How to calculate a log house from a rounded log? Shrinkage of a wooden house from a log: principles of education Builders' mistakes: typical and rough

If you are faced with the task of finding a supplier of construction services if you want to build wooden house or a bathhouse, then it is inseparably linked with the concept that involves the calculation of a log house. Calculating the amount required material, you can find out what its cost is for 1 m 3. This will be the actual cost of the kit. Here, each owner of the building area tries to understand what constitutes the cubic capacity of the building.

In order to calculate the volume of the beams in the house on your own, you will have to use the main specified parameters, namely: heights and axial dimensions. This will allow you to calculate the running meters of the beams in the house. The simplest way is to multiply the length in linear meters in the crown by the number of crowns.

Determination of the number of crowns and calculation of material

In order to calculate the required number of crowns for a building made of a rounded log, you need to know what the working height of the log is.

Figure 1. Characteristics and dimensions of a rounded log.

It depends on how wide the groove of the timber has. Figure: 1 illustrates a table that can be applied to a standard groove. If you divide the height of the cant by the working height of the cant, you can get the number of crowns needed for the job.

For example, you can calculate the volume of beams for a house, the dimensions of which are 6x9 m.The example assumes that it is necessary to make calculations for a log house, the height of which is 3 m.

The task is to calculate how many crowns in the house are made of rounded logs with a diameter of 220 mm. To do this, 3000 mm must be divided by 191 mm, which is equivalent to 15.71 mm. This suggests that 16 crowns are needed for a given height.

Using the data indicated in the drawing of a house made of rounded logs, you can determine how many running meters in one crown. Do not forget about the protrusions, which are corners.

In this example, the crown length is calculated as follows: 9 + 9 + 6 + 6 + 6, which is equivalent to 42 running meters. This suggests that you can calculate the running meters in the house from the example as follows: 42x16, which will be equal to 672. After that you have to take into account the halves of the zero crown, the data of which must also be added, they are needed to shift the rows.

The halves are calculated as follows: 3x6, which is equivalent to 18 running meters. For the reason that one solid bar is needed to obtain 2 halves, 18 must be divided by 2, you get 9 running meters of bars in halves.

Ultimately, we managed to get 681 running meters, but the openings were not taken into account here. If you subtract running meters of openings, you can get 546 running meters.

Then comes the turn of the calculation, which consists of the frame. This must be done using the formula: π * r ^ 2 * l (here π equals 3.14; r is the radius of the timber; but l is the length or number of running meters in the house). The calculation itself is as follows: 3.14x0.11x, 011x546, which is equal to 20.75 m 3. This means that the volume of the log of which the blockhouse is in this example is equal to 20.75 m 3.

Do not forget about illiquid leftovers, as well as losses in the process of sawing parts of the building kit. This number can be equal to the limit of 3-7 percent. This allows us to assume that the test volume of the building from the example will be about 22 m 3.

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House kit material cost

If we take into account that the price of 1 m 3 of a set of logs is equal to 8.5 thousand rubles, then the cost of this log house from a rounded log will be equal to 187,000 rubles.

This price is not only lower than that presented by developers working with stone and brick, but is also justified in many respects. First of all, in a dwelling built of wood, natural air exchange will take place through the walls, the volume of which per day is approximately equal to 20% of the total volume of air in the premises, which is true even with closed windows and doors.

This will allow maintaining the oxygen balance most suitable for a person in the rooms in terms of humidity and heat indicators. It is worth considering that climate systems will not need to be operated to maintain normal vital signs. In such a dwelling, you will be warmer, because wood has a slight thermal conductivity.

When comparing brick and wooden walls the latter will surpass the former in terms of thermal insulation characteristics. The same ratio of thermal conductivity indicators can be achieved with a wall thickness of 10 cm and a wall of brick 51 cm. These examples can be considered more than illustrative.

If you decide to build a log house, and use a rounded log as a material, then you are already familiar with all the features of the calculation. Now it only remains to choose the most profitable service provider by comparing the cost of a log house that each of them offers to their consumers. It is important and correct to choose a rounded log, and this issue must be approached with no less seriousness.

