What to put in the expansion joint between the walls. Expansion joints of buildings

Expansion joints are widely used in many industries. We are talking about high-rise construction, the construction of bridge structures and other industries. They represent a very important object element, while choosing the required type of expansion structure will vary depending on:

values of static and thermohydrometric changes;
the value of a certain load capacity of transport and the required level of travel comfort during operation;
from the conditions of detention.

The purpose of the expansion joint is to reduce the load on individual parts of structures in places of expected deformations that can occur during fluctuations in air temperature, as well as seismic events, unforeseen and uneven sedimentation of the soil and other influences that can cause their own loads, which reduce the bearing properties of structures. In visual terms, this is a cut in the body of the building, it divides the building into several blocks, thereby giving a certain elasticity to the structure. To ensure waterproofing, the incision is filled suitable material. These can be various sealants, waterstops or putties.

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The installation of an expansion joint is the prerogative of experienced builders, so such a responsible matter should be entrusted exclusively to qualified specialists. The construction team must have decent equipment for the competent installation of an expansion joint - the durability of the operation of the entire structure depends on this. It is necessary to provide for all types of work, including assembly, welding, carpentry, reinforcing, geodetic, concrete laying. The technology for installing an expansion joint must comply with the adopted specially developed recommendations.

The maintenance of expansion joints in general does not present any difficulties, however, it provides for periodic inspections. Special control must be carried out in the spring, when pieces of ice, metal, wood, stone and other debris can get into the expansion space - this can interfere with the normal functioning of the seam. In winter, caution should be exercised in the use of snowplows, as their actions can damage the expansion joint. If a malfunction is found, contact the manufacturer immediately.

Since hydraulic structures made of reinforced concrete or concrete (for example, dams, navigable buildings, hydroelectric power plants, bridges) are of considerable size, they undergo force effects of various origins. They depend on many factors, such as the type of foundation, the conditions of production work, and others. Ultimately, temperature shrinkage and sedimentary deformations may occur, which risk leading to the appearance of cracks of various sizes in the body of the structure.

In order to ensure the integrity of the structure to the maximum extent possible, the following measures are applied:

rational cutting of buildings with temporary and permanent seams, depending on the conditions of both geological and climatic
creating and maintaining normal temperature regime during the construction of buildings, as well as during further operation. The problem is solved by using low-shrinkage and low-temperature cement grades, its rational use, pipe cooling, and thermal insulation of concrete surfaces.
increasing the level of homogeneity of concrete, achieving its adequate extensibility, reinforcement strength in places where cracks may occur and axial tension

At what point do the main deformations of concrete structures occur? Why are expansion joints necessary in this case? Changes in the body of the building can occur during the construction period with high thermal stress - a consequence of the exotherm of the hardening concrete and fluctuations in air temperature. In addition, concrete shrinkage occurs at this moment. During the construction period, expansion joints can reduce excessive loads and prevent further changes that could be fatal to the structure. The buildings are, as it were, cut along the length into separate sectional blocks. Expansion joints serve to ensure the high-quality functioning of each section, and also exclude the possibility of forces occurring between adjacent blocks.

Depending on the period of operation, expansion joints are divided into constructive, permanent or temporary (construction). Permanent seams include temperature sections in structures with a rocky base. Temporary shrinkage joints are created in order to reduce temperature and other stresses, thanks to which the structure is cut into separate posts and concreting blocks.

There are a number of types of expansion joints. Traditionally, they are classified according to the nature and nature of the factors causing deformation in structures. Here they are:

Temperature
Sedimentary
anti-seismic
Shrink
Structural
insulating

The most common types are temperature and sedimentary expansion joints. They are used in the vast majority of construction of various structures. Thermal expansion joints compensate for changes in the body of buildings that occur during temperature changes environment. To a greater extent, the ground part of the building is subject to this, therefore, cuts are made from the ground level to the roof, thereby not affecting the fundamental part. This type of joint cuts the building into blocks, thus ensuring the possibility of linear movements without negative (destructive) consequences.

Sedimentary expansion joints compensate for changes due to various uneven loads of the structure on the ground. This is due to differences in the number of floors or a large difference in the mass of ground structures.

The anti-seismic type of expansion joints is provided for the construction of buildings in seismic zones. The device of such sections allows you to divide the building into separate blocks, which are independent objects. This precaution allows you to effectively counteract seismic loads.

