CLT Construction
In practice
What is CLT?
Cross Laminated Timber or CLT is a wood-based building material that is in the form of a multi-layered board.
These laminated wood panels consist of solid wood boards that are stacked in layers, crossed at 90 degrees, and glued together to increase the rigidity and stability of the panels in all directions.
CLT panels come in different thicknesses, i.e. 3, 5 or 7 layers (thickness varies from 0.5 cm to 5.0 cm), which makes it a space-saving and lightweight material.
CLT panels are made in the factory from sawn timber of fir, spruce, maritime pine, Scots pine or Douglas fir.
Technology
This is an environmentally friendly and fast construction method. The elements that make up the structure of the house (walls, interior walls, floors and ceilings) are cut directly from the CLT panels.
Thus, the panels are pre-cut to size in the factory as needed and arrive on a truck-mounted crane to be unloaded and joined together in record time (2 to 4 days).
In this way, the finishing works can follow each other quickly, as no drying time is required before the roof is applied, saving a considerable amount of time in the planning and execution of the site!
This construction technique responds to the need to use a sustainable building material that has equal or better properties than other conventionally used materials (concrete or steel).
CLT construction is a real improvement over other techniques used for wooden structures, such as timber frame construction, solid wood structures not cross-glued, glued laminated timber with nails...
Advantages
Quick assembly
After the architect has carefully drawn up the plans and approved the panels, the assembly is almost a piece of cake! The entire construction project can be created in just 6 months.
Simplicity and modularity of the material
With the CLT wood panel, all the details can be easily realized and it is completely modulable over time. In fact, wood is easy to work with and allows great architectural freedom due to its lightness, flexibility and resistance.
For an equivalent construction, wood is a material up to seven times lighter than concrete. Nevertheless, lightness does not mean fragility!
In fact, wood is much more resistant than you think. It is not for nothing that wood is used for building houses, especially in the Nordic countries and in Canada. However, the climate there is quite harsh.
With wood, the style of the house can be easily adapted to the architecture of the region: Brick, stone, concrete, facing, cladding, plastering.... The style can be rustic or contemporary. Wood "goes with everything"!
Energy saving
First of all, CLT panels are inherently good thermal insulators, with which you can save about 30% on heating costs compared to a wood frame structure. The fact that the layers are crossed and the panels are glued together has the effect that the air can not pass through them, which de facto improves the thermal performance.
The low inertia of wood allows the house to heat up quickly, and condensation does not form.
Durability, resistance and safety
Wood is durable and does not deform when exposed to heat. Contrary to popular belief, it takes longer than steel or concrete to burn in the event of a fire, and it releases few toxic gases when burned.
CLT has very good seismic resistance with a high ability to absorb vibration. This ability will vary depending on the number of layers and the structure of the building.
Researchers from the Institute of Timber Construction, Structural Design and Architecture IHTA at the Bern University of Applied Sciences BFH have studied the dynamic properties of glulam structures. The test results, most of which are available, close a serious knowledge gap.
Comfort and well-being
Thanks to the ability of wood to regulate the moisture content of the air, the rooms have a good climate. In addition, CLT provides adequate insulation in both winter and summer, and provides very good sound insulation without the wood creaking.
Gain in living space
Since the insulation is placed on the outside of the wooden structure, there is a gain in living space compared to a conventional building.
Excellent value for money
Less expensive than a traditional house.
Ecological impact
Greenhouse gas emissions are much lower than concrete (180kg CO2/m3 for CLT versus 500kg CO2/m3 for concrete).
The use of structural wood allows for more sustainable consumption, as wood is a renewable resource.
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