Proper insulation home and expansion joints in particular, the opportunity in our difficult times to save on heating by 2-4 times. Heating is an expensive pleasure and we have to save money by looking for more and more new opportunities.
Today, many have already begun this urgent work, but how to do it correctly? Let's go in order?!
What is an expansion joint?
There is a problem
Insulation of expansion joints is one of the most difficult areas when insulating multi-storey buildings. residential buildings: the installer has practically no opportunity to reach the walls from the outside (the gap does not allow), and the methods invented earlier are not economically feasible today.
Many people make a common mistake: they insulate the walls in contact with the expansion joint from the inside. This is absolutely impossible to do, because the dew point moves closer to the inner edge of the walls, which leads to them getting wet and moldy. But we breathe all this!!!
Why insulate it?
There are often complaints from people that cold penetrates into this gap between buildings and the walls inside industrial and residential buildings are cold.
The hard-to-reach expansion joint in winter, when exposed to low temperatures and blowing winds, is not protected in any way, and therefore precious heat is lost, and the cost of heating the room increases.
Is this work necessary? You judge and decide.
- Energy savings of about 30% during the heating season.
- The sound insulation of the building is improved.
- Increasing indoor temperatures.
- Eliminate conditions for the appearance of dampness and mold.
Our company offers new approach to solving this problem.
We offer insulation of expansion joints using polyurethane foam (PPU)
Polyurethane foam (PPU)- strong, lightweight and durable thermal insulation material. PU foam does not shrink and can expand and contract depending on climatic conditions, which means it will last longer and retain its immediate function.
Manufacturing takes place directly at the construction site, when the two components, when mixed in compliance with the required proportions, enter into chemical reaction, are sprayed onto the surface, within 3..5 s they foam 30 - 150 times and harden. It has high density, which means it will become a reliable protector from dampness, even if there is damage to the walls. Low thermal conductivity, high noise insulating properties .
Technology for insulating expansion joints
Before work begins, a team of professional installers closes protective film walls to avoid contamination. Installers, using special equipment, rise to the required height.
Next, work begins directly on insulating the thermal seam. The main advantage of thermal insulation using polyurethane foam is the ability to seal the expansion joint only around the perimeter, without completely filling it. This approach creates a closed air space inside the seam and protects it from drafts, preserving warm air inside.
Technologically, it looks like this: Layer by layer, two layers are deposited opposite walls expansion joint, until the gap between the layers becomes 5-10 cm. Next, spraying is done again, this time from above, pulling the gap completely from beginning to end. At the end of the work, the expansion joint itself is covered with a corrugated galvanized sheet. The effectiveness of this technology is that it is seamless, completely solves the problem, and is low-cost.
The best solution to the problem
Today, everyone understands that saving is a necessity. It is not known how much and how quickly tariffs for housing and communal services will increase in the future, you will finally stop overpaying every month, you will be able to live in comfort and warmth, and most importantly, you will get rid of the problem “ cold wall" Once and for all. We found the optimal, and most importantly economic profitable solution problems of insulation of expansion joints of a building.
To insulate expansion joints you will need the help of our specialists who will do accurate calculations cost and effect of insulation, they will carry out the necessary work efficiently and on time.
Deal with this issue in advance, in summer period, since the technology is used only at air temperatures above 15 C.
Expansion joint- this is a seam with a width of at least 20 mm, dividing the building into separate compartments. Thanks to this dissection, each compartment of the building receives the possibility of independent deformations.
The purpose of the expansion joint is to reduce the overload on individual parts of the systems in places of expected destruction, which can occur due to fluctuations in the weightless temperature, as well as seismic phenomena, sudden and uneven sedimentation of the soil and other actions that can cause personal overloads that reduce the load-bearing characteristics of the systems . In visual terms, there is probably a section in the body of the building; it divides the building into a number of blocks, giving these some elasticity to the building. To supply waterproofing, the section is filled with the material that was used. Probably have every chance to exist different sealants, waterstops or putty.
Expansion joints are divided into three main types
Depending on the purpose, expansion joints are divided into three main types: – temperature-shrinkage joints are installed to avoid the formation of cracks and distortions in the external walls of buildings due to differences in air temperatures outside and inside the building. Seams of this type cut the structures only of the ground part of the building - walls, floors, coverings and ensure the independence of their horizontal movements relative to each other. In this case, foundations and other underground parts of the building are not dissected, since temperature differences for them are smaller and deformations do not reach dangerous values.
