What Is A Cross-Laminated Timber in Cabinetry?
What Is A Cross-Laminated Timber?
Cross-laminated timber (CLT) is a type of engineered wood panel made by gluing together multiple layers of solid-sawn lumber from a single log, with each layer arranged perpendicular to the others.
This creates a symmetric panel with improved structural rigidity in both directions, as compared to regular timber which has varying properties depending on the direction of force.
CLT is similar to plywood but with thicker layers, and distinct from glued laminated timber (glulam) which has all layers oriented in the same direction.
Cross-laminated timber (CLT) is a building material that can be used as an alternative to concrete for constructing walls, roofs, floors, and ceilings. It is particularly suitable for multi-story taller wood construction, including pre-insulated wall and roof sections, cantilevered floors and balconies, load-bearing elevator shafts and stairs.
CLT can be used in a variety of building types, from residential and office towers to schools and civic buildings. It can be left exposed for its aesthetic appearance or covered when necessary.
The lumber in the outer layers of CLT wall panels is typically oriented vertically to increase its load-bearing capacity. Similarly, in floor and roof systems, the outer layers run parallel to the direction of the longer span.
How Is CLT Made?
The process of creating CLT panels starts with selecting wood, removing defects, and cutting it to size. Adhesives are then applied, the panels are assembled and pressed together, and they are cut to the desired dimensions.
Quality control is performed before the panels are delivered to a construction site. CLT panels can be custom-made but transportation limitations often dictate their size. They are manufactured in a controlled factory environment and must meet specific standards.
Most CLT panels are made for specific projects, with specific dimensions, shapes, and features. Advanced technologies such as BIM are often used for precise fabrication.
CLT panels can also be combined with concrete to create a hybrid system called timber concrete composite, which is used to reduce cross sections, increase spans, and reduce noise and vibrations.
History Of Cross-Laminated Timber
The first patent for cross-laminated timber (CLT) was developed in the 1920s in Tacoma, Washington by Frank J. Walsh and Robert L. Watts. However, some sources date the first patent back to 1985 in France. Gerhard Schickhofer made significant advancements in CLT in Austria in the 1990s, using the theories he developed during his PhD research to start production of CLT with the help of sawmills and government funding.
He and his team were able to create the first CLT press using water-based pressure, and in 1998, CLT was approved for commercial use by the Austrian and EU government.
This led to a period of growth in production and projects in Europe, but CLT has only recently begun to gain popularity in North America.
Benefits Of Cross-Laminated Timber
Cross-laminated timber (CLT) has several benefits as a building material, including design flexibility, environmental sustainability, carbon sequestration, prefabrication, thermal insulation, light weight, strength and stiffness, and fire safety.
CLT can be used for walls, floors, and roofs, and is made from wood sourced from efficiently managed forests. It is also prefabricated, which can lead to quicker construction times, cost savings, and reduced disruption to the neighborhood.
Additionally, CLT panels provide good thermal insulation and are light weight, making them suitable for sites that might not be able to support heavier materials. They also have high in and out of plane strength and stiffness and perform well under seismic forces.
Although CLT is flammable and has a D class fire rating, it is still able to retain its load bearing capacity for 90 minutes during a fire, providing better overall fire safety performance than unprotected steel.
Drawbacks Associated With Cross-Laminated Timber
CLT, or cross-laminated timber, is a newer building material that has some drawbacks. These include increased costs from transportation and production, a limited track record and lack of knowledge among engineers and contractors, and issues with acoustics and vibrations.
Additionally, building codes for mass timber projects are not as developed as those for concrete and steel, which can make developers hesitant to use CLT.
The research conducted on CLT has not yet been fully integrated into the building industry due to its resistance to deviating from established practices.
