Cross-laminated timber (CLT) is widely used in North America for walls, floors and roofs, and is becoming increasingly used in Europe, where the CLT market is rapidly growing. CLT constructions have many benefits, but they must be protected to last in the long term.
What is CLT ?
CLT stands for cross-laminated timber. CLT panels are made up of several layers of softwood (spruce, fir, pine, etc.). These layers, or ‘boards’ are stacked together at right angles and glued over their entire surface. CLT panels can be either 3, 5 or 7 boards thick.
CLT layers are therefore arranged differently to those of cross-laminated cells (CLCs). This is because CLCs are made up of several layers of wood that are stacked parallel to each other.
Lower environmental impact than concrete
Made of solid wood, CLT is interesting from an ecological point of view. It is estimated that CLT constructions produce 180 kg of CO2/m3 in greenhouse gas emissions, while concrete constructions produce more than 500 kg of CO2/m3.
Knowing that the construction industry accounts for 44% of the energy consumed in France and emits more than 123,000,000 tons of CO2 per year, greenhouse gas emissions must be taken into account.
Using wood as a building material also represents a more sustainable form of consumption, with wood being a renewable resource.
A high-performance, lightweight material
Mechanical stability and earthquake resistance may vary depending on the number of layers and overall construction’s structure. This material also has greater thermal performance — since the layers are crossed and the panels are glued together, it doesn’t let any air through — and is very compact (0.5-5 cm thick) and lightweight.
Cross-laminated timber is prefabricated and cut to size in factories according to requirements. Although the design plan must be carefully put together, it’s very easy to assemble the wooden structure once you have the materials.
Unlike concrete constructions, which need to dry, cross-laminated timber constructions can be put up straight away (walls, windows, roofs, etc.).
Both builders and customers appreciate this significant reduction in construction time.
CLT panel regulations
Depending on its function and location within the construction, the CLT element must be usable in conditions corresponding to a use class defined based on the risk of biological attack (insects and fungi). Generally, CLT constructions must be designed in use classes 1 or 2, according to the European standard NF EN 335: Durability of wood and wood-based products — Definition of hazard classes of biological attack
- Class 1: interior, no wetting, only risk of insects. g.: wooden floor
- Class 2: interior, risk of accidental/temporary wetting, risk of insects/fungi. g.: structure
Thanks to AXIL CLT SYSTEM, CLT constructions can be tinted and protected in the long term.