Shrinkage of a new building: when to make repairs? Shrinkage of a house made of profiled timber of natural moisture They give a rather large shrinkage.
Your worries are in vain.
Many so-called "experts" unknowingly spread the myth of the catastrophic consequences for the repair from the shrinkage of a panel house - this is not true.
Panel and monolithic-frame houses give a slight shrinkage when the owners move into their apartments.
The calculation of the foundations of residential buildings (most often pile) is carried out for maximum static and dynamic (horizontal and vertical) loads and multiplied by the load safety factor (according to GOST 27751-88 "Reliability of building structures and foundations. Basic provisions for calculation.") This factor always more than one, sometimes it reaches 1.5.
The negative consequences of shrinkage are relevant for new brick buildings.
In the apartment you bought in a panel house, there may be small cracks in the corners of the rooms (at the junction of the panels) and thin (hairline) cracks in the horizontal corners on the ceiling - the junction between the wall and the ceiling. There can be no cracks along the wall or ceiling, since each individual wall and floor is molded at the factory as a separate monolithic reinforced concrete panel. In one plane, there are no joints between the slabs or panels, therefore, there can be no cracks on the walls or ceiling.
For about twenty years I have been living on the first! floor of a 22-storey building and not even a cracked wallpaper in any corner.
As for your question regarding the laying of tiles in the bathroom, you can safely cover the walls and not listen to the "would-be specialists" who picked up information from the Internet and claim the opposite.
The thing is that cracks cannot appear in the bathrooms of panel houses due to shrinkage of the house or other deformations.
In panel houses, during installation in each apartment, a unified concrete sanitary cabin with separate or combined bathrooms is installed, in the left or right version (in relation to the sewer riser).
Such cabins are molded at the plant in a monolithic reinforced concrete design (walls + ceiling). After the product gains strength in the steam chamber, it is removed from the mold and a pallet is welded to it from below (to the bathroom), which later serves as the floor of the bathroom. You probably noticed that the floor of your bathroom is 10 centimeters higher than the main floor of the apartment. This is one of the proofs that your bathroom is a separate monolithic product.
Based on the above you can safely make repairs in the bathroom and not be afraid of any shrinkage and cracks.
When cladding walls in such bathrooms, additional difficulties are caused by the fact that all walls are tilted inward (installed as if not on a plumb line). This is due to the specifics of production. In order to pull the finished reinforced concrete sled out of the mold, the inner molding "cans" are made conical (narrowed towards the top), so the walls of the cabin at the top are slightly thicker.
The ceiling of the sled cabin is also not even in most versions, but has the shape of an envelope with a raised center (also due to the domed structure of the formwork). The concrete ceiling in the bathroom can be pasted over with foam tiles, leveled with plaster, and a suspended or suspended ceiling can be mounted.
The strength and durability of a brick structure depends on many factors. Shrinkage of a brick house is one of them. This natural process is inevitable and leads to cracks in structures. Therefore, before starting and during the construction period, it is necessary to take into account all the reasons that can cause and aggravate the deformation of the building due to shrinkage in order to prevent or minimize its negative consequences.
Why is it happening?
Shrinkage of a brick house occurs because the foundation adapts to the weight of the load-bearing walls and floors. Since brick is a heavy building material, then the load on the base of the structure will be high, which will entail its subsidence. In addition, shrinkage occurs due to changes in air temperature. As a result of changes in weather conditions, building materials expand or contract, as well as their moistening and drying under the influence of the environment.
The consequences of the shrinkage of a brick house
Any shrinkage has a negative effect on the brick structure. As a result, such deformations may appear:
- cracks in structures;
- discrepancies in brickwork;
- peeling off plaster;
- subsidence of the wall in various areas.
What influences?
The scale of the deformation process depends on several factors. Influence is exerted by:
Groundwater contributes to problems with the home. - soil features;
- availability and level of groundwater;
- foundation quality;
- type of brick;
- climatic conditions of the area.
