The LVL-timber is called building materials produced by gluing a thin lush veneer gluing. He appeared in the domestic market not so long ago – from mid-2009. Lumber with a multi-layer structure is widely used in the construction sector. Consider its pros and cons, manufacturing technology, operational qualities and basic technical parameters.
What it is?
LVL-timber is made from a veneer made of wood array of coniferous rocks. Most often for these purposes, pine or larch is used. For the production of material, the raw material is carefully selected at the stage of its workpiece. Preference is given to wood without various defects. For the preparation of a veneer takes the richest subshive part of the trunk. According to the strength indicators, the LVL-timber is superior to a natural tree.
When operating it is not deformed, and its high density is opposed to absorb moisture. Due to this, the initial sizes and weight of the sawn timber are preserved.
Other advantages include the following characteristics:
- The absence of domestic stress points, which are often the cause of the destruction of natural sawn timber;
- resistance to mold and fungus, unattractiveness for insects and rodents;
- preservation of operational properties and technical characteristics throughout the entire period of operation;
- Excellent bearing capacity;
- The possibility of building buildings using glued timber, regardless of the time of year and weather conditions;
- resistance to aggressive media;
- extensive range of sizes;
- homogeneous structure;
- Easily processed by various tools;
- low weight compared to natural wood (due to this feature for a small building, the bulky base is required);
- the possibility of building structures with complex architectural forms;
- Reliability, long life and aesthetics.
LVL-timber produced from expensive raw materials for complex and long-term technologies. Its manufacture requires expensive equipment. All this is reflected in the price of the finished product – the construction of the construction from the LVL BROUS will require serious financial investments. This building material is considered environmentally unsafe, since when connecting layers, substances based on formaldehyde are used.
When operating, toxic substances evaporate into the environment. Special health hazard represent bars produced in violation of manufacturing technology. To another lack of weak parachuability, which makes it difficult to natural air circulation in the room.
How do lvl-timber?
The technological process of production includes several stages.
- Preparation of the wood trunks delivered to the plant. To do this, they remove the bark (at least 3 mm) on specialized equipment, after which they are immersed in hot water (up to 80 degrees) for about 24 hours. Wet wood is great for greater softness and fuel, it is easier and faster to cut into thin strips.
- Cutting wet logs on the plates with the required length, their centering and pushing to produce a veneer 3 mm thick.
- Sort the obtained billets By humidity, their dispatch to the drying units. The humidity of the dried veneer must be in the range from 5 to 8%.
- Repeated sorting material, Elimination of marriage, its subsequent transmission for the manufacture of other sawn timber.
- Bonding sheets using a special adhesive composition on the pressing equipment.
In the last stage glued veneer cut, getting a ram with the required length. Before issuing the production of products undergoes additional quality check, packaged and marked. The production process of the LVL-BROUS is fully automated, which excludes a random marriage due to the human factor.
Brushing, measured and centering blanks are made using computer programs. The quality of the veneer is checked by special ultrasound equipment.
Characteristics and properties
LVL-timber with a multi-layered structure is manufactured at industrial enterprises in accordance with GOST 33124-2014. Qualitative materials produced with strict compliance with production technology have the following characteristics:
- density – 480 kg / m³ (denser and stronger than natural wood);
- class of resistance to wear – 4;
- moisture resistance – from 8 to 12% (practically does not absorb moisture);
- Class of refractory – E (charging rate does not exceed 0.7 mm / min.);
- The formaldehyde class – E1 (the allowable rate of carcinogenic substances does not exceed 10 mg per 100 g of dry mass of the bar);
- stretching resistance – 16-22.5 MPa, bending – 48 MPa.
The material has a homogeneous structure, due to which its physical properties are preserved over the entire length. Bar glued is not deformed and does not change the dimensions and operational qualities when climate change and seasonal effects. The important properties of building materials include its excellent noise and thermal insulation. Due to such a feature in the premises erected, there will be quiet and heat. Lvl-timber, unlike metal products and natural wood, has high resistance to the effects of water and salt vapors, ammonia.
