CLT-panel: technology features, pros and cons

Today, all over the world is gaining in popularity a new technology: the building of houses of CLT-panels. In this area of ​​construction it has advantages and disadvantages

New technologies are being actively implemented in the construction sector. So managed to take advantage of the natural wood, getting rid of its main weaknesses. One of the most popular destinations is the construction of houses made of CLT-panels.

On this subject say many of our forum users. Here's what our reader writes Taarok: «In recent years, often I read on the website of Wood Housing Association on this technology, such as going to build a five-story building in Moscow. Perhaps someone has already built on this technology or understand it? If anyone has experience, share, think of this technology in a lot of pluses. "

We got acquainted with the topic and are willing to share expert opinion about the merits and demerits of CLT-panels.

Content

• History of technology
• production Features
• Construction of houses
• Benefits
• disadvantages
• To build or not to build?

History of technology

CLT-panel - multi-layer material consisting of wooden slats, stacked in rows. Products are glued and pressed together. The rows are arranged crosswise relative to each other. Vertical slats ensure high loading capacity, and the horizontal - the stiffness in the longitudinal plane.

For the first time this technology was used in Switzerland in the 90s of the last century. Modify it a little, some companies have started their own production. The first modern CLT-panels were developed in 1996 in Australia. Due to the increased public interest in eco-friendly construction technology became popular.

Of these panels began to build not only a single storey, but also high-rise buildings, apartment buildings. In Western Europe, this technology is an even greater share of the construction industry. In our country, the production of CLT-panels is actively developing.

production Features

To understand the advantages and disadvantages has provided technology, you need to understand the characteristics of the production of the building material. Many of our readers do not always properly understand its basic qualities. Thus, the user Mickas in the comments to the article "The building of CLT-panels: the German approach"I wrote the following:"... This material is appropriate to be called Megafaneroy))) for superbabki ".

Plywood is made from veneer (thin sheets of wood), and CLT lamella panels with a rectangular cross section. And, of course, the new technology can not be cheap. It opens up many prospects for the construction industry.

The panels made of coniferous wood trim, which humidity is about 12% (a tolerance of 2%). Billets are chamber drying process, and then ends. Splicing is done on the gear stud. Thus obtained material of predetermined length. Lamellas glued together and then subjected to the compact.

This is followed by trimming and polishing step to obtain a perfectly smooth surface. If the panel to be used for mounting wall, they may finish layer SIR. Then, in accordance with the building plan are cut window and door openings, channels for laying of communications. This procedure is performed on CNC machines, ensuring high machining accuracy.

The manufacturing process of a preform lasts 15 to 60 minutes. The result is a panel, a width of 60 to 400 cm and a length of 24 m. They consist of 3-12 layers, and may have a thickness of from 6 to 35 cm.

Construction of houses

Finished elements of the future buildings transported to the site, and then collected, like a child's constructor. At home builders have a plan over which the installation and assembly of each numbered panel. The construction is going on a prepared foundation.

Under construction is involved a small team using a crane and a simple power tools. The installation of one panel takes about 20 minutes on average. Single-family home builders are collected in approximately 8 hours.

After this is immediately ready for interior and exterior decoration. In this case, the walls do not need to plaster, as they after machining in production become perfectly flat surface. For all communications already prepared the necessary road, space for boards, audit boxes, etc.. Etc.. Therefore, the house will be ready for delivery in a matter of days.

Benefits

The new construction technology greater advantages than disadvantages. Therefore, its popularity is increasing. Among the advantages of houses from CLT-panels is worth noting the following:

• Made of natural wood, so the indoor set a healthy microclimate.
• Due to the special treatment of the building characterized by a lack of shrinkage. The openings can be prepared at once to mount panoramic windows.
• The walls are not blown by the wind, they do not have gaps that need to be sealed.
• Without the preparatory work in the decoration inside and outside the building, you can use any decorative materials, including curtain walls on the outside walls.

