Block houses with fixed formwork. Fixed formwork houses - advantages and disadvantages

Formwork is a kind of form for cement-sand mixture, which allows you to form the correct geometry of the walls. Builders use both removable/temporary and non-removable/permanent formwork for the foundation. The second option allows you to save time and energy on dismantling work, as well as insulate and / or strengthen the walls, so it is increasingly used not only in industrial, but also in private construction.

Basic requirements for fixed formwork for the foundation

Consider what properties a fixed formwork should have.

• Moisture impermeability of material and tightness of seams. In the absence of this characteristic, the formwork will let concrete through, which will lead to overspending of the mixture and make it impossible to build a wall.
• Structural strength. This is necessary so that the formwork can withstand the pressure of the concrete mixture from the inside and the earth outside (at the foundation level) without deformation and cracking.
• The correct geometry of the elements. From blocks of different thicknesses or with irregular angles, it would be impossible to build even walls and 90-degree joints between them.
• Long period of operation. The longer the formwork is potentially able to last, the higher the likelihood of a long life of the whole house. If the formwork collapses quickly, the unsupported walls may not be able to bear the structural loads. In cases where the formwork does not have load-bearing properties, its destruction will lead to a deterioration in appearance due to delamination. decorative finishes facade.

Fixed formwork is an important element of an energy-efficient home

Table: advantages and disadvantages of fixed formwork

Fixed metal formwork

To ensure uniform wall thickness, sheets of metal formwork are connected with metal studs.

Metal formwork is one of the most expensive, therefore it is used mainly in industrial construction. It is made from sheets of aluminum or steel 1–2 mm thick on a metal frame and connected with anchors, pads or locks. The type and number of clamps are calculated in such a way that when the concrete is poured and hardened, the sheets do not bend either inward or outward.

When the formwork is made to order for a particular building, the manufacturer's craftsmen themselves carry out a test assembly of the structure, and only after confirming the suitability and completeness of all parts, the order is sent to the buyer.

Metal formwork has the most precise geometry. Permissible deviation in the parallelism of the sheet faces - no more than 2 mm over 1 m of the length of the product.

To prevent premature oxidation and destruction of the metal due to contact with concrete and groundwater, in production, sheets of future formwork are carefully coated with paint and grease. Often, galvanized steel is also used, or a powder coating method is used, which forms a dense polymer film on the sheet. But if welding is used during installation (welding sheets to the frame or reinforcement to sheets), it will be necessary to re-apply a protective compound (grease, mastic, paint) on the places damaged by temperature.

Powder coating metal sheets- one of the most effective methods their protection against corrosion

Metal is well suited for buildings with complex geometry, since thin sheets are easy to bend at any desired angle, make a round or arch. Finished walls are obtained very neat and smooth, if desired, they can be left without decorative finishes. Architects recommend using metal formwork in areas with complex loose soils.

In order to prevent the flow of concrete, the joints of the metal formwork are connected especially carefully.

But experts note some disadvantages of metal formwork:

• significant weight of steel sheets, which requires the use of special equipment;
• the need for additional thermal insulation of walls and foundations;
• sheet grease is easily wiped off and stains workers.

Installation of aluminum sheets for wall formwork under the force of a pair of workers

Aluminum sheets with the addition of silicon, which weigh much less than steel sheets and do not require protection from the external environment, will help minimize labor costs for the transportation and installation of metal formwork.

Fixed formwork made of reinforced concrete blocks

Reinforced concrete formwork blocks are recommended for large building objects, at least - a three-story private house. Since they have increased strength characteristics, in smaller buildings such a margin of safety will be redundant. Thin-walled blocks are great for arranging the foundation of a capital fence.

Reinforced concrete formwork blocks are installed with an offset

Reinforced concrete formwork blocks have the following advantages:

• allow you to save cement-sand mortar, due to the significant wall thickness;
• suitable for the construction of basements of any depth, as well as interfloor ceilings;
• mounted with a minimum width of the seams;
• provide a building service life of several hundred years.

The best formwork is obtained from reinforced concrete blocks with indicators F75 (frost resistance), W4 (water permeability), 6% (water absorption), 350 kg / cm 2 (mechanical strength).