Shrink joints are widely used in monolithic construction. As concrete hardens, a decrease in monolithic structures is observed, namely in volume, but at the same time, excessive internal tension is formed in the concrete structure. This type of expansion joint helps to prevent the appearance of cracks in the walls of the structure as a result of exposure to such stress. At the end of the wall shrinkage process, the expansion joint is tightly sealed.

Insulating joints are arranged along columns, walls, around the foundation for equipment in order to protect the floor screed from possible transfer of deformation resulting from the building structure.

Structural joints act like shrink joints, they provide for small horizontal movements, but in no case vertical ones. It would also be nice if the construction seam corresponded to the shrinkage one.

It should be noted that the design of the expansion joint must comply with the plan of the developed project - we are talking about strict compliance with all specified parameters.

Designers of bridge structures, first of all, stand for the excellent versatility of expansion joints and their design, which would make it possible to apply one or another system of joints practically without changes on any type of bridge structures (overall dimensions, schemes, bridge deck, materials for the manufacture of span structures, etc.) .

If we talk about expansion joints installed in road bridges, then the following criteria should be taken into account:

Waterproof
Durability and reliability of operation
The amount of operating costs (it should be minimal)
Small values of the value of reactive forces that are transmitted to the supporting structures
Possibility of uniform distribution of gaps in the gaps of seam elements at wide temperature ranges
Movement of bridge spans in various planes and directions
Noise emission in different directions during the movement of vehicles
Ease and convenience of mounting

In span structures of small and medium-sized bridge structures, expansion joints of filled and closed types are used when moving the ends of span structures, respectively, up to 10-10-20 mm.

By species, the following classification of expansion joints of bridges is obvious:

open type. This type of seam involves an unfilled gap between composite structures.

closed type. In this case, the distance between the mating structures is closed by a roadway - a pavement laid without the necessary gap.

Completed type. In closed seams, the coating is laid, on the contrary, with a gap, because of this, the edges of the gap, as well as the filling itself, are clearly visible from the roadway.

Covered type. In the case of a closed expansion joint, the gap between the connecting structures is blocked by some element at the upper level of the carriageway.

In addition to the specific feature, the expansion joints of bridge structures are divided into groups according to their location in the carriageway:

under the tramway
in the curb
within the pavement
on the sidewalks

This is the standard classification for bridge expansion joints. There are also side, more detailed divisions of the seams, but all of them must be subordinate to the main grouping.

Based on the experience of operating bridges in Western Europe, it is obvious that the service life of a bridge structure (any) is almost one hundred percent dependent on the strength and quality of expansion joints.

What are expansion joints between buildings? Experts classify them according to a number of criteria. This may be the type of structure being served, the location (device), for example, expansion joints in the walls of the building, in the floors, in the roof. In addition, it is worth considering the openness and closeness of their location (indoors and outdoors, in the open air). A lot has already been said about the generally accepted classification (the most important, covering all the most characteristic features of expansion joints). It was adopted on the basis of the deformations with which it is designed to fight. From this point of view, the expansion joint between buildings can be temperature, sedimentary, shrinkage, seismic, insulating. Depending on the current circumstances and conditions, various types of expansion joints are used between buildings. However, you should be aware that all of them must correspond to the initially set parameters.

Even at the design stage of the building, specialists determine the location and size of expansion joints. This happens taking into account all the expected loads that cause deformation of the structure.

When installing an expansion joint, it must be understood that it is not just a cut to the floor, wall or roof. With all this, it must be correctly designed from a constructive point of view. This requirement is due to the fact that during the operation of structures, expansion joints take on enormous loads. If there is an excess of the bearing capacity of the seam, there is a risk of cracks. This, by the way, is a fairly well-known phenomenon, and special profiles made of metal can prevent it. Their purpose is expansion joints - profiles seal them, provide structural reinforcement.

The seam between the buildings serves as a kind of connection between two structures that are close to each other, but at the same time have different foundations. As a result, the difference in the weight load of the structures can be negatively affected, and both structures can give undesirable cracks. To avoid this, a rigid connection with reinforcement is used. In this case, it is necessary to make sure that both foundations are already properly settled and are sufficiently resistant to the upcoming loads. The device of the expansion joint is carried out in strict accordance with the generally accepted rules of action.

Expansion joint between walls

As you know, the walls are the most important element in the structure of the structure. They perform a load-bearing function, taking on all the falling loads. This is the weight of the roof, floor slabs, and other elements. From this it follows that the reliability and durability of the building largely depends on the strength of the expansion joint between the walls. Moreover, the comfortable operation of the interior also depends on the walls (bearing structures) that perform the important function of protecting from the outside world.

