Classic version forms for foundations and walls in monolithic houses is a temporary structure made of wood and chipboard. Fixed polystyrene foam formwork – alternative way construction that does not involve 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 made of this material allows you to build a lightweight concrete structure. 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 parts can be purchased from hardware store or place your order online.

Another advantage of such forms is that they protect reinforced concrete from moisture. IN winter period this is especially important. 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, the most useful property of such forms is that their use allows you to preserve the structure of concrete during low temperatures(but not below +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 drawback similar technology 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 prevent normal ventilation 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, it is necessary to study the various options for permanent formwork 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, which 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 of these is wood chips, which provide 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 quite 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. The ideal option would be to lay concrete 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 in self-construction of houses and other structures is strip foundation. Before organizing such a foundation, it is necessary to carry out the 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! The organization of fittings is not prerequisite. 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 act as a heat insulator. It is important to remember that before you start pouring 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 pressure of cement 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 similar technique wall casting requires understanding technological process. More often this type construction is used by non-professionals in the case of 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 exercise in this case they are reduced to a minimum. Before starting construction, it is necessary to study the step-by-step algorithm of actions and nuances that will allow you to answer the question of how to properly make the 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, special forms are often used for casting walls - 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 their 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 polystyrene foam, it is necessary Special attention pay attention to their docking. 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 is 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.

Save on finishing walls and other surfaces are not worth it, 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 concrete surface by 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 finishing methods outer surface 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 efficiency, 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. The outer pipe is 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 requires the presence of 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 placed 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 the structure is more technologically advanced when compared with traditional method, taking into account the use of removable beams for floor formwork.

It is important to remember that independent use of 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 to pour 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.

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:

1. 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.
2. Suitable for the construction of complex multi-storey buildings and simple buildings;
3. The installation process takes significantly less time.
4. Minimum weight of blocks.
5. Not susceptible to fungi, mold and termite attacks.
6. Expanded polystyrene is much cheaper than wood.
7. 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 environmentally friendly pure 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:

1. 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.
2. A house built using foam plastic is almost impossible to reconstruct.
3. Removable foam formwork can be installed and concrete can be poured at a temperature not lower than +5 degrees.
4. 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. Additionally, the panels are reinforced with reinforcing 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 blocks using tongue and groove technology, this way you can reduce the number assembly 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 during cooking concrete mortar If you used crushed stone, then 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.

To pour the foundation, you need a forming element that will hold the liquid mass of concrete. For this purpose, formwork made from wooden shields, which is removable. The construction of formwork takes a lot of time. It has to be secured with many elements, and after pouring it has to be disassembled again. Permanent formwork is also used, which remains in the ground after pouring. New innovative technologies allowed us to create permanent formwork, which can be assembled like a children's construction set. The most well-known lately is the formwork for foundations made of polystyrene foam, with the use of which all processes for creating the foundation have remained unchanged, except for the method of forming the formwork itself.

Technology for using permanent polystyrene foam formwork

• Preparing to build the foundation

Let us consider in detail the entire process of creating a foundation.

When the project is ready and the dimensions of the foundation are known, the site should be cleared and leveled. After this, it is marked, according to which the main contours of the foundation begin to be determined. In the traditional version, you should then dig a trench according to the dimensions of the contour, lay a cushion of a mixture of sand and crushed stone in it, and then install the formwork. The pillow helps equalize loads, drains and is a heat insulator. A typical removable formwork is a complex wooden structure that includes many elements. In this case, you need to have certain skills and abilities. At this stage, significant differences appear new technology creating permanent formwork.

• Assembly of permanent formwork

How to make foundation formwork from polystyrene foam? Everyone knows the children's Lego set, which is assembled from cubes with protrusions and depressions. The protrusions of one cube are inserted into the depressions of another, and the result is a monolithic structure. A new formwork is created in a similar way. The protrusions and depressions of each formwork block are located below and above, respectively. It is assembled from separate blocks with jumpers inside. The body of the block and the lintels are made of the same material - polystyrene foam. The width of the cavities inside the blocks is calculated for the width of the foundation. Formwork is also made from individual elements and then assembled into a single structure. Blocks can be solid or collapsible. Collapsible design block is used to assemble the foundation according to a non-standard option.

In order for the blocks to hold the concrete, sand and gravel cushion the reinforcing bars on which the blocks will be placed are clogged. Then a layer of concrete is poured on top of the pillow, which levels the bottom to a horizontal level.

