Wooden formwork for the foundation. DIY installation of removable formwork

The main stage in the construction of any type of foundation is the arrangement of the formwork. Formwork for the foundation is a solid support-panel structure that gives concrete or reinforced concrete products the required shape.

The panel base can be made of plastic, metal, plywood or board. With the right approach, even a private developer can perform its installation, fixation and dismantling.

Why do you need formwork and its types

The main task of the structure is to ensure the strength of the finished structure. In addition, foundation formwork meets the following requirements:

distributes concrete pressure along the entire perimeter of the base;
retains the required shape when pouring the foundation;
quickly and easily erected, provides reliable sealing of the future foundation structure.

Practical and reliable materials are used for the construction, which provide additional strength and durability of the base.

There are two main types of formwork: fixed and demountable (removable).

Removable formwork used in the construction of a base that requires decorative cladding. Such a frame is completely dismantled after the concrete mixture has completely solidified. The main advantage of the structure is the possibility of its reusable use for the construction of foundations of various types.

Fixed formwork becomes the main part of the concrete base. In addition, it improves the heat and sound insulation characteristics of the foundation. For the arrangement, polystyrene foam plates and hollow concrete blocks are used. Such materials allow you to create a foundation of suitable size and configuration. Such a frame is convenient and easy to install, does not require the use of protective elements - supports and spacers.

Materials for creating permanent formwork

The device of non-separable formwork is made of the following materials: wood, metal, reinforced concrete and expanded polystyrene plates.

Made of wood

Wooden formwork is the most affordable option that does not require the involvement of expensive installation equipment. For its manufacture, plywood in sheets and edged boards are used. The only drawback is the need to use auxiliary fixing elements to strengthen the finished structure.

Made of metal

The most durable and reliable option, for the construction of which steel sheets up to 2 mm thick are used. The advantages of the design include the following:

allows you to erect a base of various complexity and configuration due to the flexibility of the metal;
provides reliable waterproofing protection of the foundation;
suitable for the construction of strip and monolithic foundations;
allows you to decorate the base, raised above the ground.

The main disadvantages of the design are the high price and the complexity of the installation work.

Reinforced concrete

An expensive and time-consuming option, for the manufacture of which reinforced concrete slabs are used.

Significant advantages of the design: the ability to reduce the consumption of concrete mix, increased strength and durability.

The disadvantages include: large weight and dimensions of the plates, the need to use specialized equipment and additional fixing elements for installation.

From expanded polystyrene

The most reliable and demanded formwork option. Expanded polystyrene has the following advantages:

light weight;
availability of installation;
variety of forms;
high hydro and thermal insulation characteristics.

But the main drawback of the material is the high price.

Materials for the construction of demountable formwork

Demountable formwork is made of wood and metal. For the manufacture of wooden structures, laminated plywood and wooden boards are used. It is preferable to use products from spruce, pine, linden and aspen.

Formwork panels must meet the basic requirements: to be durable, wear-resistant and resistant to the negative effects of moisture. For the construction of a wooden frame, specialized equipment is not required, and all work can be done independently.

The metal structure is made from plates with a polished surface. A similar frame is suitable for the construction of foundations for private houses. The metal base provides reliable protection against the flow of concrete mixture at the joints of the plates.

The advantages include: low construction costs, availability and high performance of the material. The disadvantages are: the complexity of the installation and the need to attract specialized equipment.

How to calculate the formwork structure

For calculations, the type of material chosen for the formwork around the house is taken into account. An example is given for calculating a wooden structure.

For work, a standard board is used with a length of 600 cm, a width of 10 to 15 cm, and a thickness of 2.5 cm.

The perimeter (P) of the future foundation is divided by the length (D) of one board, the height of the foundation (B) is divided by the width of the board (W), and the obtained values are multiplied among themselves to determine the required amount of material (M).

For example, P - 1500 cm, D - 600 cm, height - 35 cm, width - 10 cm.

M = P / L × H / W = 1500/600 × 35/10 = 8.75 boards.

One cube of lumber includes 40 to 65 boards. To the cost of the material for the formwork should be added the cost of consumable fasteners - nails, staples, spacers and reinforcing rods.

Formwork construction using the example of a strip foundation

To make the formwork for the strip foundation, you need to follow the instructions below.

Excavation works

After drawing up a working project and calculating the required amount of material, an earthen trench is prepared.

Important! To simplify installation between the walls of the structure and the trench, it is necessary to make a technological gap of 2.5 cm.

