Construction of houses with fixed formwork. Myths and misconceptions about fixed formwork houses Projects of houses with fixed polystyrene foam formwork

house from fixed formwork, also called a thermo-house. And that's why. The walls of the house are initially assembled from hollow polystyrene foam blocks. Then these voids are reinforced for the longitudinal rigidity of the frame and filled concrete mix. It turns out a single monolithic structure. With a thickness of such walls of a fixed formwork house of 25 centimeters ( standard size block 1200x250x250 mm) its heat saving indicators are comparable with brick wall 50-65 centimeters thick.

Technology Benefits

After analyzing the reviews of the owners of houses from fixed formwork, we can highlight the following advantages:

Accelerated construction time of the frame of the house, combined with low cost;
The pressure on the foundation is reduced, which makes it possible to reduce its cost;
No need for powerful lifting mechanisms(perhaps they will be required for laying floor slabs);
The pouring of the concrete mixture can be carried out using a low-pressure concrete pump or manually through a funnel specially designed for this purpose;
High rates of heat saving walls;
The ability to build a house of any configuration, ease of assembly of the frame (blocks are easily sawn and attached according to the principle of the Lego constructor);
Long service life of a structure built using this technology;
The strength of the walls with their smaller thickness is comparable to brick;
Increasing the usable volume of the premises;
Insulation (as well as sound insulation) of erected walls is not required, except for buildings located in cold climatic conditions. For areas with low temperatures blocks of increased thickness (up to 50 cm) are produced;
Reducing the cost of heating in the house;
A large selection of types of polystyrene formwork elements (corner elements, blocks with plugs for openings, etc. are produced);
Ease of finishing. Such walls do not need to be leveled before finishing work. Any finishing materials can be used for them (siding, non-combustible drywall, ceramic tile etc.);
A house built using non-removable polystyrene formwork is not subject to rotting, mold formation, and destruction by rodents;
The possibility of laying communications (cables, pipes) inside the walls. For this, the blocks have special holes for this;
The corners of the building have precise geometry;
The possibility of using blocks of such formwork for the device strip foundation. For waterproofing such a foundation, it is enough to equip the drainage system.

Technology Disadvantages

The disadvantages of polystyrene fixed formwork include:

Danger of destruction of unprotected polystyrene foam walls when interacting with aggressive liquids (gasoline, solvents, acids, etc.). Therefore, such walls need a mandatory finish;
Limitation of the load on the walls of the building (for example, pressure on bearing wall should not exceed 70 kilograms);
The release of harmful toxic substances when the foam is heated. Therefore, protection is often used with the help of special fire-prevention layers.

Important! Some owners of such buildings prefer to dismantle the inner layer of polystyrene foam. you can tear off the foam inside. It is worth noting that in this case the heat capacity of the walls decreases.

Due to the poor vapor conductivity of such formwork, ventilation in the house must be carefully designed;
Mandatory grounding of the house is required.

What buildings are being built using this technology

There are practically no restrictions here. This technology can be used to build:

private houses, dachas, cottages;
low-rise apartment buildings up to 9 floors high;
outbuildings (shed, chicken coop, etc.);
warehouses, hangars;
sports facilities (pools, ice arenas, sports and recreation centers);
various public spaces.

Important Points

According to the reviews of the owners of such houses, we can give advice - do not use the fixed formwork of little-known companies. The density of expanded polystyrene in it should be at least 25-35 kg / m 3. Otherwise, it is fraught with:

crumbling or cracking of polystyrene foam blocks, which in the future will lead to a spill of the concrete mixture from the formwork;
curvature of the formwork under the weight of concrete and, as a result, the unevenness of the walls;
the inconvenience of laying reinforcement and knitting formwork blocks together;
the release of toxic substances during the operation of the building;
and ultimately a waste of time and money.

Before buying formwork of this type, be sure to ask the seller to present a hygiene certificate for it.

Other types of industrial fixed formwork

These types include:

Expanded clay blocks. By appearance they look like cinder blocks. This is the very first type of fixed formwork. Today it is rarely used due to the high cost and the need for insulation.
Glass-magnesite structures. They are lightweight, but cannot be used for load-bearing walls.
Arbilite structures. Consists of cement and wood shavings. They have high thermal insulation performance, but are quite expensive.

