We assemble the log house after shrinkage. The worst mistakes in wood construction. Screw expansion joint of the structure siege

A house made of solid or glued timber is inevitably upset. This is the result shrinkage of the wall material (shrinkage), which is most pronounced in the first few years after the construction of the building. But then the linear dimensions of the wood will fluctuate, the reason for this is the seasonal change in temperature and humidity conditions. That is why, even at the design stage of a wooden house, it is necessary to provide special measures to compensate for wall shrinkage, especially when it comes to building a house from a log or bar.

Shrinkage of houses from logs and beams

House shrinkage due mainly to the property of wood to dry out with a decrease in its moisture content. The amount of log shrinkage is determined by many factors... First of all, the moisture content of the log or timber, its original dimensions (primarily thickness), the type of wood, the wood processing technology (primarily drying), the operating conditions of the building and its dimensions (the higher the wall, the greater the amount of shrinkage), the construction season at home (summer, winter), build quality and qualifications of workers (quality and tightness of fit), construction technology (method of connection and type of used).

Moreover, the changes in the dimensions of the wooden element are different in the tangential and radial directions, that is, the changes in the dimensions along the width of the bar or log are much greater than along the length. In addition, the amount of shrinkage varies depending on the type of building material - logs, rounded logs, beams, profiled beams, glued beams, etc.

In principle, data on the shrinkage of materials can be obtained from, but in practice, these data may be far from theory. On average, at calculation of shrinkage you can build on the following data:

The log shrinks up to 150 mm;
A rounded log shrinks up to 100 mm;
Sliced or not planed timber can shrink up to 60 mm;
Profiled timber of natural moisture shrinks up to 40 mm;
Chamber-drying profiled timber will shrink up to 20 mm;
Glued laminated timber is least susceptible to shrinkage, the amount of shrinkage is not more than 15 mm.

For example, the HONKA company provides the following data in the manual for the assembly of log houses:

a wall made of rounded logs shrinks on average 30-60 mm / m,
laminated veneer lumber wall - about 10-30 mm / m.

The difference is noticeable, and in many cases fundamental, because the height of the log house will decrease in any case. So that shrinkage does not violate the structure of the building, a number of measures and methods are provided for its compensation. To begin with, the very shape of the profile of a bar or log affects the amount of wall shrinkage.

The profile of a rounded log can be supplemented with narrow longitudinal expansion grooves

For example, the profile of rounded logs can be supplemented with narrow longitudinal expansion grooves reducing stress in the wood and avoiding severe cracking of the log. The number of grooves is from one to three, moreover, one of them is located, as a rule, in the upper part of the log. Thanks to the grooves, changes in the profile shape are reduced and, therefore, the shrinkage of the log walls is reduced. The higher the level of technical solutions of the manufacturer of wooden building materials, the more complex the profile of the wall elements it offers.

Shrinkage of walls and partitions in a wooden house

By themselves, log walls do not require special assemblies to compensate for shrinkage, since a log frame is a homogeneous structure and all its elements will drop by about the same amount. However, there are rigid parts in the building that either do not settle, or settle much less than the frame. Therefore, the construction of such parts requires special solutions.

So, in the house, vertical elements (pillars, columns, etc.) are often provided, serving as a support for the parts of the house located above. Adjustment mechanisms are needed to reduce the height of the pillars and columns so that their height matches the height of the walls of the log house. Most often for this use screw mechanisms shrinkage compensators, special jacks, which are called so - jack screw adjustable shrinkage compensator.

Wooden posts are rigid elements. So that they do not interfere with the shrinkage of the upper structures of the log house, they provide for adjusting mechanisms that make it possible to reduce the height of the pillars.

The jack is placed in the gap between the vertical and horizontal elements, rigidly fixed to one of them. The size of the gap is selected based on the estimated value of the shrinkage of the building (usually the jack allows you to change the height of the support by 8-10 cm). As the frame shrinks, the screw mechanism is adjusted, thereby changing the height of the column or pillar. The jack can be installed at the bottom or top of the vertical support. From the point of view of the shrinkage of the structure, its location is not important. And from the point of view of ease of use, the jack located at the bottom is preferable - then you do not need a ladder or scaffolding to perform the work.

The adjusting mechanisms are screw jacks that are installed in the gap between the vertical and horizontal elements, rigidly fixing on one of them.

The gap between the vertical and horizontal elements, as a rule, is covered with a decorative casing, which is removed during adjustment. Sometimes the screw mechanism is left open. How often do you have to close the gap? It depends on the type of wall material, the shape of the profile, the season (seasonal changes in the moisture content of the wood) and the assembly technology of the log house. In some companies, the interval between jobs is usually from two weeks to three months, in others it is four to six months. It takes approximately 15 minutes to adjust each jack.

