Polystyrene foam into the formwork on one side. Construction of houses from polystyrene foam permanent formwork
Construction technologies are constantly being improved - quality improves, new methods are developed, and working times are reduced. In our country, foam plastic formwork has been used relatively recently, while in European countries they have known about it for more than 50 years. Thanks to such formwork, the sound insulation properties of the building are improved and the efficiency of the heating system is increased. In essence, this is a structure that consists of a large number of foam blocks connected through special jumpers. Among the main advantages of formwork is a reduction in time and labor costs.
Foam formwork
Foam formwork - design diagram
This is a hollow structure into which reinforcement is installed and concrete is poured. The formwork is made of polystyrene foam blocks connected by jumpers. This technology, as already noted, significantly simplifies the construction process, since the additional arrangement of both thermal and sound insulation in in this case not required.
Polyfoam itself as a building material is quite durable, moisture resistant, not chemically active and safe for health. It weighs little, so the formwork blocks can be manipulated even without the use of special equipment. And this, in turn, significantly reduces the cost of construction.
During the production of the described products, a fire retardant is used, which increases the fire safety of the finished building significantly. Such formwork (also called permanent formwork) is characterized by simplicity of design, and even those who do not have much experience in building houses can handle its installation. All that is required in the work is accuracy and utmost attention.
Classification of permanent formwork
Depending on the purpose, formworks are divided into two large categories.
- Construction– serve as a kind of frame in monolithic structures. The cavities in the blocks are filled with concrete during construction. As soon as the mixture hardens, the walls are sheathed with fire-resistant material of at least 3 mm thickness (this can be either plasterboard or ordinary plaster).
- Decorative– made of blocks with reinforcement and insulating material inside. They are assembled directly on the walls using lintels (no sealants or solutions are used). Walls made in this way do not need cladding.
Note! In addition to polystyrene foam, there are a number of other materials that can be used in the construction of permanent formwork.
- Expanded clay concrete structures are the first options for permanent formwork. Externally they resemble ordinary cinder blocks. They are not very popular because they are expensive and require additional insulation.
- Glass-magnesite structures weigh little and are used mainly for internal partitions, because their load-bearing capacity is low.
- Arbolite structures are constructed from wood chips and cement. They have excellent thermal insulation properties, but are quite expensive.
Note! In light of everything said above, it becomes obvious that foam formwork is the best option, because other materials have many disadvantages. By the way, about the advantages and disadvantages.
Video - Fixed polystyrene foam formwork
Advantages of expanded polystyrene formwork
As we just found out, it is better to use foam plastic for formwork. It's environmentally friendly safe material, in the production of which no toxic substances are used. Other advantages of this material include:
- ease of installation, allowing you to save a lot of time and money;
- long service life;
- the ability to dig a not too deep trench during installation;
- efficiency;
- For waterproofing protection of the base, drainage is quite sufficient;
- foam boards do not attract rodents as much as other materials, and, moreover, do not rot;
- high thermal insulation properties, allowing significant savings on insulation;
- installation channels in blocks designed for laying various types of communications.
Flaws
Of course, the structures also have weak sides, even if they are few in number. These include:
- impossibility of construction in winter period;
- mandatory grounding of a house under construction;
- The humidity in such walls will be very high, and therefore it will be necessary to install forced ventilation.
How to calculate construction costs?
To become more familiar with the savings achieved by using foam formwork, let’s calculate approximate cost erection of walls. Calculations are made based on the current cost of the material (more on this at the end of the article) and the size of the building itself. An approximate calculation of the required materials will look like in the following way:
- concrete- about 125 liters per 1 sq. m. (price depends on the cost of the required materials);
- – 3.3 pieces per 1 sq. m. (about 500 rubles);
- fittings- about 10 kilograms per 1 sq. m. (the exact cost depends on current prices).
And if we proceed from prices in Moscow, then approximate calculations for the construction of one floor will look like this (the cost of the work itself is not included):
- total area (various types of openings are not included) – about 180 sq. m.;
- concrete solution for a given area - about 27 cubic meters, that is, 81 thousand rubles;
- the price of the formwork itself is about 88.2 thousand rubles;
- fittings - 1800 kilograms or 37.8 thousand rubles.
It turns out that the total cost of everything consumables for one floor will average 207 thousand rubles.
Dimensions of permanent foam formwork
Name | Dimensions | Thermal insulation thickness | |
---|---|---|---|
internal | external | ||
Series 25 (one-piece) | |||
Main wall block | 1250x250x250 | 50 | 50 |
Wall end block | 1250?250?250 | 50 | 50 |
700?250?250 | 50 | 50 | |
500?250?250 | |||
Series 30 (one-piece) | |||
Main wall block | 1250?300?250 | 50 | 100 |
Wall end block | 1250?300?250 | 50 | 100 |
Corner wall block (right/left) | 1250?300?250 | 50 | 100 |
500x300x250 | |||
Series 35 (detachable) | |||
Wall block | 1200?300?250 | 50 | 100 |
Series 50 (one-piece) | |||
Main wall block | 1250?300?500 | 50 | 100 |
Wall end block | 1250?300?500 | 50 | 100 |
Corner wall block (left/right) | 450?300?500 | 50 | 100 |
650?300?500 |
How is foam formwork made?
Stage one. Let’s say right away that there is nothing complicated in making polystyrene foam formwork, but only on condition that you strictly follow our instructions. So, first mark the area and prepare all the materials necessary for the work. Draw up a construction plan for the future building, and then, in accordance with it, mark out the area for the foundation.
It is important that each of the corners is aligned with utmost clarity using a mounting level. Moreover, you need to carefully level the entire area of the construction site, since only under such circumstances will you be able to apply the required markings with a minimum error.
Stage two. Next, arrange a trench for the future foundation. The depth of this trench should be 0.5 meters and the width should be only 0.4 meters. When working, pay special attention to the horizontalness of the bottom of the pit. The fact is that the formwork will not be removable, therefore, it will no longer be possible to level the surface for the walls.
Stage three. Then proceed to make a drainage pad. Such a pillow should be laid exclusively on a leveled surface (the mounting level will help you!). Use as a pillow sand and gravel mixture– pour it onto the bottom of the trench in a 15-centimeter layer and level it. This way, the future load from the building will be distributed as evenly as possible.
The pillow will also have another function - a thermal insulator and a drainage system. Insert reinforcing rods into the cushion - in the future they will take part in connecting the formwork blocks.
Stage four. Pour a thin layer of concrete mortar over the pillow - it will serve as a kind of “sole” for the base. Thanks to this “sole,” the surface will be as smooth as possible, which is very important when constructing formwork with your own hands.
