Helpful information

Have you noticed how some freshly washed clothes become smaller in size? If this happens, then the material shrunk- became shorter. The same can happen with fabric cuts for sewing.

It is important to remember this feature when buying a cut, otherwise you will be in for an unpleasant surprise:

you immediately, without processing the fabric, sew a thing, and it will “sit down” after soaking and ironing;

you wash the canvas, and it turns out that it is not enough.

To prevent this from happening, you need to purchase more fabric than the pattern suggests. And after the purchase, the cut follows heat-treat to take its final shape.

Most often, the exact percentage of fabric shrinkage is found out after washing. But if the material cannot be washed, it should be wetted or steamed.

Why tissues shrink

The main reason lies in the peculiarities of production. During the creation of the fabric of the thread of the future canvas stretch and give them a certain position. Taking water and thermal "baths", the material seeks to regain its optimal shape, as a result of which its length and width decrease.

If the threads of one of the systems (warp or weft) are strongly twisted or otherwise squeezed, they will want to "straighten up". And this will happen due to the shortening of the threads of another system.

Another common cause of shrinkage is fiber swelling. In this case, the threads become thicker and shorter.

How to deal with shrinkage

To prevent shrinkage, wet-heat treatment of the fabric is needed. They call her decatization . IN general view this process looks like this: the material is moistened, ironed and left to dry completely. A more specific method of decating depends on the characteristics of the structure and composition of the fabric chosen for sewing.

Shrinkage rates for fabrics and knitwear

Before buying a cut, you need to find out how much shorter it will become after wetting.

The most convenient source of information on fabric shrinkage is table. If you know the type of material and its composition, you can quickly find out the extent of its "shortening".

Rough wool fabrics"Sit down" a little less - by about 2.5-3%. But knitted materials become much shorter than ordinary fabrics (unless, of course, they contain elastane).

Knitwear used for sewing outerwear, gives significant shrinkage - 8-10% on average. For more accurate length and width loss values, see the table below.

Linen knitwear on average shrinks by 8-10% in length and 10-12% in width.

If the type of material and its composition is known, it is easy to determine the degree of fabric shrinkage using the tables above. To the resulting number you need to add the length of the cut.

Basic Formula for calculations looks like this:

(D*U/100) + D = D 0.

Here D - this is the required length of the material for cutting, At - percent shrinkage, D 0 - the length of the cut when buying.

Important! To the resulting number, you need to add a few more centimeters to the “smooth” value. After all, the piece that we “add” to the desired length will also “sit down” during decatification.

For example, you are going to purchase 170 centimeters of cotton corduroy. He "sits down" by about 5%. So the calculation will be

170*5/100 + 170 = 178.5 cm.

Wooden houses in the era of the active invasion of chemistry into the construction field are deservedly popular among developers. However, for the environmental 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 speaking, the instability of geometric dimensions under the influence of the natural shrinkage process.

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 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, cracking and twisting of logs.

Let us consider in more detail what factors affect 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 shrinkage period of the house and the amount of decrease in the height of its walls is determined by the following factors:

• Logging material type - simple or rounded log, profiled or glued beam;
• Size material (length and thickness);
• The degree of wood moisture (natural or after chamber drying);
• House dimensions;
• Construction technology;
• Type of wood;
• Construction season.

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

• Regular log - up to 10 cm.
• The rounded log gives from 8 to 10 cm of shrinkage.
• Walls from a bar of natural humidity - up to 6 cm.
• Profiled non-dried 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 being assembled. Therefore, a log house built in the summer should dry for 12 months, and for a winter house, 8 months of exposure is enough. Given this circumstance, builders offer customers to assemble buildings in the winter.

In winter, moisture from logs freezes out slowly, so the deformation of wood occurs more evenly than in summer. In the log house, set in November, by the beginning of summer, the process of subsidence of 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 in summer.

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

A house under 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 sheathing of internal partitions and flooring.

Construction technology

This is a very important factor influencing the amount of shrinkage.. The beam and logs laid in the wall must fit very tightly to each other. At the same time, the seams between them are caulked with an interventional sealant - jute or tow.