You should be aware that the thicker the material of the walls, the higher the requirements are placed on the expansion joints arranged in them. Despite the fact that outwardly the walls appear to be monolithic, in fact they have to undergo various kinds of loads. The causes of deformation can be:

air temperature fluctuations
the soil under the structure may settle unevenly
vibration and seismic loads and much more

If cracks form in load-bearing walls, then this can threaten the integrity of the entire building as a whole. Based on the foregoing, expansion joints are the only way to prevent changes in the body of structures that could become fatal.

In order for the functioning of the expansion joint in the walls to be correct, it is necessary, first of all, to correctly perform design work. Thus, the calculation of actions must be carried out at the design stage of the building.

The main criterion for the successful operation of an expansion joint can be called the correctly calculated number of compartments into which it is planned to cut the building to successfully compensate for stresses. According to the established quantity, the distance that must be taken into account between the seams is also determined.

As a rule, in walls with a load-bearing function, expansion joints have an interval of approximately 20 meters. If we are talking about partitions, then a distance of 30 meters is allowed. At the same time, builders are required to take into account the areas of concentration of internal stresses. The distance is determined by the type of expected expansion joints, which in turn depend on the factors that cause changes in the body of the structure.

In addition, at the initial moment of designing in the walls of structures, the width of the cut for expansion joints is taken into account with special care. This parameter is of great functional importance, as it determines the magnitude of the expected transverse spacing of the structural elements of the building. You should also think about ways to seal expansion joints in advance.

Expansion joints in industrial buildings

The length of industrial structures, as a rule, is almost always greater than civil buildings, so the device in such seams acquires great importance. In industrial buildings, specialists provide expansion joints according to their purpose. They can be anti-seismic, sedimentary and even temperature.

Expansion joints in frame buildings cut the building into separate blocks, as well as all structures based on it. In industrial buildings of mass construction, as a rule, expansion joints are arranged, which in turn are divided into longitudinal and transverse. The distance between the seams in industrial buildings is assigned according to the constructive solution of the building, as well as the climatic conditions of construction, the value of the air temperature inside the room. If we are talking about reinforced concrete one-story structures of industrial buildings, then the gap between the seams is allowed without calculating the rise of 20%.

Transverse expansion joints on one-story industrial buildings are made on paired columns without taking into account the insert. In multi-storey buildings - with or without an insert and also on paired columns. It is worth noting that seams without an insert are more technologically advanced, since they do not need additional enclosing elements. To date, expansion joints are made in the form of an elastic arch from mineral wool boards of medium hardness. They are crimped with galvanized roofing steel - cylindrical aprons. In the place of the expansion joint, the carpet is reinforced with several layers of fiberglass.

Temperature longitudinal seams in buildings on one floor are arranged on 2 rows of columns with an insert, its width, depending on the binding in adjacent spans, is considered from 500 to 1000 mm. If the longitudinal expansion joint is combined with different indicators of the heights of adjacent spans, therefore, other dimensions of the inserts are taken. The same conditions are observed in places where perpendicular spans are mutually adjacent to each other.

If we are talking about industrial buildings with a constructed reinforced concrete skeleton without special overhead cranes, it is possible to arrange expansion longitudinal seams on such columns as single ones. Such a seam is easy to install, thereby allowing you to ignore the additional elements in the walls and coatings, as well as paired columns or truss structures. The same can be said for industrial buildings without cranes with a mixed or metal frame.

During the construction and design of structures for various purposes, an expansion joint is used, which is necessary to strengthen the entire structure. The task of the seam is the safety of the structure from seismic, sedimentary and mechanical influences. This procedure serves as an additional strengthening of the house, protects against destruction, shrinkage and possible shifts and distortions on the soil.

Definition of an expansion joint and its types

Expansion joint- a section on the structure, which reduces the load on parts of the structure, which increases the stability of the building and the level of its resistance to loads.

It makes sense to use this stage of construction when designing large premises, placing a building in places of weak soil, active seismic phenomena. The seam is also made in areas with high rainfall.

Based on the purpose, expansion joints are divided into:

temperature;
shrinkage;
sedimentary;
seismic.