An example of the location of the reinforcement in the formwork of reinforced concrete blocks, designed for two rods

Among the shortcomings of reinforced concrete blocks, there are:

• high weight (a block of 510x400x235 mm weighs 30 kg), due to which it is transported only by trucks, and only workers with a crane mount it;
• high price - about 500 rubles per unit.

Claydite-concrete blocks do not have such shortcomings. Providing high strength of the walls, these analogues of reinforced concrete blocks also do not require insulation of the house, since they already contain a heater - expanded clay.

Fixed plywood formwork

Moisture-resistant plywood is most often used for formwork, but even in this case, this material is usually used to create a temporary form. After all, the service life and weather resistance of a laminated plywood sheet is an order of magnitude lower than the same parameters of a concrete wall.

Permanent plywood formwork is acceptable in the following cases:

• in the manufacture of a temporary structure (for example, little house, in which the owner lives during the construction of the main house);
• during the construction of non-residential buildings (chicken coop, barn, wood storage);
• when it is necessary to save on construction as much as possible;
• if the walls and foundation are insulated along the outer contour and the plywood is completely protected from external influences.

In addition to dubious durability and strength, plywood formwork will require both a lot of labor and careful handling. Since the sheets do not have a tongue-and-groove system and special joints, you will have to assemble the structure with self-tapping screws, additionally seal each joint and make an external crate with supports (so that the plywood does not bend). In addition, non-waterproof plywood swells and peels from water, and laminated plywood repels the concrete mixture and never forms a monolithic wall with it, so it is very important to find waterproof material with good adhesion.

Technoblock - an example of the successful use of plywood in formwork

Designation in the picture:

• 1 - decorative facing layer;
• 2 - a layer of insulation;
• 3 - plastic supports for fittings;
• 4 - concrete pouring(a cavity is provided for it in the block);
• 5 - plywood sheet.

As a result, despite the cheapness and environmental friendliness of plywood, experts recommend using it only for temporary formwork. For a permanent one, it is better to use a technoblock - a composite product with an inner plywood layer.

Fixed formwork made of wood concrete

Arbolite is a relatively new, but already time-tested material. Formwork blocks made of concrete and wood chips began to be made recently, but such a mixture was used to insulate floors in Soviet times. Arbolite blocks are much cheaper and lighter than reinforced concrete blocks, so they are actively used in individual low-rise construction.

In some models of wood concrete blocks, a layer of insulation is provided - stone wool or polyurethane foam

Compared to other types fixed formwork wood concrete blocks:

• they are easily cut with tools for working with wood, which allows them to be adjusted on the spot to the desired parameters: cut corners, make arched curves, cut out fragments for better adhesion of walls at the corners of the building, reduce height / length;
• mounted quickly and without special equipment (1 m 2 of the wall is only 8 blocks);
• provide high strength, sound absorption and thermal insulation with a smaller wall thickness (compared to brick and polystyrene foam);
• safe for the health of others, waste can be industrially processed;
• strong enough to attach clamps downpipes and loaded elements of facade systems (guides for hanging siding, etc.);
• are not afraid of fires (can withstand up to 90 minutes of open fire);
• frost-resistant, suitable for regions with a harsh climate.

The disadvantage of wood concrete is its water permeability, therefore it is recommended to use it for building walls on a ready-made waterproofed strip or slab foundation. The use of wood concrete for arranging the foundation is undesirable, since it will need to be very carefully protected from moisture.

An example of the arrangement of formwork from wood concrete and brick

Arbolite is produced in the form of hollow blocks and panels. In the second case, the panel serves only as the inner contour of the wall, and the outer one must be equipped with bricks. The cavity between the materials is filled with concrete and reinforced, as with other types of formwork. This option is more difficult to install, but the finished house turns out to be warm (wood concrete), beautiful (brick) and durable (merging the strength characteristics of the three materials).

When buying blocks and slabs of wood concrete, pay attention to the eco-label, as some manufacturers use binders that are harmful to health (phenol, naphthalene). Be careful, plasticizer toxins can be released from the material even at room temperature.

Manufacturers of wood concrete formwork blocks offer options for both high-rise buildings and small buildings. Be sure to consult with a consultant so as not to spend extra money on concrete for pouring thin-walled blocks or not to mistakenly take blocks with too small voids.

