Structural plywood and non structural plywood are often mentioned in discussions on applications for construction, architecture and design. Further, terms such as appearance-grade, architectural, lightweight, interior and heavyweight are frequently used to describe the different variations and their application.
Matilda Veneer aims to break down structural plywood and non structural plywood for better understanding of their differences, benefits and project suitability.
What is Plywood?
In simple terms, it is a wooden sheet of material made up of multiple (two or more) layers of timber, with alternating grain directions. The layers are bonded together using strong resins, pressure and heat to create a composite material suitable for use in a myriad of commercial and domestic projects.
Plywood Vs Veneer
Where a wood veneer refers to thin slices of wood glued onto core panels (typically wood, particle board or medium-density fibreboard - MDF), plywood is essentially composed of multiple layers of veneer, manufactured together to form one material, which is much stronger structurally.
Durability and Grades
There are four types of glue bond used when manufacturing plywood, giving different levels of durability. This is the main differentiator in what makes each variety either structural or non-structural plywood. This is because some types of adhesives are better than others at resisting the weather and elements.
Type A Bond
Specified for marine and exterior plywood, this bond uses phenol-formaldehyde resin, which does not weaken under wet, cold or hot conditions. Under the Australian Standard for structural plywood (AS 2269), only plywood using A-Bond glue can be considered for a structural rating. However, it is important to note that this does not mean all A-Bond plywood is ‘structural plywood’ – the manufacturer would need to test their products accordingly to determine whether it could be structurally rated.
When a product is structurally rated, it will usually be listed as such – but when in doubt, the structural rating specifications should be requested from the manufacturer.
Type B Bond
Using a melamine fortified urea formaldehyde resin, this bond is suitable for exterior applications such as concrete formwork. While the Australian Standard for structural plywood doesn’t permit the use of B-Bond plywood despite its structural potential, it is still a high quality glue and rightly considered an exterior option.
Type C Bond & Type D Bond
These two types of bonds use urea-formaldehyde resin, which is not recommended for structural applications, but provides great aesthetic for design and appearance-grade applications. These are non structural, as they do not have a structural rating.
Structural Plywood and ‘Type A’
The term ’structural’ is related specifically to the Australian Standard for structural plywood (AS 2269), which specifies the requirements for the manufacture, grading, finishing, and branding of structural plywood. As per the Standard, only Type A-Bond is permitted. There are eight standard stress grades, so it is important to choose the right stress-grade for your application.
Key benefits of structural plywood varieties:
- Resistant to chemicals, corrosion, and damage
- Resistant to exposure to the elements such as heat, cold, and humidity
- 2x shear carrying capacity compared to timber
- Offers dimensional stability to a high degree
- Offers a high strength to stiffness to weight ratio
- Allows nails close to panel edges
Non Structural Plywood
As the name suggests, non structural plywood is any plywood not certified as structural under AS 2269. This includes all glue types and veneer grades. Non structural plywood can still be strong and provide structural integrity to a project; however, it is not certified to do so. Meaning, in some applications, non structural plywood may not be permitted.
Non structural plywood, sometimes referred to as interior plywood, is mostly used for decorative and aesthetic finishes and applications, such as wall and ceiling linings. Non structural plywood, being intended for use in non structural applications, is mostly applied where a high-quality visual finish is required such as panelling, joinery and furniture.
Non structural plywood varieties can provide stunning visual effects, which is why they are often referred to as appearance-grade plywood. Non structural plywood can be lighter or cheaper, or simply allow for more of the focus to be on producing visually-beautiful pieces.
Non structural plywood can be more cost-efficient in some instances and allows for greater weighting towards aesthetic appeal. However non structural plywood, as the name suggests, is not a good fit for exterior or structural purposes. It is often used for ceilings, wall linings, furniture and aesthetic design or decorative applications.
C Bond and D Bond are true interior plywoods. Both have non-structural specifications, with C-bond being the best option where a higher tolerance to humidity is required than D-Bond (although it is important to note that C-Bond products are not technically considered to be moisture resistant products).
Key benefits of non-structural plywood varieties:
- Visually pleasing – non structural plywood is great for applications where design is the key purpose
- Where structural requirements are not a concern, more focus can be weighted towards both appearance and versatility with non structural plywood varieties
- It can be a lightweight option
- Non structural plywood can be more cost-effective
- For design and decorative applications, non-structural plywood is a great option for visual projects
High Quality Non-Structural and Structural Plywood and Veneer
Matilda Veneer is Australia’s leading manufacturer of timber veneer and plywood products, which have been used in leading architectural projects and award-winning applications, including the Melbourne Cricket Ground, airport terminals around the world, hotels, universities, hospitals, shopping centres, iconic locations such as the Sydney Opera House and the Dr Chau Chak Wing Building in Sydney.
Matilda Veneer’s range of plywood products includes fire rated solutions such as Fireply X, Matilda Fireply and Hoop Pine FR Panel, as well as appearance grade panels such as Hoop Pine, Birch and Matilda Lite Ply. The range includes both structural and non structural plywood and a huge range of veneers.
Image: Hoop Pine Plywood – Dr Chau Chak Wing Building, Sydney