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

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

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

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

screw jack

We have already mentioned the need to install a pigtail, 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.

At the same time, the pillars are made a little shorter so that the beams do not deform them, and the load transfer goes through screw jack. As the beams dry, they shrink, so the compensator is regularly twisted, reducing its length.

Timbered 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. Due to this, log shrinkage does not lead to the formation of a gap, but additionally seals the seam under the action 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 glued laminated timber 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 longitudinal torsion of the glued beam. However, more cheap technology profiling, 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 during its processing the outer most dense layer of wood (4-5 cm) is partially removed, therefore the log house 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 for its strong and durable woods, such as oak or larch.

If the assembly team does not own the technology of wall shrinkage compensation, then it is better to install the roof only after the house dries well.

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 the installation of the walls, you can immediately proceed to the installation of the roof. Her weight will be additional factor, which positively affects the density of the connection of the crowns.

The strength and durability of a brick structure depends on many factors. Shrinkage brick house 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 bearing walls and overlays. Since brick is a heavy building material, the load on the foundation 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 changing weather conditions, building materials expand or contract, as well as their moisture and drying under the influence of the environment.

Consequences of shrinkage of a brick house

Any shrinkage negatively affects the brick structure. As a result, such deformations may appear:

• cracks in structures;
• masonry discrepancies;
• peeling plaster;
• subsidence of the wall in various areas.

What influences?

The scale of the deformation process depends on several factors. Influenced by:

Groundwater contributes to the appearance of problems with the house.

• soil features;
• availability and level of groundwater;
• foundation quality;
• brick type;
• climatic conditions of the area.

Before starting any construction, it is advisable to conduct a geodetic assessment of the territory. It is recommended for selecting a site for construction with harder soil and with the maximum remoteness of groundwater, if any. Based on these conditions, the choice of building materials is carried out. suitable type. The type of foundation is chosen taking into account the upcoming 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 the norms in the preparation of mortar for masonry;
• violation of the conditions of storage of building materials;
• unfavorable climatic conditions during the construction of the building.

Don't skimp 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.

Strength and terms of shrinkage

High-rise buildings sit down much longer.

Brick houses are subject to rather strong shrinkage. First of all, this process is typical for the foundation due to the heavy 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 plot. The adaptation process takes place within 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.

After the completion of the construction of the house, the shrinkage process is inevitable. It occurs due to the fact that the material dries out, moisture evaporates from it, and because of this, it literally shrinks and decreases in size.

Many people are afraid of shrinkage, but this is a completely natural process that cannot be avoided and should not be worried about. But, so that shrinkage does not lead to unpleasant consequences, it should be taken into account during construction. This is especially true for houses built of wood. If the tree is not well dried before construction, then after the shrinkage is completed, the volume of the walls can noticeably decrease, which will subsequently become a huge problem.

The time it takes for a house to completely shrink depends on many factors. The process is influenced by the material of the building, the climatic zone and weather phenomena, the season when the construction was completed, and much more. In general, if you follow some simple rules, then this process will not cause any inconvenience.

What is home shrinkage

House shrinkage is the process of evaporation of moisture and drying of the material, as a result of which it decreases in size. When building a house, experienced builders must take into account future shrinkage, because if this is not done, then you can get into an unpleasant situation.

Due to the drying of the material, the height of the walls, door and window openings can be significantly reduced, which will lead to a change in the size of the building. This is especially true for houses built from natural wood. Brick, aerated concrete and other materials also shrink, but to a lesser extent.

There are two main types of shrinkage at home:

1. Temperature. The material tends to expand or contract due to temperature changes.
2. "Shrinkage". The material changes its dimensions due to excessive drying or getting wet.

house shrink time

In the process of shrinking a house, two very important factors should be taken into account: the time of shrinkage of the house and its size. Before starting construction, it is impossible to determine with a high degree of accuracy how long the shrinkage will last, and how much it will ultimately affect the area of ​​\u200b\u200bthe walls.