• Possibility of construction of multi-storey buildings. In Europe, this technology erect shopping malls, stadiums, hospitals, apartment buildings, and so on. D.
• The building has a high fire resistance. When testing a wall thickness of 180 mm was heated from the backside to the 10 ° C per hour under the influence of heating 1200 ° C.
• When planning the interior, exterior, you can implement any architectural style.
• The structure is environmentally friendly. In addition to the natural wood used in the production of E1 class glue. This composition, used in the manufacture of furniture.
• Under construction is the minimum amount of waste and debris.
• House of CLT-panels is characterized by high seismic resistance. The building can withstand an earthquake up to 9 points. Therefore, they are erected even in Japan.
• Low thermal conductivity (0.13 W / m * K), a high specific heat (2.1 kJ / kg). Therefore, the rate of home insulation CLT panels is 3-5 times higher than the buildings of brick and concrete. Such houses in the presence of an appropriate insulation can be built in the northern regions.
• Walls and floors are of high footfall sound absorption.
• Structure weighs 6 times less than a similar concrete building.
• The floor decks are no dynamic vibration. Panels are static strength, size stability in all directions.
• The inner space of the room rises to 10%, since the walls are thinner than 1/3 compared to laminated veneer lumber and concrete.

This technology is used actively the US military in the construction of buildings. Before this building have been tested on the basis of the Air Force. To this end, several houses were built. They blew up a total of 7 times, and the power of the explosion was equal to more than 275 kg of TNT equivalent.

As a result of this experiment, it was found that in terms of blast resistance of the building of the CLT is not inferior to steel profiles. These designs have stood the greater load than the manufacturer said.

In addition, such houses are built, even in regions with high humidity, for example, in the Asia Pacific region and in the countries on the coast of Northern Europe.

disadvantages

As with any other technology in the buildings of have their drawbacks cross laminated timber. Chief among them are the following facts:

• One of the main drawbacks is the high cost - in comparison with other building materials. For the average developer it can be expensive service. But the finished house will be built quickly, and it will be high quality. Unlike other wooden buildings from CLT stable home to various adverse factors. Therefore, such a construction will be durable.
• The disadvantage is the need to create an additional layer of insulation, if the house is built in a cold climate. However, the insulation in such circumstances need buildings from any other building material.
• This is a new technology, so to say exactly how many such houses in operation until hard. Experts can only make assumptions. Therefore, many developers prefer traditional materials.

Deficiencies in building technology presented not so much. Benefits objectively more. Critics argue that the shortcomings can be attributed to the presence of the glue that binds the slats, formaldehyde. But CLT panels are environmentally friendly material, glue them to a minimum quantity. This composition corresponds to the E1 class, even in accordance with strict European standards considered acceptable. This adhesive is used for the manufacture of furniture, children's bedroom, schools and hospitals. Therefore, in rooms built of laminated panels no specific chemical smell.

To build or not to build?

If you are in doubt about whether to build a house out of cross laminated timber, pay attention to the world experience. New technologies have shaken the world of construction. In the West being built all over the houses of the cross-laminated panels. This technology does not require the use of metal frameworks, concrete.

If you are willing to spend a considerable sum for the construction of your home, you can be sure that these costs will be repaid in the future.

Proof that the building material is a promising is the fact that because of his build apartment buildings. In Melbourne in 2012, it was built 10-storey building height of 32 m. The Australians broke the record UK builders who have previously built in London residential building of 9 floors 30 m in height.

These designs are found very strong and stable. At the same time they weigh less concrete buildings and much warmer. Therefore, energy consumption for space heating is reduced by almost 25%.

World engineers and designers conducted a series of studies and calculations, finding that such panels can build buildings up to 30 floors. If CLT combined with metal and concrete, building height can be increased even more.

Today, it has developed projects 33-storey skyscraper, to be built in Stockholm from CLT-panels. A Chicago engineers plan construction 44-storey skyscraper.

Against the background of these daring projects construction of private houses from cross laminated wood it seems really rational. Skeptics may question the reliability of such houses. However, international experience confirms that this technology has a right to exist. Some experts argue that for her future.

On the construction of CLT-panels read in the article "Wooden monolith. House of CLT - panels». To learn how to build such houses Germans in one of the previous material. In the video - Asuntomessut 2019: how to build holiday homes in Finland. An overview of recent trends.

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