CSA) O121 standard, and CSP to CSA O151.
What is plywood used for?
BC manufacturers produce a range of plywood products for structure and non-structural uses suitable for both wet and dry service conditions, including subflooring, single-layer flooring, wall, roof and floor sheathing, structural insulated panels, webs of wood I-joists and concrete formwork. As exterior wall and roof sheathing, plywood can provide resistance to lateral forces such as wind and earthquake loads and form an integral component of the building envelope. It may be used as both structural sheathing and finish cladding. For exterior cladding applications, specialty plywoods are available in a broad range of patterns and textures, combining the natural characteristics of wood with the strength and rigidity. Other uses of BC-made plywood include RV fabrication and cargo-van panels, pallets, industrial containers, marine applications and furniture manufacturing.
Victoria Hill, New Westminster
Photo credit: KK Law
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Plywood can be chemically treated to improve resistance to decay or fire. A pressure process is used to preserve plywood in accordance with CSA O80 standards. It will also withstand some amount of water contact, unlike some comparable products. It will return to its nominal thickness as the wood dries. Plywood manufacturers are required to test their products to determine the effects of fire retardants, or any other chemicals.
How does plywood compare to other products?
Similar to oriented strand board (OSB), plywood is often a go-to product and is preferred for its many common uses. It provides exceptional light-weight strength and durability. When compared to OSB, plywood is lighter, stiffer and retains less water. Regardless of their differences, plywood and OSB are comparable products fabricated to meet the same standards of strength and structural performance.
BC Wood Supplier Directory
Looking for suppliers of plywood?
With the province of British Columbia recognized as a global leader in sustainable forest management, you can specify BC forest products with confidence. Connect with suppliers of plywood today.