Fixed formwork made of CSP

DSP (cement particle board) or sawdust concrete is another variation of a mixture of cement and crushed wood. It differs from wood concrete in the type of binder and the addition of sand. Therefore, DSP is a denser, stronger and heavier material, and its thermal insulation is worse than that of wood concrete.

Cement particle boards can serve as a finishing material when covered with decorative mineral chips.

Among the advantages of wood concrete formwork:

• the material breathes, so the house does not need to be equipped with forced ventilation and deal with the greenhouse effect in other ways;
• DSP is able to withstand fires, its fire resistance is confirmed by laboratory studies;
• plate consists of natural materials therefore does not harm nature and health;
• gives the house high strength: with a thickness of 25 cm, the wall is able to withstand three times more loads than a brick wall of the same thickness;
• DSP is resistant to sudden changes in temperature, therefore it is suitable for regions with a sharply continental climate;
• the material has sufficient stability and geometric stability so that the distance between the floors can be 2.8–3 m;
• you can build houses using cement-bonded particle boards even in winter, until the temperature drops below -20 ° C;
• DSP requires minimal finishing, inside the house it can be painted or wallpapered without putty.

An example of creating a reinforced foundation formwork from cement-bonded particle boards

European builders have been using CSP fixed formwork for more than 25 years, so there are many houses that confirm the durability and reliability of this material. Cement particle boards are well suited for both individual and multi-storey buildings, even in the harsh northern climate.

Fixed formwork from profiled sheet

A profiled sheet, profiled sheet or corrugated board has also found its use as a fixed formwork, although it is much more often used for the manufacture of fences, roofs, and outbuildings. Important: the profiled sheet is only suitable for arranging composite floor slabs and for large spans (from 5 m) requires additional temporary supports. For the construction of walls, this material is not used because of its small thickness, which reduces its resistance to mechanical stress in a vertical position.

An example of a ceiling structure with a profiled sheet base

Formwork made of this material attracts builders with such features:

• the metal is completely protected by galvanization and / or a polymer layer, so it does not rust;
• in industrial buildings, the material can be left without decorative finishes, the ceiling is visually pleasing and practical;
• profiled sheet performs not only the function of a form for concrete, but also serves as sheet reinforcement;
• corrugated board transfers the load to the metal frame of the building, so the internal walls do not carry heavy loads and it becomes possible to save money by building them from lightweight materials (aerated concrete, sandwich panels);
• sheets of small thickness are simply cut with scissors for metal, formwork of any shape can be created from them.

To ensure good adhesion to concrete, choose special profiled sheets with teeth for formwork.

This is what it looks like interfloor overlap based on corrugated board from inside the building

Fixed formwork made of profiled sheet is used mainly in industrial construction, as it requires construction metal frame building and metal floor beams. It is not suitable for an individual house, as it will be unreasonably expensive.

Fixed formwork made of expanded polystyrene

Expanded polystyrene / polystyrene is the most popular material for fixed formwork. Its demand is due to factors such as:

• light weight, which makes it easy to transport;
• tongue-and-groove connection system for the most simple installation;
• speed of laying (foam blocks of fixed formwork are larger than concrete ones, so work progresses faster);
• variety of types (reinforced, with protective impregnations);
• thermal insulation properties thanks to which the house does not need additional insulation;
• soundproofing;
• biological inertness that prevents the development of mold, moss, etc.

Examples of polyurethane foam formwork blocks of different configurations

Opponents polystyrene formwork indicate its danger in case of fire and a low degree of environmental friendliness. Even if you buy eco-labeled materials, this does not guarantee that the formwork will not harm your health or nature.

It is also important to keep in mind that foam formwork will be a good choice for buildings with a simple shape, since the range of corner and rounded blocks does not yet satisfy all consumer needs.

Fixed formwork made of glass-magnesite

Glass-magnesite sheets or LSU have been used as permanent formwork since the middle of the 20th century for the purpose of constructing heat-insulated houses. The material consists of a mixture of magnesium oxide and chloride, perlite, sawdust, fiberglass and polypropylene fabric. Not all components of glass magnesite are natural, but the finished composition is completely safe for people.

