Cross-Laminated Timber, CLT-panels are a fairly new building material for our country. Let’s talk about it in detail, Our site of advice will tell you about the features of such panels, the pros and cons of using in the construction of residential buildings.
CLT panels have another, more understandable name – multilayer glued wood panels. They were developed and created for the first time in Austria and Germany at the end of the last century, but studies of the qualities and properties of the new material dragged on for several more years. Since the early 2000s, the production of CLT panels has already become widespread in Europe, including for multi-storey construction..
The popularity of CLT panels in European countries is due to the fact that this material is considered as an environmentally friendly alternative to reinforced concrete, as well as the ability to quickly and relatively inexpensively erect buildings.
Unlike sandwich panels, which the portal devoted a separate article to, CLT panels are made of one material – wood. Lumber layers are glued together under pressure, forming an actually finished wall.
Layers of wooden lamellas are laid perpendicular to each other, crosswise, which is clearly visible in the photo above. The outer layers usually have the same orientation, while the inner ones, perpendicular to the outer ones, can be made of cheaper wood in order to save money. Most often, softwood is used for the production of CLT panels, as the most affordable. But there are poplar products, as well as various combinations, including different types of wood, including hard ones. Of course, this affects the price of the panels..
Important! Vertical lamellas are designed to provide increased load-bearing capacity of CLT panels, while horizontal ones are responsible for rigidity in the longitudinal plane.
Most often, the number of layers of CLT panels is odd, because the bottom and top must be in the same direction and made of the same type of wood. However, there are also symmetric configurations with an even number of layers..
Important! Multilayer CLT panels are sometimes referred to as “megaphane”. There is something in common, we agree. But this material differs significantly from the rest of the glued wooden structures in both thickness and production features..
Standard workpiece dimensions:
- The thickness is from 6 to 100 centimeters, it all depends on the number of layers, of which there is a minimum of 3 and a maximum of 12. In addition, the thickness of the entire panel depends on the used boards, lamellas. They are usually from 2 centimeters thick.
- Width from 60 to 400 centimeters.
- Length from 6 to 24 meters.
The dimensions are solid, these are real finished walls that significantly speed up the construction process. The most popular size is 6×9 meters, which is one full wall of a private house. The minimum and maximum dimensions of CLT panels differ from manufacturer to manufacturer, but usually the minimum is 3×3 meters.
CLT panels need to be ordered from the manufacturer in accordance with the design of the house. Ready-made elements with window and door openings are brought to the construction site, where the foundation, most often lightweight, is already ready. House assembly can be carried out by a team with one crane and simple power tools in just one working day, 8 hours. The routes for engineering communications in the walls are also laid in production, so it is very important to give the manufacturer a clear project, a plan of the house, otherwise there may be intractable problems during assembly.
There are many advantages of CLT panels, which allows some experts to call them the material of the future:
- The material is environmentally friendly – wood, what can I say. The production uses E1 class glue, furniture, that is, safe for humans.
- CLT panels provide a healthy indoor climate.
- No shrinkage, unlike log cabins.
- You can immediately install ordinary and panoramic windows into the walls, install doors.
- There are no cracks in the walls, that is, there is no need for sealing.
- There is no need to plaster the walls, they are already smooth and beautiful. What’s inside, what’s outside.
- You can build multi-storey buildings.
- You can choose any style of the house, any layout.
- The construction process leads to the formation of a minimum amount of garbage and waste.
- CLT panels are off! Yes, they are wooden, but thanks to the gluing under strong pressure, they are very dense. Tests have shown that a wall made of this material can withstand heating up to +1200 ° C..
- Buildings turn out to be earthquake resistant, now they are being built in Japan. CLT panels can withstand a 9-point earthquake.
- Heat capacity 2.1 kJ / kg, thermal conductivity 0.13 W / mK. This is three times higher than that of concrete and brick houses. Buildings from CLT panels can be built in the Far North.
- High level of noise absorption.
- The house weighs a little, you can save on the foundation.
- The walls are one third thinner than similar ones made of concrete and timber. This increases the area of the interior.
- No dynamic vibrations, all panels are statically strong in all directions.
Despite such significant advantages, CLT panels, like other products made of cross-laminated timber, have disadvantages:
- The technology is new. It is impossible to say for sure how long houses built from CLT panels will stand – only time will tell how durable they are. Currently, one can only make forecasts and assumptions, which alarms many developers.
- The price is high. Manufacturing CLT panels is not cheap in itself. In addition, there are still few manufacturers in our country and the cost is increasing due to low competition between them. Therefore, those who want to save money choose traditional building materials..
- Walls made of CLT panels in cold climates still need to be additionally insulated. However, in the northern regions this requirement also applies to other building materials, it is not necessary to say that this is a drawback of exclusively transversely glued panels..
Today CLT panels are increasingly used in the construction of houses, not only in Europe, but also in Asia, including in countries with a very humid climate. And they show high resistance to such difficult conditions. In addition, the convenience and reliability of CLT panels was appreciated by the US military, who build hulls and barracks from them. Tests have shown that such structures are not inferior to steel profiles in terms of explosion resistance..
We are confident that CLT panels will continue to gain popularity as a building material due to their good characteristics and quick assembly of buildings..