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.
A comprehensive guide to the most common timber terms from A to Z.
Criteria and Indicators
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
Cross-laminated Timber (CLT)
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.