Special technical solutions will also be needed when a wall or partition of another type (for example, brick or frame), subject to less shrinkage, is adjacent to the log structure. This means that its connection with the frame must be sliding. This connection can be done in different ways. Most often it is carried out according to the "thorn-groove" principle, where the thorn and the groove have the ability to move somewhat in the vertical direction relative to each other. Usually a groove is made in the wall of a log house, and a spike in the form of a wooden bar is attached to the end of a brick or frame wall. The space between the spike and the groove is filled with heat-insulating fibrous material (and others). The connection to brick walls, through which capillary moisture can spread, must contain a waterproofing layer.

Connection of the frame partition with the log wall: 1. Log house 2. Frame partition 3. Groove

The adjoining of a brick partition to the above log structure: 1. Log house 2. Brick partition 3. Decorative strip 4. Shrinkage margin 5. Screw jack

A gap is left between the upper edge of a brick or frame wall and the part of the log house located above for unhindered shrinkage of the latter. The size of the gap is determined based on the estimated shrinkage (in most cases, it is 8 - 12 cm).

Creation of an additional self-supporting brick partition on which the finishing material will be fixed

So that the gap is not noticeable in the interior, you can close it with decorative strips attached to the log house (and, therefore, go down with it), or you can create a niche in the partition where the log house will be upset. At the junction of the upper part of the frame partition to the frame, steel rod elements are usually provided to ensure the rigidity of the structure.

Shrinkage compensation for the truss system

When creating a rafter system, the shrinkage of the log house is also taken into account. So, in the case of using layered rafter legs, the distance between the upper and lower supports may vary. Accordingly, the rafter must be able to move without causing stress and deformation in the building structure.

Roof truss systems are used in houses where there is a middle load-bearing wall or columnar intermediate supports. The ends of the rafter legs rest on the outer walls of the house, and the middle part on the inner wall or supports.

To do this, the lower end of the leg is fixed to the wall using a sliding joint of one type or another. Most often, fasteners are used in the form of two brackets: one is rigidly fixed on the wall, the other on the rafter. These brackets allow the rafter to move relative to the wall.

There is no consensus among experts whether a sliding connection is necessary at the point of support of the upper end of the rafter leg on the ridge bar. Some insist that this is a mandatory measure that helps prevent deformation of the rafter system due to the shrinkage of the log house. Such a measure consists in the fact that a certain distance is left between the rafters converging on the ridge and they are attached to the ridge beam also by means of a sliding (usually hinged) connection. Other experts believe that sliding fasteners in the place where the rafter rests on the wall is sufficient to compensate for the shrinkage of the log house.

Fastening the rafter leg on the log wall: 1. Rafter leg 2. Brackets that allow the rafter to move relative to the wall 3. The frame

In the case of trusses in the form of trusses, the shrinkage of the log house does not lead to a change in the slopes of the roof slopes. However, it is impossible to rigidly connect the gables made of logs or beams to the trusses, since the gable walls are higher than the front ones, and the amount of their shrinkage will be different.

The rafter structure must be designed taking into account the shrinkage of the building. Most often, layered rafter legs are used, which rest on one side on the upper element of the log house, and on the other, on the ridge beam or the wall of the house (when the roof slope is adjacent to the wall). On the ridge, at the point of convergence of the rafters of adjacent slopes (or at the point where the rafters meet the wall), a distance of about 3 cm should be left so that when the roof shrinks, the rafter legs can lower freely.

The fastening of the upper part of the leg itself is performed using a metal hinge of one type or another, which allows you to change the slope of the rafters when the log shrinks. A sliding attachment is also necessary in the knot where the lower part of the leg rests on the wall of the log house. Here, as a rule, a factory-made sliding support is used, thereby making it possible for the rafter leg to "slide" relative to the wall.

Shrinkage compensation for windows and doors

Among the structures that do not change their dimensions in the log house are windows and doors. To prevent their deformation due to wood shrinkage, a special system of filling the opening allows. The window or door frame is not attached to the log house, but to a special casing box (okosyachka, shedding).

The connection of the box to the walls of the building must be sliding. The design of this unit is different. As a rule, a groove is cut out at the ends of the log elements. Mounting bars are inserted into the grooves, fixing them at the bottom of the opening. A casing box is attached to the bars. The gap between it and the end surfaces of the log house is filled with fibrous insulation (linen, jute linen, etc.) to prevent freezing in the opening area. A gap is left between the upper part of the box and the element of the frame covering the opening, allowing the frame to be lowered. Its size is determined by the size of the likely wall shrinkage and most often is 5-7 cm.