Before starting any construction, it is advisable to conduct a geodetic assessment of the territory. It is recommended for choosing a site for construction with harder soil and with the maximum distance of groundwater, if any. Based on these conditions, the choice of building materials of a suitable type is carried out. The type of foundation is chosen taking into account the forthcoming load and in compliance with safety requirements. In addition, the following characteristics affect the shrinkage of a brick house:
- the use of bricks with an increased rate of water absorption;
- non-compliance with standards when preparing a solution for masonry;
- violation of the storage conditions for building materials;
- unfavorable climatic conditions during the construction of a building.
You should not save on building materials for laying the foundation. The strength, reliability and durability of the erected structure as a whole depend on its quality and compliance with standards.
Shrinkage strength and timing
High-rise buildings sit down much longer.
Brick houses are subject to fairly strong shrinkage. First of all, this process is typical for the foundation due to the high load under the weight of the bearing walls. The subsidence of a brick house will be the greater, the softer the soil on the building site. The adaptation process takes 2-8 years and usually does not have consequences leading to destruction. The timing depends on the height of the building. For multi-storey buildings, the period is longer and more difficult. In case of non-compliance with the requirements of construction technology, shrinkage lasts throughout the entire period of operation of the building and its service life is reduced.
Wooden houses in the era of active invasion of chemistry in the construction field are deservedly popular among developers. However, a considerable price has to be paid for the ecological 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 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 summer must dry within 12 months, and for a winter house, 8 months of aging is enough. Considering this circumstance, builders offer customers to assemble buildings in 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 crowns settling 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 ends completely 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 out, 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 the 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 assembling 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 to compensate 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 proceed with the installation of the roof. Its weight will be an additional factor that has a positive effect on the tightness of the connection of the crowns.
Buying an apartment in a new building or becoming the happy owner of a private house, you want to start interior decoration as soon as possible, so that the house will finally acquire a cozy look and become comfortable to live in. But experts warn: do not rush and buy finishing materials. Why? Because the building has yet to go through one more stage - shrinkage. All structures, without exception, are subject to this process. It is based on the interaction of the physical properties of materials and the environment. That's when the structure is settled, the shrinkage of the house will stop, the decoration will justify the money and effort spent. In a hurry, residents run the risk of wasting time and money, because finishing materials can become unusable under the influence of internal deformation of the house structure.
After what period of time you can go from a rough repair to a real one, you can find out a thorough one by finding out the features of shrinkage in different types of houses, taking into account the influence of factors. If everything was calculated and made correctly, then the shrinkage will take place practically without affecting the used tiles, wallpaper, laminate. The owners do not have to dismantle the raised floors and find the tiles that have broken off the wall.
Shrinkage is a natural process for new buildings. The foundations and piles must be adjusted to the weight of the floors and walls. In addition, if the house is an apartment building, then you need to take into account the weight of everything that residents bring inside. Development companies include the time required for the final stabilization of the structure in the project plan. What factors affect the degree of shrinkage of a building? This is a whole list of criteria based on research results:
- the peculiarity of the soil in the selected area (on solid soils, the process is completed faster than on moving ones);
- type of foundation;
- ground water level.
In a new home, the process can take from 2 to 6 years. On average, a building adapts in 2-3 years. It should be borne in mind that the greater the weight of the structure, the more difficult the process is. A brick structure will adapt worse than a cellular concrete structure, which has much less weight.
Shrinkage of a brick-monolithic house 
What is the shrinkage of a wooden house
When can you start repairing and finishing
The desire to tidy up the living space is more than understandable. The rough finish does not add comfort. However, no matter how strong the desire to take on repairs, hold back your emotions and financial resources. Construction experts strongly recommend waiting at least 2 winter periods. During this time, the active part of the house shrinkage process will pass and further finishing will not suffer, or will take place with minimal losses.
In the process of shrinkage, the floors and walls are slightly displaced relative to the original geometric shape. It is impossible to determine these changes by eye, but it is quite enough to deform the finishing materials on the walls, floor and ceiling.