Different options of glass-magnesite sheets with decorative finishes

LSU is a great option for building or renovating a house with a weak foundation. Since the sheets themselves and the lightweight concrete mixtures used for pouring weigh much less than bricks, reinforced concrete blocks and other traditional materials, they do not load the structure of the building so much.

Among the advantages of glass magnesite:

• multifunctionality: it is suitable for creating foundations, walls, ceilings, fences, etc.;
• high thermal insulation, which is associated not only with the properties of the formwork itself, but also with the advantages of the filler (fiber foam concrete grade D250-D320, concrete with polystyrene foam balls M300);
• fire resistance;
• complete moisture resistance, which makes the material suitable for the construction of baths and saunas, use in areas with a humid climate and in wetlands;
• small wall thickness with LSU formwork will save space inside the house;
• the rough surface of the sheets is easy to veneer with clinker tiles, decorative plaster or any other finishing material;
• the sheet can be slightly bent if necessary for the construction of a half-tower or other decoration of the house (the radius of curvature is 3 m).

If you plan to cut LSU boards on site, purchase spare jigsaw blades. This material wears out nail files several times faster than wood concrete and plywood.

Glass-magnesite sheets will come to the court at all stages of building a house

Glass-magnesite sheets, like arbolite, often form only the inner contour of the formwork, while the outer one is most often built from decorative brick. As a result, the exterior finish is unnecessary, and a thin layer of putty will be enough inside. The technology is suitable for building houses up to 5 floors on a ready-made strip / slab foundation. In addition, it requires more time and effort than the use of expanded polystyrene or CSP formwork (excluding decorative finishes).

So far, glass-magnesite sheets are produced only in China and Korea; LSU quality control is also carried out there. There are no domestic analogues of this material.

Installation instructions for fixed formwork from prefabricated blocks

We will consider the technology of building a foundation from ready-made hollow blocks using the example of lightweight concrete products. Unlike reinforced concrete blocks for high-rise buildings, these "bricks" can be installed by hand without a crane and a manipulator.

1. Prepare a pillow under the block foundation by filling and tamping down layers of sand and fine gravel. A thin screed should be poured over the pillow to simplify the further laying of the blocks, as well as to avoid concrete leakage when pouring the foundation.
   

   Before installation, a sand and gravel cushion must be shed with a thin layer of concrete

2. Pull the thread along the trench and lay the first layer of blocks on the pillow, trying not to deviate from this guide. It is necessary to mount so that the gap between the elements is minimal. If the gap increases significantly throughout the trench, the cause may lie in the unevenness of the pillow. In this case, the row needs to be disassembled and a more even base made.
   

   Due to the correct geometry of the blocks, the foundation tape is smooth and clear.

3. Connections between walls should be provided with special blocks of slightly greater length. If there are none, a recess should be made in the universal blocks, as in the picture. This will ensure reliable adhesion of perpendicular foundation tapes.
   

   At the junctions of internal and external walls, you need to put special corner blocks

4. Lay metal or fiberglass reinforcement in the slots of the blocks. For low-rise construction two parallel rods are enough, but if necessary, three can be arranged.
   

   The blocks have special grooves for reinforcing rods.

5. At the junction of the walls, the bars must overlap so that the length of the free end is at least 2 cm.
   

   Pay attention to the location of the upper and lower rods in relation to each other, they should form a regular square

6. When the length of the rod is not enough, it can be increased by tying a new rod with a special thin wire. It is advisable to make 2-3 dressings in different areas of the overlap.
   

   Bandage the reinforcement should be with an overlap of 15-20 cm

7. Install the second row of concrete blocks exactly on top of the first. Do not allow even small deviations, if necessary, trim the position of the block with a mallet.
   

   Install the second row of hollow blocks on top of the first

8. Pour the prepared formwork with a liquid cement-sand mortar so that the concrete level does not reach the grooves for the reinforcement.
   

   The concrete level should be slightly above the middle of the top row of blocks.

9. Before the concrete begins to dry, try to expel excess air by piercing the space inside the formwork with a reinforcing bar from top to bottom. After that, place the reinforcement vertically, especially carefully strengthening the outer corners and joints of the walls.
   