Fixed formwork can be made independently from moisture-resistant plywood, cement-bonded particle boards or flat slate sheets. It turns out quite durable, resistant to moisture. However, the wall has low thermal insulation properties. Therefore, building insulation is required, for example mineral wool. You will also need reinforced waterproofing and tie-down fasteners.

Fixed formwork not only reduces the cost of construction, but also serves as a heater. In this article we will talk about:

various types of fixed formwork;
their value;
application features;
advantages and disadvantages of each type of formwork;
technologies for building houses using fixed formwork;
approximate construction costs compared to the construction of monolithic, brick and block houses.

What is fixed formwork

Many types of fixed formwork are ready blocks, from which a wall is assembled and then concrete is poured into them. From these blocks, the perimeter of the house is collected and internal walls. Between themselves, the blocks are connected using grooves and ridges or metal plates and corners. The height of the blocks is 10–50 cm, the length is 40–200 cm. Fixed formwork is distinguished by the material from which it is made:

expanded polystyrene;
polystyrene concrete;
wood cement (wood concrete);
sandwich (combination of various materials).

Expanded polystyrene (styrofoam)

The cheapest material for the manufacture of formwork, its cost is from 400 rubles per m 2. Such formwork is made in the form of cells 20–25 cm high and up to 100 cm long. The wall thickness depends on the formwork model, so the customer can choose both the thickest one, which provides the greatest thermal insulation, and with the minimum wall thickness. Blocks of such formwork are assembled like a children's designer, because grooves are cut along the long sides of each block, as well as on one of the ends, and ridges are cut on the other end. When choosing such a formwork material, it is impossible to pour more than three rows (60–65 cm) at a time, otherwise the mass of concrete will squeeze out the foam plastic and the formwork will not be able to give the wall desired shape. Another serious drawback is that such formwork does not allow steam to pass through, so the rooms will always be humid. When building houses with such formwork, it is very important to foresee in each room proper ventilation, which compensates for this negative effect.

Polystyrene concrete

Polystyrene concrete is a mixture of concrete and polystyrene foam balls that reduce the thermal conductivity of the material. In terms of heat-insulating properties, such a material, with equal wall thickness, is inferior to polystyrene, but it is devoid of its main drawback, because polystyrene concrete passes steam well, therefore it removes excess moisture from the rooms. There is no single block size, but on average the height is 30–50 cm, and the length is up to 200 cm. To fasten the formwork cells, grooves and ridges are used, as well as additional elements (corner, end, etc.). The average cost of such formwork is from 600 rubles per 1 m 2 of the wall. The advantage, compared to foam formworks, is the greater height of concrete pouring at a time - up to 150 cm, if there is a vibrator of suitable length.

chipped concrete

Shchepobeton (arbalit) - these are slabs of a mixture of concrete and sawdust or shavings. Unlike previous formworks, they are supplied as individual slabs rather than prefabricated cells, which is why traditional formwork is made from chipped concrete, which then remains on the concrete as a heater. The cost of one m 2 of formwork (two slabs 200x50 cm in size and 25–45 mm thick) is 750–900 rubles. In terms of thermal insulation, these slabs are comparable to polystyrene concrete formwork, but they are much more convenient in terms of finishing, because you can screw screws or drive nails into them. As in conventional formwork, it is necessary to provide screeds that will keep the slabs from being squeezed out by concrete.

Sandwich

A sandwich is a combination of various materials, most often wood concrete and polystyrene. At the same time, the foam is placed on the side of concrete, because it is sensitive to ultraviolet and oxygen. Arbolit is not afraid of either the sun, or water, or air. Walls in such formwork do not need to be insulated even in areas extreme north, however, the presence of polystyrene foam or expanded polystyrene blocks the removal of excess moisture through the walls of the house, so high-quality ventilation is necessary. Sandwich slabs are mounted in the same way as chipped concrete formwork. The cost of one plate measuring 200x50 cm starts from 750 rubles.