After the leveling layer has hardened, the formwork for the polystyrene foam foundation is installed. Expanded polystyrene blocks are placed on reinforcing bars protruding from the bottom of the trench. The blocks are connected to each other using the tongue-and-groove type, as well as with additional brackets. Vertically, the blocks are laid out in the same way with bandaging as bricks are laid. This way the vertical seams overlap. At the corners the blocks are cut in half. They are easy to cut by hand. Builders use special machines for this when high productivity is required.

If necessary, the strength of the connection is increased through the use of special foam. To strengthen the corners, it is necessary to use special corner elements. This design does not require additional fastenings, which are widely used for wooden removable formwork. However, it doesn't hurt to be on the safe side additional fastening, if the foundation is of large width and height. To do this, the polystyrene foam formwork for the foundation is additionally reinforced with boards, which are pressed against it from the outside and secured with spacers.

At the bottom of the trench, check for gaps under the blocks. They should be sealed with cement-sand mortar.

• Laying reinforcement

Reinforcement is placed in the formwork. The blocks provide space for reinforcement. First, vertical posts are installed to provide additional stability. Horizontal reinforcement is laid longitudinally overlapping in the grooves at the bottom and tied together with wire, with transverse rods and posts. The upper part is reinforced in the same way. The lower part of the reinforcement is installed immediately after laying the first layer of blocks. This greatly simplifies its installation.

• Preparing places for communications

The foundation requires passage holes for communications. To do this, transverse pieces of pipes are placed in the blocks. large diameter. This can be done before installing them in the formwork. Passages must be made in different places and with a reserve. A larger internal cross-section will allow you to lay communications at an angle and with a slope.

Advantages and disadvantages of permanent formwork

Flaws:

1. Expanded polystyrene does not like high temperatures. If a warm basement is built, then the walls with insulation should be reliably lined.
2. Thermal insulation from the bottom of the foundation is much worse than from the side.
3. High price.
4. Laying concrete is more labor-intensive, as uniformity is required.
5. The waterproofing properties of polystyrene foam do not provide complete waterproofing of the foundation. It requires separate waterproofing.
6. It is unknown how polystyrene foam block lintels will affect the strength of the foundation. Reinforcement with transverse reinforcement is required.
7. The material must be protected from action ultraviolet radiation. To do this, it is lined on the outside.

Technology with permanent formwork is used for the following purposes:

• housing construction;
• insulation of basements;
• insulation of swimming pools;
• insulation industrial premises and heated warehouses.

Where to buy permanent formwork?

The blocks are sold in large specialized stores. Typically, the length of the block is 500-1250mm, and the height and width are 250-300mm. There are companies whose main activity is the technology of permanent formwork made of polystyrene foam. They supply products and can install them and pour the foundation at the request of the customer. You can order blocks of the most suitable format from these companies. Buying formwork directly from a company may be more profitable, since stores make large markups on sales.

Before purchasing, you should correctly calculate the required number of blocks, taking into account the fact that they will be cut during installation and waste will remain. In addition, the blocks may be defective or damaged during installation. Therefore, stock availability is necessary! The house design may include curved surfaces. Therefore, to install the foundation, certain block designs may be required, which should also be ordered. U different manufacturers can be different ways fastenings, sizes and shapes of blocks. Therefore, you should buy everything at once and from one supplier.

Previously, wooden formwork was mainly used to pour concrete mortar. But with the advent polymer materials range formwork systems expanded significantly.

The use of permanent formwork made of expanded polystyrene allows you to reduce labor costs for installation, and de installation work will not be required, since polystyrene foam formwork remains part of the monolithic structure for the entire period of operation.

Scope of application of expanded polystyrene formwork

Expanded polystyrene formwork is used in various fields of construction. This material is in demand in construction:

• public facilities;
• residential properties of various sizes;
• storage facilities;
• industrial buildings;
• agricultural objects.

In addition, forms made of extruded polystyrene foam can be used to create superstructures on existing structures. In most cases, permanent formwork is used for the foundation made of polystyrene foam. When using these forms, work proceeds much faster than using traditional methods.