The main mistakes in the construction of chopped wooden houses.

Log houses have been serving people for more than one millennium. Solid wood houses give their owners incomparable pleasure from living in a comfortable micro-environment. Solid wood has a high heat capacity (2.4 times higher than that of ceramic bricks), which makes it possible to smooth out daily temperature fluctuations. Also, the porous structure of wood allows you to naturally regulate the humidity in the room through the cycles of absorption and evaporation of moisture. The log house is relatively resistant to ground and foundation movements. Wood surfaces often do not require any additional treatment other than sanding and coating with antiseptics to create beautiful interiors.

However, only properly felled wooden houses will give their owners comfort. The construction of a log house requires high carpentry skills at the 6th grade level. Without experience and qualifications, it is almost impossible to cut down a wooden house without mistakes. And mistakes during construction can negate all the advantages. log house... Houses built with mistakes are easy to recognize: builders or owners have to additionally insulate and sheathe them from the outside and from the inside in order to hide defects, eliminate the through-blowing of locks in the corners and inter-crown seams. One of modern options houses made of solid wood, practically devoid of the shortcomings of log cabins, are houses made of glued beams. Due to the peculiarities of this technology, blowing through the seams and cracking the tree in such houses is practically impossible.

In this article, we will briefly touch on the most common mistakes in the construction of log houses.

1. Errors in the preparation of the log house.

Errors when choosing a material for construction.

According to GOST 9463-88 "Round timber of coniferous species", round timber of pine, spruce, fir and larch is suitable for the construction of houses. Larch is the most expensive material, the hardest and most resistant to decay. Spruce is less dense, has excessive knotty and is prone to more cracking. The optimal tree for building a house is a pine aged from 80 to 120 (140) years old, grown in the northern regions (Arkhangelsk, Angarsk, in Karelia) on dry sandy soil, not less than 24 meters high. The best pine logs have a deep red or yellow-red kernel color, indicating high density wood. Loose varieties have a pale yellow core. Winter felling forest against folk legends actually has a higher moisture content of sapwood (25-50% higher than in summer), more starch and, therefore, is more easily attacked by fungi. You can determine the round timber of winter felling using a qualitative test for starch: a stroke is applied to the debarked wood with an iodine pencil. If the stroke turns blue - in front of you is a tree felled in winter.
For construction, it is allowed (this does not mean that you have to agree to purchase such materials) timber with such defects as mushroom blue and colored sap spots (no more than 1/20 - 1/10 of the end diameter), wormholes (no more than 5-10 pieces per 1 running meter), lateral cracks from shrinkage no more than 1/20 -1/5 of the end diameter, trunk curvature no more than 1-2% (1-2 cm per 1 running meter). Logs used for construction must have a run-down (thinning of the log to the top) of no more than 0.8 cm per 1 m of length.

Rot (sapwood, rotten, sound) and tobacco knots (decomposed knots of brown or white color, crumbling under load) are not allowed in round timber.

The minimum diameter of a round timber for a residential building is 22-24 cm. The width of the grooves should be at least half the diameter of the log, and in the northern regions it can be increased even more. With a smaller size of the grooves, the consumption of timber decreases, but the thickness of the joints between the joints becomes smaller, and the house becomes "colder".
Cutting of corners can be done without the rest "in the paw" or with the rest - "in the corner". The "corner" cabin makes connections more reliable and the frame more stable. In addition, the wood allowance better protects the lock from weathering. Cutting "in the paw" is usually used for the subsequent sheathing of corners or the entire frame. For residential buildings, the device for connecting logs in the corners must have internal locking elements that exclude through blowing of the corner (connecting the logs "in the bowl" with a stop or "in a flash" with a stop). Due to its geometry (overturned bowl), the cut-out allows for better moisture removal and faster drying of the joint. Cutting internal locking elements requires a high qualification of the carpenter, this work takes more time and costs more. Otherwise, the corners of the residential building will be protected from blowing only with tow (heat-insulating material). This is one of the main disadvantages of rounded log houses, where log joints are manufactured industrially without additional internal locking elements.