In some buildings, due to the peculiarities of their location, combinations of methods are used to protect against several causes of deformation at once. This can be caused when the terrain on which the construction is being built has soil that is prone to subsidence. It is also recommended to make several types of seams when erecting extended tall houses, with many different designs and elements.

Temperature joints

These construction methods serve as protection against temperature changes and fluctuations. Even in cities located in areas with temperate climate during the transition from high summer temperatures to low winter temperatures, cracks of various sizes and depths often appear on houses. Subsequently, they lead to deformation not only of the box of the structure, but also of the base. To avoid these problems, the building is divided by seams, at a distance which is determined based on the material from which the structure was erected. It also takes into account the maximum low temperature characteristic of this area.

Such seams are used only on the wall surface, since the foundation, due to its location in the ground, is less susceptible to temperature changes.

Shrink seams

They are used less often than others, mainly when creating a monolithic concrete frame. The fact is that concrete during hardening is often covered with cracks, which subsequently grow and create cavities. In the presence of a large number of cracks in the foundation, the building structure may not withstand and collapse.
The seam is applied only until the foundation has completely hardened. The meaning of its use is that it grows until all the concrete becomes solid. In this way, concrete foundation completely shrinks, without being covered with cracks.

After the final drying of the concrete, the cut must be completely minted.

To ensure that the seam is completely sealed and does not let moisture through, special sealants and waterstops are used.

Sedimentary expansion joints

Such structures are used in the construction and design of structures of different heights. So, for example, when building a house, in which there will be two floors on one side and three on the other. In this case, that part of the building with three floors exerts much more pressure on the soil than the one with only two. Due to uneven pressure, the soil can sag, thereby causing strong pressure on the foundation and walls.

From the change in pressure, the various surfaces of the structure are covered with a network of cracks and subsequently subjected to destruction. In order to prevent deformation of structural elements, builders use a sedimentary expansion joint.

Strengthening divides not only the walls, but also the foundation, thereby protecting the house from destruction. It has a vertical shape and is located from the roof to the base of the structure. Creates a fixation of all parts of the structure, protects the house from destruction, deformation of varying severity.

Upon completion of the work, it is necessary to seal the recess itself and its edges to fully protect the structure from moisture and dust. For this, ordinary sealants are used, which can be found in hardware stores. Work with materials is carried out according to general rules and recommendations. An important condition for arranging the seam is its complete filling with material so that there are no voids inside.
On the surface of the walls, they are made of tongue and groove, with a thickness of about half a brick; in the lower part, the seam is made without a shunt.

In order to prevent moisture from getting inside the building, a clay castle. Thus, the seam not only protects against the destruction of the structure, but also turns out to be an additional sealant. The house is protected from groundwater.

This type of seams must be arranged at the points of contact of various sections of the building, in such cases:

if parts of the building are placed on soil of different flowability;
in the event that others are added to an existing structure, even if they are made of identical materials;
with a significant difference in the height of individual parts of the building, which exceeds 10 meters;
in any other cases where there is reason to expect uneven subsidence of the foundation.

seismic seams

Such structures are also called anti-seismic. It is necessary to create this kind of fortification in areas with an increased seismic nature - the presence of earthquakes, tsunamis, landslides, volcanic eruptions. So that the building does not suffer from bad weather, it is customary to build such fortifications. The design is designed to protect the house from destruction during earth tremors.
Seismic seams are designed according to their own scheme. The meaning of the design is the creation of separate non-communicating vessels inside the building, which will be separated along the perimeter by expansion joints. Often inside the building, expansion joints are arranged in the form of a cube with equal sides. The faces of the cube are sealed with a double brickwork. The design is designed for the fact that at the time of seismic activity, the seams will hold the structure without allowing the walls to collapse.

The use of various types of seams in construction

With temperature fluctuations, structures made of reinforced concrete are subject to deformation - they can change their shape, size and density. When concrete shrinks, the structure shortens and sags over time. Since subsidence occurs unevenly, when the height of one part of the structure decreases, the others begin to shift, thereby destroying each other or forming cracks and depressions.

Nowadays, each reinforced concrete structure is an integral indivisible system, which is highly susceptible to changes in the environment. So, for example, during the settlement of the soil, sharp fluctuations in temperature, sedimentary deformations, mutual additional pressure arises between the parts of the structure. Constant changes in pressure lead to the formation of various defects on the surface of the structure - punctures, cracks, dents. To avoid the formation of defects in the building, the builders use several types of cuts, which are designed to strengthen the building and protect it from various destructive factors.

