Wood was always considered a favorite material for many but it had several limitations when it came to complicated construction and tall buildings. Of late, Wood is seeing a kind of revival with some innovative work being done in this segment. Cross-laminated Timber or CLT as it is called is one such innovation. CLT is claimed to be as strong and fire-resistant as structural steel or concrete.
Cross-Laminated Timber is made from solid-sawn lumber. Each layer of boards is orientated perpendicular to adjacent layers and glued to the wide faces of each board, usually in a symmetric way so that the outer layers have the same orientation.
An odd number of layers are most common but there are configurations with even numbers as well (which are then arranged to give asymmetric configuration). The cross gluing allows using the panels with two span directions whereby some differences in stiffness and strength are observed along the two directions. It is similar to plywood, but with distinctively thicker laminations.
Until recently, CLT was mainly made using softwood but with the introduction of Hardwood species like Tulipwood by AHEC has made CLT much stronger and more aesthetically pleasing.
Advantages of Hardwood Cross-Laminated Timber
1. Faster Construction
It is faster to build with Cross-Laminated Timber since the panels are digitally designed, factory pre-cut and then assembled at the construction site.
2. Fire Retardant Quality
Experts believe Cross laminated Timber has an inherent Fire-retardant quality due to its massive cross-section. When exposed to fire, it chars on the outside as opposed to other materials which may bend and warp rapidly.
3. Strength & Durability
CLT is an engineered wood product created by adhering together pieces of timber layered on top of each other in opposite directions. The results are large—up to 10 feet long by 40 feet wide by 1 foot thick -solid wood panels that maximize the inherent tensile strength of wood.
Timbers sourced from the sustainable forest are much more environmentally friendly than sourcing materials from the earth’s core which is impossible to replenish back. At the same time, timber also traps Carbon dioxide.
5. Savings on Energy Costs
Because wood is 350x more insulating than steel and 5x more insulating than concrete, a building framed with hardwood cross laminated timber will have lower energy costs.
dRMM used 20 panels of five layer cross laminated American tulipwood, ranging in size from 0.5m - 12m long for the construction.
World’s First Building Made From Hardwood
Recently, the world’s first building is made from hardwood cross-laminated tulipwood opened in Oldham, the UK, designed by dRMM Architects. Maggie’s is a charity that provides practical and emotional support to people living with cancer. dRMM chose tulipwood for the design of Maggie’s Oldham for the positive influence wood has on people and for the beauty, strength, and warmth inherent to American tulipwood. Co-Founder of dRMM, Prof. Alex de Rijke says, “From the Oldham project inception we knew it was the right material for Maggie’s, not only structurally and visually, but conceptually. An elevated, open plan, all-timber and glass building - with trees growing through it, and every detail considered from the perspective of use, health, and delight - was always going to be special.”