   Vertical reinforcing bars can be installed one by one at a distance of 1.5 m from each other

10. After the concrete has dried, proceed to build the foundation. Install and bandage the reinforcement, mount two new rows of blocks and fill the formwork with concrete. Continue like this until the foundation reaches the height you want.
    

    New reinforcement is installed on top of the concrete screed

11. The last row of foundation blocks is poured until a flat horizontal surface is formed. While the concrete is not dry, it can be trimmed with a small board or a long trowel for plaster.
    

    The foundation is ready for the construction of the walls of the future house

The foundation of concrete hollow blocks for a private house according to the described technology is mounted by two workers in 2-3 days, taking into account the time for setting the concrete of the first layers.

Comparison of the costs of creating a foundation from solid and hollow reinforced concrete blocks and a monolithic one with temporary formwork

The comparison shows that a foundation made of hollow concrete blocks is 18% cheaper than a solid one and 36% cheaper than a strip monolith poured with temporary wooden formwork. This is achieved by saving on the amount of reinforcement, reducing labor costs, the amount of concrete, etc. But building walls from reinforced concrete blocks will turn out to be too expensive (compared to polyurethane foam, wood concrete), it is better to use it only for the foundation.

Do-it-yourself fixed formwork

Consider the process of creating fixed formwork from sheet materials with independent cutting using the example of EPS (extruded polystyrene foam).

1. Dissolve the sheets into fragments corresponding to the width and length of the compacted trench. From the remnants, cut out strips for sides 20-25 cm high. total length sides should correspond to the double perimeter of the trench + 20% for overlap at the corner points.
   

   You can cut sheets of expanded polystyrene not only with power tools, but also with a hand saw

2. Lay the sheets in the trench so that the sides rest on the XPS layer and do not touch the ground. Secure the sheets at the corners by piercing the material with CBT system plastic ties.
   

   When laying XPS sheets in a trench, try to minimize gaps

3. Install the halves of plastic ties between the vertical sheets and fasten them together. If the system does not click tight enough, seal the connections with pliers.
   

   Plastic ties are easy to install by hand

4. Install reinforcing bars above and below the horizontal braces. To keep the metal in the thickness of the concrete, place pieces of polystyrene foam under the bars. Special grooves on plastic ties will help maintain the same distance between the reinforcement bars throughout the foundation.
   

   Both metal and fiberglass reinforcing bars are suitable for reinforcement.

5. Tie the rods together with a thin wire folded 2-3 times. In the same way, the reinforcement can be tied to plastic ties.
   

   Installed reinforcing rods must be tied with a thin wire, welding is unacceptable

6. Build up the foundation with whole sheets of XPS, after attaching narrow strips of the same material to them with plastic clips. Arrange the prepared sheets as shown in the picture. When installing, pay attention to the location of the grooves and ridges on the sheet.
   

   We begin to increase the height of the foundation

7. Attach the vertical sheets to each other with ties, install and tie up the reinforcement according to the technology described above. You should get at least two plastic-reinforcing belts, approximately at a distance of 10 cm from the top and bottom edges of the sheet.
   

   Plastic spacers between the plates are installed in the same way

8. Fasten the stopper plate to the sharp ends of the plastic ties and cut off the ends that are left free.
   

   The protruding tails of the screeds are easy to cut with wire cutters

9. Fill the reinforced formwork with cement-sand mortar. To prepare concrete, you can use your own concrete mixer, but you will need a lot of mortar. If you doubt that you can pour the entire foundation in a day, it is better to use the services of an industrial concrete mixer tank.
   

   Pouring concrete foundation

10. Remove air bubbles with a construction vibrator and level the concrete surface. In this case, it is impossible to expel air with a reinforcing bar, since the metal will damage the formwork, easily piercing the XPS sheet.
    

    The upper plane of the concrete layer must be at the level of the outer layer of the formwork

After the concrete of the foundation has completely hardened, you can continue pouring the walls using the same technology, but such a foundation can also be used with other materials.

Video: technology for building a house with fixed formwork from chip blocks

When giving preference to one of the fixed formwork options, consider not only your financial capabilities and labor costs, but also the purpose. For example, in areas with swampy soil you should not use blocks based on wood chips, and in cold regions you should pay attention to a material with a minimum coefficient of thermal conductivity. In this case, you can quickly build warm house without extra financial costs.