The technology of building houses with fixed formwork

The layout of the site and land work is carried out in the same way as for any brick houses. First, they mark out the site and dig a trench or pit, then compact the bottom and pour in a sand and gravel cushion. After that, a base plate is poured, the width of which is 3–5 times the width of the foundation. Usually the width of this pillow is 80–120 cm. The pillow is reinforced, both horizontally and vertically, releasing reinforcement from it by 2–4 meters along the wall line. This is necessary in order to connect the foundation wall and the pillow. It is very important during pouring to check the surface of the pillow with a level, if it turns out to be uneven, then you will have to fill in the screed, which will level the surface of the pillow and increase the construction time of the house.

pouring foundation walls

After filling the pillow, it is allowed to stand for 25–28 days, after which the first rows of fixed formwork are installed. Such formwork is preferable, because the foundation must be insulated, otherwise the heat loss of the house will increase, and heating costs will increase after them. For the foundation, it is desirable to use polystyrene foam or polystyrene concrete formwork, because wood concrete in conditions of high humidity will begin to collapse in 10–20 years. If you are using styrofoam formwork, be sure to reinforce it with plastic ties. They will prevent the foam from being squeezed by concrete during compaction with a vibrator. If you are using arbolite or sandwich formwork, then tie the outer and inner sheets with ties and fix them with spacers. This will keep the formwork from being crushed by the concrete and keep the walls vertical.

Pour no more than three rows of any formwork at a time, and pour the third row of formwork only up to the middle. This is necessary so that cold bridges do not appear in the foundation. Use the same filling method for walls. The next day, install the next 3 rows of formwork and pour concrete. The maximum interval between fillings is 30 hours, if it is exceeded, the strength of the wall will decrease. With a step of 1-2 meters, create a belt from reinforcement horizontally laid around the entire perimeter - it will tie the wall and keep it from shifting and deformation.

Composition of concrete

It is very important to use the right concrete, because the traditional composition of this mixture does not have the necessary fluidity, and the addition of water reduces its strength. Therefore, here are the correct components and proportions for pouring one m 3 of the foundation from the walls into a fixed formwork:

cement 305 kg;
sand 825 kg;
crushed stone 1170 kg;
water 125 liters;
plasticizer 1-2 liters.

Plasticizers are sold in any hardware stores and they are inexpensive. Therefore, do not save on plasticizers, because with their help you will get a stronger and more fluid concrete, which will more easily fill the entire internal space of the formwork and create a monolithic wall.

Floor installation

In fixed formwork houses, 3 types of floors are used:

reinforced concrete slabs;
monolithic slab;
wooden.

Reinforced concrete slabs are made at factories of reinforced concrete products (reinforced concrete products), therefore, with a relatively low mass, they are very durable. After all, they are not monolithic, but with voids inside, due to which their mass is reduced. However, a crane is required for the installation of such plates, so they are rarely used.

A monolithic slab has a huge mass, so it is used only in houses standing on dense or rocky ground. To fill such a slab, a removable formwork is mounted and supports are installed. Then it is reinforced with two layers of mesh of steel, fiberglass or carbon fiber reinforcement and poured with the same concrete that was used for the foundation walls. After 10 days, the formwork can be removed, while the construction of walls must be continued the next day. Only in this case the ceiling will be monolithic with the wall.

Important: The concrete floor must pass through the junction between the rows of blocks, only in this case you can reduce the likelihood of the formation of cold bridges. Therefore, the inner side of the formwork is cut to the level of the removable formwork, and the outer side is left intact.

Wooden floors are the most popular because they are lighter than concrete, cheaper and easier to install. They must also pass through the junction of the rows of removable formwork, otherwise the appearance of cold bridges cannot be avoided. To install a log in the outer and inside the formworks are cut into holes according to their size, then the logs are inserted and supported from below so that they do not push through the formwork. After a day, the lag supports are removed, and after 25–28 days a subfloor is laid on them.

Filling the walls of the house

For pouring walls, the same technology is used as for the foundation. The difference is that reinforcing belts are installed around the openings for installing windows and doors, that is, they are ringed with reinforcement. Also, a reinforcing belt is needed under the roof, it will bind the wall and increase its strength. In the process of pouring the walls, do not forget about the ventilation holes that must be made in accordance with the ventilation plan. After pouring the last row, the box is left at home for 28 days, then mounted truss system and lay the roof. Only after that proceed to the interior and exterior decoration, as well as the installation of windows and doors.

Exterior and interior decoration

Formwork made of wood concrete and polystyrene concrete can stand for 1–3 years without finishing, but it should not be delayed with finishing. Expanded polystyrene formwork must be finished in the first year. This is due to the high sensitivity of the material to oxygen and ultraviolet. Arbolit and polystyrene concrete are finished in the same way as any brick or concrete walls, that is:

plaster;
cover with siding;
mount a ventilated facade.

