In the previous article "New construction technology - CLT" we have introduced you to the essence of CLT construction, and in this text we will list six basic advantages offered by CLT engineering.
Right at the beginning, we will point out that every advantage is well worth attention and that with every study of this area, the benefits are flowing hour by hour. However, we will highlight the 6 most obvious for now.
The technology of multi-layer glued wooden panels represents the most modern technology of today and something that will be highly appreciated in the future. Find out below if CLT is affordable only for people with deeper pockets.
Advantage 1 - Sustainability
The durability of wood is already very well known, but it is not bad to repeat it. Trees act like a sponge that absorbs carbon dioxide from the air. While absorbing carbon dioxide, the tree simultaneously releases oxygen into the air. Once the wood "absorbs" the carbon, it is later released from the wood only if it dries naturally or if it is burned. When wood is processed mechanically, carbon dioxide is trapped in the molded material.
By using solid wood products for building construction, the material will reduce carbon dioxide:
- 1m3 CLT panels will remove 0.8 tons of carbon dioxide from the atmosphere, so that 1m3 CLT panels will have an average of 240 to 250 kg of carbon dioxide in them
- Cement production results in the emission of 870 kg of carbon dioxide per ton of cement ("The cement industry plays an important role in climate change", Dr
Robert McCaffrey for "Cement and lime" a magazine
- The production of cement creates about 1.75 tons of carbon dioxide emissions per production of one ton of steel (The Carbon Trust)
- Granular slag (a standard mix of 40-50%) can reduce carbon dioxide emissions, but only by about 100-130kg per ton (Ecocem)
CLT wood panels can be produced using low polluting technology, relatively low energy, minimal fresh water and zero percent waste in manufacturing processes.
Advantage 2 - Structural durability
Multi-layer adhesive structural panels can be used for building elements (walls, floors, roofs) or as part of hybrid constructions, and thanks to the "decorative lamination" production process, it is possible to produce dimensionally stable panels of various visually appealing shapes. The high stiffness of the panels provides significant robustness and wall elements that can be extended as cantilevers. The structural capabilities of decorative laminated wood panels are similar to those of concrete and can be used for similar applications.
One of the biggest concerns for end users with solid wood products and cross laminated timber construction is fire. The fear is that a building built of wood will burn completely if there is a fire, but of course, it is wood; just as glass will melt, just as concrete will crack. An important question is actually the predictability of the material in the fire and how long it can burn without losing its properties. Wood is actually very predictable in fire - the outer layer of a cross-laminated timber panel will catch fire first, then build up a layer of insulation that provides 30,60, XNUMX or more minutes of fire resistance, depending on the number and size of the panels.
Advantage 3- Easy construction methods
CLT systems are included in the MMC technology because of the simple and fast construction process. The panels are mainly equipped with self-tapping wood screws and steel supports, which significantly speeds up the process compared to traditional building materials. The video http://youtu.be/bURy80-ZE7Y shows the construction of a private residence in Highgate (United Kingdom) developed by "BLISS" applying CLT panels supplied by him "KLH UK". Due to the relatively positive tolerances of the factory-made panels, caulking, i.e., air tightness between the joints, can be achieved with pre-compressed foam and/or special tape that is glued over the outer joints. As they are crossed, the laminated panels quickly provide a dry, weather-resistant material outdoor conditions without temporary props. This provides an outer protective layer that acts like a shell that can become waterproof very quickly. CLT panels can be supplied in different finishes, so the customer has the opportunity to choose whether he wants an environment that exudes the natural look of wood or the wall will be covered with another material. As the panels are made to measure in the factory, waste at the installation site is minimal and the construction process is quiet and clean with minimal equipment and tools compared to traditional construction methods. The use of the CLT system supports the contractor's accreditation .
Advantage 4 - Money saving
The costs of building a building using CLT panel technology should be viewed in a broader context and over a longer period of time. What is given by the current calculation of the construction, during the exploitation of the object, becomes a calculation that is very favorably amortized by the user. Cost savings with this construction are obtained throughout the entire life of the built project. The speed of construction reduces the overall construction program, which results in a reduction in the contractor's preliminary work, lowers the contractor's costs and lowers the construction costs for the end client. The reduction of total project construction costs is based on:
- Less weight in the overall structure results in a more economical substructure/foundation design (less concrete)
- Planning can be accelerated; for example. windows can be ordered in advance because there is a high degree of accuracy that is given by precise CNC cutting
Advantage 5 - Saving time
As already described, the efficient speed of construction with these wood panels can ensure significant time savings on the project. As materials that are made in factories, it does not require other materials during construction, therefore fewer people are involved in construction, and CLT panels arrive on site ready for assembly. The following savings are achieved:
- Construction services - about 30-50% faster
- Installation of windows and doors - 20-30% faster
- Installation- 20-30% faster
Advantage 6 - Design flexibility
The ways in which CLT panels can be cut and routed allow for enormous design flexibility and architectural freedom.
In order to use the great potential of CLT, it is important to have a clear design that is signed in advance by the client and the entire design team, because the clarity and precision of the project plan itself (preparation) is as important as the construction itself.
Wood is a material that is easy to process, and today's CNC machines provide the possibility of identical processing of fitting elements and curves, the way designers and architects envisioned it.
So far, over 280 such houses have been built in Great Britain. Since the awareness of such ideas has been growing in recent years, a lot of companies have developed that make this kind of material. Architect Alec de Rijke says: "If the 19th century was the century of steel, the 20th century of concrete, then it is 21st century related to wood construction".