Glossary

In wood anatomy, a general term for the minute units of wood structure that have distinct walls and cavities, including wood fibres, vessel segments, and other elements of diverse structure and function. In dense hardwoods, the fibre cells are thick walled and make up the major part of whole zones of wood. These fibrous zones dry slowly.

The carbohydrate that is the principal constituent of wood and forms the framework of wood cells.

 Forest certification refers to the assessment of forest management by an independent third party auditor according to performance criteria for sustainable wood production. The Responsible Wood Forest Certification Scheme (formerly the Australian Forestry Standard, AFS),  Programme for Endorsement of Forest Certification  (PEFC) and Forest Stewardship Council (FSC) are the three certifications in Australia. Responsible WoodProgramme for Endorsement of Forest CertificationForest Stewardship Council More on Certification

The process by which the source of a timber product is verified. This entails 'tracking' the timber from the forest through all the steps of the production process until it reaches the end user. The process is usually necessary before a timber product can be labeled as being produced from a sustainable source.

A separation of fibres along the grain forming a fissure, but not extending through the piece from face to face. Checks commonly resulting from stresses built up during seasoning. They run radially, across the growth rings.

A wedge-like, sharp-edged tool used for cutting or shaping timber.

Either of the two outside members of a truss (a) connected and braced by the web (b) members. The term also applies to beam flanges or the perimeter members of a plywood diaphragm.

The external covering or skin of walls of a building. Timber cladding includes natural or treated timber boards, and plywood.

The clear horizontal distance between the supports of a load bearing member.

A test that measures the resistance of a timber to splitting longitudinally along the radial and tangential planes

A window, or row of windows, in the upper part of a room where it can admit light from above an adjacent roof

Wood with narrow, inconspicuous growth rings. The term is sometimes used to designate wood having small and closely spaced pores, but in this sense the term "fine textured" is more often used.

Similar to a wood screw except larger and with a hexagonal head so that it can be turned with a spanner.

Wood with wide conspicuous growth rings in which there is considerable difference between earlywood and latewood. The term is sometimes used to designate wood with large pores, but in this sense the term "coarse textured" is more often used.

The flattening of single cells or rows of cells during the drying or pressure treatment of wood. Often characterised by a caved-in or corrugated ("washboarded") appearance of the wood surface.

A horizontal board that connects pairs of rafters on opposite roof slopes.

A free standing axially loaded compression member, usually vertical.

A state or condition of being pushed or shortened by a force

A state or condition of bDeformation or fracture of wood fibres across the grain resulting from excessive compression along the grain. eing pushed or shortened by a force

A fabricated or cast metal bracket into which timber structural members abut, used to joint timber compression elements to other structural members.

A treatment applied to equilibrate the moisture content of wood to a particular value.

The sustainable use of forest resources in a manner that does not degrade the collective resource values of a region over the long term

A piece of flat steel fixed over a butt joint between timber beams to provide a continuos tension connection.

A vertical or horizontal gap, filled or unfilled, to accommodate differential movement between various elements of a construction

A length of timber laid horizontally on the top of a column to transfer loads and to provide a seat for beams. A compound corbel includes several lengths of timber instead of one.

Species - An adjustment of the readings of the resistance-type electrical moisture meter to compensate for different species of wood. Corrections are tabulated in AS/NZS 1080 1:1997 Temperature - An adjustment of the readings of the resistance-type electrical moisture meter to compensate for changes in the temperature of wood. Corrections are tabulated in AS/NZS 1080 1:1997

A defined area of forest, usually with consistent characteristics.

A metal sleeve threaded internally and used to connect threaded rods or bolts

Increase in deformation following prolonged loading.

A cut in an unseasoned joist, bearer or stud designed to reduce movement in a floor or wall as the structural timber seasons.

A criterion is a category of conditions or processes by which sustainable forest management may be assessed. A criterion is characterised by a set of related indicators that are monitored periodically to assess change. An indicator is a measure (measurement) of an aspect of the criterion. An indicator can be quantitative or qualitative variable which can be measured or described and which, when observed periodically, demonstrates trends.

To cut across the grain.

An Arrangement in which the fibres and other longitudinal elements of a piece of wood deviate from a line parallel with the edges of the piece. Cross grain may be either diaonal or spiral grain or a combination of the two

CLT is a solid timber panel produced by bonding layers of timber together with the grain alternating at 90 degree angles for each layer. CLT is manufactured in a similar way to glulam, exept that glulam is layered with the grain. Cross-laminating layers of wodd veneer improves the structural properties of wood by distributing the along-the-grain strength of wood in both directions, and this means that CLT panels can be used to form complete floors, walls and roofs. More Information    

A method of slicing veneers whereby the average inclination of the growth rings to the wider face is tangential or less than 45 degrees. This method is also known as flat cut.

In the shape of a cross

A concave curvature across the grain or width of the a piece of timber.

To change the properties of an adhesive by chemical reaction (which may be condensation, polymerisation, or vulcanisation) and thereby develop maximum strength.

The decomposition of wood by fungi.

Timber used in surfacing parts of bridges and other structures subjected to vehicular or pedestrian traffic.

In timber and other forest products, the result of any process that lowers the value of the wood.

A kiln working on the heat pump principle. Moisture evaporated from the timber by a flow of warm air is condensed on the evaporator coils of a refrigeration unit and drained away. The refrigerant is compressed and passed through condenser coils, re-heating the air stream.

The separation of plies or laminations through failure of the bond, visible at an edge.

As applied to timber, density is the mass of wood substance and moisture enclosed within a piece expressed in kilograms per cubic meter. As the mass will vary dependant on the amount of moisture in the piece, density is often expressed at a specified moisture content, usually 12%.

The difference between dry and wet bulb temperatures. It is a measure of humidity.

The temperature at which the relative humidity of a body of air is 100 per cent. Further cooling causes vapour in the air to condense as water droplets.

Timber in which the annual rings are at an angle with the axis of a piece as a result of sawing at an angle with the bark of the log. A form of cross grain.

The change of a square or rectangular section timber to a diamond shape during drying. Diamonding occurs where the growth rings pass through diagonal corners of the section of the piece and is caused by the difference between tangential and radial shrinkage. It is a form of distortion.

1. In a beam, an element at right angles to the span with the function of connecting the beams so that they resist load as a unit. 2. A relatively thin, usually rectangular, element of a structure that is capable of withstanding shear in its plane and acts as a bracing elements.  

Movement of water through wood from points of high moisture content to points of low moisture content by molecular diffusion.