Timber

Timber is wood prepared for use in construction, carpentry, and other structural applications. It can be used in solid form or as engineered products such as plywood, glulam, laminated veneer lumber (LVL), and cross-laminated timber (CLT).

Timber is broadly classified as softwood or hardwood. Softwoods (pine, spruce, fir, cedar) are generally lighter and faster-growing; hardwoods (oak, maple, beech) are denser and stronger. After harvest, timber is seasoned to reduce moisture, typically to about 10–15% for indoor use. Drying can be air-based or kiln-based.

Timber strength and stiffness depend on grain direction and species. It is anisotropic, with greater strength along the grain. It is relatively lightweight, workable, and insulates well. Exposure to moisture causes swelling and possible decay; durability is increased by species choice, protective treatments, or design strategies that shed water.

Uses include structural framing, flooring, and furniture. Engineered wood products improve uniformity and performance: plywood, LVL, glue-laminated timber, and CLT panels are common in modern construction, including multi-story buildings.

Sustainability: Timber is renewable when forests are managed responsibly. Certification schemes such as FSC and PEFC help ensure legality and sustainable harvesting. Lifecycle carbon storage can favor timber over many materials, but impacts depend on forest management, milling, transport, and end-of-life handling. Deforestation remains a concern.

Durability and maintenance: Timber must be protected from moisture, pests, and UV exposure. Exterior uses often require coatings or treatments; some species are naturally durable. Fire resistance can be enhanced with design strategies, shielding, or coatings, particularly in larger constructions.