The shrinkage time depends on the climate and the season when the construction was completed. The ideal option is the completion of construction by the end of autumn and the beginning of winter. Then you can put the house into operation after 6 months, as the structures will pass the winter frosts and have time to dry out evenly in the spring. If the construction was completed in the summer, then ideally the house should go through all the seasons and stand for a whole year. However, the shrinkage time depends not only on the season of completion of construction, but also on climatic conditions and weather. If the building or part of it is located in the shade or constantly gets wet from the rain, the drying process of the material may take longer.

It is best to start construction at the maximum open area, and after the shrinkage of the house, plant plants and erect other buildings. Thus, the walls will be better blown and will not be in the shade, so that the drying process will be accelerated. It should be noted that with the right approach, the climatic features of a particular development area should be taken into account by specialists or determined using regulatory documents.

Factors Affecting Home Shrinkage

The amount of shrinkage, as well as its duration, depends on many different factors:

1. Building material. If the house is being built from wood, then its type and natural humidity should also be taken into account. The maximum shrinkage is given by houses built from freshly cut logs. In this case, it can reach up to 8-10%.
2. Material storage conditions. In the event that the material was not stored correctly and had time to be heavily saturated with moisture, then the percentage of shrinkage will be higher.
3. The location of the house. In this case, the main role is played by the presence of shadows and the degree of ventilation of the site.
4. Weather conditions at the stage of construction and preservation of the house.
5. Building scale.
6. Technological type of construction.
7. Competence of builders. This is a fairly important factor that plays a significant role in the amount of shrinkage at home. Experienced and competent professionals know how to reduce the percentage of shrinkage and avoid problems associated with this process.

Given all of the above, we can say that the amount of shrinkage depends on a wide variety of factors, not all of which can be somehow influenced. However, it is quite realistic to find competent builders, properly store the material or start construction in an open and well-ventilated area. When building a wooden house, these issues should be taken especially seriously.

How to eliminate shrinkage

There are just a few enough effective methods how to reduce shrinkage at home. However, for each material, these methods may differ.

Shrinkage of a wooden house

The most effective way to reduce the shrinkage of a wooden object. To do this, you can use the following methods:

• Seam sealing. Harnesses or tow can act as a sealant.
• Draft all rows of logs with a mallet or vibrator. Due to this, the material is joined as tightly as possible.
• Proper storage of material. The tree should dry for some time in a dry and ventilated place.
• Okosyachka of structural elements of openings with the help of bars, the thickness of which does not exceed 50 millimeters. The bars are mounted in special grooves, due to which the design characteristics are enhanced.
• The use of profiled timber, which has a natural degree of moisture. They are perfectly connected to each other thanks to the grooves and spikes. With them, you can not be afraid of gaps, which can lead to unpleasant consequences during shrinkage.
• The use of glued timber. Such material will help reduce and shorten the shrinkage process, but it is very expensive, so it is used quite rarely.

Shrinkage of a brick house

Brick houses shrink less than wooden houses, but the consequences of such a process can be much worse. Strong shrinkage of a brick house can lead to cracks in the walls and even a violation of the building structure.

To avoid strong shrinkage at home will help expansion joints that are made in brickwork. Thanks to such seams, the stability of the structure to temperature changes increases, and the load on the structural elements Houses. An expansion joint is a cut in the masonry that separates the wall into separate parts. This increases the elasticity of the entire building. Such seams must be sealed with special insulating materials.

Reduce shrinkage at home can and right choice bricks. Choose a brick with low water absorption characteristics. Also, do not forget about the correct storage of the material. If you store a brick in the open air, then it can get very wet and absorb a lot of moisture, which will negatively affect the “shrinkage” of the material.

Shrinkage of aerated concrete houses

Aerated concrete, although it is good stuff, which has its advantages, but it is also subject to shrinkage. At the same time, cracks may appear on the walls during shrinkage. different sizes and should be taken seriously. Just plaster cracks, as many do non-professional builders, not enough.

