Log cabin is considered the simplest design, but one drawback - you need to wait for time for it to shrink. This is due to the loss of natural moisture from the fibrous structure of wood. You can use profiled timber for construction, where the shrinkage of the log house will be insignificant, since the material undergoes preliminary shrinkage in production in special furnaces. But how long it takes for natural shrinkage, it is worth figuring out.
Factors affecting the shrinkage of the log house
Shrinkage of logs can occur in two ways: natural shrinkage and mechanical shrinkage. The first is considered a more complex process, since many factors affect shrinkage: weather conditions, wood density and the season of its harvest. it is desirable to produce in winter, when the presence of moisture in tree trunks is reduced. Moreover, there will be enough time for shrinkage before the construction season.
Losing moisture, the log becomes not only lighter, but its volume in diameter also decreases. The rate of this process is directly dependent on temperature. environment the higher it is, the faster the moisture will evaporate. It will be possible to erect a log house from the seasoned material, and immediately insert windows, doors, lay the floor and ceiling. For northern latitudes, where the climate is damp, this method will not work; it is better to use the mechanical shrinkage of the log house there.
A log house assembled from raw logs undergoes mechanical shrinkage over time. This is due to the pressure of the upper trunks on the lower ones, as a result of which they are slightly compressed. In addition, one more point is won here - tight pressing interventional insulation which improves thermal insulation. The finished structure must withstand at least six months, only then you can start finishing.
Log cabin compensation methods
While the frame is shrinking, its deformation must be monitored. Each tree, even if it is of the same variety, can have a different density, and, hence, the level of humidity. For this reason, the wood will dry unevenly, which can lead to cracks, twisting and cracking of the logs. Therefore, many experts advise building log cabins in winter period when moisture freezes out slowly, and shrinkage occurs evenly. By the summer, such structures are already ready for further finishing.
Particular attention should be paid to window openings, for the first time it is better to install a pigtail - a movable box assembly, which, when the walls shrink, will move evenly along the guide grooves. An expansion gap of 3-4 cm should also be left above each opening so that the cross beam does not crush the structure. Even if a small gap remains, it is closed later by cashing.
Vertical posts are made a little shorter, taking into account the shrinkage of the log house up to 10%. To warp cross beams it was uniform on all sides, a screw jack is installed between the pillars and floor beams and fastened to self-tapping screws. As pressure increases, the height of the device is reduced by lowering the nut down.
The method of connecting logs at the corners also affects the shrinkage of the structure. A successful crown connection is considered to be the "Canadian bowl", which has the shape of a wedge. Due to this, the logs do not form cracks during shrinkage. Whole log gives less shrinkage than rounded. This is due to the fact that the second is removed upper layer, which is considered the densest.
From the above, it is possible to determine the time for shrinkage of the structure, although it is very difficult to determine the exact period. The most basic process takes place during the first year, and the structure takes its final form after only 6 months, although the structure continues to shrink imperceptibly over the next few years.
Shrinkage is a natural process characteristic of such natural material like wood.
It represents a slight change in the height of the outer and internal walls buildings as the building material dries, i.e. loss to them natural humidity.
Shrinkage is determined only by the width wooden beam and can reach 8–17% of the original size.
Why use a beam
Wood – natural and ecological pure material, with high operational characteristics. Therefore, it is not surprising that for the implementation of most projects modern baths a beam is used, which has a number of undeniable advantages:
- Wooden beam is environmentally friendly, safe and natural, does not contain harmful substances;
- It is practical and easy to use, fits well and does not leave waste. In addition, timber is more economical and affordable in comparison with a log;
- The construction of a bath can be done independently even by a novice master. The project will require ready plan future construction, minimal experience with building material and a basic set of tools;
- The construction of walls from a bar is carried out immediately on the foundation, which greatly simplifies the construction process.
It is impossible to avoid the loss of the natural moisture of the timber, but when right approach to the technology of erecting a bath and taking into account slight shrinkage, it is possible to minimize the consequences of such a process.
If you do not take into account the possible degree of shrinkage wooden bath, the following adverse effects may occur:
- Distortion of window, doorways and flooring;
- The appearance of gaps between the timber and frames;
- Damage to interior and exterior trim.
