Plywood has been one of the most useful construction material in architectural history. Its origins date back to the earliest empires of mankind. Plywood has since evolved into many forms.
Two of the more popular terms that you may come across when choosing the correct type of plywood are structural and nonstructural plywood.
While the two terms may seem very similar, mixing them up will have potentially catastrophic consequences.
The fundamental difference between structural and non-structural plywood
The main difference between structural and non-structural plywood is the type of glue used in the manufacturing of the boards.
Plywood boards that meet structural standards have A-Bond types of glue bond. These are boards that are produced from phenol formaldehyde resin which will create a glue bond that will not weaken if exposed to wet conditions as well as temperature changes. B-Bonds are also considered structural plywood and made with Melamine-urea-formaldehyde.
Non-structural plywood, on the other hand, falls under the C-D Bond. This means that the boards are produced from urea formaldehyde resin and is not suitable for structural as well as outdoor use. The glue bond will deteriorate when it is exposed to wet and damp conditions as well as temperature changes.
Suitable applications for structural plywood
As the name suggests, structural plywood is best used for building and construction purposes like beams and hoardings.
But this type of plywood can also be used in crates, internal structures, bins, boxes, and outdoor furniture.
Some structural plywoods are also used for wall and roof bracing. If you want the best structural plywood board in terms of longevity and durability, get the A-Bond type as those can definitely withstand some serious beating from the different elements.
If you are looking for something that can withstand a lot of moisture, there is a special type of structural plywood called Marine Grade Plywood. This type of board is so adept at taking in water that it can even withstand hours of continuous boiling without de-laminating. Marine Plywood is made with glues that are WBP which stands for weather and boil proof.
Structural plywood can be both A and B-Bond type. The difference with the two is that A-Bond is still much more durable than its B counterpart. Plywood boards with B-Bond are still suitable for exterior door skins and concrete formwork where it has some protection from harsh weather elements.
Suitable applications for non-structural plywood
Non-structural plywood is sometimes called interior plywood and is often used for aesthetic finishes inside the structure.
The C-Bond plywood board has a higher grade face and is your best option if you want it painted on. Applications of C-Bond type include ceilings, wall linings, furniture, and decorative applications. C-Bond type plywood boards have a higher tolerance to humidity and should be used instead of D-bond boards in high humidity areas.
D-bond plywood boards, on the other hand, have more blemishes than a C-bond and much less tolerance to humidity. The applications are pretty much the same. The appearance and weakness to moisture make the difference between C and D-bond.
When choosing plywood types, a little research can save you a lot of money in the long run. While some non-structural plywood may look great, it is certainly not a good fit for exterior and structural purposes.
The same goes for structural plywood boards as they may not be pleasing enough to be installed within interiors. By knowing the difference between structural and non-structural plywood, you will find it easier to figure out which type to use for what purpose and can leave you with a beautiful and strong structure.