Dado
A rectangular groove cut across the grain of a board, wider on the bottom than at the top. Used for shelf joints and partition fitting.
Read the definitionThe glossary
The trade terms you'll come across.
Plain-English definitions for the words that turn up when you're buying, specifying or working with timber.
Debarking
Debarking is the removal of bark from a log before sawing. Mills do this to reduce grit/contamination that dulls blades, improve cut quality, and reduce bark content in downstream products.
Read the definitionDecay
The breakdown of wood fibres caused by fungal action, typically when moisture content exceeds 20%. Results in loss of strength, discolouration, and eventual structural failure.
Read the definitionDecay resistance
The natural ability of certain wood species to resist fungal degradation, largely determined by extractive content, particularly in heartwood. Teak and white oak are naturally decay resistant.
Read the definitionDensity
Mass per unit volume. For timber it is usually reported in kg/m³ at a stated moisture content (often ~12% MC).
Read the definitionDiffuse-porous
A hardwood with pores of relatively uniform size throughout the growth ring (no strong earlywood pore band).
Read the definitionDilated rays
Horizontally oriented wood rays that have been widened or expanded. Often seen in quarter-sawn timber as distinctive figure elements.
Read the definitionDimensional stability
Dimensional stability is how little (or how much) a piece of wood changes size as moisture content changes. It depends on species shrinkage values, T/R ratio, cut angle, board width, moisture range in service, finish, and construction method.
Read the definitionDovetail
A interlocking woodworking joint consisting of trapezoidal pins and tails, creating a strong mechanical bond without adhesives. Cornerstone of fine cabinetmaking.
Read the definitionDrying rate
The speed at which timber loses moisture during seasoning. Varies by species, thickness, and initial moisture content. Ring-porous hardwoods typically dry faster than diffuse-porous species.
Read the definitionDrying stress
Drying stress is internal stress created when wood dries unevenly, producing moisture gradients between shell and core. It can lead to checking, honeycombing, and case hardening if not managed during drying and conditioning.
Read the definitionDurability
In timber, durability is the natural resistance of wood (especially the heartwood) to biological deterioration such as fungal decay and insect attack when exposed to moisture. It is distinct from strength: a wood can be strong but not durable, and vice versa.
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