As soon as new technologies appear, information war immediately begins, which has many rumors and speculation. In the construction industry, just as soon as a new innovative technology for building houses appeared, by means of fixed formwork, as supporters traditional ways launched anti-agitation, and are trying by all means to discredit the main material of houses from fixed formwork - polystyrene foam.

At the same time, the material itself has high operational properties, durability, low cost and other advantages. We will try to refute all the myths and misconceptions associated with polystyrene foam and blocks made from it.

Misconception 1 - the house will "float" from any flood.

These conjectures are based only on a complete misunderstanding of the building technology associated with this material. Where do such arguments come from? Some confuse fixed formwork and sandwich panels, which are used for frame houses. Yes, polystyrene foam is used for this type of houses, but only as a heater! And during a flood, such a house floats like a matchbox along the stream.

In the case when a house of their fixed formwork is being built, it is applied monolithic concrete, the mass of which is 350 kg/m2. Further, this technology includes the use of reinforced stubble to connect walls and foundations to each other. The rods are immersed in the foundation in advance, and as a result a monolithic structure is formed. This provides not only flood resistance, but also seismic resistance, resistance to hurricanes and temperature extremes.

Misconception 2 - walls are easy to break

Again, this conjecture is associated with sandwich panels. The monolith layer is at least 15 cm, excluding the plaster layer. Talking about the fragility of such a thickness is very stupid. And we note that the walls are reinforced with metal rods and mesh, located every 5 cm - good impact resistance is provided. The roof, walls and foundation are a monolith, which almost impossible to break. Loads withstand colossal.

Misconception 3 - the harmfulness of the material to health

Speculation that polystyrene foam is harmful is absolutely unfounded. The Association of European Manufacturers conducted an experiment: when burning this material at a temperature of 300 degrees, toxic substances are released, but their number is an order of magnitude lower. Than when burning wood, leather, chipboard, rubber and others. No other harmful factors were identified. The composition of expanded polystyrene includes only minerals that even mice don't eat! The material does not interact with salt, water, lime or cement.

Misconception 4 - Styrofoam burns like a matchbox

It is worth noting that this building material include flame retardant additives that do not support combustion at all. Also note that the wall of expanded polystyrene is plastered with a layer whose thickness is at least 3-5 centimeters. This ensures maximum fire safety. Direct impact there is no fire on the expanded polystyrene itself, since the thickness of the reinforced formwork (monolithic concrete and metal rods) is at least 5 centimeters.

Misconception 5 - the material is not well understood

The history of expanded polystyrene has been reciting for more than 70 years. Over the past 12 years, rigorous testing of the material for combustibility, flammability, toxicity, degradation, aging and other studies has been carried out. According to tests, expanded polystyrene does not change in the temperature range from -40 to +60 degrees. In construction, styrofoam has been tested for life cycle at 60 years old - without destruction.

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

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

What is fixed formwork

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

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

Expanded polystyrene (styrofoam)

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

Polystyrene concrete

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

chipped concrete

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

Sandwich

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

The technology of building houses with fixed formwork

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

pouring foundation walls

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

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

Composition of concrete

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

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

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

Floor installation

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

• reinforced concrete slabs;
• monolithic slab;
• wooden.

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

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

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

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

Filling the walls of the house

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

Exterior and interior decoration

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

• plaster;
• cover with siding;
• mount a ventilated facade.

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

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

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

The cost of building a house with fixed formwork

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

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

Despite the high cost of formwork, savings come from:

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

Where to buy fixed formwork

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

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

Conclusion

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

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

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

Technology Benefits

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

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

Technology Disadvantages

The disadvantages of polystyrene fixed formwork include:

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

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

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

What buildings are being built using this technology

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

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

Important Points

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

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

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

Other types of industrial fixed formwork

These types include:

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

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

Nikolai himself is building a private house in Samara. He told us how to save space on a land plot with a width of only 12 meters, using universal ties for TECHNONICOL fixed formwork.

Background and technical data

Construction objects on the site: bath - 35 m2, house - 110m2.

Problem: land plot very small in area, you need to save every meter.

