The Difference Between Structural and Non-Structural Plywood

One of the most practical and useful materials within the construction industry, plywood can be used in a variety of different ways for a host of different jobs. All types of plywood can be categorised as either structural or non-structural, while plywood itself is available in multiple different forms and types.

Both structural and non-structural plywood are heavily utilised within the trade sector, and understanding the difference between the two types is vital. Here’s the difference between structural and non-structural plywood. 

Difference Between Structural & Non-Structural Plywood 

The type of glue that is used throughout the manufacturing process is the main difference between structural and non-structural plywood. Essentially, type-A or type-B bond glues are used for structural plywood boards, and type-C or type-D bond glues are used for non-structural plywood boards. 

While type-A bond glues are built on phenol formaldehyde resin, type-B bonds are based on a combination of melamine-urea formaldehyde. The bond that is created by both these types of glue is generated between the pile, and has the strength to withstand both temperature changes and damp conditions. The main difference between the A and B types is that the A-bond is a lot more durable than the B-bond, though both are still suitable for a variety of different uses. 

The type-C and D bond glues making up non-structural plywood boards are based on urea formaldehyde resin. This resin is known to deteriorate faster when subjected to high humidity and fluctuations in temperatures. This results in the type of plywood being unsuitable for structural use and outdoor use, too.   

Applications Suitable For Structural Plywood 

Getting the right wood for the project is essential. For the majority of the time, structural plywood is used within home construction, for example for:

• Flooring

• Roof sheathing

• Wall sheathing.

If a building code or requirement is specifying a particular material thickness, it’s generally structural plywood that is required – especially if the material is likely to be exposed to wet conditions. 

As the name suggests, structural plywood will be appropriate for creating structural support, such as support features like beams and hoardings within the construction of homes and buildings, as well as for use when creating roof bracing and walls. Structural plywood can also be used for plywood flooring, too. 

 

Not just suitable for heavier applications, structural plywood can also be used for packing crates, storage sheds, storage boxes, children’s play equipment, outdoor furniture and playhouses.

For durability, the A-bond type will ensure both longevity and resilience against harsh weather conditions, while the B-bond type is ideal for applications such as concrete framework and exterior door skins.

If you’re in search of a material to endure a large amount of moisture, such as for baths or saunas, marine grade plywood is the product for the job. The plywood is capable of withstanding very wet conditions. Made with weather and boil-proof glues, marine grade plywood is capable of enduring hours of continuous boiling without delamination – making it the ideal product for use in wet rooms. Before marine grade plywood can qualify as structural plywood, it must meet a certain, specific set of criteria, so ensure you’re aware of the requirements needed before parting with your money. 

Applications Suitable For Non-Structural Plywood 

Non-structural plywood, sometimes known as interior plywood, is more suitable for aesthetic finishes within the home. With a higher grade face compared to D-bond glues, C-bond plywood boards are the better option to choose if you plan on applying paint or similar materials to the boards. 

Furniture, wall linings and ceilings are all examples of where C-bond non-structural plywood would be appropriate, as well as when applying to decorative elements around the home or workspace. C-bond plywood boards also have a higher tolerance to humidity than their D-bond counterparts, which means their ideal for use in high-humidity spaces with internal areas. 

With less of a tolerance to humidity, D-bond plywood boards are best kept away from high-humidity areas when using interior plywood. Though not referred to as being a moisture-resistant product, C-bond plywood products do have a higher moisture resistance than D-bond products do. Other than that, both C-bond and D-bond boards are fairly similar in their applications, however D-bond boards do have slightly more visible blemishes than C-bond boards do, and C-bonds therefore often display a finer finish.

To Conclude 

Before you spend money on purchasing your plywood, it’s important to understand the type you need, as well as the bond-type appropriate for the job. Whether you’re looking for the right material for the kid’s outdoor playhouse, or are looking for decorative additions to furniture, there's suitable plywood available to ensure both durability and endurance. Doing this research ahead of your purchase, and understanding the difference between structural and non-structural boards, will save you both time and money later on.