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The use of profiled timber and logs in the construction of houses

Softwood used in the construction of pine, spruce, larch, fir, cedar. For the manufacture of load-bearing structures are more suitable pine and larch, in contrast to the spruce and fir are less susceptible to rotting. In the European construction industry because of its prevalence ranks first pine. Hardwood in the case are much rarer ones are most applicable oak, ash, beech, birch, aspen.

If closely considered a cross section of a tree trunk, it is possible to distinguish the following main parts - the core (5), wood, cambium (2) and the cortex (1). The core - a thin < tube > in the center of the barrel, it has a low strength and is easy to rot. Wood (from the inner bark of the stem (3) to a core) in cross section is a series of concentric (annual) rings around the core.

During the growth of the cell walls of the wood of a tree adjacent to the core, gradually change its composition, soaking resin from conifers and deciduous - tannins. Movement of juice in this part of the barrel is stopped, Wood is becoming more solid and less prone to rot. This part of the stem at the softwood called nucleus, while others - mature timber. Some of the younger wood, which is located closer to the crust (it still has living cells), called sapwood (4). It has a lot of moisture, relative-enforcement easily rots, it is characterized by low strength, is subject to considerable shrinkage, and prone to warping. Species for which the kernel is different from the sapwood darker color and less humidity, referred to by sound (pine, larch, oak, cedar and others.) We sang-tree species (spruce, fir, beech, linden, etc.), A central part the trunk is different from the sapwood only less humidity. In the sapwood species (birch, maple, alder, aspen, etc.), A significant difference between the center and the outside of the barrel can not be detected.

Such a detailed description of the macrostructure of the tree will need in the future to understand what is the purpose of sound cylindering logs breeds - pine and larch. By their microstructure Wood is a natural polymer forming the fiber of its cells have a tubular shape and directed along the barrel. With this Wood has a number of advantages - a high strength, elasticity, low density, and hence low weight, low thermal conductivity, resistance to chemically aggressive media, natural decorative, ease and simplicity of handling and installation. Of particular importance are the thermal insulation properties of wood: low thermal conductivity - its indisputable advantage (see. Table). The most important characteristic of heat-insulating properties of the structure is the value of thermal resistance, establishing a link between the physical properties of the material and the thickness of its layer. It is defined as the ratio of the thickness of the material to its thermal conductivity.

The coefficients of thermal conductivity of basic building materials.

Material

Density kg/cu m

Thermal conductivity, W/m`C

Reinforced

2500

2.04

Foam

1000

0.47

Masonry of solid brick: glinyanogocilikatnogokeramicheskogopustotnogo

180018001200

0.810.870.52

Pine and spruce: volokonpoperek along the fibers

500500

0.350.18


The greater the thermal resistance of the material from which the house is built, so it is warmer.

The superiority of wood bricks for thermal insulation properties obvious: a brick wall thickness of 510 mm (two bricks) has almost the same thermal resistance as the wall thickness of timber 100 mm.Odnako along with the merits of timber have disadvantages: anisotropy (its properties are very different along and across the fibers), structure defects, hygroscopic and, as a consequence, humidity deformation putrescibility and flammability.

Most significantly on operational properties of wooden structures affect hygroscopic putrescibility and flammability. In order to reduce their negative impact primarily used drying, impregnation of wood preservatives or flame retardants, as well as measures to prevent moisture designs in operation (protection from rain, isolated from soil, stone, concrete, device good natural ventilation, and so on. D. ). Currently, for antiseptic treatment of wood and antipyrine applied composition RACs, replacing the previously widely applied impregnant MS, PP, PPL. For centuries skillfully cut wooden buildings, adjusting log to a log, butt to the apex, skillfully thus eliminating natural sbeg tree trunk. With the expansion of the construction required to simplify the process. The solution came in the form of logs (with the same diameter along its entire length of the structural) and sliced ​​- timber.

Mechanized otsilindrovyvaniya technologies used and abroad at the beginning of the century. Wooden houses from the reduction in the number of operations in the assembly become easier and faster to build, in addition, the use of logs allowed the assembly to create a more rigid structure. Since the log to a log is adjusted more tightly, improving the insulating properties of the walls, and the building itself is aesthetically pleasing.

For the production of logs and profiled bar, which replaced the usual four-kantnomu, mainly used pine. When cylindering this classic rock sound is cut loose more sapwood and remains a solid, resin-impregnated core. The log will only win.

Cutting sapwood leads to yet another positive effect - a decrease in the width of the cracks when dry, which in turn improves the thermal insulation of the walls. With logs cracking fight deliberately, causing cracks in the vertical plane-sti. To do this, make a shallow timber along the vertical propyl.

When cylindering, as well as in the production of corrugated timber, a high purity of the treated surface, Wood becomes extremely smooth, which makes it possible not to apply additional materials for interior and exterior of buildings and thus avoid unnecessary costs.

Trendsetters in the production of logs, profiled timber and construction of these houses believe Finnish companies.

Profile logs, produced by the leading companies, far from the traditional round profile Modern profiles have special wedge locks, which together with a heater over-imposes between the logs, reliably protect the house from wind and moisture.

With the construction of buildings made of logs and profiled bar used for fastening structures (as in the traditional assembly technology) pins, screws, pins, staples, and adjustable anchors. Assembled house definitely gives upset, but it is much less than that of the conventional timber houses. It contributes to reducing the amount of rainfall forced screed construction. Since the house is made of well-treated material, it basically does not require additional finishing, it is possible to live almost immediately after its construction.

The natural texture of the wood creates a special drawing walls, because the wood is used operational humidity, the house can immediately okra-Sit outside. This further protects the wood from moisture.

The wooden house made of logs and profiled bar to quickly erect and environmentally friendly, it combines a relatively low cost with high performance. The natural beauty of wood and the fantasy of the architect can create from this material with modern-day comfort Zago-homes and cottages. All of the above has made these wooden houses are very popular both abroad and in our country.

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