The expansion joint machine is the privilege of the most experienced builders, therefore this serious craft should be entrusted only to competent specialists. The construction team must have high-quality equipment for the installation of an expansion joint, which depends on the survivability of the operation of the entire system. It is necessary to predict the future of work without fail, including assembly, welding, carpentry, reinforcement, trigonometry, and concrete laying. The development of an expansion joint assembly must comply with generally accepted and deliberately researched recommendations.
Expansion joint - Wikipedia: Expansion joint - designed to reduce loads on structural elements in places of possible deformations that occur when air temperature fluctuates, seismic phenomena, uneven soil settlement and other influences that can cause dangerous self-loads that reduce the load-bearing capacity of structures. It is a kind of cut in the structure of a building, dividing the structure into separate blocks and, thereby, giving the structure a certain degree of elasticity. For sealing purposes, it is filled with elastic insulating material.
Distances between temperature-shrinkable seams
The distances between temperature-shrinkage joints are assigned depending on the climatic conditions of the construction site and the material of the external walls of the building. For example, in residential buildings this distance is 40? 100 m at brick walls and 75? 150 m with walls made of concrete panels(the lower the outside air temperature at the site of construction of the building, the smaller the distance assigned between expansion joints). The building compartment located between two temperature-shrinkable seams or between the end of the building and the seam is called a temperature compartment or temperature block;Rational cutting
In what particular episode do the main destructions of concrete buildings occur? What are expansion joints needed in this case? Changes in the body of a building are likely to occur at the time of construction due to high temperature stress - a consequence of the exotherm of hardening concrete and fluctuations in temperature. This is due to the reduction of concrete in this episode. At the moment of reinforced concrete, expansion joints are ready to reduce unnecessary overloads and prevent subsequent changes that can become inevitable for buildings. The structures, as if by desire, are cut according to their length into individual collapsible installations. Expansion joints They work to ensure high-quality functioning of each section, and also eliminate the possibility of stress occurring between adjacent blocks.
The more popular types are temperature and sedimentary expansion joints. They are used in most constructions different buildings. Temperature expansion joints will compensate for changes in the building body that appear due to changes in temperature around the circle. The manure fraction of the structure is subjected to this to a great extent, so cuts are made from the soil to the roof, thus not affecting the solid fraction in any way. This type of seam cuts the structure into installations, providing such a role, providing the possibility of rectilinear movements in the absence of negative (uncontrollable) results.
Does one or the other visit expansion joints between houses? Experts systematize them according to a line of indicators. Probably it is possible to exist the type of system being serviced, the location space (of the device), for example, expansion joints in the walls of the structure, in the floors, in the roof. In addition to this, it is necessary to take into account the sociability and security of their location (inside the building and outside, in an open atmosphere). A lot has already been said about the generally accepted systematization (more fundamental, covering the most distinctive symptoms of expansion joints). Sympathy begins in the base of the distortions with which it is called to fight. From this point of view, the deformation stitch between houses can be thermal, silt, heat-shrinkable, earthen, insulating. In connection with current events and criteria between houses, different future expansion joints are used. But you must know that they must always meet the characteristics given at the beginning.
Sedimentary seams
– settlement joints are provided in cases where unequal and uneven settlement of adjacent parts of the building is expected. Such settlement can occur due to elevation changes individual parts buildings more than 10 m, with different loads on the foundation, as well as with heterogeneous soils under the foundations. 