In order to reduce the pressure between the elements in multi-storey or extended buildings, it is necessary to use sedimentary and temperature-shrinkage types of seams.

In order to determine the required distance between the seams on the surface of the structure, the level of moisture content of the material of the columns and connections is taken into account. The only case when there is no need to install expansion joints is the presence of rolling supports.
Also, the distance between the seams often depends on the difference between the highest and lowest ambient temperatures. The lower the temperature, the farther apart the recesses should be. Thermal shrinkage joints permeate the structure from the roof to the base of the foundation. While sedimentary isolate different parts of the building.
A shrinkage joint is sometimes formed by installing several pairs of columns.
The temperature-shrinkage joint is usually formed by arranging paired columns on a common foundation. Sedimentary seams are also designed by installing several pairs of supports that are opposite each other. In this case, each of the support columns must be equipped with its own foundation and fasteners.

The design of each seam is designed to be clearly structured, securely fix the elements of the structure, be reliably sealed from Wastewater. The seam must be resistant to temperature extremes, the presence of precipitation, resist deformation from wear, shock, mechanical stress.

Seams must be made in case of uneven ground, uneven height of the walls.

The expansion joints are insulated with mineral wool or polyethylene foam. This is due to the need to protect the premises from cold temperatures, the penetration of dirt from the street, and additional sound insulation is provided. Other types of heaters are also used. From the inside of the room, each seam is sealed with elastic materials, and from the side of the street - with sealants that can protect against atmospheric precipitation or flashings. The cladding material does not cover the expansion joint. At interior decoration the seam is covered with decorative elements at the discretion of the builder.

Any structures and structures are subject to deformation for various reasons: building settlement after construction during operation, temperature and seismic effects, soil heterogeneity at the base of structures. Undoubtedly, in the design and construction it is necessary to take into account all these factors and make the facility as safe as possible for people, as well as minimize the possibility of damage and the risk of frequent repairs. Because in modern world Increasingly, large and massive structures are being built, both residential and commercial, industrial, it is impossible to do without the use of expansion joints in all structural elements of buildings.

Definition, purpose of expansion joints

In order to reduce stress in structures due to deformation and shrinkage of elements of buildings, bridges, roads and other structures, expansion joints are arranged in them. These are elements that divide the entire structure into separate blocks, which allows them to move freely in certain directions. This phenomenon significantly reduces the risk of destruction of structures in places of possible deformation. Sections separated by such seams settle evenly within their volume, without interfering with the integrity of neighboring blocks.

Types of expansion joints

There are many classifications of expansion joints.

Types of expansion joints according to the nature of the load, due to which deformation occurs:

Sedimentary. These deformations occur due to uneven compaction of soils under different parts of the building. This can happen for several reasons. First, changes are affected by uneven weight distribution. In modern architecture, houses are often built with different heights, with many design features in parts of the building. Secondly, the reason may be the heterogeneity of soils under individual parts of a structure or house. Homogeneous soil under the entire base is considered an ideal case, which is extremely rare. With a significant difference in the values of the settlement of individual elements, vertical deformations can occur in the form of fractures, shears, cracks, and displacements. Settlement-type expansion joints are calculated for each case separately and arranged vertically along the entire height of the building from the foundation. They are designed to compensate for the difference between the settlement of individual structural blocks.
Shrink. Such deformations are caused by a decrease in the volume of structures and elements. All concrete monolithic parts and masonry are subject to this phenomenon: when solidifying and hardening, the mixture loses moisture. This aspect is also calculated, and the structure is divided into certain parts to avoid cracks, breaks, etc.
Temperature. It is especially important to take into account this type of deformation in areas with climate change: summer-winter. At different times of the year, the structures of the outer parts are exposed to temperatures, which affects their volume. Especially in winter, when the wall with inside indoors and outdoors has a significant temperature difference. Despite the fact that its inner part has a constant temperature, and the outer part undergoes great changes, inside the structure, internal stress that can reach the limit and lead to irreversible consequences. To solve this problem, temperature seams are arranged. Often they coincide with shrinkage. Unlike sedimentary joints, expansion joints are necessary only in the ground part of buildings, since the foundation does not experience large temperature fluctuations if it is calculated and arranged correctly.
Seismic loads occur in areas with frequent earthquakes and ground vibrations. In these cases, the buildings are specially divided into separate independent blocks, separated by special seismic expansion joints, which have a special structure, which makes it possible to maintain the integrity of structures during seismic activity.