The moisture content of timber for construction. SP 64.13330.2011 " Wooden structures»Allows the use of raw solid wood for the construction of houses with a moisture content of up to 40% under the following conditions: the predicted wood shrinkage should not disturb the structure and flexibility of the joints, and the timber itself should be antiseptic and conditions for drying, drying and protection from moisture should be provided for them ... It is optimal if the log house dries up, installed in place on the foundation and under the roof. Drying period from 6 months to 1 year. If the log house stood at the seller in the feet (separate parts of the log house with 5 crowns, convenient in height for processing) without a roof for 6-12 months, then with a high probability this means that the tree will be rotted. It is permissible to purchase log cabins that have stood under the roof.

It is important to understand that the higher the moisture content of the timber, the greater the shrinkage of the tree, and the wider the gap between the joints, the gaps in the corner joints (especially with cutting defects), the more the wood will crack.

Why don't they cut down houses from dry wood? Dry wood has a higher density and hardness and is much more difficult to process. The rounded log is subjected to the order of a chamber drying after processing. However, kiln-dried wood can bend as the equilibrium moisture builds up at the construction site. Finnish and Karelian dry-standing pine of equilibrium moisture content is used in construction, but this is already an exclusive product. In addition, a properly assembled frame made of raw wood, during drying in the assembled state, "sits down" in place, reducing the size of the through-slots and, accordingly, the coefficient of wall blowing. It is important to know that it is possible to paint (not mean treatment with antiseptics) wood only if its moisture content does not exceed 15%. Otherwise, the wood will crack strongly when it dries. Therefore, the treatment of log cabins is permissible only with vapor-permeable antiseptics. Treating a wet (damp) log house with a vapor-proof antiseptic will also cause the wood to crack as it dries.

For dowels (dowels), only dry (no more than 12%) straight-grained wood without knots should be used. Birch pins must be antiseptic.

Fastening of logs to metal elements (trimming of reinforcement, long nails) is not recommended, as moisture accumulates on the media section, and the metal element becomes the centers of biological destruction of wood. Usually, the reinforcement is used by unscrupulous builders for fastening and "tension" of curved logs, which then leads to a violation of the normal shrinkage of the frame, the formation of cracks and bulging of individual logs. It is strictly forbidden to punch the corner joints of the logs with nails, as this will interfere with the movement of the tree during shrinkage, and will contribute to the formation of cracks (after the wood has dried, the nails will rise above the surfaces).

Types of timber processing for construction.
The most traditional for Russia is round timber. In Scandinavia, they use a carriage (from the Norwegian "lafteverk" - log house) - logs hewn from two opposite sides on two edges, or a semi-carriage - hewn one edge from the inside of the log. The cost of a hewn log house can be 35-50% higher than a log log house. When processing round timber, builders sometimes leave unremoved areas of the bast (under-bark). According to the norms, no more than 20% of bast can remain on the round timber. However, it is better to remove the bast completely with the help of shaving (planing), since the bast contains a lot of polysaccharides, which are an excellent medium for feeding microorganisms and insects that can damage the wood. Also, when ostrozhka, young layers of sapwood that are less resistant to infection by fungi and insects are removed.

2. Errors in the assembly of the frame.

Waterproofing must be installed between the first flashing ring and the foundation. Until now, builders for some reason use for waterproofing a non-durable cardboard-based material - roofing felt, in which through holes and cracks are formed in 7-10 years. For waterproofing, it is necessary to use modern bitumen-polymer materials with a service life of 25-50 years. Of course, the complete absence of waterproofing is also unacceptable. The use of a backing board under the flap reduces heat loss by heat transfer from the frame to the foundation, reduces the risks of biological destruction of the flare. According to the requirements of SP 64.13330.2011 "Wooden structures", such wooden linings (pillows) should be made of antiseptic wood mainly hardwood (oak, aspen). If necessary, the underlays can be replaced with new ones. Replacing the cap is a much more time-consuming procedure. The lower rims of the house must be protected from moisture. The greatest harm is caused by splashes of precipitation reflected from the ground and snow pressed against the wall. To protect logs from splashes and snow, it is recommended to raise the foundation above the planning mark by at least 40-50 cm.

