Thickness
Ply means layer. The thickness of the sheet is determined by the ply. More ply creates a thicker and stronger board. The minimum number of plies are 3ply and can go up to 5 or more. Plywood with fewer plies are thinner and weaker even if they’re of the same thickness.
3ply: These sheets are 2 to 3mm thick and are the most common type of plywood for home interiors
5ply: This plywood is the most versatile option that is 4mm thick. This type of plywood works great for indoor and outdoor furniture and decorative boards
Multi-ply: This plywood has 7 or more layers. It’s strong and durable enough for permanent structures like roofing.
Grade
Plywood often comes with grades that can determine its quality and appearance.
A-grade: Ideal for furniture pieces and cabinets, A-grade plywood has a smooth and sanded surface with minor defects.
B-grade: This grade of plywood is similar to the A-grade variety with a few knots; however, the defects can go up to 1 inch across.
C-grade: This grade is unsanded with minor knots and defects like discolouration. They are ideal for structures where appearance is not important.
D-grade: Similar to C-grade, D-grade plywood is unsanded and has snags that have not been repaired.