A cushion of sand and fine gravel is placed on the bottom to reduce the consumption of concrete mixture. Next, the base is reinforced with reinforcing bars.

Assembly of structural elements

The next stage is the installation of the formwork for the strip foundation from the selected material with additional structural reinforcement.

After the completion of the preparatory work, the frame is poured with a concrete mixture at the level. And if the pouring technology has been followed, in a month you can start the main construction work.

For pouring the foundation, concrete M 150 and 200 is used, with a high groundwater level (groundwater level), it is recommended to choose concrete M 300 and 350.

To create a wooden frame, boards with a thickness of 25 to 45 mm of arbitrary width are used. The wider the board width, the stronger and more reliable the finished formwork.

A shield with a height equal to the height of the base is assembled from the prepared material.

Separate parts of the shield are fixed to each other with bars on self-tapping screws, while the caps should be located on the inside. Slots and voids are clogged with wooden slats according to the size of the finished shield.

Assembling the formwork for a monolithic slab

Installation of formwork for a monolithic foundation is carried out according to the following scheme:

Installation of vertical supports - telescopic legs made of metal or wooden logs up to 12 cm in diameter.The distance between the supports is 100 cm, the distance from the posts to the wall is 22 cm.
Installation of fixing ledgers on supports to provide additional formwork reinforcement. To do this, you can use channels, longitudinal beams or I-beams.
Installation of the frame in a horizontal position on the installed crossbars, while its dimensions must correspond to the dimensions of the future foundation.
Height adjustment of supports and installation of vertical structural elements.
Checking the horizontal position of the installed formwork with a level.

In some cases, the surface of the frame is covered with a film to create a waterproofing layer. This will ensure easy dismantling of the formwork and an even surface of the concrete base.

Violation of the technology of installation of formwork for tape or monolithic bases can have negative consequences that the owner of the building will have to face. A year after commissioning, the first cracks and faults may appear on the load-bearing walls, internal partitions and the foundation, which will lead to shrinkage and deformation of the entire building structure.

Many experts recommend entrusting the construction of formwork for the foundation to professional builders who are able to implement any technically complex project in practice. But this does not mean that a private developer will not be able to participate in the construction process. The main thing in this matter is compliance with all established rules and recommendations.

It is explained by its high reliability and ease of construction. Even a person who does not have much construction experience can easily fill a site under a garage or a fence. Knowledge about the installation of formwork will never be superfluous and will allow you to correctly calculate the required amount of material for pouring. Therefore, today we will talk about how to make a formwork for a strip foundation with our own hands.

The term "formwork" designates a special construction fence, with the help of which the molded concrete is poured. In the process, the liquid solution is poured into a prepared form, vibrated with special devices for compaction and removal of air bubbles, leading to internal destruction, and left to harden.

At the same time, the formwork allows you to give the future foundation various shapes and configurations, and also, when executed with a certain accuracy, allows you to get a flat horizontal surface of the strip foundation, ready for masonry work.

Formwork types

According to the classification, the formwork can be divided into several groups: by material, manufacturing method, removable or non-removable.

The metal formwork fence has high reliability, is able to withstand a large volume of poured concrete, and is assembled in the shortest possible time. The assembly of any necessary figure, be it a square or a rectangle, is done in a few elementary operations. Special fasteners allow sliding and sliding metal sheets, giving the required volume for pouring. The disadvantages of this type include the high cost. This equipment is mainly used on large construction sites and in specialized construction teams, the profile of which is pouring foundations.

For people who need formwork for single use, the wooden version is perfect. The assembly process takes more time compared to a metal analogue, but the cost of the raw materials used is several times lower.

There is also a variant of permanent formwork, which are blocks of expanded polystyrene into which concrete is poured. This type of formwork is at the same time insulation for the foundation. This tool is installed in the required place, it is poured into the cavity, after which the entire system remains in place. A foundation of this kind is one of the smoothest and confidently holds the palm in the rank of budget.

Budget formwork

If at a construction site there is an acute question of how to make the formwork for the foundation as cheap as possible, then the cheapest means of creating such a structure is to use old doors. This method is ideal for small volumes of pouring, it allows you to reduce manufacturing costs at times. Assembly and fitting has some difficulties, since the convexity of the doors does not allow pouring an absolutely flat foundation at once, but this problem can be easily eliminated. A huge advantage of door formwork is the solidity of the structure, which reduces the cost of spacer material.