Rice. 3.67. Schemes for installing expansion joints in buildings: a – temperature-shrinkage; b – sedimentary: 1 – aboveground part building; 2 – underground part (foundation); 3 – expansion joint Sedimentary joints dissect vertically all structures of the building, including its underground part. This allows for independent settlement of individual volumes of the building. Settlement seams provide not only vertical, but also horizontal movements of dismembered parts, so they can be combined with temperature-shrinkage seams. This type of expansion joints is called temperature-sedimentary; – anti-seismic joints are provided in buildings located in earthquake-prone areas. The anti-seismic seam, like the sedimentary seam, divides the building along its entire height (above-ground and underground parts) into separate compartments, which are independent stable volumes, which ensures their independent settlement.
| seam 1 | seam 2 | seam 3 |
| 44% concrete | 27% concrete | 56% concrete |
| structure 18 | structure 134 | structure 1903 |
All kinds of systems and buildings are subject to destruction according to various factors: sedimentation of the structure after construction during operation, temperature and seismic effects, heterogeneity of soils at the base of the systems. Of course, during design and construction, it is necessary to take into account all these reasons and make the item very harmless to people, and also reduce the likelihood of defects and the risk of frequent repairs. Since in modern world More and more often, huge and powerful buildings are being built, both residential and commercial, industrial; it is impossible to build without the introduction of expansion joints in all the important details of the buildings.
Expansion joints are widely used in many industrial areas. We are talking about high-rise construction, construction of bridge structures and other industries. They represent a very important object element, and choosing the required type of dilatation structure will vary depending on:
- the magnitude of static and thermohydrometric changes;
- the magnitude of a certain transport load 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 due to fluctuations in air temperature, as well as seismic phenomena, unexpected and uneven sedimentation of the soil and other influences that can cause their own loads that reduce the load-bearing properties of structures. In visual terms, this is a cut in the body of the building; it divides the building into several blocks, giving these a certain elasticity to the structure. To ensure waterproofing, the cut is filled with suitable material. It can be various sealants, waterstops or putty.
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Installation of an expansion joint is a prerogative experienced builders Therefore, such a responsible task should be entrusted exclusively to qualified specialists. Construction crew must have adequate equipment for proper installation of the expansion joint - the longevity of the entire structure depends on this. It is necessary to provide for all types of work, including installation, welding, carpentry, reinforcing, geodetic, and concrete laying. The technology for installing an expansion joint must comply with accepted specially developed recommendations.
The maintenance of expansion joints in general does not present any difficulties, but requires 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 dilatation space - this can serve as an obstacle to the normal functioning of the seam. IN winter period Care should be taken when using snow removal equipment, since its actions can damage the expansion joint. If a malfunction is detected, contact the manufacturer immediately.
Since hydraulic structures made of reinforced concrete or concrete (for example, dams, shipping buildings, hydroelectric power stations, bridges) are of considerable size, they undergo force impacts of various origins. They depend on many factors, such as the type of base, production conditions and others. Ultimately, thermal shrinkage and settlement deformations may occur, risking the appearance of cracks different sizes in the body of the structure.
In order to ensure the safety of the solidity of the structure to the maximum extent, the following measures are applied:
- rational cutting of buildings with temporary and permanent joints depending on both geological and climatic conditions
- 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-heat grades of cement, its rational use, pipe cooling, thermal insulation concrete surfaces
- increasing the level of homogeneity of concrete, achieving its adequate tensile strength, strength for reinforcement in places possible occurrence cracks and axial tension
At what point do the main deformations of concrete buildings occur? Why are expansion joints needed in this case? Changes in the building body can occur during construction under high temperature stress - a consequence of the exotherm of hardening concrete and fluctuations in air temperature. In addition, at this moment concrete shrinkage occurs. IN construction period expansion joints can reduce excessive loads and prevent further changes that could be fatal to the structure. The buildings seem to be cut along their length into separate sectional blocks. Expansion joints serve to ensure high-quality functioning of each section, and also eliminate the possibility of forces occurring between adjacent blocks.
Depending on the service life, expansion joints are divided into structural, permanent or temporary (construction). Permanent seams include temperature cuts in structures with a rock foundation. Temporary shrinkage joints are created to reduce temperature and other stresses; thanks to them, the structure is cut into individual columns 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
- Antiseismic
- Shrinkage
- Structural
- Insulating
The most common types are temperature and sedimentary expansion joints. They are used in the vast majority of constructions of various structures. Expansion joints compensate for changes in the body of buildings that occur due to temperature changes environment. The ground part of the building is more susceptible to this, so cuts are made from the ground level to the roof, thereby not affecting the fundamental part. This type of seam cuts the building into blocks, thus ensuring the possibility of linear movements without negative (destructive) consequences.
