crosslaminated

Cross-laminated timber, commonly abbreviated CLT and also referred to as crosslaminated timber, is a prefabricated engineered wood panel formed by stacking layers of sawn timber with their grain directions alternating at right angles and bonding them with structural adhesive. The perpendicular layup creates greater rigidity and dimensional stability in both major directions, allowing CLT panels to function as structural walls, floors, or roofs in buildings. Panels typically have three to seven layers, though higher-layer configurations exist, and overall thickness commonly ranges from about 60 to 300 millimeters.

Manufacture involves drying and cutting boards, laying them in alternating orientations, and bonding the layers with structural adhesives before hot- or cold-pressing into large panels. Quality control focuses on moisture content, wood grade, adhesive integrity, and panel flatness. CLT panels are largely produced in controlled factory settings and delivered to construction sites for rapid assembly.

Properties and uses: CLT offers a high strength-to-weight ratio, notable stiffness, and favorable fire performance due to a predictable charring rate of wood. It also provides good acoustic and thermal insulation. The panels are employed as walls, floor diaphragms, and roof decks, enabling rapid, modular construction of residential, commercial, and institutional buildings, including some multi-story and tall timber projects.

Standards and sustainability: CLT is governed by national and international standards and building codes that address structural performance and fire safety. It is derived from renewable timber sources and can reduce embodied energy and carbon compared with concrete or steel, though overall environmental impact depends on forest practices and adhesive systems.