Is the shrinkage of a timber house as bad as it is made out to be?

A large and spacious house in the Moscow region made of environmentally friendly, beautiful and high-quality timber is the blue dream of almost any family. When the first steps towards the cherished goal have been taken - a plot has been purchased, documents have been agreed upon, the main stage of construction is coming to an end - the desire to immediately move 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 residents, threatening to postpone the celebration for a couple of years. But is everything really that scary? Let's figure it out.

Increasingly, future owners of houses, cottages, bathhouses and country houses when choosing suitable material prefer 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, victims of these same “experts” and unfair myths about houses made of timber.

On the Internet you can find many horror stories about wooden house will certainly sag by 10, or even 20% of the total height (and because of inexperience, some believe in the 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 no longer close. As a result, people begin to think about looking for other material and even give up on their dreams. And completely in vain. Most of these stories are exaggerations, fabrications, or the consequences of choosing the wrong contractor, and not at all the material.

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

What is shrinkage?

Shrinkage is a completely natural, natural and common process. 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 (timber natural humidity). In any case, after the construction of the building, being on outdoors and under pressure, the wood will get rid of residual moisture and dry out. Dried - just a couple of centimeters, natural humidity - about 4 centimeters.

The second reason for shrinkage is mechanical. The lower beams find themselves under the weight of the entire house, and over time they fit deeper into the grooves. In fact, such shrinkage is even useful, since the logs adhere more strongly to each other, the wind does not blow through them, and the house becomes warmer. To reduce the time required for mechanical shrinkage of a house, our company’s specialists carry out forced shrinkage. With the help of special tools, even at the construction stage, the joining gap is minimized, and the beams begin to fit more tightly to each other.

Our distant ancestors, who built wooden huts for centuries, were able to predict and take into account shrinkage. Now it is described in detail in GOST 6782.1-75 “Lumber products from softwood. The amount of shrinkage." Accordingly, there is nothing terrible in this process. Of course, if real professionals design and build a house taking into account all conditions.

How long does it take for a house to shrink?

When we're talking about When it comes to shrinking a house made of timber, you can often hear two directly opposite opinions - you can live in the house right away and will have to wait 2-3 seasons. The first sin is caused by unscrupulous companies that are in a hurry to hand over a turnkey project or house as quickly as possible, the second is by people who are not very well versed in the intricacies of the work.

In fact, intensive shrinkage occurs during the first 3 months from the moment of construction. During this time, the wood loses about 70% of the total volume it can lose. Further, the process slows down and becomes less noticeable and significant. However, completely exact dates 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 situation is easiest with dried timber with grooves and tenons 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, and drying occurs more intensively in the summer. As a result, to next stage finishing can begin in six months.

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

So, after building a house, you should wait from six months to a year, and only then start laying communications and finishing works.

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

The time of drying wood and shrinking the house can be regarded by many as an unpleasant brake, forcing you to completely stop all work and fall into a kind of “hibernation”. Indeed, there is a list of actions that should not be performed. Namely, you cannot:

• turn on the heating in the house and light the stove. Wood should dry gradually, naturally, while such sudden heating can disrupt processes, lead to cracks and uncontrollable consequences;

• finish the house with solids facing materials, like siding, wall panels, tiles. During the shrinkage process, the height of the walls decreases; accordingly, after a few months the cladding will bend, move in waves or even break;

• conduct final repairs using expensive materials, since after complete shrinkage, most likely, it will have to be completely redone.

However, waiting for the shrinkage to complete does not mean that work must be stopped completely. In the first months of intensive drying, it is not only possible, but even necessary to coat the timber with antiseptics, fire retardants and other compounds. They will extend the life of the house and prevent the appearance of mold, mildew and other troubles. If you carry out work at the shrinkage stage while the house is empty, you will be able to completely avoid negative effects on health. It is important to pay attention that the selected compositions are breathable and do not interfere with the drying process of the wood.

In addition, contrary to popular misconception, you can install windows and doors in your house, as well as install a roof. But this must be done in a special way - with compensation 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 quickly as possible, already a couple of months after the construction of the building, it is not forbidden to lay a subfloor and carry out preparatory work for laying communications. In general, shrinkage does not threaten to completely stop work, but will only limit and slow it down.