Sedimentary expansion joints compensate for changes due to uneven various types of structural loads on the ground. This occurs due to differences in the number of floors or large differences in the mass of ground structures.
The anti-seismic type of expansion joints is provided for the construction of buildings in seismic zones. The arrangement of such sections makes it possible to divide the building into separate blocks, which are independent objects. This precaution allows you to effectively counteract seismic loads.
IN monolithic construction Shrinkage seams are widely used. As concrete hardens, a decrease in monolithic structures is observed, namely in volume, but at the same time excess internal tension is formed in the concrete structure. This type of expansion joint helps prevent the appearance of cracks in the walls of the structure as a result of exposure to such stress. When the wall shrinkage process is completed, the expansion joint is tightly sealed.
Insulation joints are installed along columns, walls, and around the foundation for equipment in order to protect the floor screed from possible transfer of deformation resulting from the building structure.
Construction joints act as shrinkage joints; they involve small horizontal movements, but in no case vertical ones. It would also be good if the construction seam corresponded to the shrinkage seam.
It should be noted that the design of the expansion joint must correspond to the plan of the developed project - we are talking about strict compliance with all specified parameters.
Designers of bridge structures, first of all, advocate the excellent versatility of expansion joints and their design, which would allow one or another system of joints to be used practically without changes on any type of bridge structures (dimensions, diagrams, bridge deck, materials for manufacturing spans, etc.) .
If we talk about expansion joints installed in road bridges, 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 reactive forces that are transmitted to bearing structures
- Possibility of uniform distribution of gaps in the spaces of suture elements over wide temperature ranges
- Moving bridge spans in all possible planes and directions
- Noise emissions in different directions when moving vehicles
- Simplicity and ease of installation
In the span structures of small and medium-sized bridge structures, expansion joints of filled and closed types when moving the ends of spans, up to 10-10-20 mm, respectively.
Based on the type, the following classification of expansion joints in bridges is obvious:
Open type. This type of seam involves an unfillable gap between the composite structures.
Closed type. IN in this case the distance between mating structures is closed roadway- coating laid without the necessary break.
Filled type. In closed joints, on the contrary, the coating is laid with a gap, because of this, the edges of the gap, as well as the filling itself, are clearly visible from the roadway.
Overlapping type. In the case of a covered expansion joint, the gap between the connecting structures is blocked by some element on upper level roadway.
In addition to the type characteristic, expansion joints of bridge structures are divided into groups according to their location in the roadway:
- under the tramway
- in the curb
- between sidewalks
- on the sidewalks
This is the standard classification of bridge expansion joints. There are also secondary, more detailed divisions of seams, but all of them must be subordinate to the main grouping.
Judging by 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 the expansion joints.
What are the types of expansion joints between buildings? Experts classify them according to a number of characteristics. This may be the type of structure being serviced, 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 closedness of their location (indoors and outdoors, outdoors). About the generally accepted classification (the most important, covering all the most characteristic features expansion joints) a lot has already been said. It was adopted on the basis of the deformations that it is intended to combat. From this point of view, the expansion joint between buildings can be temperature, sedimentary, shrinkage, seismic, or insulating. Depending on the current circumstances and conditions, different types of expansion joints are used between buildings. However, you should know that all of them must correspond to the initially specified parameters.
Even at the building design stage, specialists determine the location and size of expansion joints. This occurs taking into account all expected loads causing deformation of the structure.
When constructing an expansion joint, it is necessary to understand that it is not just a cut in 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 the load-bearing capacity of the seam is exceeded, 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 - the profiles seal them and provide structural reinforcement.
The seam between 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 may have a negative impact, and both structures may develop unwanted cracks. To avoid this, a rigid connection with reinforcement is used. In this case, it is necessary to make sure that both foundations have already settled properly and are sufficiently resistant to the upcoming loads. The construction of the expansion joint is carried out in strict accordance with generally accepted procedures.
Expansion joint between walls
As you know, walls are essential element in the structure of the building. They perform a load-bearing function, taking on all falling loads. This is the weight of the roof, floor slabs, and other elements. It follows from this that the reliability and durability of a building largely depends on the strength of the expansion joint between the walls. Moreover, comfortable operation interior spaces also depends on walls (load-bearing structures), which perform the important function of fencing from the outside world.