Stage five. After the concrete solution has hardened, place the foam blocks on the reinforcing rods installed in the previous steps. Install jumpers between the blocks, with the help of which they will be connected to each other. It is typical that the blocks must be connected according to the tongue and groove principle, which will minimize the number of additional assembly seams. For corners, use special corner joints - this way you will protect yourself from labor-intensive fastening of elements in the corners.
Stage six. Having installed a row of blocks No. 3, align them vertically. Make sure that the side surfaces always coincide with one another.
Stage seven. As soon as all the voids inside the polystyrene foam plates are filled, you can begin to actually pour the concrete solution. To compact it, experts recommend using special deep vibrators. Having finished compacting the surface, take a trowel and carefully level the upper “mirror”. It is worth adding that foam formwork involves adding coarse crushed stone to the concrete (it is important that the size of its fractions exceeds 0.8 centimeters).
Note! This kind of formwork has recently become increasingly popular, since it does not need to be dismantled after the solution has hardened, but on the contrary, it will also serve as an additional thermal insulation layer in the future.
Stage eight. This completes the construction of the formwork. As a result, you will get walls that will look like a “sandwich” in cross-section: two rows of foam plastic, between which there is a heavy-duty concrete monolith. It is typical, but the inner layer will be thinner than the outer one, due to which the insulating properties of the material will be excellent.
Video - How to build foam formwork
Price of foam formwork
In specialized stores, foam blocks are sold for corner, end and wall blocks. They must be purchased separately. The cost itself, of course, largely depends on the thickness of the outer layer (read: insulation), although if the order is wholesale, the price can drop significantly. Below are the average prices of the most popular manufacturers.
- The products of the Minsk company BelTeploDom will cost approximately $19 per sq. m.
- Blocks from Auto-B.A.N are cheaper - only $8.
- The St. Petersburg company Bamlex produces formwork elements that sell for an average of $15.
- Finally, blocks from Chelyabinsk “Construction Technologies...” cost an average of $12.
It is worth noting that people often encounter certain difficulties when constructing foam formwork. This is often due to:
- with non-compliance with construction technology;
- with questionable quality of the elements themselves.
Areas of application
The described auxiliary structures made of polystyrene foam are used in the construction of monolithic reinforced concrete structures and foundations. Sometimes formwork is used as decorative material(see varieties) for various architectural objects.
In addition, foam blocks with insulation are often used when finishing windows and constructing interior partitions. And thanks to their excellent external properties, the modules can also be used for finishing office premises.
Before proceeding directly to the installation work, it is necessary to calculate the approximate cost in order to know about future costs.
That's all, good luck with your work. Warm winters!
The classic version of the form for the foundation and walls in monolithic houses is a temporary structure made of wood and chipboard. Permanent formwork made of polystyrene foam is an alternative construction method that does not involve the presence of waste. This design increases the strength of the building and improves its energy efficiency, acting as thermal insulation. However, such material has some features that cannot be ignored.
Manufacturers of this material point to its many advantages compared to standard construction formwork options. These advantages need to be known to every person who has decided to use a non-removable type of polystyrene foam construction.
The advantage of permanent formwork made from this material primarily lies in the fact that such a structure has auxiliary functions. The main one is the organization of the form for the walls and foundation of a monolithic building. Due to its physical properties, polystyrene foam is good insulation. This is a very important property, since this type of formwork cannot be dismantled after the concrete has hardened.
If formwork boards are used, they must be dismantled. Wood is not a thermal insulator, so polystyrene foam blocks are considered a better investment. Permanent formwork from this material allows you to build lightweight concrete design. Moreover, such a building retains 30-35% more heat than a structure with a red brick analogue. Thus, the use of expanded polystyrene allows you to reduce the costs of other materials from which the foundation or walls are made.
An alternative to polystyrene foam forms is plastic formwork. The price for this design is slightly higher, but it is more reliable. Non-removable plastic elements can be purchased at a hardware store or you can order them online.
Another advantage of such forms is that they protect reinforced concrete from moisture. This is especially important in winter. As a result, thanks to expanded polystyrene blocks, the service life of the foundation and walls increases by approximately 20%. Quite often, it is this fact that pushes people to use such formwork for building a house. Elements of various shapes and dimensions are made from expanded polystyrene.
Note! Constructing a building using polystyrene molds reduces financial costs by approximately a third.
The price of floor formwork made from polystyrene foam is usually the determining factor when choosing it. However, most useful property of such forms is that their use makes it possible to preserve the structure of concrete at low temperatures (but not lower than +5 °C). In this case, the concrete hardens in a normal mode, which has a positive effect on its qualities after hardening.
In turn, pouring concrete material into a wooden form gives a completely different result. In such formworks (at low temperatures), concrete hardens faster and its structure is damaged.
Fixed polystyrene foam formwork: design flaws
Such designs also have their drawbacks. Some of them are quite significant. For example, one of the most serious disadvantages is the fact that a building made using such formwork cannot be reconstructed. Therefore, it is recommended to think through its design in advance. In addition, all communications located in the structure must be laid during the construction phase.
A house made of permanent formwork is made taking into account certain rules, which are very important to follow in order to obtain a reliable building that is resistant to adverse environmental factors. Blocks made from polystyrene foam require careful installation. It is very important to maintain tightness, as otherwise moisture will penetrate into the voids.
Another disadvantage of this technology for the construction of residential buildings is that polystyrene foam forms cannot be used at temperatures below 5 °C. In such a situation, the concrete simply will not harden. In hot weather, concrete requires additional moisture, otherwise it will not harden properly.
It is also worth noting that permanent formwork blocks made of polystyrene foam interfere with the normal ventilation of the concrete structure. The solution to the problem in this case is to install ventilation communications. This coercive system will provide the necessary ventilation while maintaining the high efficiency of the fixed structure.
Types of permanent formworkdepending on the material of manufacture
Before starting installation, you must study various options permanent formworks that can be purchased today on the construction market. The main feature by which these products are classified is the material of manufacture. The choice of raw materials depends on the complexity of the future construction and its individual characteristics. Let's consider what raw materials are most often used to make concrete forms.
Expanded polystyrene. Many people are interested in the question of what polystyrene foam is. This material is a standard raw material used in the production of permanent formwork. The second name for expanded polystyrene is gas-filled foam. It is characterized by a number of positive qualities that determine the popularity of using forms made from it.
Helpful information! Expanded polystyrene has fairly high strength characteristics and provides reliable thermal insulation for concrete.
Arbolit. This material includes 2 main components: wood shavings and concrete. Individual elements of permanent wood concrete formwork are presented in blocks. They have empty spaces, which are reinforced and filled with mortar during installation. The advantage of this raw material is that it has high strength. The soundproofing qualities of wood concrete are also its strong point. The disadvantages of this material used for the manufacture of formwork include low thermal insulation and high cost.