Installation of a door frame to a casing in a wooden house

For the device of the casing box of the window, first, a mounting bar is inserted into the groove made in the end of the log wall. Then the box itself is attached to the bar. Insulating material is placed between it and the wall.

To avoid heat loss, a heat-insulating material is placed in the gap - a sheet of flax, jute, etc., strips of mineral wool, foamed polyurethane strips, etc. it is quite rigid and can deform the structure of a window or door when the frame shrinks. To decorate the gaps at the joints of the filling elements with the frame, external and internal platbands are used.

An expansion gap (from above) is left between the casing and the blockhouse element located above it.

When arranging fillings for window and door openings in houses made of solid and glued timber, two types of risks are likely. Firstly, the impact of the log wall on the filling elements due to the settlement of the building. This risk is eliminated by creating sliding joints with parts of the log house that form an opening, organizing a gap over the filling structure, attaching the platbands to the filling elements, and not to the walls of the log house.

The second group of risks is insufficient tightness of joints in the places of sliding joints. The use of polyurethane foam to fill the gaps between the casing and the frame is unacceptable, since the hardened foam will prevent shrinkage, because of this, the frame will either "hang" over the opening filling structure, or it will be deformed and damaged. The best solution is the use of plant-based thermal insulation in the gaps in combination with a film protection - a layer of vapor barrier from the inside of the house and vapor-permeable wind insulation from the outside.

Shrinkage compensation in staircase construction

When designing and installing a staircase in a wooden house, it is necessary to provide for a number of measures to exclude the influence of the building's draft on it. The staircase is installed at the final stage of construction, when some shrinkage has already occurred. The base of the stairs (kosour or bowstring) is attached to the upper floor using sliding fasteners (metal corner with a vertical groove, etc.), intermediate fixation to the walls is unacceptable.

Installation of an internal ladder: 1. Screw with washer 2. Corner with vertical groove 3. Overlap log 4. Shrinkage margin

Consideration should be given to the shrinkage of the log structure when securing the railings and stair railings.

If the flight staircase has a platform, then it also cannot be fixed to the walls - it should be supported by racks on the lower floor, and then the shrinkage of the walls will not affect the structure. In addition, during construction work, it is not necessary to bring the upper, adjacent to the ceiling, part of the staircase into the floor plane of the upper floor. It is necessary to leave a gap for the value of the calculated shrinkage between the top of the stairs and the floor, which is leveled in the process of slab settlement.

Finishing a wooden house taking into account shrinkage

Wood house owners often want to decorate certain spaces (for example, tiling a bathroom). So that the finishing layer is not damaged during the shrinkage of the log house, it is fixed to the base, either connected to the log walls with sliding fasteners, or completely independent of the walls. There are many options for sliding fasteners.

Base arrangement for finishing: 1. Log house 2. Frame made of wooden blocks 3. Corner with a vertical groove and a screw with a washer 4. Gypsum fiber or plasterboard boards

One of them involves a frame made of metal profiles or wooden bars with longitudinal grooves. The frame is attached to the wall with screws through the grooves, moreover, the screws are not tightened tightly so that they can move vertically when the wall shrinks. The base for finishing is rigidly fixed to the frame. A gap is formed between the wall of the room and the base by the thickness of the frame (usually it is about 5 cm).

If you provide ventilation in the gap (at the bottom of the structure, provide for the possibility of air flow, and at the top - hoods), this will increase the durability of the wall and base. An expansion gap is left between the upper edge of the finish and the ceiling, which is decorated (for example, covered with a false ceiling). The undoubted plus of the base on the frame is the relatively small load on the floor overlap. Minus - some risk of deformation of the frame with excessively rigid attachment to the wall or with uneven shrinkage of adjacent log walls of the room. Skewing can damage the finish. This disadvantage is more often manifested in houses made of chopped and rounded logs of natural moisture than in houses made of laminated veneer lumber.

The frame is in the form of wooden bars fixed to the log wall with sliding fasteners. The base will be fixed on the frame for finishing

For rooms located on the ground floors of a building with a foundation in the form of a reinforced concrete slab, there is another solution. The finishing layer can be mounted to additional self-supporting partitions made of ceramic bricks with a thickness of half a brick or from a tongue-and-groove gypsum board (such a structure is often called a "glass"). These partitions are erected at a distance of at least 2.5 cm from the wooden walls, making holes at the bottom and top for the supply and exhaust of air. If a suspended ceiling is made in the room, then it is attached only to the upper ceiling so that they go down together.