Making formwork with your own hands

The first step, before starting work on the formwork itself, is the preparation of the land plot. After digging a trench, you can calculate the required material. The use of sheets of glued wood of medium thickness will allow you to quickly assemble the structure to the required dimensions. The use of boards is possible, but this method has several disadvantages:

low accuracy of the lateral surface of the foundation with the final result;
high probability of solution breakthrough at excessive pressure in one area;
lengthy assembly.

If you decide to build the formwork from boards, then for the work you need to use an edged board with a thickness of 40 mm or more. Boards of lesser thickness can easily bend under the pressure of concrete, which will negate all efforts and costs. Boards that are too thick will lead to unnecessary costs, although this will not affect the bearing capacity of the formwork. Therefore, each builder decides for himself which board to use for formwork, based on the budget and on the technical characteristics of the future foundation.

As a rule, the inner cavity of the formwork, made and boards, is covered with a layer of greenhouse film, which prevents concrete from flowing through the cracks between the boards.

When using sheets, the load is distributed evenly, which avoids overpressure in specific areas. Adequate spacer material is an important component. Let's talk more about it.

Special devices and stops, which will support the formwork from the outside and pull together from the inside, will avoid the destruction of the structure. As a rule, to strengthen the formwork of the strip foundation, studs are used, which are installed inside the formwork, secured from the outside with nuts and serve to keep the structure from the pressure of concrete from the inside.

The second element for strengthening the formwork is the jibs, which are installed from the outside in increments of 1-1.5 meters along the entire length of the formwork on both sides. These supports provide additional stability to the entire formwork.

Formwork for non-standard shapes

Columns, roundings and other structures or their individual elements require a special approach. It is recommended to use plastic or metal inserts for these places, which will preserve the intended shape and aesthetic appearance with maximum accuracy. Reinforcement with additional spacers will never be superfluous - you completely eliminate the risk of leakage.

Separately, it should be said about the provision of technological holes in the foundation. Such holes include air vents and outlets for communication pipes. To do this, special embedded sleeves are made in the formwork from plastic pipes, which then make it possible to obtain through holes in the foundation.

Conclusion

The foundation is the basis of any structure and the guarantee of its long service life, therefore it is worthwhile to take the most responsible attitude to its preparation and pouring. Careless attitude and use of inappropriate materials automatically reduces the service life several times. At the beginning of the construction process, every owner wants to end up with a strong and beautiful structure that will serve him and his children.

Do not neglect information from professionals when building on your own. Having an experienced foreman on your team will help you properly allocate available resources and build a solid foundation for your future home. An important detail when pouring is reinforcement - the creation of a mesh of metal rods that create a powerful frame for reinforcement. Taking into account all the nuances from the choice of raw materials to the process of filling the box with concrete is required to obtain the required result.

Finally, we offer you a visual look at the self-erection of the formwork for the strip foundation:

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

Basic requirements for permanent formwork for foundations

Let's consider what properties the fixed formwork should have.

Moisture resistance of the material and tightness of the seams. In the absence of this characteristic, the formwork will allow concrete to pass through, which will lead to an overrun of the mixture and make it impossible to build a wall.
Structural strength. This is necessary for the formwork to withstand the pressure of the concrete mixture from the inside and the ground from the outside (at the level of the foundation) without deformation and cracking.
Correct geometry of elements. Blocks of different thicknesses or irregular angles would have been impossible to construct even walls and 90-degree joints between them.
Long period of operation. The longer the formwork can potentially exist, the higher the likelihood of a long life for the whole house. If the formwork collapses quickly, the unsupported walls may not be able to withstand 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 of the decorative finish of the facade.

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

Table: advantages and disadvantages of fixed formwork

Advantages	Minuses
Ease of construction, the final result depends less on the skill of the workers (in comparison with self-made removable formwork).	In houses with permanent formwork, high humidity is often observed, which makes it necessary to equip a powerful ventilation system.
Good heat and sound insulation (in comparison with buildings made of bricks and reinforced concrete slabs).	Impossibility of construction in the cold season, since a large mass of concrete hardens poorly at low temperatures.
Ease of finishing work due to the flat formwork surface without cracks and differences in wall thickness.	The need for additional moisture in the concrete during a hot period in order to prevent cracking of the walls.
Reduced construction period compared to houses made of brick, stone, gas blocks.	Buildings with a metal reinforcement cage must be grounded as quickly as possible so as not to expose people to the risk of lightning.
The durability of buildings with reinforced concrete formwork is 300 years or more.	The complexity of dismantling during alteration and reconstruction, especially if the pouring reinforcement with metal rods was used.
The technology is suitable for the construction of buildings of any size and number of storeys, from summer houses to shopping malls.	In the event of a fire, the formwork material can emit harmful substances.
Minimization of construction waste (in comparison with construction technology with removable formwork).	In case of insufficient or incorrect external processing of expanded polystyrene blocks, water, insects, small rodents can get into the walls.

