Glossary

The amount of moisture in air. It is usually expressed as the weight of water vapour in a unit weight of dry air Relative - At a given temperature, this is the amount of moisture in air as a percentage of the maximum moisture carrying capacity of the air.

The support structure at either end of an arch or bridge. The intermediary supports are called piers.

The direction at right angles to the length of the fibres and other longitudinal elements of the wood.

A substance used to bond two surfaces together.

Agenda 21 is a comprehensive plan of action for achieving sustainable development in the 21st century. It includes a wide range of economic, social and environmental factors that affect sustainable development. Chapter 11 of Agenda 21, the major output of the United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro, 1992, deals specifically with forestry issues.

The velocity of air in the passages between rows of boards in a rack.

Timber that is dried by exposure to air in a yard or shed, without artificial heat (also see seasoning).

The direction parallel with the length of the fibres and other longitudinal elements of the wood.

A device for connecting timber members to concrete or masonry

Instrument for measuring velocity of airflow.

Exhibiting different properties when measured along its different axes.

Anti-kickback fingers are standard safety equipment on most new table saws. The anti-kickback fingers are incorporated into the blade guard and prevent the stock from being thrown at the operator by biting into it when kickback occurs. As long as the stock if fed through the blade in a normal fashion the anti-kickback fingers don't come into play. It is only when the stock binds and kickback occurs that they are important.

A chemical that is applied to timber to prevent or retard chemical or fungal stain development.

A curved structure resting on supports at each end that supports loads primarily in compression

The sharp intersection of two surfaces, eg. the face and edge of a piece of wood .    

A characteristic of an action or production stage in information processing, such as a kiln number or a log grade.

Timber that is sawn so that the growth rings are inclined at less than 45 degrees to the wide face.

A rigid or flexible barrier used to direct and control the flow of air.

In drying, a group of timber with similar drying and product characteristics.

Structural member, other than a triangulated frame, which supports load primarily by its internal resistance to bending.

A sub floor timber beam placed across piers or stringers and supporting floor joists

An artificial ridge of earth

Any angle not at 90 degrees. Also, a tool for marking such an angle.

The breaking down of timber by natural or biological agents such as fungi and insects.

Biodiversity is the variety of all life forms: the different plants, animals and micro-organisms, their genes and the ecosystems of which they are a part. Biodiversity underpins the processes that make life possible.

All living animals and plants

Figure on the surface of wood that has numerous rounded areas resembling small eyes.

The notch in a rafter that rests on the top plate of a wall.

1. A piece of sawn, hewn, or dressed timber of greater width than thickness. Usually 19 mm to 38 mm thick and 75 mm or more wide. 2. Manufactured products supplied as rigid or semi-rigid sheets, eg. fibreboard and particle boards.

The forest areas of the Northern North Temperate zone dominated by coniferous trees such as spruce, fir and pine.

A botanical name is the formal scientific name conforming to the International Code of Botanical Nomenclature (ICBN) and, if it concerns a plant cultigen, the additional cultivar and/or group epithets must conform to the International Code of Nomenclature for Cultivated Plants. The botanical names of Australian and imported species of timber and their relationship to trade names are defined in AS 2543 Nomenclature of Australian Timbers and AS 1148 Nomenclature of Commercial Timbers Imported into Australia.

Moisture which is closely bound to the cell wall constituents of wood.

Water molecules bound into the cell wall of timber. They are weakly bound chemically to the molecules of the cell wall and energy is required to break them free.

A curvature in the longitudinal direction of a board causing the wide face to move away from a flat plane.

A truss where the top chord of the truss is curved to an arch shape.

A built-up beam with solid timber flanges (a) and plywood or wood-base panel product webs (b).

Secondary structural members that normally do not support gravity loads but are required to provide lateral stability to other structural members or to transfer horizontal loads to the supports.

Bracing installed between floor joists to stiffen floor and distribute live loads. Also called cross-bridging.

In wood, any decay caused by fungi that attack cellulose rather than lignin, producing a light to dark brown friable residue.

The Building Material Ecological Sustainability Index is based on life cycle assessment but attempts to combine a number of criteria into three primary ones. There are: resource depletion, inherent pollution & embodied energy. These characteristics within these criteria are given a rating from 1 (not important) to 5 (very important) in terms of their environmental impact.

1. A hard, woody outgrowth on a tree, more or less rounded in form, usually resulting from the entwined growth of a cluster of buds. Such burls are the source of the highly figured burl veneers used for purely ornamental purposes. 2. In lumber or veneer, a localised severe distortion of the grain generally rounded in outline.

An end joint formed by abutting the squared ends of two pieces of timber.

Intentional vertical curve built into a beam or truss to offset load deflection or to improve its appearance.

A thin layer of tissue between the bark and wood that repeatedly subdivides to form new wood and bark cells.

A projecting structural member which is rigidly fixed at one end but unsupported at the other

A carbon sink is something that removes or stores carbon dioxide from the atmosphere, for example growing vegetation.

A drying defect characterised by the presence of compression stresses in the outer zone and tensile stresses in the core. It occurs when rapid drying has caused permanent set of the outer zones of a piece of wood.

An adhesive, primarily for internal use, prepared from casein, sodium silicate, lime, soda and other compounds. It was used largely in plywood manufacturer, has some resistance to water but is not waterproof, ages well and can be made resistant to mould.

A variation of the crown cut method of slicing veneers. The growth rings are exactly parallel to the slicer, producing on the face of the veneer an inverted 'V' figure resembling the spire of a cathedral.

Copper chrome arsenate, a wood preservative. More on timber preservation