Fibrolite. This raw material, like the previous one, consists of 2 components. The first one is wood shavings, which provides the fibrous structure of the individual elements of such formwork. The second component is represented by an inorganic binder. The main advantage of such formwork is its resistance to temperature fluctuations.
Chip cement. This material is considered less popular than the above options for permanent formwork. The technology for installing woodchip cement has its own nuances. Among the advantages of this material, it is worth highlighting very good sound insulation and resistance to temperature fluctuations.
Economical option: permanent foam formwork
Today it is possible to install permanent formwork from foam boards. This option is quite common, as it allows you to significantly save money when building a house. Penoplex is a material used for insulation and has good strength characteristics. This allows it to be used as concrete forms.
Penoplex slabs have dimensions of 60x100 cm. The dimensions of these products prevail over the parameters of standard structures made of polystyrene foam. In order to install formwork around a polystyrene foam house, it is necessary to correctly calculate the material. It is also important to understand that such products do not have their own locking elements. Thus, before purchasing material, it is necessary to think over a system for fastening individual parts to each other.
The use of penoplex allows you to reduce financial costs to a minimum. This is especially true when compared to the costs required to build a standard structure. Floor formwork on telescopic racks, wall panels and the use of plywood will cost much more.
Helpful information! A common option for organizing fastening parts is the use of special jumpers, which are equipped with threads along the edges. Such elements are made from reinforcement. The main thing to remember is that such jumpers are installed between foam boards.
This design option is less expensive, but at the same time more complex due to the selection of clamps. The price of permanent formwork made of polystyrene foam is higher, but its installation does not require unnecessary steps. If necessary, you can purchase clamps for foam boards, which are used when installing polystyrene foam structures.
Fixed foam formwork: types of structural parts
Formwork elements may have different designs, which is determined by their operational purpose. Today there are such options for these products made from polystyrene foam:
- panels;
- blocks (cast and prefabricated);
- frame systems.
Frame systems are double-circuit structures with empty space between the walls. When installing such formwork, reinforcement is laid inside and the solution is poured. If you make a section of a finished wall made using this technology, you will be able to distinguish three layers: two outer layers, represented by formwork, and a middle one made of reinforced concrete.
Foam blocks are divided into two large groups: cast and prefabricated. During the assembly of the formwork, these elements are aligned so that they are located on top of each other. Moreover, no adhesive mixtures (for example, glue) are used for joining. The blocks are laid out in a checkerboard pattern.
Cast products are also called thermoblock. This is due to the fact that they have a fairly high density (up to 40 kg/m³). Features of the structure influence the thermal insulation characteristics. A block of this type consists of 2 sheets, which are joined together using special jumpers. The assembly of such parts and the connection of their individual elements are carried out at the manufacturing stage. It is worth noting that such structures have one drawback: they warm up rather poorly. This is due to the location of the insulation with inside pie wall.
The sizes of blocks of cast foam formwork may vary. However standard option Products with dimensions of 1000x250x250 mm are considered. The mass of such a block is usually about 1 kg. The thickness of the insulation located on both sides (outside) is 50 mm. Accordingly, the same indicator of the concrete layer will be 150 mm.
Related article:
![]()
How to do it for strip and slab types. Detailed example calculating the need for reinforcing bars for the foundation.
The insulation in the forms used to pour concrete can be different. The future characteristics of the structure depend on the choice of insulator material. It is important to remember that such a layer traditionally performs two main functions. The first of them is shape-forming, and the second is thermal insulation. Depending on the type of blocks, the cost of polystyrene foam varies. How much are Various types forms? Pricing takes into account the design, as well as the thickness of the insulation layer.
Note! It is not recommended to carry out concreting in more than 3 rows. Ideal option the concrete will be laid in 2.5 rows, since in this case the seam will be located in the middle of the block.
Prefabricated polystyrene foam blocks for formwork
Formwork can be represented by prefabricated elements, which differ from cast ones in their structure and have some application features. Such blocks consist of two sheets, which are assembled into a single structure before installation work begins. It is important to note that such elements can be made not only from expanded polystyrene, but also from other materials. The distance between sheets 1 and 2 remains unchanged due to special components called spacers.
Building a house from permanent formwork of this type has several features that need to be emphasized. The main difference between prefabricated forms is that their use allows the use of more than 3 layers in the walls. Moreover, the combination of materials in this case does not play a role, while buildings made using cast blocks require strict adherence to the sequence of materials. Insulation in such a situation will always be located outside.
A common solution is a pie wall, which includes two facing layers of rigid sheet material. An insulating material (expanded polystyrene) is laid close to the outer sheet of this type. The second layer in this situation is reinforced concrete.
The design of a house made from permanent formwork is prepared in advance. It contains all the necessary data indicating design features, dimensions and individual solutions in accordance with the situation.
It is worth noting that such forms have one significant advantage over their cast counterparts. It lies in the fact that, if necessary, you can change the width of the internal cavity into which the reinforcement is laid and the solution is poured. This indicator is changed by using spacers. If such a need arises, longer retaining elements can be purchased.
All costs must be indicated in the formwork estimate. The device, prices, dimensions of individual elements - all this is recommended to be noted in the preliminary installation diagram.
The design features of prefabricated forms affect the degree of wall heating. The absence of polystyrene allows this figure to be increased. If necessary, collapsible structures used for the construction of buildings can be made with your own hands.
Installation of formwork for strip foundations: installation features
The most popular type of foundation used for self-construction houses and other buildings - strip. Before organizing such a foundation, it is necessary to carry out appropriate preparatory work. These include project development and preparation construction site. In addition, you need to mark the area allocated for the construction of the foundation.
The installation of formwork for a strip foundation is not particularly complicated, but there are some nuances that need to be known and observed. For example, it is recommended to fill in layers. The process itself occurs as follows: the cavity located in the block is filled with a concrete solution, after which all that remains is to wait for it to harden.
Helpful information! Arranging the fittings is not a requirement. It is installed if there is a need to increase the strength characteristics of the structure.
The reinforcement is tied inside the block elements. There is no need to dismantle the polystyrene foam, as it will serve as a heat insulator. It is important to remember that before you start pouring the cement mortar, you will need to check the accuracy of the placement of the blocks in the ditch.
If necessary, permanent formwork for a polystyrene foam foundation is strengthened using additional elements. It is very important to achieve the correct base geometry. This technology has many advantages. When using permanent blocks made of expanded polystyrene, the cost of organizing the foundation is reduced by at least a third.
Formwork for a monolithic foundation: Self-installation steps
After organizing the foundation of the future structure, you can begin installing the formwork. This operation is conventionally divided into three stages: installing blocks, tying reinforcement and pouring mortar. Each stage is carried out in accordance with building codes and rules. During work it is necessary to observe safety precautions. Let's look at each stage in more detail.