Expanded polystyrene formwork is trimmed in the same way as a foam-insulated wall:

plastered with a reinforcing network sticker;
mount siding or a ventilated facade with fastening to concrete.

From the inside, a house built with the help of fixed formwork is finished in any way you like.

The cost of building a house with fixed formwork

The construction of such a house is cheaper and takes less time than the construction of buildings from:

bricks;
cinder blocks;
arbolite blocks;
foam blocks;
monolithic concrete.

Despite high cost formwork, savings are due to:

reducing the cost of construction equipment;
reducing the time of erection of walls and foundations;
reducing heating costs.

Where to buy fixed formwork

It is possible to order fixed formwork directly from the factory that produces it. In this case, you can choose between standard offers and custom-made formwork. The latter option will cost a little more, but custom-made formwork will better suit your conditions. For example, you can order blocks of thicker polystyrene foam, so that the house will be warm even in the most severe frosts. Or you can change the thickness of the wall - this is especially true for fixed foundation formwork, because it is desirable that the foundation be 1.5–2 times wider than the wall of the house. After making your order, the formwork will be delivered to the place of construction of the house and you will be able to start construction.

If for some reason you cannot or do not want to order formwork at the factory, then it can be purchased at construction markets and sites where building materials are sold in bulk. However, the cost of the formwork will be slightly higher than the factory one, even taking into account the delivery, because intermediaries take their percentage for the storage and sale of goods.

Conclusion

Fixed formwork - inexpensive modern material, which reduces the cost of building a monolithic house. After reading the article, you learned:

what types of fixed formwork are;
what is the price of fixed formwork;
how to build a house from fixed formwork;
why the construction of such a house is cheaper than houses made of brick, concrete and other similar materials;

Modern construction is developing and improving daily. Advanced technologies are used in any technological stage erection of the object. A special area in which new materials and methods are used is the construction of the foundation from which the construction of each building begins. Not so long ago, builders used formwork structures assembled from boards and boards, but new methods have allowed the introduction of advanced techniques, which include the most promising option - fixed formwork for walls, which is an integral part of the reinforced concrete structure. The indisputable advantage of such formwork is the speed of installation. In addition, the house from the fixed formwork immediately turns out to be insulated, additional work on this issue will not have to be carried out.

Appropriateness for building a house

Fixed formwork, used in the construction of a house, gives its elements additional reliability and strength. In addition, this element contributes to the following factors:

work on laying materials and erecting the necessary structures is accelerated;
by reducing the thickness of the walls, the total mass of the structure is reduced;
formwork structures of a fixed type are used in almost every design solution for the construction of facilities;
modern materials for arranging formwork are used in various climatic conditions without changing their characteristics;
the formwork system can differ in a molded or structured surface, which makes it possible not to carry out additional finishing of facades.

Varieties of fixed formwork for walls

Fixed formwork used to build a house is classified according to the materials used in the manufacture.

In most cases, builders use the following design options:

Styrofoam

The most common type of formwork system, for the manufacture of which a strong and lightweight material is used, characterized by high anti-corrosion capabilities. Expanded polystyrene formwork creates excellent thermal insulation properties, supports gas exchange in the concrete mass, ensuring uniformity of hardening and a set of required strength indicators.

Mortar with wood chips

Block material is prepared from a mortar mass, to which wood chips are added, pre-treated with fire-fighting and water-repellent agents. This type of formwork has good sound insulation. Due to the air bubbles formed near the chips, a good heat-insulating layer is obtained.

Fiberboard

For the manufacture of the same boards, wood shavings are used, for the connection of which cement material or magnesite is used. This option of fixed formwork for concrete walls Great for building foundations. The design has sufficient strength, is not affected by moisture and temperature changes, does not allow vapors to pass through, and creates an excellent heat-insulating layer.

Advantages and disadvantages of houses with fixed formwork

Construction works at the facility using such a formwork system can be carried out with negative temperature air at least ten degrees.

If you analyze the reviews of the owners of houses built using this technology, you can understand how many positive and negative points it has. So let's take a look at the pros and cons of this advanced technology.

