Beam is, of course, one of the most popular and common types of building material. It is used for the construction of walls and roofs of houses, when assembling ceilings, fences, and so on. And, of course, in order for the assembled structure to turn out to be reliable, it is important to choose the most suitable section of the beam during its construction. Standard dimensions in the manufacture of this material by manufacturers must be observed exactly. There are several types of timber on the market today according to this indicator.
Length of lumber
In most cases, specialized enterprises and workshops supply the market with 6 m timber. This material is convenient both for transportation and for the assembly of most building structures. Also, if desired, for example, owners of suburban areas who decide to build a house, a bathhouse or a garage, can purchase a beam of standard length 2, 4, 8, 10 and 12 m.
Sometimes it happens that it is not possible to pick up the material of the required dimensions. In this case, you can buy a standard beam of 6 m and cutit into the appropriate number of parts. There are also fairly simple methods for building timber when assembling various kinds of building structures. For example, to get a beam of 8 m, you can:
- cut a 6-meter beam into 3 parts, getting three pieces of 2 m each;
-
attach one of their segments to another whole beam at 6 m.
Section
It will not be difficult to change the length of the purchased lumber when building various kinds of structures. 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 square and rectangular sections. Both of these types of timber are equally popular with developers. In this case, materials of the first variety can have a standard section:
- 50 x 50mm;
- 100 x 100mm;
- 120 x 120mm;
- 150 x 150mm.
Also very often in the construction of buildings, timber 200x200x6000 mm or 250x250x6000 mm is used.
Standard timber is available on the market in the following sizes:
- 50 x 100mm;
- 100 x 150mm;
- 200 x 250 mm.
Rectangular lumber is well suited for the construction of, for example, truss systems. Square beam is most often used to assemble building boxes.
Dimensions of glued material
Most often, when building various kinds of buildings, of course, an ordinary bar is used. Such material is not particularly expensive, but has some disadvantages. For example, log cabins from an ordinary bar give a strong shrinkage. Also, such material often does not have a very regular geometric shape.
Therefore, recently a special type of timber - glued - has become very popular among developers, including frequent ones. Such material lasts much longer than usual, has an attractive appearance, and is practically not afraid of moisture.
Of course, attention to the dimensions should be paid when choosing this type of timber. The length of lumber of this variety can be 6 or 12 m. At the same time, in the cross section of a glued beam:
-
width can be equal to 80-380 mm for maple and from 80 to 280 mm for pine and spruce;
- height can be 80-240mm and 135-270mm respectively.
Profile timber
Such material (along with ordinary and glued) is also used in construction quite often. The profiled beam 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 performance characteristics, as well as in terms of service life, the materi althis type of glued is still inferior.
Standard width of profiled timber can vary between 80-230mm. The height of such lumber made of pine, spruce or aspen is in most cases 140 mm. For a profiled larch beam, this figure 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 is to buy it for the owner of a 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 comfortable to live in and warm.
When choosing a cross-section of a beam for assembling a particular structure, accurate calculations should be made. The owner of a suburban area who decides to build any building on it will need to find a middle ground in which its performance will be optimally combined with the size of the material.
The calculation of the required section of the beam according to SNiP is carried out, according to the following formula:
S=Kt x R where
Kt - coefficient of thermal conductivity of the timber;
R - heat transfer coefficient of the walls.
The last figure may vary depending on the region where the house was built. So, for example, for Moscow, the R indicator will be 3.16, for Rostov - 2.63, for Arkhangelsk - 3.56.
The thermal conductivity of the beam itself, in turn, depends on what kind of wood it is made ofmade. For cedar, for example, this figure 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 lumber thickness. If, when performing calculations, it turns out that a 180 x 180 cm option is needed to build a warm house, the site owners will have to purchase a 200 x 200 mm beam. That is, the indicator when drawing up a project always increases upwards.
Use in roof construction
Walls made of timber are collected in our country, mainly only in wooded regions. In the steppe regions, this material is quite expensive. And therefore, only the roofs of buildings are erected from it here. Using a beam, in this case, a truss 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 a beam in this case does not play a special role. But the strength of lumber also depends on the cross-sectional index. Of course, the truss system of the house should easily withstand the weight of both the "pie" of the roof itself and the snow lingering on it. Also, when choosing a beam section for assembling the roof frame, the wind load must also be taken into account.
How to calculate cross section
Depending on this indicator for a beam when using it to assemble a truss system can depend on several factors:
- project length of the rafter leg;
- step with which it is supposed to mount 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.
Determining the dimensions of the beam section for the truss system in a particular region will not be particularly difficult. In any case, the material commonly used is:
- for the legs themselves - size 100 x 150 or 100 x 200 mm;
- for power plates - section 100 x 100, 150 x 150 mm;
- for racks - 100 x 100 or 150 x 150 mm.
For the Mauerlat of large buildings, a beam of 200 by 200 mm or even 250 x 250 mm can also be used.
SNiP requirements for timber thickness depending on the purpose of the structure
The following types of buildings can be built on suburban areas:
- household;
- country houses;
- residential buildings.
All of these types of buildings can be built using timber. But the material in all these cases, of course, can be selected in different dimensions. When assembling a box of various outbuildings, a bar 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 assemble from it, for example, a bathhouse, sauna, barn, garage or utility block.
Country houses differ from residential ones in that people do not live in themyear-round. Many citizens visit suburban areas, mainly only in summer, in late spring or early autumn. Therefore, too serious requirements in terms of the ability to retain heat are usually not imposed on the walls of such buildings. But such facilities, since the owners live in them, including in the off-season, should still be warm enough. A bar when assembling 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. It is advisable to use such material, for example, in the cold regions of the country - in the Urals or Siberia.
There are, of course, special requirements for residential buildings in terms of the ability of walls to retain heat. The calculation of the required cross section in this case is carried out according to the formula discussed above in the article. In most regions of Russia, a beam of 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, among other things, bars can also be used. Such lumber can be used in the assembly of street small architectural forms, fences, benches and other things. They differ from a bar in a smaller section. Of course, the workshops comply with certain standards in the manufacture of such lumber. The dimensions for the bar are as follows:
- for softwood - width and height from 16 to 25cm (3 cm spread), 32, 40, 44, 50, 60, 75mm;
- for hardwoods - 19 to 25 (3 cm), 32, 40, 45 and 50 to 100 (with a spread of 10 cm).
Edged board
The standard length of this type of sawn timber can vary within 1-6 m with a gradation of 0.25 m., 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 in suburban areas as often as timber. At the same time, the most popular option among private developers is a material of this type with a width of 150-200 mm and a thickness of 2-4.5 cm.
