Plywood

The strongest, lightest, most versatile utility and decorative product made from a renewable resource, plywood is kilo for kilo stronger than steel.

Plywood is a multi purpose type of engineered wood which is made from thin sheets of wood veneer. Plywood has been manufactured for thousands of years and was originally produced due to a shortage of fine wood. A common reason for using plywood instead of timber is its stability, with its superior resistance to cracking, shrinkage, twisting and warping.

There are many different qualities of plywood available suitable for a huge range of applications. Veneer quality, glue type and timber species are the differentiating elements that will determine the plywood type suitable for a specific application.

Plywood can be used in construction for bracing, concrete formwork, hoardings, exterior and external cladding, flooring, boat building, packaging as well as for decorative applications with furniture, cabinetry, benchtops, doors, partitions and signs, to list a few.

HOW IS IT MADE?
Plywood is made up of thin layers of sheets of timber veneer, called plies. These are glued together with each of the plies’ grain direction running at right angles. This is called cross banding and is used to make the plywood stronger. The sheet of plywood is then pressed, usually with heat, to cure the glue for a stable sheet. Plywood usually comes in an odd number of plies which is said to reduce warping and ensure the ‘face’ and ‘back’ veneer layer’s grain runs in the same direction.

THE BENEFITS OF PLYWOOD INCLUDE:
Renewable Resource – A natural product from a renewable source
Beautiful – Preferred because of its warmth and natural markings
Strength – the unique cross layering structure makes it kilo for kilo stronger than steel.
Efficiency – Uses less of the log than timber
Versatility – Can be bent and formed to meet various sizes and shapes
Durability - Long lasting and good resistance to damage

PLYWOOD GRADES
Plywood grades are determined by a veneer quality on the face and back of each panel. The grade is indicated by letters (ie. C/D Plywood). The first letter states the quality of face veneer (best side), while the second letter denotes the surface quality of the back of the panel.

"A": is the best quality available. Can be defect free or contain small knots, providing they are replaced with wooden plugs or repaired with a synthetic patch. This veneer has virtually no blemishes and is very well sanded providing a smooth paintable face quality.

"B": Second highest quality veneer grade suitable for a high quality paint finish. It may contain small knots and narrow surface splits. The surface is usually sanded smooth.

"C": Considered to be a non appearance grade, but a good choice for general construction purposes. Some manufactures may repair the defects and knots with synthetic filler. Panels are typically not sanded.

"D": Considered to be the lowest quality veneer and often used for the back surface for construction grade panels. It can have several defects, large and small, as well as open knots up to 75mm in diameter. "D" grade veneers are neither repaired nor sanded. They are designed specifically for structural applications where the decorative appearance is not a requirement. This grade is not recommended for permanent exposure to the weather.

Interior Plywood: Plywoods for interior use only are made from various hardwood and softwood species, and can only be used in interior applications such as wall sheathing, furniture (where exposure to moisture is limited) and cabinetry. Interior plywood is available in most grades, as well as in a number of hardwood species.

Marine Plywood: When moisture resistance is a priority, marine ply uses the best adhesives and is manufactured to the highest standards. It is most commonly graded as AA, with two top grade faces. It also has an A bond glue which will not deteriorate in wet weather conditions, in the heat or in the cold. You can recognise the A bond glue by the black colour it is when dried.

Exterior Plywood: The most common type of plywood, readily available at hardware stores and retail outlets. Exterior Plywood is structural and can be used for bracing, cladding, building and other applications where a strong yet inexpensive material is needed.

Structural Plywood: Structural plywood can be used for bracing, cladding, building and other applications. When the appearance of the face is of lesser concern than the strength and stability of the material, structural plywood will typically be the choice. The resins used are designed for extra strength to avoid separating of the layers. Structural plywood is usually a CC or CD grade.