Helpful information

Ever notice how some freshly washed items get smaller? If this happens, then the material shrank - became shorter. The same can happen with the sewing cuts.

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

· You immediately, without processing the fabric, sew a thing, and it "shrinks" 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 wet-heatso that it takes its final form.

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 fabrics shrink in size

The main reason lies in the specifics of production. During the creation of the fabric, the threads of the future canvas stretch and give them a certain position. Taking water and heat "baths", the material strives 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 strong twisted or somehow squeezed, then they want to "straighten up". And this will happen by shortening the threads of another system.

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

How to deal with shrinkage

To prevent shrinkage, a wet-heat treatment of the fabric is needed. They call her decating ... 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 selected for sewing.

Shrinkage rates for fabric and knitwear

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

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

Knitwear, which is used when sewing outerwear, gives a significant shrinkage - 8-10% on average. More precise values \u200b\u200bfor the loss of length and width can be found in the table below.

Underwear jersey shrinks on average by 8-10% in length and 10-12% in width.

If the type of material and its composition is known, the determination of the degree of fabric shrinkage can be easily carried out using the tables above. To the resulting number, you need to add the length of the cut.

Basic formula for calculations it looks like this:

(D * Y / 100) + D \u003d D 0.

Here D Is the required length of the material for cutting, Have - percentage of shrinkage, D 0 - cut length upon purchase.

Important! To the resulting number you need to add a few more centimeters to the "even" value. After all, the piece that we "add" to the desired length will also "shrink" when decating.

For example, let's say you're going to buy 170 centimeters of cotton velvet. It "sits down" by about 5%. So, we get the following calculation

170 * 5/100 + 170 \u003d 178.5 cm.

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

The main problem here is the anisotropy of wood, or, simply put, 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 wooden house - the phenomenon is inevitable, and this process does not end even several years after the house is delivered, 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 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 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 are determined by the following factors:

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

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

• An ordinary log - up to 10 cm.
• Rounded logs shrink 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. Taking this into account, 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 settling the crowns ends. After that, you can put doors, windows in it, start finishing without the risk of cracks in the wall cladding. Another advantage of winter construction is the assembly price, which is almost 20% lower than the summer one.

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

A 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 the 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 non-profiled timber 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 eliminate 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 frame was done using high-quality wood and special expansion joints.

Screw jack

We have already mentioned the need to install a box, 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 transferred through screw jack... As the beams dry up, they sit down, so the compensator is regularly tightened, reducing its length.

A log house will give less shrinkage, if builders use the so-called "Canadian cup" to connect the crowns. Its main advantage is the special wedge-shaped joint. Due 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 rims and the roof.

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

By gluing individual boards into a single structure, it is possible to minimize not only shrinkage, but also the longitudinal torsion of laminated veneer lumber. However, more cheap technology profiling, 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 wood species 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 start installing the roof. Her weight will become additional factorpositively affecting the tightness 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 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. The 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 is carried out suitable type... 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 water absorption rate;
• 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 the structure.

Not worth saving on building materials for laying out the foundation. 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.

After the completion 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 contracts and shrinks 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 with wood. If the tree is not dried well before construction, then after the shrinkage is completed, the volume of the walls may noticeably decrease, which will subsequently become a huge problem.

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

What is shrinkage at home

House shrinkage is the process of moisture evaporation and drying of the material, as a result of which it shrinks 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 out of the material, the height of the walls, door and window openings may significantly decrease, 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 home shrinkage:

1. Temperature. The material tends to expand or contract due to temperature extremes.
2. "Shrinkage". The material changes its size due to excessive drying or wetting.

House shrinkage time

In the process of shrinking a house, two very important factors should be taken into account: the shrinkage time 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 in which the construction was completed. Ideal option completion of construction by the end of autumn and the beginning of winter. Then you can put the house into operation in 6 months, since the structures will pass the winter frosts and have time to dry out evenly during the spring period. If the construction was completed in the summer, then ideally the house should go through all 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 the weather. If the building or part of it is located in the shade or is constantly wet from rain, then the drying process of the material may take longer.

It is most correct 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, due to which the drying process will accelerate. It is worth noting that with the right approach, the climatic features of a particular building area should be taken into account by specialists or determined using regulatory documents.

Factors Affecting House 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 moisture should also be taken into account. Houses built from freshly cut logs give the maximum shrinkage. In this case, it can reach 8-10%.
2. Material storage conditions. In the event that the material was stored incorrectly 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 house conservation.
5. The scale of the building.
6. Technological type of construction.
7. The literacy of the 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.

Considering 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 possible to find competent builders, store the material correctly, or start construction in an open and well-ventilated area. When building a house of wood, these issues should be taken especially seriously.

How to eliminate shrinkage

There are several enough effective methodshow to reduce shrinkage at home. However, these methods may differ for each material.

Shrinking a house made of wood

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

• Sealing of seams. Cords or tow can act as a sealant.
• Draft all rows of logs with a mallet or vibrator. Thanks to this, the material fits as tightly as possible.
• Proper storage of material. The tree should be dried for some time in a dry and ventilated place.
• Ossyachka structural elements of openings using bars, the thickness of which does not exceed 50 millimeters. The bars are mounted in special grooves, thereby enhancing the design characteristics.
• Use of profiled timber with 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 laminated veneer lumber. Such material will help to reduce and shorten the shrinkage process, but it is very expensive, so it is rarely used.

Shrinkage of a brick house

Brick houses are less prone to shrinkage than wooden houses, but the consequences of this 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.

Expansion joints, which are made in brickwork... Thanks to such seams, the resistance of the structure to temperature changes increases, and the load on structural elements at home. An expansion joint is a cut in the masonry that divides the wall into separate parts. This increases the resilience of the entire building. Such seams must be sealed with special insulating materials.

Reducing shrinkage at home can be right choice bricks. You should choose a brick with low water absorption characteristics. Also, do not forget about the correct storage of the material. If you store a brick outdoors, 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 house

Aerated concrete, although it is good stuff, which has its own advantages, but it is also prone to shrinkage. Moreover, in the process of shrinkage, cracks may appear on the walls. different sizesand this should be taken seriously. Just plaster the cracks like many do non-professional buildersis 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 of aerated concrete house is that the drying process of the material is uneven. The surface dries much faster than the inner part of the material. So outside gas silicate blocks dry out, which is why they shrink, but in the inner part this process does not occur. As a result, the outer parts of the material do not withstand, and cracks appear on them, which begin to grow over time. It is not difficult to guess that there are two ways to reduce the shrinkage of aerated concrete house:

• accelerate the drying of the inside 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 laying. But the main thing here 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 be careful to ensure that all blocks are moistened evenly.

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

Is it possible to avoid the shrinkage of a private house

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

To do 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 bricks shrink differently, and when building from these materials, there are nuances that workers must take into account. In general, if you approach the construction process correctly and follow the recommendations specified in this article, you can avoid any problems associated with the shrinkage of a private house.

Your worries are in vain.

Many so-called "specialists" unknowingly spread the myth of catastrophic consequences for shrinkage repair 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 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 the 22nd 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 in bathrooms panel houses cracks cannot appear due to shrinkage of the house or other deformations.

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

Such cabins are molded at the factory in monolithic reinforced concrete (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 facing walls in such bathrooms, additional difficulties are caused by the fact that all walls are tilted inward (installed as if not along 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 variants, but has the shape of an envelope with a raised center (also due to the domed structure of the formwork). Concrete ceiling in the bathroom, you can paste over with foam tiles, level with plaster, mount a stretch or suspended ceiling.