How to minimize the time and consequences of shrinkage of a house made of timber?

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

There are several ways:

Give preference to dried timber. It produces less shrinkage which is completed faster. True, the material costs a little more than natural moisture timber;

Build a house in winter so that it dries in summer;

Force shrinkage of the walls by hammering the beams deeper into the grooves using a special mallet;

Choose high-quality insulation that is less susceptible to compression;

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

Turn to real professionals who have extensive experience in building houses from timber, who are able to draw up and implement a plan thought out to the smallest detail for the construction of your ideal home.

So, shrinkage is a complex but completely natural process. It won’t necessarily be big or even just noticeable to the naked eye; it won’t force you to postpone your housewarming party for many years or put the construction project on hold. 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.

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

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

This forces builders to use special methods by reduction negative consequences for the building.

Shrinkage wooden house- an inevitable phenomenon, and this process does not end even a few years after the completion of the house, 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 increases or decreases in volume accordingly.

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

Let's take a closer look at what factors influence the degree of shrinkage wooden houses and what can be done to ensure that this process does not cause undesirable consequences.

What determines the amount of shrinkage of a wooden house?

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

• Type of log house material – simple or rounded log, profiled or laminated timber;
• Material size (length and thickness);
• Wood moisture level (natural or after chamber drying);
• House dimensions;
• Construction technology;
• Wood species;
• Construction season.

Shrinkage of a house with walls 3 meters high, depending on the type of material, occurs in the following range:

• An ordinary log is up to 10 cm.
• A rounded log shrinks from 8 to 10 cm.
• Walls made of timber with natural humidity - up to 6 cm.
• Profiled undried timber - 4-5 cm.
• Kiln-drying profiled timber – about 2.5 cm.
• Glued laminated timber – no more than 2 cm.

How long a house takes to shrink depends on the time of year (season) when it was being assembled. Therefore, a log house built in summer must dry for 12 months, and for a winter house, 8 months of drying is sufficient. Considering this circumstance, builders offer customers to assemble buildings in the winter.

In winter, moisture from logs freezes out slowly, so deformation of wood occurs more evenly than in summer. In a log house erected in November, by the beginning of summer the process of subsidence of the crowns ends. After this, you can install doors, windows, and begin finishing without the risk of cracks appearing in the wall cladding. Another advantage of winter construction is the assembly price, which is almost 20% lower than in summer.

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

A house for shrinkage 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 internal partitions and flooring.

Construction technology

This is a very important factor influencing the amount of shrinkage. The beams and logs laid 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 non-profiled timber is used for construction, then assembly is carried out on metal or wooden dowels - vertical rods that prevent torsion of the logs. After the drying of the log house is completed, a second caulking of the seams is performed, which closes the resulting shrinkage cracks.

During the drying process, the logs of the upper crowns begin to put pressure on the window and door frames. Therefore, if installed incorrectly, the entire joinery will inevitably move and jam. To eliminate this, a movable design of the boxes is used. It moves along the guide grooves along 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 drying the walls, this gap is closed with wooden casing.

How long a house takes to shrink is an important, but not the most important question for its owner. It is much more important to be firmly confident 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 socket, 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 secured 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 transferred through a screw jack. As the beams dry, they shrink, so the compensator is regularly tightened, reducing its length.

A timber house will shrink less, if builders use the so-called “Canadian cup” to connect the crowns. Its main advantage is the special wedge-shaped joint. Thanks to this, 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 crowns and roof.

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

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

The disadvantage of rounded logs is that, that when processing it, the outer most dense layer of wood (4-5 cm) is partially removed, so a log house made from it shrinks significantly and requires careful protection from moisture and rot.

The correct approach to assembling any log house is to use strong and durable wood species, such as oak or larch.

If the assembly team does not have the technology to compensate for wall shrinkage, then it is better to install the roof only after the house has dried thoroughly.

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

Building a house from wood has many advantages, but it also has some disadvantages. The main one among them is the significant shrinkage of the log house: this is the name given to the reduction in the height of the walls due to the shrinkage of the wood material.