Installation of blocks. First, the first row of the form is installed, which will be used to pour concrete. It is worth noting that installation is carried out only on a waterproofed base surface. The formwork for the polystyrene foam foundation must be tightly fixed using reinforcement rods. These elements are the connecting link between the base and the formwork itself.
Experts advise checking the accuracy of the work performed, as deviations from the original design dimensions are possible. The presence of outlets for partitions is also very important point, which you need to pay attention to. After organizing the first row, you can begin laying the second. The technology for installing blocks involves a chessboard system, in which each subsequent row is shifted relative to the previous one. As a result, the joint of the elements of the first row should fall in the middle of the block of the second strip.
Knitting reinforcement. Installation metal structure is one of the most important aspects of organizing any type of construction pie. Reinforcement is used to strengthen foundations, walls, and monolithic ceilings. The formwork for the foundation, consisting of blocks that are laid in rows, must be surrounded around the perimeter with rods located in a horizontal plane.
In order to simplify the installation of fittings, each block has special grooves that are located in the jumpers (internal). Horizontal rods are mounted in such a way that each subsequent element overlaps the previous one (overlapping). Next, the rods are connected to each other, as well as to vertical elements using a special wire.
Note! Reinforcement not only increases the strength of the structure, but also reduces the cement pressure on the mold.
Pouring the solution. Before you start pouring permanent formwork with your own hands, it is recommended to take care of laying communications inside the forming structure. The cement mortar used for formwork must not contain foreign additives or impurities (for example, crushed stone). The operation itself is quite simple. Pouring is carried out step by step, and the height of the concrete layer should not exceed 1 m. This indicator corresponds to the size of 3-4 permanent blocks of the structure.
The price of permanent formwork for the foundation is lower than the cost of standard analogues, which involve the use of plywood and boards. It is important to remember that the poured solution requires leveling. For these purposes, a special tool is used - a vibrator. If you do not have the necessary electrical equipment, you can use a regular bayonet shovel.
Permanent formwork for walls: casting technology
Independent use of such a wall casting technique requires an understanding of the technological process. Most often, this type of construction is used by non-professionals in the construction of private one-story houses, as well as garage structures. The construction of formwork made of polystyrene foam can be done alone. However, several people will complete the installation of walls much faster.
The advantage of using polystyrene foam molds is that they are lightweight. Thus, physical activity in this case is reduced to a minimum. Before starting construction, it is necessary to study step-by-step algorithm actions and nuances that allow you to answer the question of how to properly make formwork.
Walls made using this method are recommended to be installed on strip foundation. This base is best suited for construction using permanent foam molds. It is important to remember that the use of cement mortar to fill walls often imposes a certain limitation on the number of rows of blocks. Experts advise placing 4 rows of forms, and they must be securely connected to the base of the building through reinforcement.
Helpful information! It is not recommended to pour all the concrete at once. First, you should perform a partial pour and wait some time for the solution to shrink. As a rule, this procedure takes no more than 3-4 hours. Next, the cement mortar is added.
When constructing monolithic structures, casting walls are often used special forms– shields. They are connected using special coupling bolts and form a gap into which concrete is poured. Such products can have different dimensions. For example, their maximum height is 3.3 m, and the width ranges from 0.25 to 2.4 m. After the solution hardens, this structure is dismantled. The size of the formwork panel is selected depending on the individual characteristics of the structure being built.
It is worth noting that another feature of permanent formwork used to fill walls is its instability. This is due to the fact that the concrete poured into molds has a large mass. Thus, even blocks laid in 4 rows and equipped with reinforcement require daily waiting. This time is quite enough for the solution to settle and thicken.
When installing permanent blocks made of expanded polystyrene, special attention must be paid to their joining. Individual structural elements must be connected with special care so that the surface of the first rows is as smooth as possible. Otherwise, when adding subsequent rows, the wall may collapse due to their distortion.
An alternative to polystyrene foam is plastic. Plastic formwork for monolithic construction used when it is necessary to ensure good strength and rigidity of the structure. The advantage of such products is that they are highly wear-resistant.
Cladding work allows not only to give a wall cast in formwork a complete look, but also to enhance its protective characteristics. Finishing is carried out on almost all types of structures. After pouring the wall, as a rule, there is no need to level it. This is determined by the design of the forms. Thus, there is no need to apply a thick layer of plaster.
There is no point in saving on the finishing of walls and other surfaces, since the total cost of work is already reduced due to the use of polystyrene foam. The price of this material is much lower than the cost of traditional formwork options.
Most often, a special mesh, which can be made of fiberglass or metal, is sufficient to decorate the wall. This mesh is connected to the concrete surface using adhesive composition, after which it is sealed with plaster or putty.
It is in this way that not only standard rectangular walls are processed, but also round columns. The formwork for such structures is most often made of plastic. There are also cardboard forms.
Note! In addition to standard methods of finishing the outer surface of concrete, there are other, no less popular options. For example, very often tiles and artificial stone are used as cladding.
For interior decoration As a rule, plasterboard material is used for walls. Installation of gypsum boards is carried out in two ways - using profile elements or glue. This cladding method is very popular not only due to its simplicity and effectiveness, but also because this material provides good sound insulation.
Racks for organizing a permanent form of floors
The traditional option for organizing floors in monolithic or any other buildings involves the use of special telescopic (sliding) racks. These products are used to fix temporary flooring, which is made from moisture-resistant plywood for formwork. This method is not convenient, as it requires a lot of time and quite a lot of physical exertion.
The stand, which plays a supporting role, consists of several structural elements. The lower part of the telescopic product is equipped with a tripod, which ensures the stability of the pipe. In turn, in the upper part there is a special attachment, which is necessary for capturing and holding the construction beam - the crossbar. All racks for floor formwork are divided into two categories depending on the location of the thread. Some of them are equipped with open threads, while others are equipped with closed threads.
The pipe, which has a smaller cross-section, is distinguished by the presence of special holes along its entire length. The pitch of the holes can be different - from 11 to 17.5 cm. Outer pipe equipped with a support nut. As a result, when it becomes necessary to fix the rack at a certain level, a special earring is threaded through the holes in the pipes. This element has a support (nut), so it is held in the desired position.
Telescopic formwork posts can vary in length. This figure ranges from 1.7 to 4.5 m. They can withstand quite heavy loads (up to 4 tons). It is worth noting that such support products are made of metal, so they are coated with special anti-corrosion compounds, since steel can rust.
Permanent formwork for floors: features and characteristics
Unlike the standard method, which assumes the presence support posts, polystyrene foam formwork for floors has a completely different installation technology. As the basis for such a system, special matrices are used, which are made from dense and durable polystyrene foam.