How is it shown? For example, ceramic tiles crack or come off in the kitchen or bathroom. The appearance of cracks in the tile joints in the same premises is possible. Wallpaper may fall behind, paint and plaster on the ceiling and walls may crack and crumble. The consequence of shrinkage will be the "excitement" of laminate and parquet panels. The openings of windows and doors are sagging.
The conclusion suggests itself: until the process of shrinkage of the building has passed, it is better to spend money exclusively on cosmetic repairs.
Shrinkage may cause cracks in floor tiles Is it still possible to make a thorough interior decoration? Even experienced master finishers will not give a 100 percent guarantee. If you really want to, then as a way out, experts suggest using materials that have a sufficient degree of elasticity to transfer the changing geometry of surfaces, these include:
- stretch ceiling;
- vinyl tiles;
- non-woven or liquid wallpaper;
- special plasters with elastic effect.
If the type of building allows a small percentage of deformation, then the materials used in the decoration will be able to adapt to the displacement of surfaces and maintain the quality of the coating. "Gutta-percha" finishing will cost more than usual, therefore, before deciding on an experiment, you should weigh your possibilities.
When purchasing a home with finishing made by the developer, also get ready to carry out renovations in a few years. However, by that time, the active phase of shrinkage has already been passed, and you can safely use the materials you like.
Shrinkage of the foundation can contribute to cracking of gas silicate masonry Features of shrinkage in different types of houses
Shrinkage of a house is a change in the geometric parameters of building elements due to the drying of the materials from which they were made. This process must be taken into account when erecting a structure, since it is natural and it is impossible to do without it. With competent calculations, shrinkage will take place harmoniously and without consequences for the structure.
The settlement of the building, with which shrinkage is sometimes confused, on the contrary, is not natural and signals the instability of the soil in the selected area or the weakness of the foundation. Settlement can cause not only cracking of walls, but even their collapse.
The degree of shrinkage of the building directly depends on the material chosen for the construction. Wood buildings are considered the most problematic in terms of shrinkage. Concrete, foam blocks and bricks are also subject to this process, but not in such a pronounced form.
| House type | Main shrinkage period | Features of the course |
| Panel | 2-3 years |
|
| Monolithic frame | 1 year |
|
| Brick | 3-4 to 5-6 years old |
|
Deformations in concrete floor slabs Panel
Shrinkage of a panel house occurs on average per year. The changes are so noticeable that the rough coating can in no way hide the traces of deformation. It is recommended to use coatings for the first repair, which can then be easily dismantled - laminate or linoleum. Most of the shrinkage can be quite noticeable in relation to the change in the geometry of the planes of the walls, floor and ceiling. The result can be noticeable cracks and distortions in the area of corners and tile joints. The slabs themselves remain unharmed. Very often, after shrinkage, apartment owners have to think about the need to level the floor. Ideally, of course, it is better to wait altogether with the repair before the active stage of shrinkage has passed. It may not be so comfortable, but financial losses will be minimal.
Brick
In the production of building materials, the technology includes the so-called shrinkage protection. Therefore, if the shrinkage has a significant percentage, this signals a low quality of the material, or a violation of the standards by the builders during the construction of the building.
At the production stage, the brick goes through a drying procedure, due to which the percentage of moisture in the product is reduced to zero. This means that further evaporation, which could lead to material shrinkage, is excluded. Concrete does not hold water in itself. In this case, freezing in the cold season or improper distribution of the load within the structure may become the cause of shrinkage. If the building was erected in the autumn-winter period, there is a high probability that the materials may get wet, and after being saturated with moisture, they will freeze. As a result, moisture inside cracks and pores turns into ice, which tends to expand. This can lead to severe external cracks.
Another disadvantage of brick buildings is the large number of seams. These gaps, if the masonry was of insufficient quality, can accumulate moisture inside itself, which, under the influence of temperature changes, will expand or decrease. The porosity of a brick, in comparison with other types of building materials, is its advantage and disadvantage at the same time. When building brick houses, builders must be very careful to ensure that all gaps are minimal and well designed. The degree of shrinkage of a brick house in comparison with a wooden one is minimal, but it will take 3-4 years in duration.