Let's start with the advantages:

construction time is reduced, while saving cash for additional insulation;
the pressure on the foundation is reduced;
when building houses from fixed formwork, there is no need to use serious lifting equipment;
concrete mixture is poured with a concrete pump under low pressure. In addition, such work is allowed to be performed manually;
walls are distinguished by a high coefficient of heat preservation;
it is possible to erect objects of various configurations, the frame is mounted easily;
a building erected using this technology is operated for a long period;
with a small wall thickness, their strength indicator is comparable to brickwork;
increases the usable space in the premises;
additional protection against extraneous sounds and heat loss is not required. The exception is objects built in areas with a cold climate;
the cost of heating the facility is reduced;

formwork elements are produced in a large assortment according to their shape differences;
the finishing process is simplified, since the walls do not need additional alignment. In addition, many developers use fixed decorative formwork for walls;
the walls of the house are not subject to the processes of decay, mold, rodents;
in the walls there is a possibility for laying communication pipes, for which special technological holes are provided in the formwork blocks;
the corner sections of the object are distinguished by precise geometric shapes;
from fixed formwork, you can build a strip foundation for the house, for which you don’t have to arrange a waterproofing layer - just lay the drainage system.

Unfortunately, in addition to the advantages, developers highlight certain negative points:

when heated, the foam releases dangerous toxins, which creates harm to health;

the vapor permeability of the walls is poor. It is necessary to provide a ventilation system for the premises;

grounding is mandatory in the house;

unprotected polystyrene foam can be destroyed by exposure to aggressive environments.

Some developers dismantle the foam layer inside the premises, which leads to a decrease in heat capacity.

Installation of various types of formwork for the walls of the house

To build a house from fixed formwork, you should know that the subtleties of installation work are determined by the material chosen for this. For example, a reinforced concrete block stone must be installed with a crane, which will increase the cost of installation work. If you decide to install fixed formwork for walls with your own hands, you should consider using foam blocks. In this case, the work is carried out easily, but you will have to know certain features. The fact is that erroneous actions made during the assembly of the formwork structure cause dew points to appear in the walls, which leads to the formation of dampness.

Technological features of the construction of a formwork structure made of foam plastic are as follows:

a site for construction work is marked out, a foundation pit is dug, at the bottom of which a sand cushion up to fifteen centimeters high is arranged;
after that, rolled waterproofing is overlapped;
steel reinforcement is installed vertically, the lower row of horizontal rods is mounted;
formwork blocks are set, connected to each other by light pressing;
after installing the first row, the second is mounted, only reinforcement is inserted into the free grooves of the next block;
as soon as installation work completed, concrete mortar is poured. Filling is carried out along the entire contour, in small layers.

Fixed formwork for walls is mounted in almost the same way. They begin to install it when all the work on pouring the foundation is completed. The layout of wall block elements begins with corner sections.

To build a fixed formwork for pouring the ceiling, telescopic support elements are used. Used to make molds sheet material- profiled sheets, wood concrete plates, polystyrene.

Finishing work

Consider how the interior decoration of a house is carried out, the walls of which are built from fixed formwork.

Facing work is necessary to increase the decorative effect and protect the material from external influences, and this feature applies to both block and frame structures. Taking into account the fact that it is not required to level the walls, many developers do without applying a thick layer of plaster. Just on adhesive composition a fiberglass or metal mesh is applied for reinforcement, after which the surface is treated with putty or decorative plaster.

Note that the margin of safety of such walls is very solid, and it is quite enough to finish the surfaces with tile or stone materials, sheathe them with siding, mounting it on the frame subsystem. Today, the building materials market offers a decorative formwork structure with a facing layer that imitates facade stone. True, this option is not in special demand, since its cost is quite high.

The evenness of the walls simplifies not only the external, but also interior decoration. In most cases, the surface is sheathed with drywall sheets attached to special profiles or to an adhesive composition.

There are no restrictions on finishing materials, but if the fixed formwork consists of polystyrene foam elements that do not allow air flow through themselves, it is recommended to use natural finishing materials.