Shrinkage of a house made of timber or logs is an inevitable process, due to living natural material. Wood is an anisotropic material, and with natural shrinkage, the wood element changes its size. The main shrinkage of a house from a bar as a result of shrinkage occurs in the first years of the life of a wooden house, but the change in the geometric dimensions of the walls of the house never stops, and the shrinkage of a house from a bar ranges from centimeters at the beginning of the shrinkage process, to millimeters years later.

Reasons for the shrinkage of houses made of timber and logs

The porosity and anisotropy of the properties of wood is the reason that the logs and beams from which the house is composed constantly absorb moisture from the air when the humidity rises and give this moisture when the atmospheric humidity decreases. The radial increase in size is much greater than the linear one, and this unevenness leads to the appearance of gaps between the crowns of log cabins, shear and torsion deformations, leading to cracking in the logs.

Dependence of the amount of shrinkage of houses from a bar and a log

The shrinkage values of a house made of logs or timber depend on:

The initial moisture content of the wood and the type of material. Glued laminated timber, assembled from lamellas that have passed chamber drying, gives a minimum shrinkage in a log house of no more than 20 mm per three meters of log height. A log house made of profiled timber shrinks in the range of 40-50 mm for every three meters of wall height. A bar of natural moisture will give a decrease in height of about 60 mm by three meters in a log house. The greatest shrinkage is given by a log house - about 100 mm per three meters of log height. Calibrated (rounded) logs shrink slightly less - about 800-100 mm.

The linear dimensions of the elements of the house, length and thickness, or diameter.
The linear dimensions of the structure. For houses made of logs - more from the height of the walls, since the shrinkage of the logs is non-linear, the log decreases much more in diameter than in length.
Wood species.

The time elapsed from the end of felling. during the first three months, there are intense shrinkage processes. The main shrinkage ends after three years. The load-bearing walls and roof are ready in the shrink-fit house. But window, door blocks, internal partitions and flooring are performed only after the frame has shrunk. Interior finishing is done last.

Technologies. The skill and experience of the installers allow them to make precise adjustments to the connections of the rims and corners of the frame.
Season, climatic and weather conditions of the construction area. The summer frame is usually left for precipitation for at least a year. The winter felling house gives the maximum draft one and a half times faster, and more uniform.

Compensation for shrinkage of a house made of beams and logs

To compensate for the settlement of the house, the right technology is important, namely:

Tight fit of logs and beams in the walls of the house, with the laying of natural mezhventsovy insulation - jute, flax, moss.

For cutting walls from non-profiled timber, it is necessary to assemble using dowels - vertical fasteners passing through several crowns. The best dowels are considered to be wooden, made of birch wood. Dowels prevent torsion of logs and beams in the wall and provide vertical stability and rigidity to the walls of the log house. the second caulking is carried out after the log house has dried, the gaps formed as a result of shrinkage of the logs or timber are filled with insulation.
All window and door blocks are installed according to the compensatory type - in casing boxes, also called jamb. The joints of the casing and the walls of the log house are not rigid, but sliding, of the thorn-groove type, and when the log frame settles, windows and doors are guaranteed not to be deformed. Above the blocks of windows and doors, gaps of the order of 30-40 mm are required to prevent the pressure of the upper rim of the opening on the block. Polyurethane foam is never used to strengthen and seal window and door blocks in wooden log cabins, since foam gives a rigid connection and can cause deformation destruction not only of blocks, but even of the crown of a log house.

All vertical load-bearing elements of the log house - posts, columns, are made shorter than the geometry of the log house shows, and are installed on compensatory devices, in the form of screw jacks. Once every few months, as the frame settles, the jack screw is tightened in the direction of decreasing the length. Using screw jacks, it is possible to ensure the safety of racks, crowns, and log beams. The device of jacks is simple, their main elements are two plates and an adjusting anchor with a nut. The plates have holes for bolts for attaching the jacks to the racks and beams (walls) of the log house.

Conclusions about the shrinkage of houses from a bar and logs

The felling technology, as well as the choice of the felling method, greatly affects the degree of shrinkage. One of the cutting methods - the Canadian bowl - is considered one of the best for cutting a log house precisely in the context of shrinkage. The wedge-shaped shape of the joints with a decrease in size as a result of the shrinkage of the timber leads to an even greater seal of the joint under the weight of the overlying rims and frame structures. Not all joints are compacted during shrinkage, some of their types are suitable only for dried material, since they form cracks during shrinkage.