TO additional factors the protection of the log house includes splash guards protruding above the plinth, long eaves of roofs (75-120 cm) and equipping roofs with gutters and pipes.

Orientation of logs during stacking. Each tree has a natural curvature due to wind loads during tree growth. When laying logs, they are certainly laid with the curvature upward so that the loads from the overlying structures compensate for the bending of the wood. If you do not follow this principle, then the logs will stick out to the sides. Normally, the deviation of the crowns of chopped walls from the horizontal by 1 m of length should not exceed 3 mm.

The size of the inter-crown gaps should not exceed 1 mm. With the Russian felling system, it is quite difficult to fulfill this condition, since as the tree dries out, the cracks open. The advantage is possessed by the Norwegian felling system with a wedging longitudinal groove and a sliding self-wedging lock, in which, as the tree dries, the logs shrink relative to each other, reducing the size of the inter-crown slots.

In Russia, traditionally, they continue to insulate the gaps in log houses with natural materials such as flax, jute, felt, moss, etc., which are not elastic, subject to biological destruction, and are a breeding ground for microorganisms and insects. All of these materials require repeated caulking. Meanwhile, in Scandinavia, an elastic self-expanding polyethylene foam tape is used as a mezhventsovy sealant, the use of which eliminates the need for repeated caulking.

If possible, you should avoid joining logs in crowns along the length. Such connections weaken the structure of the log house, and the walls of the log house can deform. The logs used in the construction should be as solid as possible. And it is definitely not worth making connections at the intersections of the walls, where load concentrations arise.

Shrinkage and swelling of wood along the grain are manifested in to a greater extentthan across the fibers. Therefore, all vertical posts and columns must be equipped with platforms-jacks with shrinkage compensators, which are twisted to the required amount of shrinkage, which can last up to 6-8 years or more. Perhaps a more aesthetically pleasing option is to install shrinkage compensators at the bottom of the columns, where they are less visible.

It is not recommended to cut openings for windows and doors in the log house before the end of the first active period of wood drying (6-12 months). During the same period, you should not hem the floor, ceiling and sheathe walls, as this will interfere with normal ventilation and drying of the wood.

Particular attention should be paid to the ventilation of the underground space when installing wooden floors. The minimum cross-sectional area of \u200b\u200bone air vent must be at least 0.05 m 2, and the total air air must be at least 1/400 of the underground area. It should be noted that this floor structure is already archaic. In the world, floors are mainly used on the ground, which allow you to use geothermal heat, avoid problems with moisture in the underground space and the flow of radioactive soil gases into the house.

3. Errors in finishing a log house.

When installing window and doorways remember that the minimum distance between the openings is 90 cm. The walls must be reinforced with dowels. For installation in log houses, it is better to use windows and doors with frames at least 10 cm wide, which does not allow window and door block to deform with secondary caulking at home.

Fastening of window bars for door and window frames should be sliding - without the use of nails, since the shrinkage of a wooden house can last long enough. Above the windows and doors, compensation gaps are left under the fold of the upper log for shrinkage in the amount of 5-8% of the opening height.

It is better to use self-expanding elastic for window and door frame sealing. sealing tapes... Regular polyurethane foam may deform when expanded window frames, and when the tree shrinks, form cracks. If it is used, then after hardening it should be covered from the outside from the sun and moisture with waterproof vapor-permeable self-adhesive butyl rubber tape. The inside of the foam should be covered with vapor barrier tape. Unprotected foam breaks down quickly, as in the house in the photo below.

Finishing the inter-crown seams of the assembled log house after the end of the first stage of intensive drying (12-24 months) with glazing beads or a rope is only decorative, contributing to the waste of money and time, but not protecting the walls from blowing. Modern elastic and vapor-permeable mezhventsovy sealants (for example, from the domestic manufacturer SAZI) allow you to protect the mezhventsovye slots from blowing through and create an aesthetic appearance walls.

Application of mezhventsovy sealant.