Solution: foundation, plinth, bath walls and two-story house by the method of insulated fixed formwork using universal screeds to reduce the thickness of the foundation and walls.

Contractor: there is no contractor, hiring specialists for construction under their own management.

My name is Nikolay, I am a private developer from Samara. My building plot is quite small - only 12 meters wide. I know no more about construction than you do, but I decided to do everything with my own hands with the help of hired workers.

When choosing materials for building the foundation of a house and a bath, I relied on knowledge gained from various sources. And, interestingly, the arrangement of fixed formwork using universal screeds was not initially discussed at all. Just to insulate external surfaces, I purchased XPS TECHNONICOL CARBON ECO extruded polystyrene foam, and screeds came in addition to it. After reading about the properties of screeds and the method of their installation, I decided that it would be the best choice in my case.

Why did you choose fixed formwork?

Just imagine that without fixed insulated formwork and universal ties, I would have to build walls about 1.2-1.5 m thick and lay a very strong and more expensive foundation. Our winters are frosty and a smaller wall thickness would lead to greater heat loss and energy consumption. Or, in an attempt to save on energy spent on heating, my family would live in a cold, damp house. And with such a small width of the site, the wall thickness of 1.2-1.5 m is a lot!

It was necessary to find a solution to this problem. I chose monolithic construction with the use of insulated fixed formwork, in which TECHNONICOL universal screeds are used. This method made it possible to make the wall thickness half as much, and I left the saved space for arranging the terrace.

In addition, the method of installing fixed formwork with universal ties is very simple and significantly reduces the time spent on work. After all, what are universal screeds? These are fasteners that quickly and reliably connect the walls of the formwork sheets to each other. With their help, I reduced the time for arranging the bath and the foundation of the house by more than 2 times. This was facilitated by the fact that a combination of formwork and insulation was used - we did not waste time on thermal insulation of the foundation and walls.

True, at first it was unusual for my hired specialists. They, too, were not familiar with this method of laying and. We thought it would be very difficult and expensive. They held it in their hands like some kind of jewel. They could not figure out how to arrange it more conveniently, how to connect it correctly. It took almost two weeks for the first level of the foundation of the house - they worked out the laying technology. But, when we figured out the system for installing screeds, the work went very quickly. The bath, where the height of the monolith was 3.5 meters, took only 12 days!

Construction technology from fixed formwork

As it turned out, the laying scheme is quite simple:

1. formwork sheets installed;
2. fixed with ties for fixed formwork;
3. fittings installed; The material was prepared for the site www.site
4. poured concrete in a circle about 50 cm high, then vibrated the cement mortar;
5. waited for the layer to dry;
6. began installing screeds for the next layer, and so on in a circle.

It took us 3.5 weeks to build the strip foundation and walls of the bathhouse. I didn’t have to install any bulky wooden structures, spacers, etc., and then reinstall everything. And there are absolutely no complaints about the screeds. They perfectly hold the load, and, in addition, it was convenient for workers to install fittings. The main difficulty was that during the construction of the walls it was necessary to evenly set them in level. Also, with the help of fixed formwork and universal screeds, the strip foundation for the construction of the house was already poured and the basement was driven out, and I plan to build the walls using a different technology and insulate.

Another benefit that I appreciated is the savings on materials. Not only is it a formwork for construction, it is also an excellent insulation for the basement. No need to separately purchase and install insulation. With this fixed formwork, the manufacturer guarantees the absence of cold bridges in the finished structure, which is exactly what I needed. Especially for the foundation of the house.

My conclusion

Fixed formwork and universal ties are a reasonable and economical solution for private construction. Especially if you want to have time to build up over the summer. Do not just violate the terms of the instructions. It is necessary to make a fixed formwork for each layer according to the height of the simultaneous pouring, depending on the width of the tape, not higher. Before pouring another layer of concrete, let the previous layer dry so that it has time to gain the required strength.

The only difficulty was only at the beginning - the process of installing screeds was not easy due to lack of practice. But everything comes with experience. This technology will save you both budget and time. After all, the solution combines formwork and insulation. It turns out that you are simultaneously closing two construction processes.

The next stage in the construction of my house is the insulation of the facade with XPS boards. Then I will buy more roofing materials for the device of a roof of the house and a bath.