The profiled beam gives less shrinkage in the log house due to the shape - ridges and grooves along the entire length, allowing a very tight fit and partially compensating for the decrease in the size of the log house.

The minimum shrinkage is given by a house made of laminated veneer lumber. You can move into such a house and carry out almost any interior decoration in it immediately after the completion of construction.

Is the shrinkage of a house made of a bar so terrible as it is painted?

A large and spacious house in the Moscow region made of eco-friendly, beautiful and high-quality timber is the dream of almost any family. When the first steps on the way to the cherished goal have been made - a plot has been purchased, documents have been agreed, the main stage of construction is coming to an end - the desire to immediately call in and start decorating the rooms becomes almost irresistible. And then a great and terrible shrinkage of the house stands in the way of the new settlers, threatening to postpone the celebration for a couple of years. But is it really that scary? Let's figure it out.

Increasingly, future owners of houses, cottages, baths and country houses, when choosing a suitable material, give preference to profiled timber. It attracts with its strength, naturalness, excellent appearance and thermal insulation properties, relatively low cost and ease of construction. But at the same time, the more popular the buildings, the more “experts” appear, the victims of these “experts” and unfair myths about houses made of timber.

On the Internet, you can find many horror stories that a wooden house will certainly sag by 10 or even 20% of the total height (and because of inexperience, some believe in an unrealistic meter shrinkage of a house with a total height of 5 meters), the walls will dry unevenly and become covered with cracks, windows and doors will stop closing. As a result, people start to think about looking for another material and even give up their dreams. And completely in vain. Most of these stories are exaggerations, inventions, or the consequences of choosing the wrong contractor, and by no means the material.

The company "Venga" has been professionally engaged in the construction of houses from profiled timber for more than 15 years. We declare responsibly: shrinkage can and should be taken into account, tracked, controlled and minimized. By choosing the right specialists, you will not notice its consequences at all.

What is shrinkage?

Shrinkage is a completely natural process, natural and characteristic of all wooden buildings. First of all, it is associated with the very specifics of the material. In nature, a tree takes water from the soil through its roots and transfers it to the foliage, i.e. there is moisture in it. After processing, it can be dried (chamber drying timber) or not dried (natural moisture timber). In any case, after the construction of the building, being in the open air and under pressure, the wood will get rid of moisture residues and dry out. Dried - just a couple of centimeters, natural moisture - about 4 centimeters.

The second reason for shrinkage is mechanical. The lower beams are under the weight of the whole house, over time they go deeper into the grooves. In fact, such shrinkage is even useful, since the logs adhere to each other more strongly, they are not blown by the wind, and it becomes warmer in the house. To reduce the time of mechanical shrinkage at home, the specialists of our company carry out compulsory shrinkage. With the help of special tools, even at the construction stage, the docking gap is minimized, the bars begin to adhere more tightly to each other.

Our distant ancestors, who for centuries built wooden huts, were still able to predict and take into account shrinkage. Now it is described in detail in GOST 6782.1-75 “Sawn products from coniferous wood. Shrinkage value ". Accordingly, there is nothing wrong with this process. Of course, if real professionals design and build a house taking into account all conditions.

How long does the house shrink?

When it comes to the shrinkage of a house from a bar, you can often hear two directly opposite opinions - you can live in a house right away and you will have to wait 2-3 seasons. The first are unscrupulous companies that are in a hurry to quickly hand over an object or a turnkey house, the second - people who are not very well versed in the intricacies of work.

In fact, intense shrinkage occurs during the first 3 months after the construction of the building. During this time, the wood loses about 70% of the total volume that it can lose. Further, the process slows down and becomes little noticeable and significant. However, the exact timing of shrinkage cannot be called, because no one has yet learned to fully control nature. It all depends on the chosen material, dimensions and time of assembly of the house.

The easiest thing is with a dried timber with grooves and spikes of the "comb" type, if the house was built from it in winter. The dried timber dries out by only 2-2.5 centimeters, the tight connection of the grooves minimizes mechanical shrinkage, drying in the summer is more intensive. As a result, the next stage of finishing can be started in six months.

If the house was built in the summer from wood of natural moisture, the shrinkage period increases to 1 year. In winter, the timber cannot dry as effectively as in summer, therefore, it will have to stand all seasons, gradually getting used to the climatic conditions.

So, after the construction of the house, you should wait from six months to a year, and only then start laying communications and finishing work.

What can and cannot be done while the house is shrinking?