More often negative impact subject to such Decoration Materials like a block house wooden lining and siding. They quickly deform, break, fall out of the fixing elements.
If at the construction stage of the bath, shrinkage of the material was not provided, in this case, simple and effective methods will help to eliminate the negative consequences:
- Wall settlement;
- casing device;
- Usage ;
- Arrangement of technical gaps.
Factors and causes of shrinkage, process duration
The shrinkage of a log house is determined by the main factors that affect its duration. These include:
- Seasonality of construction works;
- Type of wood;
- Material type;
- The initial dimensions of the material are length and width;
- The level of natural moisture content of the material;
- Building dimensions;
- Construction technology.
The duration of shrinkage depends on the season. Baths made of timber, erected in summer, require shrinkage for 12-14 months, in winter - from 6 to 8 months.
Bath from winter wood shrinks gradually around the entire perimeter, with the beginning of the spring period and an increase in air temperature, the drying process is accelerated.
Building material harvested at other times of the year provides a long and less uniform drying. The most intense drying period occurs during the first 2–3 months. Full shrinkage time wooden building completed within 3-4 years.
The key factor influencing the shrinkage process is the moisture content of the material. The higher the humidity, the longer it takes for the log to shrink.
Given the initial moisture level of the material, the shrinkage of the structure can be longitudinal and transverse. With transverse shrinkage, there is a slight collapse of the beam and opening small cracks. In this case, the total loss of moisture can reach 17%.
With longitudinal shrinkage, the drying of the material occurs in longitudinal direction when at the joints of the main parts appear deep cracks and gaps. To avoid such consequences, the docking points are blocked with special thermal locks.
bar various kinds gives varying degrees shrinkage:
- Planed (natural humidity) - 5.8 cm;
- Glued - up to 2 cm;
- Profiled (natural humidity) - up to 3.8 cm;
- Profiled dried in the chamber - up to 2.6 cm;
- Regular log - up to 11 cm;
- Rounded log - up to 7.8 cm.
In some cases, wanting to speed up the shrinkage process of the log house, the owners begin to intensively heat interior spaces new building. This is fraught with uneven drying of the building material, resulting in inner part walls dries faster, and the outer - longer.
The result of such actions can be extremely deplorable - deformation bearing walls and floors, the general distortion of the geometry of the structure. Therefore, experts do not recommend artificially accelerating the natural process of wood drying.
How to determine the degree of shrinkage
As the building material dries, the owner of the new building can independently determine the degree of shrinkage. This can be done in 2 ways:
- Regular moisture check with a wood moisture meter. It is recommended to check the upper and lower beams, as well as internal partitions;
- Setting up beacons made of tissue paper and arranging the operational load in one of the premises for up to 3 days with mandatory fixation of deformations.
Protecting an unfinished log house in winter
In winter, an unfinished log cabin needs to be additional protection, which allows to ensure the stability, strength and safety of the erected structures. If the work on the conservation of the construction site is carried out correctly, then the resumption of construction work in the spring will take place without problems.
The structure itself, communications (subject to their summing up) and Construction Materials. All work is carried out in several directions:
- Installation of insulation between the crowns to protect against excess moisture;
- Shelter of surfaces - horizontal and vertical, where snow accumulates;
- Protection of wood with antiseptic agents.
As materials for shelter, rubemast, stekloizol or polyethylene film reinforced base. They provide a log house with high protection against increased moisture, wind and cold. For wooden structure it is not recommended to use roofing material and heat-resistant film, which have low moisture resistance.
To protect surfaces, it is necessary to prepare tapes of covering material of a certain length by rolling them over the logs and the crown, fixing them securely at the edges.
For fixing, you can use thin slats with a cross section of up to 2.5 cm or edged boards. To fix the rails, ordinary screws or nails are suitable. Fixing the film to the base is carried out using building brackets.