External insulation of a wooden house. Most often, external insulation has to be resorted to when construction defects are detected, such as blowing through walls. The main and most critical mistake is external insulation of a wooden house with vapor-tight insulation (expanded polystyrene, polyethylene foam). In this case, the tree is deprived of the opportunity to dry out, it is moistened, which increases its thermal conductivity and accelerates biological destruction. In clause 8.8 of SP 23-101-2004 "Designing thermal protection of buildings" it is prescribed to arrange the layers of multilayer walls in such a way that the vapor permeability of materials from the inside to the outside of the heated house increases, rather than decreases.

Aesthetics of a wooden house. Often, lovers of wooden houses, where all interior elements, such as walls, floors, ceilings, beams, railings, furniture are made of wood, find that, perhaps, they have gone too far with the quantity wooden surfacesthat create a feeling of life in a "wooden box". Changing furniture and painting walls comes to the rescue. However, it is wiser to plan contrasting surfaces in the house at the design stage. These can be floors, ceilings, kitchen countertops, steel elements of stairs and fences, decorative walls made of natural or artificial stone.

-\u003e Log house with your own hands -\u003e Log structure

"Bricks of a felling" - crowns.

The peculiarity of any tree is that its trunk grows unevenly in thickness: more on the south side, less on the north. Therefore, the annual rings on the south side are wider than on the north. For the example (Annual tree rings), I specifically chose a tree that grew on the southern edge and the difference in the thickness of the sides is clearly pronounced. In the crown of the log house, the logs are stacked so that the side of the log, where the annual rings are denser (north side), looks out. The north side cracks less. And the southern one, due to its lower density, is slightly warmer. However, this is possible only if the forest is combatant (even). If the log is bent, then it fits on the wall of the log house regardless of the orientation of the annual rings, either hump up or hump down. If there are a lot of curved logs and their curvature is approximately the same, then one wall can be made slightly crooked by laying the logs hump outward. In the finished log house, the curvature of the wall is almost invisible.

For reliable thermal insulation and windproofness of the walls, between the logs, in the process of laying the crowns, inter-lead seal... I am an ardent supporter of such a seal as moss - natural material, unique in its properties. For more details about its advantages, preparation, storage and laying on logs, see the topic “Moss. Caulking a log house "

Basic principles of assembly of a log house.

1. Layout of logs in the crown.

2. Vertical fastening of logs.

In order for the structure of the log house to turn out to be rigid, so that over time the walls do not swell into vertical plane (especially in the area of \u200b\u200bdoor and window openings), when assembling a log house, vertical consolidation of logs with dowels is used (in Belarus they are called dowels).

A dowel (dowel) is a round or quadrangular wooden stick, which is driven into a hole drilled in 2 - 3 logs in height at once. Any tree can be used as a material for the dowels. Dowels are inserted into each crown.

Under no circumstances should metal pins be used as pins!

During the cold season, moisture from the air passing through the inter-lead seal will condense on metal pins. The joints will be constantly wet, which will be a prerequisite for the development of decay processes inside the walls.

Sometimes grief - builders, for vertical rallying of logs, drive sharpened metal pins into the crest of the upper log with a sledgehammer. In no case should this be done!, since hammered pins prevent free shrinkage of the logs and they hang on the pins. As the logs dry out, there is an increase in the gap between the joints.

At the end of the assembly of the log house, for aesthetics, we make the projections of the edges of the logs in the corners the same. To do this: measure on the upper log such a distance from corner to end that suits us (but not less than 20 cm). Then, putting a plumb line to this mark, draw marks with a marker on all lower lying logs. With a chainsaw, we cut the ends of the logs strictly vertically (according to our markup). Since the fibers at the ends of the logs remain open, the ends of the logs will dry faster than the middle of the log. And, in this regard, large cracks will appear at the ends. In order to minimize cracking, I recommend covering the ends of the logs with acrylic varnish for outdoor use or PVA glue. In the old days, the ends of log cabins were covered with clay, lime mortar or painted with paint.

When felling a log house openings for windows you can not do it or do it knowingly smaller in size. Later, when we install the windows, the openings are cut out with a chainsaw for a specific size, taking into account the landing spike.