The time of drying wood and shrinking at home can be regarded by many as an unpleasant brake, forcing to completely curtail all work and fall into a kind of "hibernation". Indeed, there is a list of actions that should not be taken. Namely, you cannot:

turn on the heating in the house and light up the stove. The wood should dry gradually, in a natural way, while such a sharp heating can disrupt the processes, lead to cracks and uncontrollable consequences;

to decorate the house with solid cladding materials, such as siding, wall panels, tiles. In the process of shrinkage, the height of the walls decreases, respectively, after a few months the cladding will bend, go in waves or completely break;

carry out fine repairs using expensive materials, since after complete shrinkage, most likely, it will have to be completely redone.

However, waiting for the completion of shrinkage does not mean that the work must be completely stopped. In the first months of intensive drying, it is not only possible, but even necessary to cover the bar with antiseptics, fire retardants and other compounds. They will extend the life of your home, prevent mold, mildew and other troubles. If work is carried out at the shrinkage stage, while the house is empty, it will be possible to completely avoid the negative impact on health. It is important to pay attention that the selected formulations are breathable and do not interfere with the drying process of the wood.

In addition, contrary to popular misconception, windows and doors can be installed in the house, as well as a roof can be installed. But this must be done in a special way - with expansion gaps and movable joints. When shrinking, the gaps are reduced, windows and doors are not blocked. Instead of the usual polyurethane foam, special compressible materials are used.

Also, if you are impatient to complete the construction as soon as possible, already a couple of months after the construction of the building, it is not forbidden to put a rough floor, to carry out preparatory work for laying communications. In general, shrinkage does not threaten a complete stop of work, but only limits and slows them down.

How to minimize the terms and consequences of shrinkage of a house from a bar?

We have already said above that shrinkage can and should be controlled and also minimized. This is done at the design stage. The necessary calculations, taking into account the selected material, the height of the house, weather conditions, geographic location, are made by experienced engineers and designers of the company "Venga".

There are several ways:

Give preference to dried timber. It gives less shrinkage, which completes faster. True, the material costs a little more than a bar of natural moisture;

Build a house in the winter to dry it in the summer;

To make the forced shrinkage of the walls, driving the beams deeper into the grooves using a special mallet;

Choose high-quality insulation that is less prone to pressing;

Use shrinkage compensators such as screw jacks to make the shrinkage more even. This method is especially relevant if one side of the house is constantly in the sun and dries faster than the rest. Compensators help to avoid distortions;

Turn to real professionals with vast experience in the construction of houses from a bar, able to draw up and implement a plan for the construction of your ideal home, thought out to the smallest detail.

So, shrinkage is a complex but completely natural process. It will not necessarily be large and even just noticeable to the naked eye, it will not make you postpone housewarming for many years or freeze the construction site. With a professional approach, shrinkage is not only not scary, but even useful, because after it the house becomes even stronger, warmer and more reliable.

A log house from a bar will shrink in any case. Another thing is that the shrinkage of a house made of a bar of natural moisture is greater than that of a drying chamber. But this is a natural process that cannot be avoided. How long the house will dry, it is impossible to say unequivocally, since this is influenced by a number of factors. Knowing a few subtleties can prevent damage and make the process smooth.

The shrinkage of a wooden house made of not dried timber proceeds in two stages: an intensive period - the first 3 months and a gradual one - up to 1 year. Houses made of timber shrink in accordance with GOST 6782.1-75 “Sawn products from coniferous wood. Shrinkage value ", which indicates how much shrinkage of various structures will be. In fact, GOST is rarely used for the construction of a house from a bar. This happens due to factors that affect this process:

From the type of timber (profiled, simple edged, glued, etc.)
From the section of the bar.
Degrees of humidity (winter timber has a lower natural humidity).
Dimensions of a house or a bath from a bar.
Log house assembly techniques (type of corner joint, which dowels were used, etc.)
The type of wood from which the timber was made (dense wood gives less shrinkage).
What time of year is the house being assembled.

Each of these factors has its own effect on shrinkage to a greater or lesser extent. Let's consider some in more detail:

Timber type

You can calculate how much shrinkage will be (approximately) by knowing how much the material will shrink. Different timber shrinks:

Edged (planed or not planed) - up to 5-6 cm.
Profiled natural moisture - up to 2-4 cm.
Profiled chamber drying - up to 2 cm.
Glued - 1-2 cm.

Time of year when the house was going

The timber is able to absorb moisture from the environment, therefore, the assembly of a wooden frame in the summer increases the shrinkage period up to 1 year. In winter, the air is drier and the process will last from 3-6 months. In addition, the timber made in winter has a natural humidity equal to the drying chamber.