Bar LVL differs from the usual greater refractory due to a multilayer structure and small porosity. Formaldehyde-based adhesives used in the process of producing panels are neutral to oxidation and resistant to ignition.
Due to the high density and lack of cracks on the surface of the products, an obstacle is created for the penetration of fire inside the material.
LVL-timber depending on manufacturing technology is divided into 2 types. Materials are structural or with transverse layers.
These include a ram, in which all available layers are located in the longitudinal direction to wood fibers. Their main feature is the ability to withstand a large load at a small cross section. When using the structural material, it will not be necessary to install a massive foundation base. His minus includes twisting building materials at the edges at its large width values.
With transverse layers
It has a different structure with a structural bar. In its production, each 5th layer is stacked across other fibers. Due to this, the product acquires additional strength. The material with transverse layers does not twist at the edges, due to which it is advisable to use it in the manufacture of door canvases and various wide building structures.
Lvl-timber produced in various dimensions, so that the buyer has the opportunity to purchase material under certain tasks. The minimum value of the thickness of the material is 1.8 cm, and the maximum – 10.2 cm. LVL panels are available width from 10 to 180 cm. Limit length is 18 meters. At the request of the buyer, building materials is cut into parts with the required length.
In the construction market, glued timber is represented by goods with various labeling. Deciphering alphabetics:
- R, S – Bar from a dense veneer placed parallel to wood fibers;
- X, q – high quality materials with perpendicularly directed wood fibers relative to neighboring sheets;
- I is a combination of 2 previous types of veneer with lower quality;
- T – Bar from thick veneer G3-G4 varieties with parallel fiber direction.
Products, in the marking of which there is an alphabetic designation R is allowed to use to build supporting structures, S – for the facilities of the beams. Materials X and I are recommended to apply when erecting walls and various partitions. Glued bar with designation Q is designed for the installation of roofing overlaps. Building material with a brand T can be used as a lag for outdoor cladding.
There are only several production complexes specializing in the manufacture of LVL-timber. There are 2 explanations – the complexity of the technological process, as well as the small demand of the consumer due to the high cost and insufficient information about the advantages of the sawn timber.
One of the most popular manufacturers is considered “LVL-Ugra”. This is a woodworking company, the production of the power of which are located in Tyumen. She specializes in the manufacture of various types of BRUSIV, including LVL lumber. For the year, the manufacturer produces about 30 thousand to implement. M3 Bruus.
Another major company registered in g. Torzok Tver region, – “Talion Terra”. It is engaged in the manufacture of a durable multilayer bar Ultralam. This is the largest Russian manufacturer, which produces at least 150 thousand. M3 LVL panels annually.
The sawn timber is made according to the continuous pressing technology with a pre-heating that contributes to a faster and deep penetration of adhesive resin into the structure of wood.
One of the most popular foreign manufacturers of LVL-BROUS is the company FINNFOREST (Finland). It produces products under the brand name KERTO. However, lumber of domestic production will cost the consumer cheaper.
Products made on Russian woodworking factories has established itself from a positive side – they are no worse in the quality and operational properties in comparison with the analogues brought from abroad.
Scope of application
The glued lvl-timber is used in the construction of private low-rise buildings – carcasses of houses are made of. Brussia often replace beams and various components of the rafter system. With the help of LVL-sawn timber:
- Sports halls;
- various constructions of commercial and industrial purposes;
- inter-storey floors;
- Roofing panels and fence designs;
- Formwork for the subsequent fill of the concrete solution.
Material is also used to make doors, windows, furnishings, arched structures, interior decorations. Due to its high moisture resistance, it is in demand when building structures with increased humidity rates (for example, baths and saunas). Lvl-timber has many advantages, but due to the high price of about 30000-40000 rubles. / m3 of it is unprofitable to build walls. However, this is one of the best building materials, with which various auxiliary designs are built – reference pillars or beams. To reduce the cost of building a house, it is recommended to combine with other types of BRUSEV.
When choosing a LVL timber to build a wooden house, you will have to invest, but in this case it is possible to build a strong, reliable, durable, warm and externally attractive housing.