Such matrices should be laid on load-bearing walls. The advantage of this method is that these elements are lightweight, so their installation does not require serious physical effort.
Note! Before starting work, it is necessary to calculate the floor formwork.
Docking the matrices together is quite simple. Each product is equipped with a tongue-and-groove connection system. Thus, any person who does not have experience in this field can perform such an installation. Thanks to the tongue-and-groove system, it becomes possible to quickly organize a continuous flooring.
Such formwork for a monolithic floor can withstand a layer of concrete up to 15 cm thick. As a rule, this value is quite sufficient for organizing reliable design. Before you start pouring concrete, it is necessary to place reinforcement between the joint areas of the floor elements. Metal carcass must be assembled into a continuous beam that occupies the entire width of the gap.
Then you need to place the reinforcing mesh on top of the matrices. It is made of rods whose diameter ranges from 10 to 15 mm. Knitting of reinforcement is done in the traditional way - using a special wire.
The final stage of creating volumetric floor formwork involves pouring concrete, after which you need to wait for it to harden. In this way, floors are organized using polystyrene foam matrices. The result of this process is a durable structure that can withstand significant loads.
After the cement mortar hardens, the formwork made of polystyrene foam is not dismantled. It remains in the ceiling pie and from that moment begins to perform a thermal insulation function. This method of organizing a structure is more technologically advanced when compared with the traditional method, which takes into account the use of removable beams for floor formwork.
It's important to remember that independent use Such technology requires an understanding of its nuances. The main thing is that even before starting work, you need to know that laying the floor elements requires care. Any design errors or displacement of blocks during their installation can lead to the collapse of the structure.
Permanent formwork: pricesin the modern market
The cost of the blocks is an important point to pay attention to. The price of building blocks from which permanent formwork is made is influenced by two key factors:
- density of expanded polystyrene;
- dimensions of parts.
The price of permanent formwork for a polystyrene foam foundation must be taken into account in the construction estimate. When choosing individual elements of the forming structure, it is recommended to pay attention to their density. This indicator affects the resistance of the structure to pressure. The higher the density of the parts, the correspondingly higher loads they can withstand.
Note! Experts advise purchasing blocks whose density ranges from 25 to 35 kg/m³.
The average cost of a block made of polystyrene foam is approximately 160 rubles. It is worth considering that this price corresponds to products with dimensions of 1500x250x250 mm, having a density of 30 kg/m³. Structures 1.5 m long have an adjustment function due to the installation of jumpers different sizes(15-25 cm). Products whose length is 1 m are cheaper - from 130 rubles. for 1 piece
If you plan to use standard construction technology, then it is recommended to study the cost various materials. The price of telescopic stands depends on the features of their design and the manufacturer. Currently these supporting elements can be purchased for 500-5000 rubles. It is not recommended to buy the cheapest materials and tools, as they most often have low technical characteristics.
Support elements are used to hold wooden structure, which is made from laminated plywood for formwork. The price of 1 sheet of such material varies from 600 to 3000 rubles.
Fixed forms are a good alternative to standard structures that are assembled from wood and plywood. Such formwork allows not only pouring concrete, but also serves as a reliable thermal insulation material. It is actively used in private construction, but requires studying the installation instructions and observing safety rules.
The creation of permanent polystyrene foam formwork is usually thought about when it is planned to build a building from monolithic reinforced concrete. The outer blocks of this auxiliary structure are thicker than the inner ones, which makes the structure for the foundation super strong. Decide if you can take on self-installation permanent formwork made of polystyrene foam, it is worth considering its advantages and disadvantages.
Description of polystyrene foam formwork from the positive and negative sides
Permanent formwork made of lightweight polystyrene foam is characterized by such advantages as:
![](https://i2.wp.com/prorab.guru/wp-content/uploads/2017/06/nesemnaya-opalubka-iz-penopolistirola-1.jpg)
Builders include the following disadvantages of formwork assembled from polystyrene foam blocks:
![](https://i0.wp.com/prorab.guru/wp-content/uploads/2017/06/penopolistirol.jpg)
Financial costs of purchasing a synthetic support structure
When purchasing permanent polystyrene foam formwork, you leave a relatively small amount in the store. At least this design costs less than formwork made from natural materials.
The price of permanent formwork blocks made of polystyrene foam is determined by their appearance
Table: cost of formwork depending on purpose, size and thickness
Name | Dimensions, mm | Thickness of the thermal insulation layer | Price per m² in rubles |
Series 25 (one-piece) | |||
Main wall block | Length - 1250, width - and height - 250 each | Both from the inside and from the outside - 50 | From 490 |
From 500 | |||
Wall block for corners (left or right) | Length - 700 (first part) and 450 (second part), width and height - 250 each | From 500 | |
Rotary wall block | Length - 700, width and height - 250 each | From 500 | |
Series 30 (one-piece) | |||
Main wall block | Length - 1250, width - 300, height - 250 | On the inside - 50, and on the outside - 100 | From 560 |
Wall block for end zones | From 570 | ||
Wall block for corners (left and right) | Length - 1250 (one side) and 500 (other side), and width - 300 | From 570 |
Installation of permanent formwork involves the use of various fastening elements and tools. Their acquisition is relatively cheap.
In addition to polystyrene foam blocks, reinforcing bars, end caps and other devices are needed to create formwork
Table: cost of additional elements
Technology for laying permanent polystyrene foam formwork
To correctly place permanent polystyrene foam blocks before pouring liquid concrete, you do not need any special skills. By following the requirements, the structure can be assembled without problems.
The walls of the house can be assembled from ordinary wall, as well as from rotary and corner polystyrene foam blocks
How to install an auxiliary structure
When starting to construct formwork from polystyrene foam blocks, you need to understand that the process is reminiscent of assembling a construction set. Each structural detail made of artificial raw materials has recesses at the bottom and spikes at the top. Therefore, the blocks are connected tightly and easily assembled into the desired structure.
Grooves and protrusions make it easy to assemble the formwork
Expanded polystyrene formwork is installed using the following steps:
- The foundation of the house is covered with canvas, which serves as a barrier to moisture. On waterproofing material install the first line of polystyrene foam blocks. Reinforcement elements are threaded inside them (vertically), ensuring reliable connection between all fragments of the structure. When placing blocks, they look to see if the dimensions correspond to the specified parameters, monitor the shape of the formwork and leave voids for outlets for internal partitions.
- The next lines of blocks are set so that they overlap the joints of the structural elements laid earlier.