Popular Designs

The most popular among fixed formwork are:

radomir. The elements are made of a unique, safe for health material with a cellular structure. Block elements have a high density index, reaching 33 - 37 kg per cubic meter. The structure of the blocks consists of two percent polystyrene foam, the rest is air bubbles. Expanded polystyrene does not emit dust, toxic substances and unpleasant odors, it is considered inert material, perfectly passes air currents and steam, providing the necessary circulation in the living room. The thermal conductivity of the blocks is 0.037 - 0.043 W, which is several times lower than expanded clay stone, wood and brickwork. Cold bridges are not formed in the heat-insulating layer, which is considered another important advantage of the design. Radomir formwork reliably protects against impact noise, does not cause allergenic manifestations, and does not support combustion processes for two and a half hours. A wide range of formwork structures is produced, from which it is possible to build not only walls and ceilings, but also columns;
"warm house". With the help of such a building system, the process of laying and installing sewerage, plumbing and electrical wiring is simplified. Construction work is carried out simply - individual formwork elements are laid in a row, connected with locks, poured with concrete mortar. Special knowledge for such work is not required; a building box by a team of four people can be erected in a few weeks. In order for the walls to turn out to be of high quality, when using the system Warm house the base is prepared carefully - it is checked by a level so that the corners correspond to the design assignment, it is smoothed out to prevent punctures and ruptures of the horizontal waterproofing layer. The formwork blocks are installed in rows, the end sections are closed with special plugs. After that, reinforcement is laid inside the formed tray and concrete mortar is poured;

technoblock. This version of fixed formwork is distinguished by the presence of a decorative facing layer on the outside. Structurally, formwork elements consist of a pair of plates made in the form of a concrete lining. All separate parts are connected by locking elements, the thickness of the wall is twenty-three centimeters. The cladding is made of reinforced concrete slabs weighing up to thirty kilograms and measuring 1000 by 400 mm. Insulation material - dense polystyrene foam, the thickness of which varies from five to ten centimeters. Bolts, reinforcing bars, ties and brackets are used as auxiliary elements. For pouring concrete mortar there is a gap equal to fifteen centimeters. The formwork wall, which is dismantled after the concrete has hardened, is made of laminated plywood sheet, which has the ability to withstand moisture. This formwork design is distinguished by an acceptable cost, affordable for any developer. The building is well insulated. Due to the ease of installation, the construction process of the entire facility is accelerated. It is possible to combine various color shades and texture solutions, giving the facade walls a uniqueness.

Formwork cost

A monolithic object erected using a fixed formwork system will cost much less than an analogue from brick material or wood. Prices Construction Materials differ by region, but the average cost square meter formwork from a polystyrene foam block varies between 800 - 1000 rubles. The total need for formwork elements can be calculated independently using special calculators, or you can ask for help from sellers who provide such a service for free.

What is a thermodom? This building is constructed using fixed formwork made of expanded polystyrene. Building a building using this technology with your own hands is quite simple. The correct application of our advice is already 100% success in construction. You can get acquainted with all the necessary actions in construction by reading this article.

Every year there are many new technologies and developments in modern construction. The method of manufacturing fixed formwork is one of them. He gained popularity because of his merits. Inexpensive, time-saving, easy to use. This method has collected many innovations and meets all the relevant requirements. The strength of the structure and simplicity influenced the speed of construction. - this is a kind of large constructor, which is assembled into one, and reinforcement and mortar fill the void. The construction of a thermal house is impossible without the use of fixed formwork, only it is used for this type of house.

Pros and cons of fixed formwork

Each design and each material has both positive characteristics and negative sides. To know what to work with, you need to know more about them. Let's consider what these qualities are closer. For quality work, everything must be taken into account character traits fixed formwork.

Advantages of fixed formwork

The shortest time for the construction of walls compared to other technologies;
Ease of implementation, which reduces the time of the work itself;
The wall is very strong;
Affordability, which favorably affects the financial condition of the developer;
Convenience for holding independent work. Such work does not require the involvement of additional construction equipment;
This design will save up to 40% on heating;
Expanded polystyrene has great resistance to aging.

Minuses

Increased humidity in the built room, due to this shortcoming, frequent ventilation of the room is necessary;
A material such as expanded polystyrene is still under great doubt due to its safety for health;
At temperatures above 90 degrees, it can emit harmful substances for life;

Installation of the first row of blocks

The formwork is removed after, after about 20-25 days. Smooth openings remain, in the future they are trimmed with other materials. After completion, the walls are finished on the outside. Most often uses siding or blockhouse.