After shrinkage, the log house not only appears lower: due to uneven drying of the wood, various deformations, which leads to the formation of cracks and gaps in the walls. Homes from different materials shrink differently, and this is one of the important factors influencing the choice of construction type.

What does the shrinkage of a log frame depend on?

The shrinkage of a log house depends on a number of factors that must be taken into account when designing. Most materials require a long wait: immediately after construction, the log house cannot be finished and used: it will take at least six months before the main drying processes are completed and the logs or beams “sit” in their place. This process will not be fully completed until several years after construction, so many stages of construction must take shrinkage into account.

Shrinkage wooden log house will depend on the following parameters:

• From wood moisture. The higher it is, the longer the process will take, and the more changes will occur to the log house.

Because of this, timber with natural moisture is valued much lower than already dried material, processed in special chambers. Completely dried timber is much more reliable, as it has smooth edges, and the risk of deformation after assembly of the log house is much lower.

• From the material used. The shrinkage of a log frame will be maximum: it will be up to 10% of the original height.

The shrinkage of a log house made of timber is lower, although here too much depends on the material: profiled timber shrinks by approximately 3-5% if dried wood was used. Gives minimal shrinkage laminated veneer lumber.

• Depending on the time of year. Winter wood is especially often used in construction: wood cut in the cold season is more dense and reliable.

A log house is most often built before winter, after which it must stand for at least six months. With the beginning of spring, you can move on to installing a permanent roof and completing the finishing.

The shrinkage time of a log house may vary, but professionals say that it is completely completed no earlier than a year and a half after construction. In six months, you can start finishing and move into a new building, but it won’t be completely ready any time soon.

Because of this, it is necessary to use movable fastenings for partitions, install window frames and doorways. There are other subtleties that specialists must take into account during construction.

In addition, it is necessary to take into account further changes in the material: wood easily accepts and releases moisture, and when temperature changes, it expands and contracts. Because of this, fixed fasteners cannot be used during construction: over time they will collapse.

How can you compensate for the effects of shrinkage?

Shrinkage of a bathhouse frame made of logs or timber creates many problems for the owner, since in the end it can make the building much less heat-protected, and deformation of the material will lead to other unpleasant consequences. Finding a suitable log shrinkage compensator is not an easy task, but now there are several solutions:

The shrinkage of a log house made from rounded logs will be significantly less if you purchase treated wood. You should not save when choosing building materials, since the strength of the house depends on this.

Dried round logs will cost more, but when building a log house from this material there will be much fewer cracks in the walls, in addition, you will be able to spend less on insulation, and the corners of the house will be more even.

A high degree of shrinkage is one of the main reasons why the construction of a house made of logs and timber should be supervised by professionals. If you do not provide for reducing the height of the walls, you may encounter serious damage to the roof, doors and windows, as well as the appearance of cracks in the walls, which will worsen the thermal insulation of the house and pose a threat to its strength. The safest option from this point of view remains glued laminated timber, since its shrinkage will be minimal.

Nowadays, when construction with the widespread use of chemicals prevails, wooden houses are not only popular, but also justifiably respected.

However, for such advantages as comfort, aesthetics, environmental friendliness, energy efficiency, there is also a price to pay - the shrinkage of a wooden house.

Few people know that the drying process is not always stable in geometric dimensions. This natural phenomenon is called wood anisotropy. Therefore, builders are forced to use methods that reduce the negative consequences under buildings.

Shrinkage of a wooden house cannot be avoided.

This phenomenon becomes less progressive after only a few years.

To understand how fluctuations will manifest themselves more noticeably, you need to consider all the factors of this process.

Some features

By its nature, wood is a porous material. She tends to “breathe.” By absorbing and releasing moisture, the walls increase and decrease.

How much deformation there will be depends on the thickness of the logs. The length of the material is also affected to some extent. Minor swaying as a result of shrinkage of a wooden house leads to cracking, gaps and twisting of the logs. All together it manifests itself as a defect in wooden walls.

Knowing detailed factors tree, you can take certain measures to prevent an undesirable outcome. First you need to decide what increases the degree of shrinkage

The material of the selected log house, the size of the log, thickness, length, total area of ​​the house, the chosen construction technology, the construction season and the degree of moisture content of the wood are the main indicators of house shrinkage.