In addition, expansion joints in buildings are classified according to the type of structure in which they are arranged. Allocate seams located:

in the walls;
in foundations;
in concrete floors;
in monolithic slabs.

The expansion joint in each element has a separate structure. Thus, the features of changes in forms and loads for each section and direction are taken into account. This classification can additionally include an expansion joint between buildings. For example, in urban space, you can often find interconnected residential buildings and shops. They, as a rule, have different architectural features, volumes and sizes, materials of construction, but they are united by one common wall. So that these objects do not affect each other's changes, compensating seams are also arranged between them.

Design: the main nuances

When designing buildings, all possible loads that will affect structural elements are taken into account, and, depending on this, expansion joints are distributed in such a way that they compensate for all destructive effects directed to each element.

The device of expansion joints is diverse. They are produced at the construction site from special materials or from the increasingly popular finished metal profiles. The design of a metal expansion joint includes special rolled products and (if necessary) inserts made of various materials, selected depending on the place of application. For each element of the building, the guides have a different structure and are prepared from dissimilar materials, since they perform different functions.

At the design stage, not only the location of compensating cuts, their frequency, size and composition are calculated. Often, for individual places, a different expansion joint is determined. The node, which reflects the principle of adjoining structures, must be drawn and painted in detail so that there are no difficulties with its assembly at the construction site. In each case, the composition and type of the seam can be individual, since different parts of the structures experience certain loads, which are not always the same. Such situations can arise at the interfaces of blocks of different heights, destinations, weights, etc.

Expansion joint in different building elements

For all designs, the device of compensating gaps is individual, they have their own technical solution, composition, dimensions and features. Each material and design has its own expansion joint. SNiP 2.03.04-84 gives an example of calculations for the most common reinforced concrete structures in various conditions, SNiP 2.01.09-91 talks about calculations in subsiding soils and undermined territories.

Seams in foundations: purpose

The foundation is one of the most complex and critical parts of any structure in the construction. The safe functioning and reliability of the structure depend on its integrity. Therefore, in its design, everything should be thought out to the smallest detail - from the right constructive solution to correctly arranged expansion joints. The foundation experiences several types of destructive loads at once: from shrinkage and seasonal movement of the soil; uneven subsidence of different parts of the building. The outer perimeter may be subject to temperature changes (in rare cases, it is more often referred to the upper part of the foundation wall, which passes into the basement). The expansion joint in the foundations must compensate for all incoming influences and give it elasticity and mobility. In addition, it must have high-quality external waterproofing, which will prevent the penetration of moisture into the body of the seam to avoid destruction of its very foundation.

Device Features

The expansion joint in the foundations is arranged along the entire height of its walls from the sole of the base. The distance between the seams is determined by calculation and depends on the magnitude of the influencing loads, the type of soil, the material for the walls, functional purpose premises, etc. For brick buildings, the step is from 15 to 30 m, for wooden buildings - up to 70 m. In addition, compensating gaps should also be present at the boundaries of parts of the building that have different technical purposes, since the greatest stress occurs there.

The expansion joint in the foundation slab is a gap that separates it into separate blocks. It is filled with tow impregnated with resin.

One of the components of the foundation is the blind area. It also needs compensating gaps, because if it is unevenly subsided and the movement of soils, this element can simply break, which will lead to the wetting of the base walls. The blind area will cease to fulfill its protective function. Seams are arranged in increments of up to 2 meters, wooden slats are laid in them and poured on top with hot bitumen or other polymer that provides reliable waterproofing.

The junction of the blind area and the foundation wall necessarily has a movable seam. Usually its role is played by a waterproofing finish. outer wall grounds.

Expansion joints in the wall

Vertical structures are exposed to several deformation loads at once. They are affected by precipitation during operation, temperature effects (seasonal and with a simultaneous temperature difference between the outer and inner parts in cold weather), the load from the top cover, and snow masses. Therefore, when calculating the expansion joint in the wall during design, it is important to take into account all the effects and arrange divisions that will not allow the structure to collapse.

In modern construction, a wide variety of materials and methods are used for the construction of walls, which are:

prefabricated block and brick;
monolithic concrete / reinforced concrete;
prefabricated panel;
combined.

In all of them, destructive effects occur, and the stronger and harder the material, the greater the deformation loads appear in the structure. The division of the wall into blocks using expansion joints allows individual parts to deform at certain intervals without the threat of destruction of the entire element, inside which no dangerous stress occurs.