Video of building a house from fixed formwork

About the environmental friendliness of polystyrene foam

There is a lot of controversy about the environmentally friendly properties of this material. Styrene - the substance on the basis of which polystyrene foam is made is considered a poison for the human body. The most detrimental is that when the temperature rises to +90 degrees and above, this substance begins to actively release toxins into environment. However, according to MPC standards, it is fully suitable for the construction of individual housing.

Today, the main requirement in the construction of a house is profitability. But how to make the house economical not only in construction, but also in operation? One of the most best options– application of fixed formwork technology

Features of material and technology

The construction technology using fixed formwork cannot be considered new. The first houses according to this system in Europe and America were built more than 25 years ago. Who is the ancestor of this technology, it is unambiguously difficult to answer. To a certain extent, it can be considered the company DOW CHEMICAL, which in 1940 invented extruded polystyrene foam. In the early 50s. in West Germany, a technology for producing expanded polystyrene by hot molding was developed, which found application in the United States in construction for the manufacture of simple concrete forms. As for Russia, the technology of fixed formwork is still not widely used in our country. The reason is the tendency of private developers to more traditional types of housing construction (wooden and brick), as well as the manifestation of distrust of everything new and little tested. Nevertheless Russian companies There are a lot of people who build houses using expanded polystyrene formwork.

Features of expanded polystyrene

A house built using fixed formwork technology combines the advantages of monolithic concrete walls with the properties inherent in expanded polystyrene. Expanded polystyrene is obtained by foaming polystyrene during heat treatment. One of its main advantages is high thermal insulation properties due to the cellular structure of the material. Expanded polystyrene consists of foamed granules, the cells between which are completely closed and sealed. With a low density, it is characterized by high compressive strength, low dynamic stiffness, which provides high-quality insulation from impact noise; low water vapor diffusion and water absorption; fire resistance (self-extinguishing material that does not support combustion). Expanded polystyrene is highly resistant to alkaline and saline solutions, weak acids, etc. According to research conducted at the Research Institute of Building Physics (Moscow) according to special technique with temperature fluctuations from -40 to +40°C and aging in water, expanded polystyrene can be used without losing the original physical properties at least 80 years old.

Styrofoam block wall construction

The word "formwork" in private housing construction is usually used when it comes to building a foundation. This is the name of the construction of boards (and plywood), which allows you to form a foundation tape when pouring concrete. As soon as it gains the necessary strength, the formwork is removed. In the technology we are talking about, the foundation is built in the traditional way, and the fixed formwork is used only for the construction of walls. Its elements are lightweight polystyrene blocks of various sizes and shapes, interconnected by jumpers made of the same polystyrene foam, polypropylene or metal. It is not by chance that the blocks are called “Lego constructor for adults”: they have protrusions on top, and on the bottom they are similar in size and location of the cavity. The blocks are connected by light pressure on their edges. At the same time, the locks located in the upper and lower parts of the edges close tightly, without gaps. In one row, the blocks are joined using locks provided at the ends of the elements.

Expanded polystyrene modules fit so tightly to each other that during concreting, the leakage of cement laitance is absolutely excluded, as well as the ingress of air or atmospheric moisture into the technological cavities. In addition to blocks, reinforcement and concrete are obligatory "participants" in the construction process according to this technology. Reinforcement is laid horizontally and vertically in polystyrene foam blocks, and then the module cavities are concreted. As a result, a solid building structure is formed with a thickness of reinforced concrete walls of 15 cm (this is the distance between the inner surfaces of the ribs of the blocks), surrounded on both sides by a shell of expanded polystyrene. The thickness of the inner part of the block is 5 cm, the outer one is 5 or 10 and 15 cm (for the northern regions).

For the construction of a house box with a total area of 200-300 m² from fixed formwork elements professional team builders spends two and a half to three weeks

Advantages of fixed formwork technology

The fixed formwork technology has a number of advantages over traditional ones. First of all, thanks to its application, there is a significant saving of financial, time and labor costs. As practice shows, a turnkey house can be built in 4.5-5 months. The light weight of the blocks makes it possible not to use heavy construction equipment in the work. The thickness of the walls is half that of brick walls, which increases the usable area of the house by 7-10%. Lightweight wall structures allow the use of more economical types of foundations, for example, shallow ones. The construction process takes place simultaneously with thermal insulation (hence, during the operation of the facility, heating costs are significantly reduced) and soundproofing of the building. The thermal conductivity coefficient is 0.036-0.039 W / m K, acoustic insulation - 49 dB. It is important that the fixed formwork technology can be used in winter as well. Thanks to the thermal protection created by the formwork, the water in the concrete does not freeze even in severe frosts and all goes to chemical reaction with cement, forming a solid monolithic wall.

