Understanding Grades of Plywood
Plywood is a strong thin wooden board consisting of two or more layers or "plies" of wood veneers, glued and pressed together with the direction of the wood grain alternating 90 degrees to one another.
There are five basic plywood veneer grades you need to know about: A, S, B, C and D in descending order.
Each sheet of plywood will have two grades, with the first letter referring to the face veneer grade, followed by the second letter which represents the back veneer grade. This is written as AC, CD, and so on. Each grade of plywood has different characteristics for different applications with A being the highest grade and D the lowest grade. Some plywood’s have a third letter that designates them for exterior use such as DD-A.
A is a high-quality appearance grade veneer, sanded smooth and paintable for decorative uses and the most expensive grade. A grade plywood is primarily sold a Marine plywood or AA-A Marine, as it will be free of voids or flaws.
B grade veneers may contain some minor flaws or blemishes and may have small tight knots. B grade is suitable for high-quality lacquering or paint finishing.
C grade veneers are designed for non-visual applications with the veneer defects such as knot holes or voids, filled or patched.
D grade plywood sheets are the least expensive and can contain open defects such as knot holes or splits with generally no repairs. D grade is a non-appearance grade designed for structural applications.
S grade is an appearance grade veneer which allows more natural characteristics and usually paired with a D grade back for products such as Plygroove.
At Warringah Timbers, we can find the right plywood grade for your next project.