When installing polystyrene foam formwork for the foundation, the forms provide the monolithic structure with additional thermal insulation and protection from moisture. Technical and operational characteristics of polystyrene foam for foundation formwork:

• material density – 35 kg/m3;
• compression resistance of at least 0.14 MPa;

• bending resistance – not less than 0.23 MPa;
• ability to conduct heat – 0.038 W/ (m*K);
• heat transfer resistance – at least 3.5 sq.m./W;
• moisture content no more than 12%;
• water absorption coefficient no more than 2%;
• ability to transmit water vapor – no more than 0.012 mg/m*h*Pa;
• The duration of independent combustion is less than 4 seconds.

It is not difficult to assemble the formwork for the foundation with your own hands, using polystyrene foam forms, since the elements are equipped with fastenings that operate on the tongue-and-groove principle. The foam foundation formwork does not require subsequent disassembly, that is, pouring the concrete solution is the final stage of the work.

Advantages and disadvantages of polystyrene foam formwork

Before purchasing polystyrene foam blocks, you should evaluate the advantages of permanent formwork, as well as become familiar with the disadvantages of this material. The main advantages of formwork for monolithic construction made of polystyrene foam:

• versatility, the blocks are suitable for the construction of simple buildings and complex monolithic structures;
• the blocks have high strength, they can easily withstand the loads exerted by the soil;
• the material is frost-resistant and has low thermal conductivity, thus the permanent formwork blocks act as a heat-insulating material;
• simple installation, the blocks are light in weight, so they are easy to carry and install;
• the material is chemically and biologically inert. It does not emit harmful substances that could contaminate the soil or ground water. Expanded polystyrene is not susceptible to biological threats; it is not affected by mold, insects, or bacteria.

However, recognizing the undoubted advantages of polystyrene foam formwork, one cannot fail to note the presence of obvious disadvantages. Some of them can be easily tolerated, however, they must be taken into account when choosing a material. The most significant disadvantages:

• expanded polystyrene is a material of artificial origin; it does not decompose over time. Therefore, at the end of the building’s service life, the formwork must be disposed of so as not to cause damage to the environment;
• you need to work with formwork forms made of this material at a positive temperature, not lower than plus five degrees;
• the material is low-flammable and does not support combustion, but it belongs to the smoke-generating category. Therefore, when ignited, the material will begin to release toxic gas;
• Special techniques are required for the process of pouring the solution. Needs to be filled concrete mixture in thin layers along the entire perimeter. This method of pouring increases the time for construction work.

It is impossible not to note the financial side of the issue. Permanent formwork blocks are disposable, that is, they need to be purchased in sufficient quantities to assemble the formwork according to the dimensions of the structure.

Purchased blocks must be properly stored until construction begins. They need to be stored in a place that is protected from exposure to sunlight and especially from wind.

Advice! The formwork blocks are lightweight, so good rush can scatter them in different directions.

Types of polystyrene foam formwork

Modern construction market offers various options for building materials; foam formwork is presented in the following options:

• hollow blocks, which can have monolithic and removable stiffeners. Such blocks are very convenient; they are assembled according to the principle of children's Lego constructs. Therefore, it is very easy to assemble expanded polystyrene formwork with your own hands;
• facing polystyrene foam formwork, facilitating the subsequent finishing of cast structures;

• reinforced panels.

Foam formwork is available in different shapes and sizes. If necessary, you can purchase blocks of complex geometry, which makes it possible to build buildings with unique architecture. Based on their shape, standard blocks are divided into the following options:

• main blocks of rectangular shape;
• corner molds for forming corners;
• end blocks with one blank wall.

If you plan to assemble foam formwork with your own hands, you must purchase blocks in accordance with the project. To construct a building with complex architectural forms, you can order the production of molds according to an individual project. But, of course, this will cost much more than buying standard forms.

Installation of permanent formwork made of polystyrene foam

Before you begin installing permanent foam formwork, you need to become familiar with the rules for working with this material. A typical mistake is a misunderstanding of the essence of construction technology using permanent polystyrene foam formwork.

It is strictly forbidden to pour a large volume of concrete into molds at once. The solution is poured in low layers, immediately along the entire perimeter of the building, that is, the method is not a way to quickly erect a building. Let's figure out the stages of installing permanent polystyrene foam formwork for the foundation:

• markings are made on the prepared site, and then a trench is dug;

• sand is poured into the prepared trenches. It is poured in layers with careful compaction of each layer. Total thickness sand cushion should be 15 cm;

• the next stage is waterproofing; for this, rolled waterproofing material is laid out in the trenches. Layers of material are laid with an overlap and mandatory gluing of the joints with construction tape;

Advice! Poorly performed waterproofing will lead to the fact that part of the cement laitance is absorbed into the ground, and this will negatively affect the strength of the foundation being cast.

