The bar is, of course, one of the most popular and common types of building material. Use it for the construction of walls and roofs of houses, in the assembly of ceilings, fences, etc. And, of course, in order for the assembled structure to turn out reliable, during its construction it is important to choose the most suitable section of the beam. The standard dimensions in the manufacture of this material by manufacturers must be respected with precision. On the market today there are several types of timber for this indicator.
Lumber length
In most cases, specialized enterprises and workshops supply 6 meters of timber to the market. This material is convenient for transportation and for the assembly of most building structures. Also, if desired, for example, the owners of suburban areas, who decided to build a house, bathhouse or garage, can purchase a bar of standard length 2, 4, 8, 10 and 12 m.
Sometimes it happens that it is not possible to select the material of the required dimensions. In this case, you can buy a standard 6-meter beam and saw it into the appropriate number of parts. There are also quite simple techniques for building up timber during the assembly of various kinds of building structures. For example, to get a beam at 8 m, you can:
saw a 6-meter beam into 3 parts, receiving three pieces of 2 m;
attach one of their segments to another whole beam at 6 m.
Section
Changing the length of acquired lumber during the construction of various structures will be easy. The situation is completely different with the cross section of the beam. In this case, the choice must be approached with all responsibility.
On the market today there are lumber of this variety with both a square section and a rectangular one. Both of these types of timber are equally popular among developers. In this case, the materials of the first variety can have a standard section:
100 x 100 mm;
120 x 120 mm;
150 x 150 mm.
Also, very often, in the construction of buildings, a bar of 200x200x6000 mm or 250x250x6000 mm is used.
The standard beam is delivered to the market in the following sizes:
100 x 150 mm;
200 x 250 mm.
Rectangular lumber is well suited for the construction of, for example, rafter systems. Square beam in most cases is used to assemble boxes of buildings.
Dimensions of glued material
Most often, in the construction of various kinds of buildings, of course, an ordinary beam is used. Such material is not particularly expensive, but has some disadvantages. For example, log cabins from ordinary timber give strong shrinkage. Also, such a material often has a not too regular geometric shape.
Therefore, recently, a special type of timber - glued - has become very popular with developers, including frequent ones. Such material lasts much longer than usual, has an attractive appearance, is practically not afraid of moisture.
Of course, attention should be paid to dimensions when choosing this type of timber. The length of this type of lumber can be 6 or 12 m. At the same time, in the section at the glued beam:
Profiled beam
Such material (along with ordinary and glued) is also used in construction quite often. Profiled timber has a special configuration in cross section. The boxes of buildings and structures erected from it look more accurate than those built from ordinary lumber. A square or rectangular profiled beam, among other things, has the advantage of being easy to install. But according to some operational characteristics, as well as in terms of service life, the material of this type is still inferior to glued.
The standard width of the profiled beam can vary between 80-230 mm. The height of such lumber from pine, spruce or aspen in most cases is 140 mm. In a profiled larch beam, this indicator is 190 mm.
How to calculate the required cross section in terms of thermal conductivity
Of course, the smaller the thickness of the beam, the cheaper it costs to buy the owner of the suburban area. But to choose such lumber, based only on economic feasibility, of course, is not worth it. A building erected from timber should not only be not particularly expensive, but also convenient for living, and warm.
When choosing the cross-section of the beam for the assembly of a particular structure, accurate calculations should be made. The owner of a suburban area, who decided to erect any building on it, will need to find a middle ground in which its operational characteristics will be optimally combined with the size of the material.
The required beam cross-section is calculated according to SNiP, using the following formula:
Kt is the coefficient of thermal conductivity of the beam;
R is the heat transfer coefficient of the walls.
The latter indicator may vary depending on the region of construction of the house. So, for example, for Moscow the indicator R will be 3.16, for Rostov - 2.63, for Arkhangelsk - 3.56.
The coefficient of thermal conductivity of the beam itself, in turn, depends on which particular tree species it is made of. For cedar, for example, this indicator will be 0.095, for linden and birch - 0.15, for spruce - 0.11 and so on.