Elements of polystyrene foam formwork are laid out in the same way as bricks
- The structure is strengthened along the perimeter, that is, two metal rods are inserted into each line of blocks. The reinforcement is immersed in the material exclusively in the horizontal direction. To facilitate this task, small protrusions are created on the jumpers on the inside of the blocks. The metal elements are laid with overlaps and fastened to each other with steel wire. In addition, the reinforcement is connected in the same way to pins inserted vertically into the base.
To create a reinforced frame, pins with a diameter of 12 mm are suitable
- The necessary communications are carried out through the created structure. Then mounting holes are made in the formwork. It will not be possible to do this later: poured and already hardened concrete will become a serious obstacle.
- For pouring, use a composition that is devoid of large crushed stone, since it is capable of deforming the walls of the polystyrene foam structure. The formwork is filled with mortar in layers of one meter. The penultimate layer of concrete is pressed and leveled. When it has completely hardened, pour the last layer of mortar.
It is more convenient to pour liquid concrete into the formwork through a hose
Video: construction of external walls from polystyrene foam blocks
Video: construction of an internal wall from polystyrene foam elements
Video: how to connect walls made of permanent formwork with a roof
Is it possible to make a permanent structure from polystyrene foam yourself?
At the plant, polystyrene foam blocks are produced using complex technology in several stages:
- Construction raw materials are treated with water vapor, which in production is called pre-foaming. As a result, the pores of the material become wider, and the material acquires a different density - 35 kg/m³.
- Foamed polystyrene foam is kept in a hopper until it is ready for further processing. After a day, the condition of the granules in the material is normalized and excess liquid comes out of them.
- Blocks are formed from expanded polystyrene. To do this, the material is placed in special molds and foamed again.
- The finished blocks are cooled with water and removed. After this, there is a break in production for about 24 hours. The exact downtime depends on the humidity and air temperature in the room where the formwork is being made.
- Waste from production is crushed and converted into a storage facility. The remaining material can be used again.
The polystyrene foam formwork block is the result of multi-stage processing of the material
It is very difficult to repeat all of the above steps at home. In addition, the production of polystyrene foam blocks involves the use of a steam generator - an expensive apparatus.
The steam accumulator for the manufacture of permanent formwork must have certain characteristics:
- foaming temperature - from 100 to 115 degrees;
- molding temperature - from 130 to 140 degrees;
- steam pressure during foaming of the material - from 1 to 1.5 atm;
- steam pressure during the molding process - 4–5 atm;
- steam consumption during foaming of raw materials - from 50 to 100 kg/h;
- steam consumption during molding is from 25 to 50 kg/h.
Expanded polystyrene blocks are produced at the factory; it is better not to undertake their production at home
In addition to the steam generator, the production of polystyrene foam blocks requires pneumatic transport, a residue crusher, a receiving hopper and components.
One block of polystyrene foam is created in 2 minutes. On average, during one production operation at the plant, from 100 to 300 formwork elements are produced.
It turns out that making polystyrene foam blocks with your own hands is unwise. It’s easier and cheaper to purchase ready-made permanent formwork.
Video: nuances of building a house based on permanent formwork
Traditionally, when constructing monolithic structures, liquid concrete is poured into temporary wooden formwork, which is dismantled after the foundation or walls have hardened. This method is considered quite expensive and labor-intensive. Fixed formwork made of expanded polystyrene (foam) is much easier to install and does not need to be dismantled. The concrete solution is poured directly on top of it, and the porous material located in the thickness of the building mixture plays the role of additional insulation.
In addition, designs of this type have many other advantages.
Advantages of expanded polystyrene formwork
The foam frame has the following advantages:
- It has high thermal insulation characteristics. In the case of installing a foundation or walls made of foam concrete, the surface will not have to be additionally covered with sheets of foam plastic.
- Suitable for the construction of complex multi-storey buildings and for simple buildings;
- The installation process takes significantly less time.
- Minimum weight of blocks.
- Not susceptible to fungi, mold and termite attacks.
- Expanded polystyrene is much cheaper than wood.
- It is characterized by increased moisture resistance and tightness.
In addition, the foundation installed on polystyrene foam formwork will have increased energy-saving properties and vapor permeability.
However, given all the advantages of this material, permanent foam formwork also has a lot of disadvantages.
Disadvantages of permanent polystyrene foam formwork
Despite the fact that polystyrene foam is often labeled as an environmentally friendly material, this is not entirely true. Firstly, it contains styrene, which is a very dangerous substance for humans. Despite the fact that this component undergoes a polymerization process, the poison still continues to be released into environment(more active under the influence of oxygen and heat), and, accordingly, inside a residential building. In addition, the material is treated with fire retardants to increase its fire resistance. These components are also harmful to humans.
In addition, the following disadvantages can be identified:
- After the end of its service life (after 30-50 years), polystyrene foam must be disposed of, since it does not decompose, but only poisons the environment.
- A house built using foam plastic is almost impossible to reconstruct.
- Removable foam formwork can be installed and concrete can be poured at a temperature not lower than +5 degrees.
- Despite the fact that polystyrene foam belongs to the category of low-flammable (G1) and low-flammable (B1) materials, its level of smoke generation is very high - DZ. During a fire, polystyrene foam releases toxic gases.
All these nuances must be taken into account before installing the polystyrene foam formwork structure for the foundation and walls. It is also worth determining the type of formwork.
Types of polystyrene foam frames
Permanent formwork of this type is produced in several ways:
- Foam plastic hollow blocks are used, equipped with removable or non-removable stiffeners, which externally resemble elements of a children's construction set. During the manufacturing process of the frame, a wall is formed from polystyrene foam and reinforced concrete, which is enough to be covered with finishing and plastering material. Most often, this technology is used in the construction of load-bearing walls.
- Permanent facing formwork is installed.
- Special reinforced foam panels are used, the thickness of which ranges from 1 to 2.5 cm. The panels are additionally strengthened reinforcement mesh. Such structures are concreted by spraying.
Also today on sale you can find a huge number of polystyrene foam blocks with complex geometry. Thus, to prepare the formwork structure, you only need to purchase panels the right size and place them correctly.
How to install permanent foam formwork
To make a strong formwork structure from polystyrene foam with your own hands, you must complete the following steps:
- Mark the area (corners must be carefully measured) and draw up a plan for future construction.
- Prepare a trench 0.5 m deep and 0.4 m wide around the perimeter of the future structure. The bottom of the pit must be carefully leveled. Since the formwork will not be dismantled, it is necessary that it be installed on a perfectly flat surface.
- Fill the bottom of the trench with a drainage cushion (both sand and crushed stone) 15 cm high. Compact and level the underlying layer.
- Install reinforcing rods into the cushion (they will be needed to fix and connect the formwork blocks).
- Pour a thin layer of concrete onto the pad. This is necessary so that the formwork blocks are laid on a flat and durable surface.