A crack in the ceiling is the first sign that a building is shrinking. Monolithic frame
At the heart of the monolithic-frame structure is a supporting frame, made not using welding, but made with the help of vertical columns. This is a solid system in which the frame is assigned the role of support for the structure as a whole. With this approach to construction, the risk of cracking is minimized.
Shrinkage in monolithic houses is minimal compared to other types of buildings, since the one-piece structure qualitatively distributes the load on the foundation, due to which the shrinkage occurs evenly. For people living in the house, the changes are almost imperceptible, compared to a brick building. However, there may be soil subsidence under the monolith. In this case, a strong frame protects the building from significant deformations. This makes it possible to carry out repair work in a new building almost immediately.
True, if sufficient geological and geodetic studies were not carried out or there were serious violations in the construction technology, then even a monolithic structure is capable of showing unusual miracles of shrinkage.
The consequences of the shrinkage of a brick-monolithic house Factors influencing shrinkage
It has already been mentioned that the shrinkage of the foundation of a house is a natural and logical phenomenon. The degree of its severity is influenced by external and internal factors. By taking into account their influence on the structure, undesirable manifestations can be prevented in the future.
External
The group of external factors includes soil mobility - the uneven occurrence of soil layers leads to the fact that the movement at different ends of the building may differ. There are several types of this factor:
- the depth of soil freezing - it is not the soil itself that freezes, but the moisture in it. When water freezes, it causes the soil to shrink, and when it’s time to melt, it begins to expand. The soil around the foundation swells and begins to squeeze it. With a significant degree of freezing, the foundation lies at a great depth, since it must be laid deeper than the soil freezes. Accordingly, the shrinkage will be longer. In addition, the degree of freezing affects the strength of the foundation, because periodic squeezing leads to the gradual destruction of the base of the house;
- depth of groundwater - moisture has a serious effect on the foundation of a building, but the degree of its influence is not the same. The blind area protects the upper part of the foundation from water, but the lower part is located underground. Despite the fact that rainwater also penetrates into the ground, the main impact comes precisely from the groundwater. Due to the difference in humidity, the foundation may shrink in the lower and upper parts in different ways over time. If the groundwater is close to the surface, drain the foundation to reduce moisture exposure;
- horizontal - displacement leads to a tilt of the foundation to the sides;
- vertical - here the movement of layers is characterized by upward or downward displacement. The foundation either falls through or is pushed out;
- mixed mobility can displace the base of a building both vertically and horizontally. To reduce mobility and stabilize the soil, the foundation is installed on a foundation cushion of rubble, sand and concrete;
- climatic conditions - the territory of our country is characterized by a humid climate, clay and sandy loam soils, as well as low temperatures. The soil freezes deeply, which must be taken into account when building a foundation. Failure to comply with construction technology can lead to serious deformation of the building during the shrinkage process;
- season - you should not build a foundation in spring or autumn, when there is a lot of rain and the soil is saturated with moisture. This is especially important if further freezing is possible, which will negatively affect the integrity of the foundation.
The scheme of sealing a crack near a brick wall Internal
- expansion and contraction of building materials. Due to the temperature difference, substances expand or contract. In the case of the building foundation, there is an impact from both sides. Temperature affects the foundation itself and the soil in which it is submerged. So that this physical deformation does not harm the structure, expansion joints are made in the foundation;
- moisturizing and drying materials. The main process causing shrinkage is drying of building materials. When moisture evaporates, the structure of the building becomes lighter, decreases in volume. If the materials get wet, then, on the contrary, swelling occurs, weight and volume increase. Shrinkage lasts exactly as long as is required for maximum moisture evaporation, then the materials acquire maximum strength. The speed of the process will directly depend on the air temperature and humidity;
- the quality of the materials used - the foundation bears a heavy load, therefore the materials at its base must meet all the requirements and construction standards. Stamps, fractions should be used only those that are spelled out in regulatory documents. The quality of the building structure will depend on the clarity of the technology.