In the complex process of building a house, the total number of crowns is of interest. In the Russian North, where two-tier houses were built, there could be 19 or 21. Where it was warmer and the dwelling was one-story, they put 13 crowns (in any case, an odd number).

What can the number 13 indicate in a construction context? Such a number of crowns is another direct evidence that human housing has embodied the model of the world, the Universe, and the Cosmos. It is known that the most important structure-forming account of the mythological world order is the number 12 - as a derivative of the alignment of the coordinates of space (four cardinal directions) and time (three-dimensional dimension: past, present and future): 4 x 3 \u003d 12. The same number of constellations passes the sun during the year solstice, the same number of months has our calendar year, such a number of disciples with Jesus Christ. The living space of the house consisted of 12 crowns. At the same time, the wooden blockhouse closed (rounded, looped) the 13th wreath, which was already above the ceiling level, went beyond the living space and functionally performed a completely different role. He was transient, " connecting link"between the world of the living and the magic sphere - the dwelling place of the supreme gods.

A silver or gold coin was placed in the red corner between the third and fourth logs. Obviously, this ancient Slavic sign of sacrifice reflected the influence of the Christian orthodox tradition, in which the triune essence of God - God the Father, God the Son and the Holy Spirit - enjoyed special reverence.

As soon as the last log has been carefully adjusted, shifted with dried moss, the hostess brings up an earthen bowl with grain. One of the master carpenters walked around the building around the perimeter and sprinkled grain on the ground on both sides of the walls, wishing the owners happiness, health, and wealth.

Oksana Kotovich, Yanka Kruk. Zvyazda newspaper, www.zvyazda.mіnsk.by, December 2010.

Cricket

The cricket in the understanding of the Eastern Slavs was a symbol of comfort, order and prosperity, "a living guard of the house."

The cricket is an insect that likes warmth, so in winter time he lives closer to the warmth: in the beams and logs that make up the house.

If a cricket starts its monotonous song, it means that nothing threatens the house, everything is fine in the family. Conversely, it was believed that if in the middle of winter crickets left the house, it foreshadowed misfortune: fire, death of one of the relatives.

The cricket is an inviolable insect. It was widely believed that to kill a cricket was to kill the good spirit of the house, to cause trouble. In some regions, it was believed that killing a cricket could result in the death of a loved one.

And the people remarked: "If the cricket sings, it's time to sow rye."

Oksana Kotovich, Yanka Kruk. Zvyazda newspaper, www.zvyazda.mіnsk.by, September 2011.

-\u003e Sections of the site -\u003e Log house -\u003e Log house with your own hands -\u003e The first (salary) crown of the log house.

The lower crown works in the most difficult conditions - proximity to the ground, more wetting than other crowns during rain and snow. Therefore, traditionally, special attention was paid to its manufacture.

Before laying the first (lower) crown of a log house, do not forget about waterproofing, which is 2 - 3 layers of rolled bitumen waterproofing material, laid between the foundation and the logs to prevent the walls from getting wet from the foundation.

The first (flap) crown is made from the thickest logs.

If you have such an opportunity, then the first crown is best made from the wood species most resistant to decay. Larch or oak is best suited for this purpose.

Obviously, sides 1, 3 and 2, 4 are at different horizontal levels, which differ in height by half the diameter of the log. Therefore, the first crown, from which the whole frame begins, can be realized in two ways.

Despite some inconveniences, such a backing ring will be more durable due to the fact that the logs undergo minimal processing and remain almost intact.

To prevent rotting of the logs of the first crown, special attention must be paid to thorough antiseptic treatment of surfaces in contact with the waterproofing (chipped surfaces). Before laying, coat the hewn surface with an antiseptic using a brush 3 - 5 times. By the way, this is the only place in the bathhouse where I used an antiseptic.

Underlay boards must not be covered with molten resin (bitumen) or wrapped in roofing felt. A tree clogged with resin or wrapped in roofing material will rot very quickly.

Between the waterproofing of the foundation and the backing board, between the backing board and the first crown, an inter-row seal is laid.

The process of making the cap is shown in a series of videos flap (first) crown of a log house.

The first (first) crown of a log house - video technology.

Oval crown. Part 2. Chip logs