- Once the concrete “sole” has hardened, place the polystyrene foam blocks onto the reinforcing bars. Laying should begin from the corner in a checkerboard pattern.
- Install connecting bridges between the formwork elements. It is recommended to connect the blocks using tongue and groove technology, this way you can reduce the number of installation seams. For corner formwork elements, it is better to use appropriate fasteners.
- When the 3rd row of blocks is installed, be sure to align them not only horizontally, but vertically. The side surfaces of the elements must fit tightly to each other. At the same stage you need to fill out inner space formwork with concrete mortar with a density of at least B15. If you used crushed stone when preparing the concrete solution, make sure that its fraction does not exceed 0.8 cm.
- Continue laying blocks, filling them with concrete every 3 rows.
- When all the voids are filled with mortar, we can assume that the permanent polystyrene foam formwork is ready. Now you can proceed to the actual pouring of the foundation or walls. It is best to use a deep vibrator for this.
With the help of such formwork, you will get walls that in cross-section resemble a “sandwich”, consisting of 2 rows of polystyrene foam with a layer of durable concrete monolith. In this case, you will have to spend less effort and money than building a bulky wooden formwork structure.
How much will foam formwork cost?
When choosing formwork elements made of expanded polystyrene, it is better to give preference to blocks whose density is at least 20-35 kg/m3. Such products will better withstand the pressure of the concrete solution. The average cost of products is shown in the table.
Block name | Density, kg/m 3 | How many blocks can be poured with concrete in one “approach” | Cost, rub |
---|---|---|---|
Prefabricated wall block (BSS) | 18-20 | 2 | 150 |
FSU | 20-25 | 3-4 | 180 |
20 | 2 | 200 | |
BSS with thickened wall (75x50) | 25 | 3-4 | 234 |
BSS for internal partitions | 20 | 2-4 | 120 |
Main wall block (BSO) | 20 | 2 | 150 |
BSO | 25 | 3-4 | 210 |
BSO | 30 | 5-6 | 230 |
End cap (ZT) | 25 | -/- | 25-30 |
The standard length of a polystyrene foam block is 1.5 m, but meter-long formwork elements can also be found.
Prefabricated blocks are much more convenient to use, since you can adjust the width of the structure using special jumpers of different lengths (from 150 to 250 mm).
If you are engaged in construction in harsh climatic conditions, then it is better to give preference to products with enlarged walls.
In addition, you will need to purchase lightweight, thickened and standard metal-plastic jumpers, the cost of which ranges from 8 to 12 rubles. It is also recommended to buy a funnel for pouring concrete from galvanized sheet metal for 2,000 rubles.
- 3.3 blocks;
- 0.12 m 3 concrete;
- 10 kg of reinforcement.
If we take into account the cost of boards, bars, metal fasteners and other parts that would be required for wooden formwork, then a foam structure will cost several times less. In addition, after its manufacture, nothing will have to be removed from the concrete mass.
Modern monolithic building construction technology allows a person to acquire their own home in a record short time. And in many ways, the emergence of this technology was facilitated by permanent formwork made of polystyrene foam. At first, such formworks were removable and were used as a kind of form for pouring concrete. But today, with the development of the construction industry, it is already possible to build houses using permanent structures.
Fixed polystyrene foam formwork
In this case, dense foam blocks, hollow from the inside, are used. Concrete is poured into these voids, but after it hardens, the formwork is not dismantled, but remains an element of the building, performing thermal insulation functions. As a result, the house is thermally and sound insulated, while the foam grips the walls not only from the outside, but also from the inside.
Cost of formwork and average market prices
Appearance | Name | Dimensions, mm. | Thermal insulation thickness, mm. | Price (per sq.m.) |
Series 25 (one-piece) | ||||
Main wall block | Length – 1250 Width – 250 Height – 250 | internal – 50 external – 50 | From 490 rub. | |
Wall end block | From 500 rub. | |||
Length – 700/450 Width – 250 Height – 250 | From 500 rub. | |||
Rotary wall block | Length – 700 Width – 250 Height – 250 | From 500 rub. | ||
Series 30 (one-piece) | ||||
Main wall block | Length – 1250 Width – 300 Height – 250 | internal – 50 external – 100 | From 560 rub. | |
Wall end block | From 570 rub. | |||
Corner wall block (left/right) | Length – 1250/500 Width – 300 | From 570 rub. |
Comparative cost per 1 m2
Let's consider it in more detail using the example of popular manufacturers. First, let's find out: what explains this cheapness? First of all, manufacturing process not paired with special costs, because of which the price may jump slightly only due to increased demand in a particular region of the country.
Thus, the Mosstroy company produces a wide range of polystyrene foam blocks at the following prices:
- straight blocks - from 490 rubles;
- straight blocks 5 cm thick - about 800 rubles;
- 10-centimeter corner products - the same;
- jumpers and various kinds of plugs - about 25 rubles each.
Note! These are Moscow prices. If we take Blagoveshchensk, for example, then such blocks there will generally cost about 300-350 rubles apiece.
Permanent formwork made of polystyrene foam is often constructed from blocks produced by the Samara company Termomonolit. The cost of its products starts from 780 rubles; The products differ not only high quality, but also the ideal compatibility of foam with plastic.
The most expensive blocks are products from Technoblock, lined with artificial stone. They cost about 1800-2500 rubles per square. Be that as it may, the costs will still be lower than if any other building material were used.
How to calculate the cost of construction work?
So that you can clearly understand what the savings will be, we will give an approximate calculation of the cost of building a house using the described formwork. It (cost) depends not only on the price of building materials, but also on the size of the future building. Here are the building materials needed for one square meter.
Now let’s find out how much it will cost to create the formwork, if we do not take into account the cost of the work:
- the area of the walls (openings are taken away) will be 180 square meters (10x10-40);
- the price of the formwork itself is 88,200 rubles. (180x490);
- the price of filling with mortar is 81,000 rubles. (180x15 = 27x3000);
- price of fittings – 37,800 rub. (180x10 = 1.8x21000).
Let's summarize. On average, the cost of materials for such a house will be 207 thousand rubles, or, in other words, 1150 rubles per square.
Insulation of the foundation with penoplex
Previously, we talked about how to properly insulate a foundation using penoplex, talked about the cost of materials and work, we advise you to read this information
The innovative method of monolithic construction of buildings has become an excellent opportunity for those who dream of acquiring their own housing. After all, until recently, even low-rise buildings that did not differ in special dimensions required large time and financial costs. Today, cottages are built literally within a few days, and the problem of material investments is no longer so painful for the developer.
But these are not all the strengths of polystyrene foam formwork. The list of their characteristics is quite large, because technically and physically this material is at a high level. Among these characteristics it is worth highlighting:
- thermal and noise insulation;
- ease of connecting communication networks;
- environmental safety;
- possibility of combination with any of the building materials;
- ease of installation;
- moisture resistance;
- light weight;
- resistance to mold or mildew;
- non-flammability.