The main reason for the shrinkage of gas silicate blocks is the evaporation of moisture from the porous structure. At the same time, the process of drying and moistening of aerated concrete occurs somewhat faster than that of other materials.

The peculiarity of shrinkage with a house made of aerated concrete is that the drying process of the material occurs unevenly. The surface dries much faster than the inside of the material. So outside gas silicate blocks dry out, which is why they shrink, but this process does not occur in the inner part. As a result, the outer parts of the material do not withstand, and cracks appear on them, which begin to increase over time. It is not difficult to guess that there are two ways to reduce the shrinkage of an aerated concrete house:

• accelerate the drying of the inner part of the material;
• do not allow the outer parts of the material to dry quickly.

To prevent the blocks from drying out too quickly from the outside, experienced builders evenly spray them with water during masonry. But here the main thing is not to overdo it, there should not be too much water, otherwise it will slow down the drying process not only outside the material, but also inside. You should also carefully monitor that all blocks are moistened evenly.

Proper storage of the material will also help reduce the shrinkage of a house made of aerated concrete. It is recommended to cover the blocks with oilcloth to avoid getting them wet. Also, they should not be stored in the open sun. For more uniform drying of aerated concrete, blocks are best placed edgewise.

Is it possible to avoid shrinkage of a private house

Many people, when they start building a house, naively believe that they can avoid shrinkage of the building. However, it is not. Shrinkage of the house occurs in any case, and there is no escape from it. The main thing that can be done in this case is to reduce shrinkage and reduce it in time.

For this, first of all, it is worth hiring competent and experienced specialists who are well versed in all the intricacies of construction and understand the difference between materials. Wood, aerated concrete and brick shrink differently, and when building from these materials, there are some nuances that workers must take into account. In general, if you approach the construction process correctly and follow the recommendations indicated in this article, you can avoid any problems associated with shrinkage of a private house.

Your worries are in vain.

Many so-called "specialists" unknowingly spread the myth of the catastrophic consequences for shrinkage repairs. panel house - this is not true.

Panel and monolithic-frame houses shrink slightly when the owners move into their apartments.

The calculation of the foundations of residential buildings (most often piled) is carried out for maximum static and dynamic (horizontal and vertical) loads and is multiplied by the load reliability factor (according to GOST 27751-88 "Reliability of building structures and foundations. Basic provisions for calculation.") This coefficient always greater than one, sometimes reaching 1.5.

The negative consequences of shrinkage are relevant for brick new buildings.

In the apartment you bought in a panel house, small cracks are possible in the corners of the rooms (at the junction of the panels) and thin (hairy) cracks in the horizontal corners on the ceiling - the junction between the wall and the ceiling. There can be no cracks on the wall or ceiling, since each individual wall and ceiling is molded at the factory as a separate monolithic reinforced concrete panel. There are no joints between plates or panels in one plane, therefore there can be no cracks on the walls or ceiling.

For about twenty years I have been living on the first! floor 22 storey building and not even a cracked wallpaper in one corner.

As for your question regarding laying tiles in the bathroom, you can safely tile the walls and not listen to the "unfortunate specialists" who picked up information from the Internet and claim the opposite.

The whole point is that in the bathrooms panel houses cracks cannot appear due to shrinkage of the house or other deformations.

In panel houses, during installation, a unified concrete sanitary cabin with separate or combined bathrooms is installed in each apartment, in the left or right version (in relation to the sewer riser).

Such cabins are molded at the factory in a monolithic reinforced concrete design (walls + ceiling). After the product gains strength in the steaming chamber, it is removed from the mold and a pallet is welded to it from below (to the sanitary cabin), 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 facing walls in such bathrooms, it causes additional difficulties that all the walls are tilted inward (installed, as it were, not on a plumb line). This is due to the specifics of production. In order to pull the finished reinforced concrete sanitary cabin 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 a little thicker.

The ceiling of the sancabin is also in most cases not even, but has the shape of an envelope with a raised center (also due to the dome structure of the formwork form). concrete ceiling in the bathroom, you can paste over with foam tiles, level with plaster, mount a stretch or suspended ceiling.