Design and installation of expansion joints in vertical structures

For internal and external walls, the gap spacing is calculated differently; this is done at the design stage. The height of the walls is divided into compartments along the entire height, arranging expansion joints between them. The distance between them for load-bearing walls after calculations is from 20 m, for internal partitions - up to 30 m. The location of expansion joints in places of maximum stress allows you to remove these very stresses. As mentioned earlier, temperature and shrinkage joints occur in the above-ground part of the house and basically coincide, are located in places of the greatest concentration of temperature differences - at the corners of the outer walls. Expansion joints that compensate for sedimentary effects are arranged along the entire height of the wall to the base of the foundation and are evenly distributed along the length of the building.

An important nuance in the design of joints in the walls is their filling and design, since they are located on the visible parts of any building, especially if additional cladding is not implied.

Temperature expansion joints are arranged in the horizontal plane of the wall. In the process of erection, a tongue is placed in the masonry, which is covered with roofing paper in 2 layers and clogged with tow. Close the seam with a clay lock. These materials do not react to temperature changes, thereby compensating for the deformation of the wall. With manual laying, the seal is invisible and does not require additional cladding.

In modern construction, profiles for expansion joints are increasingly being used. The advantage of using them is a special design that reinforces the gap in the wall. This prevents the appearance of cracks in the area of the expansion joint in the process of exposure to destructive loads. In addition, there are inserts made of hydrophobic materials in the body of the profile, which prevents moisture from entering the wall material and further destruction. The design of the outer part of the expansion joint is made in such a way that it fits perfectly into any facade. A wide range of offered profiles allows you to choose the most suitable design for any building.

Seams in horizontal slabs

When installing monolithic floor slabs, expansion joints must be made, since concrete is a rigid inelastic material and is subject to destruction as a result of various loads and simultaneous subsidence of the entire volume of the building. With the help of calculations, the width of one floor block is determined, and according to this parameter, interfloor elements are poured. Seams are filled with waterproofing materials and seals.

Seams in concrete floors

Floors constantly take the load from interior items, equipment, and their coatings are constantly subject to wear. In one room, floors from different materials, which during operation do not seem to react to the incoming load, humidity and other influences. Such areas also need to be divided, like a monolithic concrete floor.

By appointment, expansion joints in concrete floors are divided into 3 main types.

The insulating joint has a round or square shape, separates the floor from walls, columns and other internal vertical structures, from their impact in order to avoid deformation of the floor covering. When it is constructed, the entire perimeter is laid with polymer insulation and a concrete floor is poured inside the resulting contour.
The shrinkage joint is designed to prevent cracking of concrete during hardening and operation. It is arranged in two ways: with the help of slats that form seams, which are inserted into the material until it loses plasticity; cutting and device after final surface treatment.
The structural seam is performed at the boundaries of the shifts in the pouring of the floor sections. It has a complex type of tongue-and-groove connection and allows concrete to move in a horizontal plane and does not allow changes in adjacent sections.

Expansion joints in floors are gaps that divide the surface into several blocks or sections. In the vast majority, various profile structures are used for the construction of expansion joints.

The main types of profiles for the device of joints in the floors are as follows.

Embedded - aluminum systems built into the plane of the floor covering. They are used in dry industrial premises with high traffic, regularly exposed to heavy equipment, machinery and special equipment. The profile can be reinforced with a rubber insert, it can have a decorative stainless steel overlay.
Overhead. These systems are installed at the junction of different coatings. They are a seam. Such profiles also withstand heavy loads from technology and a large number of people. With increased load, the profile can be reinforced with polymer inserts.
Waterproof profile systems are designed not only to compensate for deformation loads, but also to protect the floor cut from moisture and water ingress in rooms with little waterproofing or on open areas, parking lots, warehouses, etc. Such profiles are made of stainless steel, have special PVC or rubber gaskets in their design.
Dividing systems are soft or hard PVC profiles. They are arranged as expansion and expansion joints in monolithic floors for various purposes. PVC profiles seal and protect floor joints, they are resistant to temperatures, acids and detergents, which makes them universally applicable. Expansion joints in concrete floors are sometimes filled with polymer mastics. PVC systems are the most functional and durable, so they should be preferred.