You should know that the thicker the wall material, the higher the requirements are placed on the expansion joints installed in them. Despite the fact that externally the walls appear monolithic, in reality they have to endure various types of loads. The causes of deformation may be:
- air temperature changes
- the soil under the structure may settle unevenly
- vibration and seismic loads and much more
If cracks form in load-bearing walls ah, then this could 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 expansion joint in the walls to function correctly, it is necessary, first of all, to perform it correctly design work. Thus, the calculation of actions must be carried out at the building design stage.
The main criterion for the successful operation of an expansion joint is 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. In this case, builders are required to take into account areas of concentration of internal stresses. The distance is determined by the type of expected expansion joints, which in turn depend on the factors causing changes in the body of the structure.
In addition, at the initial stage of design in the walls of structures, the width of the cut for expansion joints is taken into account with special care. This parameter has important functional significance, as it determines the amount of expected transverse displacement structural elements 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 that of civil buildings, so the construction in such joints becomes great importance. In industrial buildings, specialists provide expansion joints according to their purpose. They can be antiseismic, sedimentary and even temperature.
Expansion joints in frame buildings cut the building into separate blocks, as well as all structures resting on it. In industrial buildings of mass construction, as a rule, expansion joints are installed, which in turn are divided into longitudinal and transverse. The distance between seams in industrial buildings is determined according to constructive solution buildings, as well as climatic conditions of construction, indoor air temperature. 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 insertion are more technologically advanced, since they do not require additional enclosing elements. Today, expansion joints are made in the format of an elastic arch from mineral wool slabs of medium hardness. They are crimped with galvanized roofing steel - cylindrical aprons. In the area where the expansion joint is installed, the carpet is reinforced with several layers of fiberglass.
Temperature longitudinal joints in one-story buildings are installed on 2 rows of columns with an insert; its width, depending on the connection in adjacent spans, is considered to be from 500 to 1000 mm. If the longitudinal expansion joint is combined with different heights of adjacent spans, therefore other sizes of inserts are accepted. The same conditions are observed in places where perpendicular spans are mutually adjacent to one another.
If we are talking about industrial buildings with a constructed reinforced concrete skeleton without special overhead cranes, expansion longitudinal joints can be installed on columns such as single columns. Such a seam is easy to install, thereby allowing you to not take into account additional elements in walls and coverings, as well as paired columns or rafter structures. The same can be said for industrial buildings without cranes with mixed or metal frames.
Any building structures, regardless of what material they are made of (brick, monolithic reinforced concrete or building panels) change their geometric dimensions when the temperature changes. When the temperature drops, they contract, and when the temperature rises, they naturally expand. This can lead to cracks and significantly reduce the strength and durability of both individual elements(for example, cement-sand screeds, foundation blind areas, etc.), and the entire building as a whole. To prevent these negative phenomena, an expansion joint is used, which must be installed in appropriate places (according to regulatory construction documents).
Vertical temperature-shrinkage joints of buildings
In long buildings, as well as buildings with different amounts floors in certain sections, SNiP provides for the mandatory arrangement of vertical deformation gaps:
- Temperature - to prevent the formation of cracks due to changes in the geometric dimensions of the structural elements of the building due to temperature changes (average daily and average annual) and concrete shrinkage. Such seams are brought to the level of the foundation.
- Settlement joints that prevent the formation of cracks that can form due to uneven settlement of the foundation caused by unequal loads on its individual parts. These seams completely separate the structure into separate sections, including the foundation.
The designs of both types of seams are the same. To create a gap, two paired transverse walls are erected, which fill heat-insulating material, and then waterproofed (to prevent precipitation from entering). The width of the seam must strictly correspond to the design of the building (but be at least 20 mm).
The spacing of temperature-shrinkage joints for frameless large-panel buildings is standardized by SNiP and depends on the materials used in the manufacture of the panels (class of concrete compressive strength, grade of mortar and diameter of the longitudinal load-bearing reinforcement), the distance between the transverse walls and the annual difference in average daily temperatures for a particular region . For example, for Petrozavodsk (the annual temperature difference is 60°C), temperature gaps must be located at a distance of 75÷125 m.