What is taken as a basis also plays an important role: you can choose a rounded log or laminated veneer lumber.

Including the height of the house is manifested according to the degree of gravity on the ground. With parameters of 3 meters in height, an ordinary log settles by 10 cm, undried timber - 6 cm, in contrast to timber that has undergone chamber drying (shrinkage is 2.5 cm).

Seasonal shrinkage. For a log house, this indicator is important: the time of its seasonal assembly. A strange pattern: summer time dictates a holding period of at least 12 months, but a house assembled in winter is allowed for finishing work after 8 months.

Experts, based on these indicators, recommend winter time assemblies. The process is explained by a simple natural phenomenon - the deformation of wood in winter occurs more slowly due to the freezing of moisture in uniform percentages.

For example, a log house installed in November finishes settling the crowns by the beginning of summer.

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Only after completing the shrinkage stage of a wooden house do experienced builders begin installing doors and windows. Without the risk of cracks starting interior decoration and wall cladding.

The process of wall movement in intensity of manifestation is noticeable in the first six months. Complete cessation is possible after 3 years.

When forming a wall, the material (timber/log) must be tightly fitted to each other. The seams must be caulked with inter-crown sealant. Jute or tow are suitable for these purposes.

Non-profiled timber is assembled using vertical rods. The use of metal (sometimes wooden) dowels in construction significantly reduces the degree of twisting of logs.

Repeated caulking of the seams must be carried out after the log house has completely dried. Secondary work eliminates the presence of inter-crown shrinkage gaps.

The inevitable drying process is dangerous because the pressure of the upper crowns is exerted on the window and door frames. Incorrect installation leads to distortion of the operating mechanism (door, window). To avoid negative consequences, a movable box design is used.

The movement occurs together with the wall along the guide grooves. However, it is important to leave an expansion joint above each opening with a margin of 3-4 cm. Thanks to this precaution, the upper crown does not touch the box and destruction is not dangerous. After completion of the work, the gap is eliminated with wooden casing.

Also, high-quality wood is an important factor when it comes to the shrinkage of a wooden house. In combination with a competent connection, the home owner will be freed from thoughts about the appearance of gaps and cracks.

Experienced builders use the “Canadian cup” method if timber is used in the work. Connecting crowns in this way takes advantage of the wedge-shaped joint. When drying, no cracks form; on the contrary, the system becomes more compact under the weight of the crowns and roof.

The cost of laminated veneer lumber, which exceeds the price of profiled logs, is completely justified. The structure of the timber is made of individual boards glued together. This technology minimizes twisting of such material.

Any wooden house project contains documentation with elevation marks. Builders adhere to these data. Experts will always tell you two sizes that are obtained during the construction of the box and after the immediate shrinkage of the wooden house.

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Shrinkage of a log house: additional points and nuances

When shrinking a wooden house, walls and partitions do not require a special unit. Since a log house is a homogeneous structure. All constituent elements move at relatively the same rate.

The presence of vertical parts in the house - columns, pillars that exceed the main part of the house - requires the intervention of regulatory mechanisms that reduce the height of these elements (along the height of the log house wall).

It is at this stage that they resort to screw mechanisms - shrinkage compensators (screw jack).

During the period allotted for shrinkage of the house, there is no need to leave your home unattended. A careful attitude towards all cracks and gaps that appear (caulking, processing) will not allow the house to “lead to the side”.

A lot depends on the professionalism of the builders. Proper installation of the log house will allow the roof rafters and all “home” floors to move freely, without damaging the main frame.

The uneven shrinkage of the house is justified by its location in relation to the sun. The south side provides a more intense process of moisture release. It is more reasonable to believe that from the north it is slower.

In winter, shrinkage significantly slows down its process, and the return of heat does not give the previous speed of shrinkage. For this reason, it is in the second year after the installation of the log house that they begin to complete the finishing work.

Wood is considered a “living” material; heating stimulates the release of excess moisture. At the same time, it will dry better with inside than outside.

If it is possible to participate in the selection of material, it is important to ensure that prepared wood, dried with a special technically. Freshly cut material guarantees additional problems.