Tracking and correcting sedimentary processes in a freshly built log house is a responsible task that requires certain knowledge and experience, and therefore it is best to conclude a contract for the maintenance of the house during the initial settlement with the construction company that erected it
Sediment is long term
Wall deformations during settlement
A house made of chopped or rounded logs should dry out gradually. In general, as the moisture content of the wood decreases, it will shrink over 7-8 years, which can be 10-12 cm. It is possible to finish the premises only in the second year after the construction of the house. At the same time, heating is also turned on, moreover, during the first heating season it maintains a temperature not higher than 10 ° C. In this case, the wood will dry slowly, and the sediment will occur more evenly, without serious deformations.
The first year of building a log house (boxes under a temporary roof) is the most responsible. It is during this period that it settles most actively, which is why there is a high probability of violation of the geometry of the building, cracking and displacement of logs, the appearance of cracks on the gables, and sagging of the truss system.
Professional maintenance of the log house during the entire period of its initial settlement will cost the customer in the amount of 16 thousand rubles. Employees construction company will visit the facility at least four times and perform necessary work according to the concluded agreement
What is log house maintenance?
primary goal control measures lies in the fact that the shrinkage of the house proceeds correctly, without distortions and deformations, and does not have negative consequences for the building structure. Sample list service work includes the following items:
One of the ways to prevent the pediments from hanging involves installing a special system on them: screws pass through the rims of the pediment, at the ends of which there are springs resting against the washers - they create an additional compression load that the pediment lacks
- Inspection of the log house in order to identify biodefeats of wood (mold, fungus, etc.).
- Checking the integrity of the temporary roof covering.
- Periodic measurement of log house settlement at control points. Since the house settles unevenly, measure the height of each wall at the corners.
- Control measurement of wood moisture.
After the expiration of the service period, the customer receives a conclusion, which reflects all the results of measurements and surveys, and analyzes the readiness of the facility for further construction work and recommendations are given for their implementation.
chain link
To prevent the gables from hanging, a dormer window (15 x 15 or 20 x 20 cm) is made in their upper part, stretching a galvanized chain through it and the lintel of the window (or door) opening. The ends of the chain outside the house are connected with a special screw tie, which is twisted from time to time, creating a load on the pediment. When tightening the chain, it is important to take into account the uneven settlement of the log house and avoid distortions. Instead of a dormer window, you can drill a small hole on the pediment, closing it after with a wooden insert.
In the construction of houses from any material has its own characteristics and wooden house is no exception to this rule.
wood features
Wood is a porous material, in the voids of which, in addition to air, there is a certain (depending on the moisture content of the material) amount of water. The tree most sensitively reacts to all atmospheric changes, passing air and moisture equally both outside and inside. In fact, this ability of hers is what is meant when they say that a tree “breathes”.
In wet, rainy weather, the tree absorbs moisture, and in dry weather, it releases the accumulated moisture. Thus, during its entire life, a wooden house is in constant motion. Its wooden elements either expand or contract. One of the design requirements wooden house is the absence of rigid mounts. Details wooden frame it should be possible to move in the process of swelling and drying of the tree. It is the process of shrinkage of wood that is the main cause of shrinkage of the log house.
Log house shrinkage - longitudinal and transverse
Depending on initial humidity source material shrinkage of the structure is on average 5 - 8%. In addition, under the weight of the structure, the logs are crushed and cracks open. This is about another 2% of the original height of the building. As a result, the total shrinkage reaches 7 - 10%, and with the initial high moisture content of the tree it reaches 15 - 17%. This is the so-called transverse shrinkage.
In addition to it, there is longitudinal shrinkage - this is the shrinkage of a log or timber in the longitudinal direction. In the process, at the joints, the parts diverge and form cracks. It is necessary to take this moment into account and cover the places of overcuts with a thermal lock.
The dependence of shrinkage on the building material
The exact amount of shrinkage cannot be calculated. Each log house is individual and “sits down” in different ways. The least susceptible to shrinkage is a frame made of glued laminated timber. The shrinkage value is 1%, which does not particularly affect the geometric dimensions of the structure. The structure of glued beams shrinks directly during the construction of the house, and by the time it is completed, the log house is almost completely shrinking.
The largest percentage of shrinkage (8 - 10%) gives a structure erected from freshly cut logs. A wooden house made of profiled timber with a moisture index of up to 20% will sag by 3 - 5%. The size of shrinkage of the house from the rounded log reaches 7%. This means that with a wall height of 3 m, in a year it will become 20 cm less and will be 2.8 m.