Types of permanent formwork
Before we begin to describe the polystyrene foam structure, we will consider other types of this technology, since it is not the only one. The point now is that permanent formwork can be constructed not only from expanded polystyrene, but also from other materials. Therefore, in this light, formwork can be:
- chip-cement;
- foam;
- universal block;
- fibrolite.
All of the described types are popular in the construction craft, but polystyrene foam is still considered a classic. And the reason for this is the numerous advantages of the material.
The main types of foam formwork
The design described in this article can also be divided into several main varieties. Moreover, this house construction tool is divided into two classifications:
- by design features;
- by area of use.
Depending on the design features, foam plastic formwork is divided into only two categories, which are equally present in the field of monolithic construction. This:
- block structures;
- panel structures.
A distinctive feature of block formworks is that they are very reminiscent of the above-mentioned construction set for children. Essentially, it is a pair of blocks that snap into place and connect to each other using special jumpers. There remains a small gap between the foam sheets, into which, in fact, you need to pour concrete mortar.
The second type of design is more reliable, especially if we're talking about about building houses. In this case, the foam panels are reinforced on both sides with iron mesh, then concrete is poured - but on top, and not inside the structure. As a result, the slabs of material are completely covered cement composition. This is very economical way construction - concrete-coated panels no longer require further processing (which distinguishes them from those mentioned above, which need to be protected from aggressive environmental influences).
Now let's look at the classification of formwork depending on the area of application. In this case, the designs can be:
- for foundation construction;
- for installation of ceilings;
- for building walls.
Areas of use of the design
Permanent formwork made of polystyrene foam in the construction process is an obvious saving of not only time, but also material costs. As a rule, savings when constructing buildings using this technology average 40 percent.
Note! This is largely due to the fact that the cost of expanded polystyrene as a building material is quite low. In addition, permanent structures made from it eliminate the need for additional manipulations related to strengthening and thermal insulation of walls.
If we compare this technology with traditional brickwork, then the material aspect of the issue is very important. And after analyzing prices for Construction Materials It becomes obvious that building a house using permanent formwork is more economical. For example, as of last year the cost of one wall erected using this technology cost the developer approximately 1 thousand rubles per square meter. For comparison: the cost of a wall made of sand-lime brick was then about 1.8 thousand per square. Aerated concrete walls were cheaper, but polystyrene foam is still the most profitable option.
Do-it-yourself installation of polystyrene foam permanent formwork
It will be quite easy for people who know about all the features of the material and the construction process as a whole to carry out installation. Each block (including the corner one) has special grooves at the bottom and protrusions at the top (like in the same Lego constructor). It is thanks to this that the reliability and strength of the connections is ensured, and this is what allows the installation of blocks. The process itself consists of several stages.
Stage one. Installation of foam blocks
The foundation is covered waterproofing coating, after which the first row of blocks is installed. Reinforcing bars are threaded into these blocks to connect them.
Note! It is necessary to carefully monitor the accuracy of the dimensions and shape of the future structure, as well as to ensure that there are outlets for internal partitions in the required places.
The next rows of blocks are slightly shifted relative to the previous ones (as is the case with bricks) in order to increase rigidity.
Stage two. Installation of fittings
Along the entire perimeter of the structure, two pieces of reinforcing rods (horizontally) of the required diameter are laid in each row. Especially for this purpose, the internal jumpers of the blocks have small protrusions. The reinforcement sections are laid overlapping and screwed with wire to each other and to vertical pins installed in the base. Thanks to the reinforcement, the structure will be more durable, and the pressure of the solution on the walls of the structure will noticeably decrease.
Stage three. Pouring the solution
All engineering Communication that will be introduced into the house must be laid before pouring. In addition, mounting holes should be provided for them. Otherwise, after the solution hardens, you will face serious difficulties.
The solution itself is prepared traditionally, although permanent formwork made of polystyrene foam excludes the use of coarse crushed stone, since it can damage its walls. The solution is poured in layers of one meter, before the last row it is compacted, leveled and allowed to harden. Similarly, the walls are built to the required height.
Video - Installation of polystyrene foam formwork
Design features and benefits
In many ways, the design of such formwork is reminiscent of the well-known children's construction set, all the elements of which are connected by snapping. Each element’s body consists of a pair of foam sheets connected by special bridges, 5-10 centimeters thick. Moreover, the thicker the sheet, the colder the room it can be used. The ends of the elements are protected by special plugs, also made of polystyrene foam.
Note! This kind of formwork is used in the construction of both private houses and buildings with four to five floors.
The main advantage of the technology is its low cost and high speed installation. The structure itself is already insulated, so in winter the heat will stay in the house, and the walls will not freeze. Moreover, the weight of the formwork is insignificant, so installation work can be carried out without the use of special equipment.
Flaws
As it turns out, foam formwork has some disadvantages. Some say this material is flammable. Yes, this is true, but few people know that wood is more flammable. It is also known about the toxicity of burning polystyrene foam, but again, if the technology is followed during construction (that is, the sheets are covered with plaster or any other material), then the flame is unlikely to reach the formwork.
Note! Of course, when purchasing, you should definitely ask the seller about the availability of certificates - this way you will be sure that you are purchasing products that are harmless to health.
Now let's talk about the really significant disadvantages.
- It is difficult to remodel a house with such formwork, so the design should be thought out in advance - this will help anticipate possible future changes (for example, to add a window you will have to cut through a concrete monolith, which is very difficult). It is also worth considering in advance the location of all communications, since it will be difficult to lay them after construction is completed.
- The blocks must be laid extremely hermetically, otherwise the external permanent formwork made of polystyrene foam will become great place for insects to live in and underground water will penetrate there. Although this can be partially prevented by using blocks treated with a moisture repellent and insecticide. But such products are more expensive.
- Finding builders who are well-versed in technology is not easy. In this regard, the cost of such work increases significantly.
- Formwork can be erected only in the warm season. If the temperature drops below zero, the concrete will no longer harden. It must be poured at least at +5 degrees, and if the weather is hot, then the concrete must be additionally moistened with water.
- At the end construction work There may be problems with high humidity. This is because the concrete is still hardening, but when it finally hardens, the moisture content may return to normal. The air can then be dried using a conventional dehumidifier.
- Walls made using this technology will not “breathe” well, since foam plastic, as is known, does not allow steam to pass through well. For this reason, the house must be equipped with high-quality forced ventilation.
- Finally, the house should be grounded due to the presence of metal fittings.
As you can see, the use of permanent formwork has not only obvious advantages, but also very significant disadvantages.