Glossary
A comprehensive guide to the most common timber terms.
The Building Code of Australia (BCA) requires building material in some building application to have particular characteristics in the early stages of a fire.
These are set out in three indexes:
- ignitibility index (scale 0-20)
- spread of flame index (scale 0-10)
- smoke developed index (scale 0-10)
Specification A2.4 of the BCA calls up tests from AS 1530.2 & 3 to establish the index ratings for materials.
Earlywood (also known as springwood) is the first-formed wood in an annual growth ring, produced when growth conditions (like water and sunlight) are optimal. It is the less dense and larger-celled.
A force acting away from the centroid (or axis) of a structural element, which induces a combination of axial and bending stresses.
Eco-labeling is the process of labelling products with officially recognised symbols or certifications that indicate they meet verified environmental performance criteria, helping consumers make informed, sustainable choices.
The outcomes or impacts—positive or negative—on the structure, function, and biodiversity of ecosystems caused by changes in the environment, land use, species populations, or resource use.
In relation to forest management, ecological sustainability is defined in Australia as "integrating commercial and non-commercial values of forests so that the welfare of society (both material and non-material) is improved, whilst ensuring that the values of forests, both as a resource for commercial use and for conservation are not lost or degraded for current and future generations". This definition has been provided by the Forestry Working Group on Ecologically Sustainable Development (1991) and adopted by the National Forest Policy Statement (1992).
An ecosystem is a biological system made up of all the organisms in a particular area and their physical environment, interacting through energy flows and nutrient cycles. Healthy ecosystems are necessary for maintaining and regulating atmospheric quality, climate, fresh water, marine productivity, soil formation, cycling of nutrients and waste disposal.
Conductive probes inserted into or placed against wood to pass a small electrical current and measure resistance or capacitance, which is then used to calculate the moisture content.
Embodied energy is the sum of all the energy used in the entire lifecycle of a product up to the point of installation, but not including its use, maintenance, or disposal. The embodied energy of a material is usually expressed in the units MJ/kg and that of a sheet building component or element MJ/m².
A coating of moisture-resistant material applied to the end grain of green logs or sawn boards to slow end drying.
The grain shown on a cross cut surface.
A useful management tool that may form part of an overall environmental management system. This process entails a systematic and objective evaluation of how the organisation is performing in relation to its policies, regulatory requirements, environmental management systems, and practices.
Environmental impact assessments predict environmental impacts of a new development at the design stage. They may be required by Commonwealth, State, or Local government legislation dependent upon the scope of the project.
The effects that human activities, natural processes, or industrial operations have on the environment—including air, water, land, ecosystems, and biodiversity.
A set of processes and practices that enable an organisation to reduce its environmental impacts and increase operating efficiency. Formal systems include those prescribed by ISO 14001 and 14004.
Formed by inserting dowels into aligned holes between timber members and injecting epoxy resin to permanently bond the dowels, creating a strong, precise, and load-bearing connection.
A structural or non-structural connection formed by applying epoxy adhesive between two materials (often timber), which then cures to form a rigid, high-strength bond.
In kiln drying, a high humidity treatment in the final stages of drying intended to reduce the moisture content range between pieces of timber and the moisture gradient within pieces of timber. Also known as equalising.
The moisture content at which timber neither gains nor loses moisture from the surrounding atmosphere.
Plywood of naturally durable or treated veneers bonded with waterproof adhesive and capable of withstanding prolonged exposure to severe exterior conditions without failure of the glue-lines.
Non-structural chemical compounds found in wood that can be removed (extracted) using solvents like water, alcohol, or acetone. Unlike cellulose, hemicellulose, and lignin (which form the wood's structure), extractives are secondary substances that vary widely between species.