IMPORTANT PLYWOOD TERMS TO KNOW

Overview

Working with plywood, as with many other things in life, means dealing with some special vocabulary. If you’re new to woodworking or even new to working with plywood, you may not know these terms. Without them, you won’t necessarily know what you’re dealing with.

Back – plywood side with the lower face grade, normally used as the back when installed

Core – inner layers of the plywood, with grain running perpendicular to the face

Cross Grain – a manufacturing defect where a piece of face veneer runs perpendicular to the board’s length

Cross Lamination – the orientation of successive veneer layers, placing them perpendicular to the adjacent layers of the plywood

Cut – refers to how the veneer is made; either rotary cut or sliced

Delamination – failure of plywood panels, where the adhesive used to attach the plies fails, usually due to water

Face – the side of the plywood with the higher grade finish

Grade / Grading – the system by which the quality of plywood’s surfaces is identified

Grain – the growth pattern of wood fibers

Gum Spot – sap or resin left over on wood veneer from milling

Hardwood – any wood that comes from a deciduous tree (one whose leaves fall off) – has nothing to do with the wood’s density

Heartwood – the center of the log, below the sapwood; also the strongest part of the log

Knot – a place on a log where a branch grew out

Knot Hole – a knot that has separated from the wood around it, leaving a hole

Pin Knot – a small knot, less than ¼” in diameter

Tight Knot – a knot that has not separated from the wood surrounding it

Open Knot – a hole or void in lumber where a knot has come out

Lap – the place where two pieces of veneer are laid next to each other in the same ply

Marine Plywood – high quality plywood made with waterproof glue and without any voids

LVL (Laminated Veneer Lumber) – an engineered plywood product made of highly compressed, pressure-cooked wood fibers combined with synthetic resin

Mineral Streak – discoloration of hardwood

Weathering – browning, graying or yellowing caused by exposure to the elements

Particleboard – an engineered wood product manufactured from small wood particles (sawdust) with a bonding resin – not the same as MDF, which is a higher grade product

Patch – material placed on defects in face veneers to repair voids, etc.

Ply – a single layer of wood veneer in a plywood product

Plywood – originally referred to an engineered wood product made by laminating several plies of wood veneer perpendicular to each other. The definition has now been expanded to include all engineered wood sheet products

Rotary Cut – the process by which veneer is peeled off a log as one continuous sheet on a lathe

Sapwood – the outer layers of living wood, just below the bark; normally not used in plywood

Checks – cracks in the wood veneer, running parallel to the wood grain

Veneer – a sliced or peeled layer of thin wood, used to make plywood