IN monolithic structures and buildings constructed using the prefabricated monolithic method, the pitch of transverse temperature-shrinkage joints (according to SNiP) varies from 40 to 80 m (depending on the structural features of the building). The arrangement of such seams not only increases the reliability of the building structure, but also allows for the gradual casting of individual sections of the building.
On a note! At individual construction arrangement of such gaps is used extremely rarely, since the length of the wall of a private house usually does not exceed 40 m.
IN brick houses seams are arranged similarly to panel or monolithic buildings.
IN reinforced concrete structures buildings, the dimensions of the floors, as well as the dimensions of other elements, can vary depending on temperature changes. Therefore, when installing them, it is necessary to arrange expansion joints.
The materials for their manufacture, dimensions, locations and installation technology are indicated in advance in the design documentation for the construction of the building.
Sometimes such seams are structurally made to be sliding. To ensure sliding in those places where the floor slab rests on the supporting structures, two layers of galvanized roofing iron are laid under it.
Temperature expansion joints in concrete floors and cement-sand screeds
When pouring cement-sand screed or arranging a concrete floor, it is necessary to isolate all building structures (walls, columns, doorways, etc.) from contact with the poured mortar throughout its entire thickness. This gap performs three functions simultaneously:
- At the stage of pouring and setting the mortar works as a shrinkage joint. The heavy wet solution compresses it; as the concrete mixture gradually dries, the dimensions of the poured canvas decrease, and the material filling the gap expands and compensates for the shrinkage of the mixture.
- It prevents the transfer of loads from building structures concrete surface and vice versa. The screed does not put pressure on the walls. The structural strength of the building does not change. The structures themselves do not transfer the load to the screed, and it will not crack during operation.
- When there is a temperature difference (and they necessarily occur even in heated rooms), this seam compensates for changes in the volume of the concrete mass, which prevents it from cracking and increases its service life.
To create such gaps, a special damper tape is usually used, the width of which is slightly greater than the height of the screed. After the solution has hardened, its excess is cut off construction knife. When installing shrinkage joints in concrete floors (if the finishing flooring not provided), the polypropylene tape is partially removed and the groove is waterproofed using special sealants.
In rooms of a large area (or when the length of one of the walls exceeds 6 m), according to SNiP, it is necessary to cut longitudinal and transverse temperature-shrinkable joints with a depth of ⅓ of the thickness of the fill. Expansion joints in concrete are made using special equipment (gasoline or electric joint cutter with diamond blades). The pitch of such seams should not be more than 6 m.
Attention! When filling heated floor elements with mortar, shrinkage joints are installed to the entire depth of the screed.
Expansion joints in foundation blind areas and concrete paths
Foundation blind areas, designed to protect the foundation of a house from the harmful effects of precipitation, are also susceptible to destruction due to significant temperature changes throughout the year. To avoid this, seams are installed to compensate for the expansion and contraction of concrete. Such gaps are made at the stage of construction of blind area formwork. Transverse boards (20 mm thick) are attached to the formwork around the entire perimeter in increments of 1.5÷2.5 m. When the solution has set a little, the boards are removed, and after the blind area has completely dried, the grooves are filled with damping material and waterproofed.
All of the above applies to the arrangement concrete paths on the street or parking spaces nearby own home. However, the step of deformation gaps can be increased to 3÷5 m.
Materials for arranging seams
Materials intended for arranging seams (regardless of type and size) are subject to the same requirements. They must be resilient, elastic, easily compressible and quickly recover their shape after compression.
It is designed to prevent cracking of the screed during its drying process and compensate for loads from building structures (walls, columns, etc.). Wide choose sizes (thickness: 3÷35 mm; width: 27÷250 mm) of this material allows you to equip almost any screed and concrete floors.
A popular and easy-to-use material for filling deformation gaps is a cord made of foamed polyethylene. There are two types of it on the construction market:
- solid sealing cord Ø=6÷80 mm,
- in the form of a tube Ø=30÷120 mm.
The diameter of the cord must exceed the width of the seam by ¼÷½. The cord is installed in the groove in a compressed state and filled with ⅔÷¾ of the free volume. For example, to seal 4 mm wide grooves cut in a screed, a Ø=6 mm cord is suitable.
Sealants and mastics
Various sealants are used to seal seams:
- polyurethane;
- acrylic;
- silicone.
