Glossary
A comprehensive guide to the most common timber terms.
Timber sections fastened together using mechanical means (not glue) to form a larger composite element, typically used in floors, beams, or walls to improve structural performance.
An engineered wood product made by breaking down hardwood or softwood residuals into wood fibres, combining them with wax and resin binders, and pressing the mixture into dense, flat panels under heat and pressure. It is widely used in furniture, cabinetry, interior linings, and joinery.
A surface-level fungal growth that thrives in damp, stagnant conditions, feeding on organic matter like timber or drywall, and can lead to discoloration, musty odors, and early surface decay if left untreated. It usually appears as tiny black spots that cover the timber surface.
A mill is a manufacturing plant that converts logs into processed wood products through cutting, sawing, drying, grading, and sometimes chemical or mechanical treatments.
The weight of moisture contained in a piece of timber expressed as a percentage of the oven dry weight.
Categorizes timber into different levels of moisture (usually expressed as a percentage of the wood’s dry weight), helping ensure the timber is appropriate for its intended use or environment (e.g. interior, exterior, structural).
| Class | Description | Moisture Content Range |
| Green timber | Freshly cut, high moisture | > 25–30% |
| Air-dried | Dried naturally, used in non-critical applications | ~12–19% |
| Kiln-dried | Dried in a controlled environment for precision use | ~10–15% |
| Conditioned | Dried and equalised for very specific uses (e.g. furniture, flooring) | ~8–12% |
| In-service class | Assigned based on expected exposure (e.g. dry, damp, wet conditions) | Varies by standard |
A progressive decrease (or increase) in moisture content between the core and the surface of a piece of wood.
An electric resistance moisture meter determines how much moisture is in timber by measuring the resistance to an electric current passed between two metal pins. Dry wood has high resistance, while moist wood conducts electricity more easily (lower resistance). They are usually calibrated for Douglas Fir. The reading must then be corrected for temperature and species.
The transfer of moisture from one point to another within wood or other materials.
An environment that has a single species of animal or plant dominant, usually associated with the artificial environments created by intensive agriculture.
A mortice and tenon joint is one of the oldest and strongest woodworking joints, used to connect two pieces of wood—typically at 90 degrees—by inserting a tenon (a protruding tongue) into a corresponding mortice (a slot or hole).
A fungal growth on timber or other wood products at or near the surface and, therefore, not typically resulting in deep discoloration. Mould is usually ash green to deep green, although black and yellow are also common. See also: Mildew.
The extent of expansion and contraction which occurs with dried wood as its moisture content responds to changes in relative humidity in service.
MRTFC is the design and construction of medium-density housing using timber structural framing, offering a cost-effective, sustainable, fire-rated, and code-compliant alternative to concrete or steel.