Assembly technology

The qualifications of the work team and the method used to assemble the log house are very important. If the timber is laid tightly enough, then the shrinkage will be less. It is also important in which corner the timber is assembled. The process also depends on the insulation, which is driven between the links, for example, moss will shrink more, and flax fiber less.

What to expect if no shrinkage is foreseen?

The percentage of shrinkage at a log house is calculated even before roofing work and the installation of doors and windows. For example, a log house with 18 links with a section of 150x150 mm can settle by 10 - 12 cm per year.

If you do not provide for these centimeters when building a house from a profiled bar, then the window and door openings will warp over time, and they will cease to function, cracks may appear in the plastic ones. Therefore, it is important to calculate and leave gaps before installing the casing. You can learn more about the installation of casing in a wooden frame from previous articles.

But the drying process is more detrimental to the finish of the external and internal. Siding, wagon, or block house can break, and even tear out some parts.

After shrinkage, a house from a bar needs additional caulking. When the hay dries, the logs may crack and the density between the links will decrease. Moreover, if this is the construction of a house made of laminated veneer lumber, then it is difficult to do secondary caulking.

Shrinkage mitigation techniques from professionals

If someone says that shrinkage and its consequences can be avoided by using a material of natural moisture, then this is a misconception. You can mitigate these effects using the following methods:

Professional upsetting of walls. The siege is done using a special mallet. It does not spoil the material and minimizes the joint gap. You can see a homemade device that resembles a tool for leveling paving slabs.
Use only high-quality insulation between wedges. The best insulation option for a bar is jute. It does not compress so much and is environmentally friendly.
Siege of window and doorways.
During installation, technical gaps are left. These openings are mounted on top of doors and windows, up to 2 cm wide. They are hidden from the eyes by platbands, but will prevent the openings from skewing.

If you build a house from a bar of natural moisture, then it is better to choose a profiled version.

Why is the shrinkage of the profiled bar less?

Due to the specifics of the structure, from the profiled timber during installation, it is tightly connected to each other, and the shrinkage will be less. In many respects, the process of shrinkage from a profiled bar depends on the shape of the groove and tenon. The so-called "comb", when there are several spikes and grooves, gives an even greater docking.

But a wooden frame made of profiled timber has a big drawback, it needs a secondary caulking, which is difficult to perform. Therefore, it is better to use a profiled beam than chamber drying or to build in winter from fresh material.

What should be considered during construction to minimize shrinkage?

Considering the above factors affecting the shrinkage of the house, it can be partially avoided. In addition to properly selected material, climatic conditions are important. Therefore, experts often recommend building in the winter season.

During subzero temperatures, moisture will leave the timber slowly, and the shrinkage will be more uniform. Specialists begin construction in mid-February, so you can start a house under the roof in March, when there is a plus on the street.

It is easier to build at freezing temperatures in the summer, so the crews are more willing to take on work. But the shrinkage of the summer frame is a long process. It is better if the house will stand for several seasons. This is how the walls adapt to different temperature conditions.

The second important point is how the future structure is located. In any case, one side will be more often in the sun, and the other in the shade. Thus, the process from the sunny side will be faster. The house may even skew.

Professional construction companies will offer this option for the location of the house, when the shrinkage is more or less uniform. In addition, you need to take into account the assembly technology and the size of the future house.

It is better to make a rough roof for a building from a material of natural moisture. Otherwise, after it has completely dried out, it will have to be restocked.

But if the planned construction is multi-storey and has large dimensions, then it is not recommended to use the material of natural moisture. Since in this case, significant distortions and all the consequences associated with them may appear. But for small buildings and with the correct calculation, a bar of natural moisture cannot be replaced.

Wooden houses in the era of active invasion of chemistry in the construction field are deservedly popular among developers. However, for the ecological comfort, aesthetics and high energy efficiency of wooden housing construction, you have to pay a considerable price.

The main problem here is the anisotropy of wood, or, simply put, the instability of geometric dimensions under the influence of the natural process of shrinkage.

This forces builders to apply special methods to reduce the negative consequences for the building.

Shrinkage of a wooden house is an inevitable phenomenon, and this process does not end even a few years after the house is commissioned, but only becomes less intense.

Wood is a porous material. Therefore, it constantly absorbs and releases moisture into the surrounding atmosphere and, at the same time, accordingly increases or decreases in volume.

The main change occurs in the thickness of the logs, and to a much lesser extent affects their length. Uneven deformation leads to gaps in wooden walls, cracking and twisting of logs.