Visible shrinkage of the log house occurs during the first one and a half to two years after the completion of construction. Each floor will shrink by 10 - 20 cm. In subsequent years, shrinkage, mostly insignificant, will continue for about another ten years.
You can move into a wooden house a couple of years after its construction. First, an empty box should be settled, without windows (for better ventilation), this will take 6 to 12 months. Then it is necessary to withstand another 6 months, but with windows. And only after that the building can be fully exploited.
To provide for the shrinkage of a wooden house is the main duty of specialists, and the first sign of their professionalism. To do this, in the window and doorways of wooden houses it is necessary to arrange seat, a gap of 6 to 10 cm. It is at this value that the building sits down. For a log house made of glued laminated timber, the gap is smaller, it is 3-4 cm.
Independence of door and window openings from the inevitable shrinkage of the walls will provide a high-quality pigtail. An okosyachka (or casing) will not only keep the shape of the opening unchanged, but also save the room from possible drafts. Another way to warm a log house is caulking. It is performed during the construction of the structure and a year after it.
It is best to entrust these responsible works to specialists. As an example, we can cite the activities of the masters of the Konotopets.ru company, who professionally and efficiently perform these and other construction operations.
Building a wooden house has many advantages, but it also has some disadvantages. The main among them is the significant shrinkage of the log house: this is the name for the decrease in the height of the walls due to the shrinkage of the wood material.
The log house after shrinkage not only turns out to be lower: due to the uneven drying of the wood, various deformations are possible, which leads to the formation of cracks and the appearance of cracks in the walls. houses from different materials seated differently, and this is one of the important factors influencing the choice of type of construction.
What determines the shrinkage of the log house
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 the construction of the log house, it is impossible to finish and use it: it will take at least six months before the main drying processes are completed, and the logs or beams “sit down” in their place. This process will not be completed until a few years after construction, so many stages of construction must take into account shrinkage.
The shrinkage of a wooden frame will depend on the following parameters:
- from the moisture content of the wood. The higher it is, the longer the process will take, and the more changes will happen to the log house.
Because of this, a bar of natural moisture is valued much lower than already dried material that has been processed in special chambers. A completely dried timber is much more reliable, as it has even edges, in addition, the risk of deformation after the assembly of the log house is much lower.
- from the material used. The shrinkage of a log house from a log will be maximum: it will be up to 10% of the original height.
The shrinkage of a log house from a bar is lower, although here a lot depends on the material: a profiled bar shrinks by about 3-5% if dried wood was used. Gives minimal shrinkage glued laminated timber.
- From the season. In construction, winter wood is especially often used: wood cut in cold season, differs in greater density and reliability.
A log house is most often built before winter, after which it must settle for at least six months. With the beginning of spring, you can proceed to the installation of a permanent roof and the completion of finishing.
The shrinkage time of a log house can be different, but professionals say that it is completely completed no earlier than a year and a half after construction. Six months later, it is already possible to move on to finishing and move to a new building, but it will not be completely ready soon.
Because of this, it is necessary to use movable fasteners of partitions, install a window and doorways. There are other subtleties that specialists must take into account during construction.
In addition, further changes in the material have to be taken into account: wood easily accepts and releases moisture, it expands and contracts when the temperature changes. Because of this, fixed fasteners cannot be used during construction: over time, they will collapse.
How to compensate for the effects of shrinkage
Shrinkage of a log house made of logs or timber creates a lot of problems for the owner, since in the end it can make the building much less heat-resistant, and the deformation of the material will lead to other unpleasant consequences. Find a suitable log house shrinkage compensator - not an easy task, but now there are already several solutions:
The shrinkage of a log house from rounded logs will be much less if you purchase processed wood. You should not save when choosing building materials, as the strength of the house depends on it.
A dried log will cost more, but when building a log house from this material, there will be much fewer gaps in the walls, in addition, it will be possible to spend less on heaters, and the corners of the house will be more even.
A large degree of shrinkage is one of the main reasons why the construction of a house from logs and timber should be controlled by professionals. If you do not provide for a reduction in 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. Glued laminated timber remains the safest option from this point of view, since its shrinkage will be minimal.
