Glossary

Is a term used to describe the use of a label or certification mark that indicates that the timber product has been produced from a certified forest and the chain of custody verified. Labeling in this way relates only to the how the timber has been grown and manufactured, not the quality of the product or its fitness for purpose.

Laminated timber consists of thin boards or planks (lamellae) glued together, usually with the grain running in the same direction, to form a larger structural member.

Laminated Veneer Lumber (LVL) is an engineered wood beam or plank made by laminating multiple layers of thin wood veneer sheets together, with all grain aligned parallel, to form a strong, uniform material ideal for load-bearing applications.

A joint made by placing one member partly over another and bonding the overlapped portions.

The thermal energy required for a substance to change state (solid ↔ liquid ↔ gas) at a constant temperature and pressure.

A force applied horizontally to a structure in any direction, such as a force caused by wind or earthquake.

Movement in a structure that is perpendicular to the major axis of loading, i.e. usually horizontal movement

Latewood (also called summerwood) is the part of the growth ring formed after earlywood, consisting of smaller, thicker-walled cells, making it stronger and denser. It is the denser and darker portion of a tree’s annual growth ring, formed later in the growing season (typically in late summer or autumn).

Perfectly horizontal.

A Life Cycle Assessment (LCA) is a comprehensive method for evaluating the environmental impacts of a product, process, or activity across its entire life cycle — from raw material extraction to end-of-life disposal

Key Steps in an LCA:

• Goal and Scope Definition - What is being assessed and why.
• Inventory Analysis (LCI) - Quantifies inputs (materials, energy) and outputs (emissions, waste).
• Impact Assessment (LCIA) - Evaluates potential environmental impacts (e.g. global warming potential, water use, pollution).
• Interpretation - Draws conclusions and identifies improvement opportunities.

The sum of all energy inputs required to create, use, and ultimately dispose of or recycle a product or building over its full life cycle.

LOSP is a non-water-based wood preservative treatment that uses a light organic solvent (like white spirit) as a carrier for biocides, making it ideal for finished or machined timber products where dimensional stability is important.

A horizontal element below a window that reflects direct sunlight up onto a ceiling surface

In building and construction, lining refers to the internal covering of walls, ceilings, or other surfaces, typically made from timber, plasterboard, plywood, MDF, or composite panels. It provides both aesthetic finish and sometimes functional benefits like insulation, acoustic control, or fire resistance.

A live load is the non-permanent load on a structure that can move, change, or shift during its use, including people, furnishings, equipment, and vehicles.

Longitudinal means along the grain or in the direction of the wood fibres, usually from end to end of the tree or timber piece.

Loose assembled means that timber parts or components are fitted together without permanent fixing (e.g. glue, nails, or screws), allowing for easy transport, adjustment, or later final assembly. Timber elements are fabricated off site but not connected together until delivered to site just prior to installation.

A general term (mostly used in North America) for wood that has been processed into beams and planks—typically by sawing logs—for use in construction, furniture, and other wood-based applications.

A lumen is the inner space or hollow interior of a wood cell, especially in conductive cells like vessels, tracheids, and fibres, which helps in transporting water and storing materials.

a Lyctid borer (also known as a powderpost beetle) is a wood-boring insect from the Lyctidae family that attacks the sapwood of certain hardwoods, causing damage by reducing the timber to a fine, powdery dust.

Lyctid susceptibility describes the likelihood that a timber species will be attacked by Lyctid borers, based on the presence and accessibility of starch in the sapwood.