The foundation must stand before the building itself is erected. Otherwise, the shrinkage process will continue under the influence of walls and supporting structures. As a result, some areas will sag, and cracks will form on the walls and foundation. If the deformation is too strong, the house can simply collapse.
Based on the above, we can conclude: the shrinkage of a house is a natural process, but not always subject to warranty periods. Its course is greatly influenced by internal, external groups of factors, as a result of which the same construction technology can give different results. Moreover, in addition to the quality of the walls and floors, the properties of the foundation and how competently it was executed are very important. Did the builders take into account the type of soil mobility, did they measure the depth of the groundwater flow? Has drainage been taken care of for the foundation and how good is the foundation pad? There are many nuances, so in order for the finishing to become a timely event, it is worth making sure that the house is built in accordance with all applicable standards.
Video
Describes in detail what problems can be encountered during the shrinkage of a building.
Photo with options for problems that may arise during the shrinkage of a building
What threatens the shrinkage of an apartment building.
In the first years, after a brick house is built, it will certainly shrink. It can last for quite a long time - up to 8 years, depending on the characteristics of the soil on which the construction was carried out. The load-bearing walls of the house put pressure on the foundation and if the soil is soft, then the house will sink deeper. So that cracks do not appear in the brickwork as a result of shrinkage, so-called expansion joints are arranged. These seams are designed to reduce stress on the structure of the house in areas where deformation may occur. These seams are a kind of cut that divide the building into blocks and give the structure a kind of elasticity. Seams are sealed with a special insulation material.
Seams can be used for various purposes - shrinkage, sedimentary, thermal, and anti-seismic.
A brick house, which is subject to shrinkage, must have both a shrinkage joint and a temperature one.
Features of shrinkage at home
Many happy owners of a new brick house do not carry out repairs in the house for 2-3 years. However, if we are talking about a single home, then you can make cosmetic repairs. It doesn't have to be very expensive, as you will still have to rework it later. It is necessary to do quite simple and not costly actions:
- plaster the walls, whitewash the ceiling and stick not very expensive wallpaper;
- parquet is best suited for the floor, it is not afraid of shrinkage;
- tiles and tiles do not need to be used, there is a great risk that it will fall off or split.
Of course, you can decide on serious repairs, but you must remember that it can be damaged by the consequences of the shrinkage of the house and, in particular, the shrinkage of the cement mortar. In order to minimize the consequences of the shrinkage of the house, it is recommended to use building and finishing materials of the highest quality, produced by the best manufacturers, during the repair. To carry out the work, it is necessary to invite experienced specialists who have already performed similar work in newly built brick houses. Brick structures are quite rigid, so their shrinkage is not so significant.
Often in brick houses, foundation settling takes place. This one can reach up to 150mm. To make the draft to a minimum, the foundation of the house is erected on a sand cushion and buried at a sufficiently great depth. It is clear that this is done at the very first stage of construction. Around the house, it is necessary to build drainage, which will reduce the pressure of groundwater on the foundation.
When building your own house, you must remember that the shrinkage of a house is not something unusual, it always happens, no matter what material they are built from.
Shrinkage of cement slurry
The cement slurry decreases in size when it dries. In addition to a change in the volume of the binder material, due to which, mainly, shrinkage occurs, this process depends on the percentage of the binder aggregate to the water binder. Also, a very significant role in this process is played by the hardening time of the solution and the weather conditions under which it hardens.
The more binder and water-binding material in the solution, the more it changes size when it dries. Shrinkage occurs as quickly as possible in the first stage of mortar hardening. Over time, the changes diminish and, in the end, cease completely. Shrinkage of cement slurries stops after 3 - 3.5 months. For standard solutions, the shrinkage value can fluctuate within a fairly wide range - from 0.1 to 0.4 mm / m. Sometimes a limiting shrinkage rate is reached equal to millimeters per meter of length.
Shrinkage is highly undesirable during tiling, as well as in mosaic work. In order for it to be small, it is necessary to make a solution with a minimum amount of binding material and add special impurities to it.