Main stages of work

We offer to get acquainted with the features of construction technology with the use of fixed polystyrene formwork on the example of the construction of one of the cottages near Moscow.

The owner of the future building came to a construction company with a project designed for a brick building. Finished projects, created for the technology we are talking about, today there are few. And customers often do not want to use standard projects, which is why, as a rule, it is necessary to adapt house designs from other materials to the “concrete-polystyrene” combination.

When the project was ready and the estimate was drawn up, the builders began to create a strip foundation. They dug trenches to the depth of soil freezing (1.7 m), put together a plank formwork, lined it with roofing material. Then tied the reinforcing cage. Above the upper plane of the foundation, under the future perimeter of the walls, vertical outlets of reinforcement 60-70 cm high were made, so that in the future it would be possible to lay two rows of blocks (with a total height of 50 cm) and there would still be a segment for tying the next reinforcing bars. The solution was supplied to the formwork by a concrete pump. Due to the difference in relief, the basement has a different height above ground level.

It is also possible to erect buildings using polystyrene foam modules in regions with severe winters. In this case, blocks with outer wall in 10 or 15 cm

The next stage - laying cut-off waterproofing, without which traditional construction is indispensable, was absent in this case. The specialists who erected the house explain this by the fact that both the foundation and the walls are made of the same material - monolithic reinforced concrete, so there is no need to cut off the foundation from the walls. Horizontal waterproofing is required if, for example, the foundation is cast from concrete, and the walls are made of wood, brick, foam blocks, etc.

After dismantling the formwork around the entire perimeter of the future building, the first row of polystyrene foam blocks was installed. Three types of elements were used: corner, ordinary (wall) and end. They have a standard length of 120 cm and a height of 25 cm. The builders placed horizontal reinforcement in the grooves of the modules. The second row of blocks was laid with an offset (according to the principle of brickwork), a multiple of 250 mm. In this row, horizontal reinforcement was inserted in a checkerboard pattern into a groove different from the center, in the third - above the reinforcement of the first row. Then vertical reinforcement was installed in the center of the blocks. As a result, it turns out that the horizontal reinforcement covers the vertical one.

Three rows of blocks are laid at a time, but two and a half are poured. If all three blocks are filled with concrete mix, then the connecting protrusions of the upper module will be soiled with mortar. And when it hardens, it will be impossible to ensure a reliable docking of the elements. To protect the mounting protrusions, special overlays are put on the upper parts of the modules. They are removed after the concrete has been poured.

According to the project, having laid three rows of blocks, the builders began to erect the ceiling of the first floor. To do this, they hammered into the ground wooden racks, connected them with intermediate beams, on which laminated plywood was laid. A double reinforcing cage 16 cm high was tied on top of it, beacons were set up and the entire area of \u200b\u200bthe future floor was filled with a concrete pump, leaving a technological hatch for laying engineering communications. Once the concrete has set, it can be walked on and further construction can continue. A concrete pump is used only for casting floors. As for the walls, concrete grade 300-350, prepared directly at the construction site, is used for their construction. This requires washed quarry sand, gravel gravel fraction 5-20, cement grade 500 and a concrete mixer. The solution is poured into the grooves of the modules with buckets, the main condition is to do this work carefully. No more than three rows of blocks are laid per day, otherwise the lower modules may break from the weight of the poured concrete.

Simultaneously with the erection of walls, door and window openings are formed. To comply with their size and geometry, wooden spacers are used.

The construction of houses using fixed formwork technology takes place in three stages: installation of polystyrene foam blocks, laying reinforcement, concreting

The overlap between the first and second floors was made similarly to the previous one. Then the walls of the second floor and pediments were erected. The latter were built in this way. They put three rows of blocks and drew a line along which the gable cut would pass. Then the elements were numbered, removed, cut along the intended line and installed in place. Then reinforced and filled with mortar. No more than three rows of modules were also laid at a time. Then the construction of the pediment continued. To prevent the concrete from flowing out of the angled modules, the workers made a temporary wooden formwork, which was fixed to the scaffolding.