Technology for dividing joints in floors

Concrete floors are poured not at once the entire area, but in parts, in several stages. Separation joints must be arranged at the junctions of different sections of the pour, since the concrete may have different properties. Often, before pouring, the perimeter of the site is limited with insulating materials, which will later serve as a seal for the joints formed. If the pouring area is large, then the seams can be cut already in the finished floors. The size of the gaps and the distance between them is calculated based on the size of the coefficient of linear expansion of concrete. The average width of the seam is 12-20 mm, the distance between the cuts is 1.5 m. The depth reaches 2-3 cm. Separation is carried out using special equipment. The seams cut on the finished floor are filled with special seals and sealed with wear-resistant polymers or specialized profiles are built into them.

Seams at the joints of buildings

Often, additional buildings are added to existing buildings: in view of saving space within the city or ease of use in private. Attachments may have various purpose: retail space, office space, saunas, garages, outbuildings. Almost always, the settlement of the main and additional buildings occurs in different ways. To avoid the troubles associated with this phenomenon, it is necessary to arrange an expansion joint between buildings.

Gaps between buildings compensate for all types of impacts: sedimentary, shrinkage, temperature, seismic. Since the main and attached buildings have one common wall, an expansion joint is organized in it, which combines the function of protection against all incoming loads.

Also, a gasket between the walls is needed when the material is heterogeneous: for example, the original structure is stone, and the additional one is wooden. In this case, the seam can be made of waterproofing material without additional structures.

If the foundation for the extension was not calculated immediately, but is being built additionally, it is imperative to separate it from the main one with a seam, because its design may differ. In this case, shrinkage and sedimentation of the base itself and the supported structure will occur.

An expansion joint is arranged along the entire height of the adjoining building.

I am making an extension to an existing house, how to solve the problem of an expansion joint and in general how to do it right?

Perhaps there is no problem. An expansion joint is arranged in cases where uneven shrinkage of the building is likely. This can happen due to the very large dimensions of the structure, a significant difference in the heights of individual sections of the house, the possibility of subsidence of foundations and soils.

At the junction of obviously uneven parts of the building (in this case, an extension of the porch), an expansion joint is needed. It can be laid not only with rigid mineral wool, but also with foam plastic, other elastic material

If you are not building in a seismic area, your house is stone or frame, no higher than two floors and has a reasonable size, it is really possible to do without a seam. It is enough to build a solid foundation under the extension. Structurally, it should be identical to the existing part, laid to the same depth. If the foundation is tape, it is important to compact the base well under its pillow, sprinkle the bottom of the trench with crushed stone, and carefully compact it. The old and new parts should be connected to each other by hammering reinforcing "ruffs" into the concrete, having previously drilled holes for them.

Various options for adjoining the extension foundation and its rigid connection with the existing one

The walls of both parts of the building must also be connected to each other.

Compromise option. There is a seam in the masonry filled with building sealant, but the walls are rigidly connected with steel brushes. This solution is suitable for the case when the main part of the building and the extension have the same type of stone walls and foundations.

If there is no confidence in the bearing capacity of the soil, or the extension is log and will shrink, an expansion joint will have to be done. You did not indicate any features of the construction of the house (the material of the walls of the main part of the house and the extension), nor the nature of the junction (flat plane, corner). The design of the seam depends on the specific situation, there can be a lot of options. Without the necessary information, we can only give general recommendations:

If there is a possibility of significant shrinkage of the extension relative to the house, the best solution would be to install not three, but four walls, including the one adjacent to the existing one. The foundation and walls of the extension will have a closed contour, which will exclude horizontal deformations, in the second illustration this is option D.
The thickness of the expansion joint in our case is 10-25 mm, it can be filled with rigid mineral wool, foam plastic, foamed polyethylene.
The roof of the extension must also be completely separated from the old part of the building. The junction can be closed with an apron, fixing it on the wall.

The junction of the walls of the old and new parts of the house, located in the same plane, should be closed with an overlay ( wooden plank, metal bar), which should be fixed to the existing wall.

Expansion joint option for stone walls. The joint is laid with an elastic filler, in this case inside with a heater, outside with a special tubular elastic bundle. A steel plate, sealed on both sides, hides the joint and protects it from water penetration.

If you are attaching a three-walled wooden log house, the joint should be made with a straight key cut or on the casing: a bar (thorn) should be located on the existing wall, a groove is selected in the attached wall. The annex, losing moisture, will settle along the guide, which prevents the logs from torsion. Nails, staples are not used, the seam is filled with traditional insulation: moss, tow, jute. Outside, a board-overlay is installed.