• reinforcement is installed: it is necessary to tie the first row of horizontally oriented rods and vertical extensions are installed:
• Expanded polystyrene blocks are installed, which are fastened together by using existing fasteners. The following rows of horizontal reinforcement are installed in the grooves of the blocks;
• when the height of the foundation is laid out, pour the prepared solution into the molds;
• 3-4 rows of bricks are laid on top or boards are attached for the basement floor.

The technology for installing permanent wall formwork has much in common with installing forms for pouring the foundation. Before making the formwork of the walls, it is necessary to complete the foundation work. Check the evenness of the corners by taking measurements diagonally. If deviations are found, it is necessary to mark by pulling the string.

The base is thoroughly cleaned of debris and dust, and rolled waterproofing material is laid. You can use it instead coating waterproofing. Next, perform the work according to the following scheme:

• begin laying blocks from the corner of the future building. Next, subsequent blocks are attached, moving along the perimeter of the foundation;
• the blocks are installed so that the connecting grooves are in the upper part;
• Having completed the installation of the first row of blocks, check horizontal line using a level;
• If during the assembly process it turns out that some of the blocks need to be cut to length, then the cut should only be made through the grooves located at the edges. The cut cannot be made anywhere else, otherwise the block will no longer be usable. All that remains is to throw it away, since it will be impossible to attach the next element to it;

• After installing the first row of forms, they begin to perform horizontal reinforcement. The reinforcement is placed in special grooves on the forms. The vertical elements of the reinforcing mesh are tied horizontally using wire. Height vertical elements should be such that they protrude above the mass of poured concrete. This is necessary so that the next horizontal row can be attached to them;
• Before you begin laying the next rows of formwork, you need to check the design to mark the location of the openings for doors and windows. Further laying is carried out, leaving the intended openings free. Frames made of boards are mounted in the openings; to fasten the board frame, they use metal corners. The frames are installed taking into account the fact that it will be necessary to ensure the possibility of conducting control monitoring of the concrete poured below, therefore a gap must be made in the lower part of the frame. To ensure a sufficient level of strength of the openings, a frame made of reinforcement is additionally mounted in them;

• When installing the second and subsequent rows of polystyrene foam forms, the blocks must be placed in a checkerboard pattern; the joints in the rows must not be allowed to coincide.

Advice! Since the assembly of a new row begins from the corner, it is the corner block that needs to be shifted relative to the bottom one. The rest will be attached to it and will move automatically.

• During the process of laying blocks, it is necessary to provide for the possibility of laying the necessary utilities. That is, it will be necessary to install pipes of the required diameter so that technological holes of the required size are formed in the walls;
• it is necessary to install the forms in 3-4 rows (no more), after which the first concrete pouring is carried out. Pour the solution using special equipment. It is necessary to order a concrete mixer equipped with a pump for draining the solution. After pouring, the solution must be compacted by vibration;

• continue working, performing operations in the same order. After the solution has hardened, the next three or four rows of molds are assembled in height and a new layer is poured.

To give walls made using monolithic technology using permanent polystyrene foam forms a finished look, finishing work is carried out. In this case, leveling the walls is not required.

Most often, walls are plastered over a pre-fixed fiberglass or metal mesh. Then the walls can be painted, finished decorative plaster or veneer with any finishing materials for facades.

The use of a permanent version of formwork forms has its advantages, but the described technology is not without its disadvantages. However, the number of advantages still outweighs, so many owners decide to choose this option. Assembling formwork blocks is reminiscent of assembling elements of a children's construction set such as Lego. The blocks are not heavy, so it is quite possible to carry out the installation work yourself. But first you need to carefully study the installation technology and act strictly according to the rules.

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, the production process does not involve 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 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 Technoblok, lined 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 performing 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 great opportunity for those who dream of owning their own home. 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 strengths 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 connection of 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 tool The construction of houses is divided into two classifications:

• by design features;
• by area of ​​use.

Depending on the design features foam formworks are divided into only two categories, 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 construction is more reliable, especially when it comes to 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 with a 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, reinforcing bars are laid in each row (horizontally) required diameter in the amount of two pieces. 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 utilities 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 installation speed. 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 will penetrate there underground water. 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.
• Once construction work is completed, 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.