Sometimes the result of the calculation is non-standard indicators of the thickness of the lumber. If during the calculations it turns out that the construction of a warm house requires the option of 180 x 180 cm, the owners of the site will have to purchase a bar of 200 by 200 mm. That is, the indicator when compiling a project always increases upwards.
Use in the construction of roofs
Walls from timber are assembled in our country, mainly only in wooded regions. In the steppe regions, this material is quite expensive. And therefore only roofs of buildings are erected from it. Using a bar in this case, the rafter system is mounted.
Of course, when assembling the roof frame, it is also important to determine the cross-section of the material. Thermal conductivity when used as a support for the roof of the timber in this case does not play a special role. But the strength of lumber also depends on the cross-sectional index. Of course, the rafter system at home should easily withstand the weight of both the “pie” of the roof and the snow lingering on it. Also, when choosing the cross-section of the beam for assembling the roof frame, the wind load is also taken into account.
How to calculate the cross section
This indicator for a bar when it is used to assemble the rafter system can depend on several factors:
design length of the rafter leg ;
the step with which it is supposed to mount the supporting elements;
indicators of wind and snow loads for this particular region.
When performing calculations in this case, various tables are used that contain ready-made information.
It will not be particularly difficult to determine the dimensions of the cross-section of the beam for the rafter system in a particular region. In any case, the following material is usually used:
for the legs themselves - 100 x 150 or 100 x 200 mm;
for Mauerlat - with a section of 100 x 100, 150 x 150 mm;
for racks - 100 x 100 or 150 x 150 mm.
For Mauerlat large buildings can also be used timber 200 to 200 mm or even 250 x 250 mm.
SNiP requirements for the thickness of the beam, depending on the purpose of the structure
The following types of buildings can be built on suburban areas:
- household;
- country houses;
- residential buildings.
All these types of buildings can be built using timber. But the material in all these cases, of course, can be selected in different sizes. When assembling a box of various household buildings, a beam with a section of 100 x 100 or 100-150 mm is usually used. Such material in most cases is very inexpensive. At the same time, you can collect from it, for example, a bathhouse, a sauna, a barn, a garage or a utility block.
Country houses differ from residential in that people live in them not all year round. Many townspeople visit suburban areas, mainly only in the summer, in late spring or early fall. Therefore, too serious requirements in terms of the ability to retain heat to the walls of such buildings are usually not presented. But such structures, since the owners live in them, including in the off-season, should still be quite warm. The bar when assembling the boxes of country houses is usually used with a section of 120 x 120 mm. Sometimes in this case, a beam of 6 m and 150x150 cm can also be used. Such material is advisable to use, for example, in the cold regions of the country - in the Urals or Siberia.
In terms of the ability of the walls to keep warm, residential buildings, of course, have special requirements. The calculation of the required section in this case is carried out according to the formula considered above in the article. In most regions of Russia, timber 200x200x6000 mm or even 250x250x6000 mm is used for the construction of residential buildings. The latter option is ideal for Siberia and the Urals.
Standard Bar Sizes
Sometimes when erecting various kinds of structures in suburban areas, in addition to everything else, bars can be used. Such lumber can be used in the assembly of street small architectural forms, fences, benches and other things. They differ from the timber in a smaller section. Of course, workshops comply with certain standards in the manufacture of such lumber. The dimensions for the bar standards are as follows:
for coniferous species - width and height from 16 from 25 cm (with a spread of 3 cm), 32, 40, 44, 50, 60, 75 mm;
for hardwood - from 19 to 25 (3 cm), 32, 40, 45 and from 50 to 100 (with a spread of 10 cm).
Edged board
The standard length of this type of lumber can vary from 1-6 m with a gradation of 0.25 m. The width of the edged boards can be equal to 75, 100, 125, 150, 175, 200, 225, 250, 275 mm, thickness - 16, 19, 22, 25, 32, 40, 44, 50, 60, 75 mm. This type of material is used in the construction of various kinds of buildings on suburban areas as often as timber. At the same time, the most popular option among private developers is the material of this type with a width of 150-200 mm and a thickness of 2-4.5 cm. The properties of the beam, its strength and other operational qualities, allow it to be used in construction.