They come in both one-component (ready-to-use) and two-component (they are prepared by mixing two components immediately before use). If the seam is of small width, then it is enough to fill it with sealant; if the gap width is significant, then this material is applied on top of the laid polyethylene foam cord (or other damping material).
A variety of mastics (bitumen, bitumen-polymer, compositions based on raw rubber or epoxy with additives to impart elasticity) are used mainly for sealing external deformation gaps. They are applied on top of the damping material placed in the groove.
Special profiles
IN modern construction expansion joints in concrete are successfully sealed using special compensation profiles. These products come in a variety of configurations (depending on application and joint width). For their manufacture, metal, plastic, rubber are used, or several materials are combined in one device. Some models in this category must be installed during the process of pouring the solution. Others can be installed in the groove after the base has completely hardened. Manufacturers (both foreign and domestic) have developed a wide range of the lineup such devices, both for outdoor use and for indoor installation. High price profiles are compensated by the fact that this method of sealing gaps does not require their subsequent waterproofing.
In custody
Correct arrangement of temperature, expansion, expansion and settlement joints significantly increases the strength and durability of any building; parking spaces or garden paths with concrete covering. When using high-quality materials for their manufacture, they will last for many years without repair.
An expansion joint in brickwork is necessary to ensure high-quality and effective protection buildings from premature destruction due to uneven shrinkage of the building or soil instability.
If created competently and correctly, it will help prevent the appearance of cracks in the walls of the building and breaks in the load-bearing walls. An expansion joint in the brickwork will help to avoid cracking of walls due to significant temperature changes. Great attention is paid to the design of an expansion joint, since the strength and durability of the building depends on its implementation.
Kinds
Thermal seams must be made strictly according to SNiP regulations There are several types of seams that increase the resistance of a structure to various factors affecting its durability:
Temperature connections provide reliable protection from the negative effects caused by changes in ambient temperatures. Their design complies with SNiP II-22-81 regulations, paragraphs 6.78-6.82.
Their peculiarity is that such seams are arranged in accordance with the height of the walls, without affecting the foundation.
At a temperature of +20°C in the hot season and -18°C or lower during the winter cold, it expands and contracts. Its height changes accordingly. The range of such changes reaches 0.5 cm for every 10 m of height. It depends on the air temperature, but in any case, when creating them, they use a tongue filled with a sealed, dense gasket in order to avoid blowing.
The width of the seam is from 0.1 to 0.2 cm, depending on the air temperature in each individual area.
Settlement joints help the building to withstand heavy loads Settlement joints are designed to protect the load-bearing walls of a building from deformation and premature destruction under the influence of increased loads. It is these loads that lead to uneven shrinkage of the building and the appearance of cracks on the walls.
These defects most often occur during the construction of multi-story buildings. Sedimentary expansion joints begin to form from the foundation of the house.
Anti-seismic seams are those whose installation is mandatory in areas with increased seismic hazard. Soil mobility and tremors lead to significant deformations, which result in cracking of walls and their subsequent destruction. The peculiarity of such seams is that with their help the building seems to be divided into separate stable blocks.
To fill the seam, insulation, sealant and mastic are used, the density of which will ensure the quality of the device and withstand the upcoming loads.
The quality of the joint filling determines the building’s ability to withstand deformation, its reliability and durability.
Device
The most common is a temperature expansion joint, since significant temperature changes become one of the most common reasons, along which the walls of buildings crack and collapse. The width of the seam being made depends on the temperature level. 
In accordance with the regulations, it cannot be less than 2 cm, and in some cases reaches 3 cm. This is due to the fact that expansion joints have sufficient horizontal mobility. The distance between seams is not less than 15 and not more than 20 m. In the hottest areas, this distance can be reduced to 10 m. Read more about the need for seams brickwork watch in this video:
The design is easy to install. The work is done using:
- tourniquets;
- elastic fillers, characterized by their ability to retain elasticity after hardening;
- bentonite or other substances containing a small percentage of concrete;
- sealants with increased elasticity.
The construction of the expansion joint begins during the construction of the house. To do this, it is enough to retreat the required distance from the main masonry and fill it with insulation or sealant. The installation process will be easier if the depth of installation of the sealant is small.