Let us consider in more detail what factors affect the degree of shrinkage of wooden houses and what can be done so that this process does not cause undesirable consequences.

What determines the amount of shrinkage of a wooden house?

The shrinkage period of the house and the amount of decrease in the height of its walls is determined by the following factors:

Type of log house material - simple or rounded logs, profiled or glued beams;
Material size (length and thickness);
The moisture content of the wood (natural or after chamber drying);
House dimensions;
Construction technology;
Wood species;
Construction season.

The shrinkage of a house with walls of 3 meters in height, depending on the type of material, occurs in the following range:

Normal log - up to 10 cm.
A rounded log shrinks from 8 to 10 cm.
Walls made of timber of natural moisture - up to 6 cm.
Profiled undried timber - 4-5 cm.
Chamber-drying profiled timber - about 2.5 cm.
Glued laminated timber - no more than 2 cm.

How long the house shrinks depends on the time of year (season) when it was built. Therefore, a log house built in the summer must dry within 12 months, and for a winter house, 8 months of aging is enough. Given this circumstance, builders offer customers to assemble buildings in the winter.

In winter, moisture from the logs freezes out slowly, so the deformation of the wood occurs more evenly than in summer. In the frame, installed in November, by the beginning of summer, the process of settling the crowns ends. After that, you can put doors, windows in it, start finishing without the risk of cracks in the wall cladding. Another advantage of winter construction is the assembly price, which is almost 20% lower than the summer one.

The most intensive process of shrinkage of walls in a log house is the first 3 months, and it completely ends only after 3 years.

House for shrinkage that this is not difficult to understand if you study the difference in the degree of its construction readiness. The figure shows that this technology does not provide for the installation of doors and windows, as well as cladding of internal partitions and flooring.

Construction technology

This is a very important factor affecting the amount of shrinkage.... Beams and logs placed in the wall must fit very tightly to each other. In this case, the seams between them are caulked with an inter-crown sealant - jute or tow.

If a non-profiled beam is used for construction, then the assembly is carried out on metal or wooden dowels - vertical rods that prevent the twisting of the logs. After the drying of the log house is completed, the second caulking of the seams is performed, which closes the formed shrinkage gaps.

In the process of drying, the logs of the upper rims begin to press on the window and door frames. Therefore, if installed incorrectly, all the carpentry will inevitably lead and jam. To exclude this - the movable structure of the boxes. It moves along the guide grooves with the wall and therefore does not deform.

An expansion joint with a height of 3 to 4 centimeters is left above each opening. It is needed so that the upper crown does not destroy the window or door frame. After the walls have dried, this gap is closed with a wooden casing.

How long the house shrinks is an important, but not the most important question for its owner. It is much more important to be firmly convinced that the work of assembling the log house was carried out using high-quality wood and special expansion joints.

Screw jack

We have already mentioned the need to install a jig, so we will focus on a device called a screw jack. It consists of two plates, a nut and an adjusting anchor. Compensators are placed on all pillars of the log house and fastened with self-tapping screws to the floor beams.

In this case, the pillars are made a little shorter so that the beams do not deform them, and the load is transmitted through a screw jack. As the beams dry up, they sit down, so the compensator is regularly tightened, reducing its length.

A log house will give less shrinkage, if builders use the so-called "Canadian cup" to connect the crowns. Its main advantage is its special wedge-shaped joint. Due to this, the shrinkage of the log does not lead to the formation of a gap, but additionally seals the seam under the influence of the weight of the upper rims and the roof.

Comparing different materials for the construction of a log house, the following important nuances should be noted. The amount of shrinkage of a house made of laminated veneer lumber is minimal, but it costs significantly more than a profiled log.

By gluing individual boards into a single structure, it is possible to minimize not only shrinkage, but also the longitudinal torsion of laminated veneer lumber. However, the cheaper profiling technology, in which longitudinal ridges and grooves are applied to the log, also compensates for this negative phenomenon well.

The disadvantage of rounded logs is that, that during its processing, the outer most dense layer of wood (4-5 cm) is partially removed, therefore, the frame from it gives significant shrinkage and requires careful protection from moisture and decay.

The correct approach to the assembly of any log house is to use strong and durable types of wood, such as oak or larch, for it.

If the assembly team does not possess the technology for compensating for wall shrinkage, then it is better to install the roof only after the house is well dry.

The shrinkage of a new house will be successful if the qualifications of the builders allow them to eliminate all the risks associated with this process. In this case, after installing the walls, you can immediately start installing the roof. Its weight will be an additional factor that has a positive effect on the tightness of the connection of the crowns.