MASS TIMBER
Mass timber is a category of prefabricated engineered wood products, including Glued Laminated Timber (Glulam) and Cross Laminated Timber (CLT) components. CLT panels are comprised of multiple layers of kiln-dried lumber, each stacked perpendicularly and bonded using high press force and formaldehyde-free structural adhesives. The large-format building elements are used as wall, ceiling and roof panels mainly in combination with Glulam beams and columns. CLT has a crosswise structure that reduces wood expansion and shrinkage to an insignificant minimum.
At the same time, this raises the structural load capacity and dimensional stability of the components. The result is a lightweight and durable building material, with favorable fire, seismic and thermal performances. European architecture has been utilizing CLT for over twenty years. Thanks to the gradual update of local building codes (In 2015, CLT was approved as a structural system in the International Building Code), North America and Asia Pacific markets are now emerging and growing particularly fast.
CLT & GL ADVANTAGE
Structural Integrity
CLT is the basis of the tall wood movement, as the material’s high strength, dimensional stability and rigidity allow it to be used in mid and high-rise construction. The world’s tallest mass timber building - Mjøstårnet Tower by Voll Arkitekter in Norway – is now reaching 18-storey and 85 metre high. With enormous structural load-bearing capacity, CLT strength-to-weight ratio is approximatively 20% higher than steel and 4 to 5 times higher than non-reinforced concrete.
Fire resistance
Mass timber can be designed to accommodate sustainable fire resistance. Exposed surfaces char on the outside at a predictable rate, which forms an insulating layer protecting interior wood from structural damage. CLT panels can be produced with fire resistances of 30, 60 and 90 minutes. As a result, mass timber fire ratings, tested according to ISO 834 standard, largely exceed all building codes requirements.
Seismic performance
High strength-to-weight ratio reduces mass timber constructions foundation size, inertial seismic forces and embodied energy. The largest shake table experiment ever conducted shook this full-size seven-story condominium built at the Japanese National Research Institute for Earth Science and Disaster Prevention’s Earth-Defense facility (“E-Defense”) in 2009. Credit: John van de Lindt. Consequently, mass timber buildings have the potential to be designed as resilient structures with superior performance in a seismic event. Besides, they can be quickly assessed and repaired, allowing for fast re-occupancy after earthquakes.
Thermal Insulation
Timber is a naturally insulating material that creates a barrier between heat and cold. CLT buildings offer an additional thermal benefit in that the precise nature of the manufacturing process means air leakage is very limited within the building envelope .
Sustainability
Global Wood Tech uses only mass timber components certified PEFC or FSC® and complying with the International standards relevant for Environmental Product Declarations (EPD). Globally, mass timber construction is a revolutionary low-carbon footprint system. The production of CLT panels results in a final storage of carbon dioxide, while producing one ton of concrete emits nearly one ton of carbon dioxide in the atmosphere. Compared to steel and concrete construction systems, the overall carbon footprint of a CLT building is lowered by up to 75%. As it is available readily manufactured from sustainably managed forests as well as its long-term storage of the carbon absorbed by the sustainably grown trees, the production of CLT results in substantially fewer greenhouse gas emissions than many non-wood materials. Due to their engineered manner panels are manufactured to exact measurements and requirements which results is less wastage and a simplified building process.
Productivity
Since mass timber panels are lightweight, prefabricated and then easily assembled on site, buildings made from mass timber have shorter project timelines and safer construction sites. Mass Timber buildings are roughly 25% faster to construct than concrete buildings, require 90% less construction traffic (trucks delivering materials), and 75% fewer workers on site.
Design versatility
Available in Non-visual quality (NVQ), Industrial visual quality (IVQ) and Architectural visual quality (AVQ) with the opportunity to order special finishes on request. CLT panels are particularly versatile. Slabs can be used for all assemblies just by varying the thickness. Furthermore, long spans are possible to achieve without supporting structures.
