Exploring the versatility of plywood
Sometimes underrated, plywood is an inexpensive, strong and stable manufactured wood panel from the family of manufactured boards, such as MDF (medium density fibreboard) and chipboard. Plywood is made from a combination of sheets of wood fibre veneer, or 'plies', and resin which have been bonded together under pressure and can be used for furniture, flooring and construction.
The benefits of plywood
Plywood is a highly versatile and durable engineered composite wood product. Its structure makes it a strong and reliable material for construction and it is less prone to warping than natural wood, due to adjacent plies which have their grain rotated up to 90 degrees. The alternation of the grain is called cross-graining and this reduces the tendency of wood to split when nailed at the edges and also reduces expansion and shrinkage, providing dimensional stability and ensuring that the panel is strong across all directions.
Sold in standard sheet sizes with a range of thicknesses – the most common being 4, 6, 9 and 12mm thick – a typical plywood panel has face veneers of a higher grade than the core plies. Within a piece of plywood, the principal function of the core layers is to increase the separation between the outer layers – where the bending stress is highest – thus increasing the panel's resistance to bending. Thicker panels of plywood can span greater distances under the same loads and are very hard to bend perpendicular to the grain direction of the surface ply thus reducing warping.
Best quality plywood products have their plies arranged in steps of 45 degrees (0, 45, 90, 135, 180 degrees) which gives strength in multiple axes. The highest quality plywood has plies set at 30 degree intervals (0, 30, 60, 90, 120, 150, 180 degrees) in seven layers which is harder to manufacture and is, therefore, marginally more costly.
Bendable plywood, commonly known as 'flexiply', is constructed from several veneers all running in the same direction which allows excellent flexibility, where a curved surface is required, for example in furniture or shopfitting. Because it requires no special equipment or prior experience, flexible plywood helps keep the costs of labour and material to a minimum.
Softwood plywood is usually formed from cedar, fir, pine or redwood and typically used for construction, e.g. roofing, subfloors and flooring, and industrial purposes. Plywood used for flooring is often constructed in a tongue and groove formation to prevent one board from moving up or down relative to its neighbour, providing a solid feeling floor when the joints do not lie over joists.
Plywood used outdoors
Exterior grade plywood can be used outside, due to the water-resistance of its adhesives, and so it can be used for cladding and in the construction of sheds and outbuildings but will still require a coat of paint or varnish to protect the outer veneer from the elements. Marine plywood material is made with waterproof adhesive, and so can be used underwater.
Usually faced with a hardwood veneer, such as ash, oak, birch, teak, maple or mahogany, decorative ply can be used in a variety of applications, including panelling and furniture, and can even have a thin veneer applied to edges to create the appearance of solid wood but with all the benefits of a manufactured material.
At Chandlers, we have a wide range of plywood materials for every project, as well as experts on hand help you choose the right product for your requirements. More information about our plywood and other timber products available at Chandlers can be found here.