Fixed metal formwork

To ensure a uniform wall thickness, the 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 of sheets of aluminum or steel with a thickness of 1–2 mm on a metal frame and is connected with anchors, overlays or locks. The type and number of fasteners 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 specific building, the craftsmen of the manufacturer's company themselves carry out the verification assembly of the structure and only after confirming the suitability and completeness of all parts, the order is sent to the buyer.

The metal formwork has the most precise geometry. The permissible deviation in the parallelism of the edges of the sheet is not more than 2 mm over 1 m of the length of the product.

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

Powder coating of metal sheets is one of the most effective methods of protecting them against corrosion.

Metal is well suited for buildings with complex geometry, since thin sheets are easy to bend at any desired angle, to make a rounding or an arch. The finished walls are very neat and smooth, if desired, they can be left without decorative trim. Architects recommend using metal formwork in areas with difficult loose soil.

To prevent concrete from leaking, the joints of the metal formwork are connected especially carefully

But experts also note some of the 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;
the grease on the sheets is easily erased and stains the workers.

Installation of aluminum sheets for wall formwork by a couple of workers

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

Permanent formwork made of reinforced concrete blocks

Reinforced concrete formwork blocks are recommended for large construction projects, at least for a three-story private house. Since they have increased strength characteristics, in smaller buildings, such a safety margin will be unnecessary. Thin-walled blocks are excellent 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 joint width;
provide a building service life of several hundred years.

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

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

Among the disadvantages of reinforced concrete blocks are:

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

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

Permanent plywood formwork

For formwork, moisture-resistant plywood is most often used, but even then 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, a small house in which the owner lives during the construction of the main house);
when constructing non-residential buildings (chicken coop, shed, wood storage);
when it is necessary to save as much as possible on construction;
if the walls and foundation are insulated along the outer contour and the plywood is completely protected from external influences.

In addition to questionable durability and strength, plywood formwork will require a lot of labor and careful handling. Since the sheets do not have a groove-ridge 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 exfoliates from water, and laminated plywood repels the concrete mixture and never forms a monolithic wall with it, so it is very important to find a 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 wood concrete formwork

Arbolit is a relatively new, but 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 back in Soviet times. Arbolite blocks are much cheaper and lighter than reinforced concrete ones, so they are actively used for 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 of fixed formwork, wood concrete blocks:

can be easily cut with tools for working with wood, which allows them to be adjusted to the desired parameters on site: cut corners, make arched roundings, cut fragments for better adhesion of walls at the corners of a 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 expanded polystyrene);
safe for the health of others, waste can be processed industrially;
strong enough for fixing the clamps of downpipes and loaded elements of facade systems (guides for hanging siding, etc.);
are not afraid of fires (withstands up to 90 minutes of open fire);
frost-resistant, suitable for regions with harsh climates.

The disadvantage of wood concrete is its water permeability, therefore it is recommended to use it for the construction of walls on a ready-made waterproof tape 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 arranging wood concrete and brick formwork

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 poured with concrete and reinforced, as when using 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 (fusion of the strength characteristics of three materials).

When buying blocks and slabs made of wood concrete, pay attention to eco-labeling, since 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 to not mistakenly take blocks with too small voids.

Permanent formwork made of cement-bonded particle board

DSP (cement particle board) or sawdust concrete is another variation of a mixture of cement and crushed wood. It differs from wood concrete by the type of binder and the addition of sand. Therefore, CBPB 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 coated with decorative mineral chips

Among the advantages of wood concrete formwork:

the material breathes, so there is no need to equip forced ventilation in the house and fight the greenhouse effect in other ways;
DSP is able to withstand fires, its fire resistance is confirmed by laboratory tests;
the plate consists of natural materials, therefore it 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 could be 2.8–3 m;
it is possible to 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 pasted over with wallpaper without putty.

An example of creating a reinforced formwork for a foundation made of cement particle boards

European builders have been using cement concrete 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 made of profiled sheet

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, outbuildings. Important: the profiled sheet is only suitable for arranging composite floor slabs and, with large spans (from 5 m), requires additional temporary supports. For the construction of walls, this material is not used due to its small thickness, which reduces its resistance to mechanical stress in an upright position.

An example of a floor structure with a base of profiled sheet

Formwork from this material attracts builders with such features:

the metal is completely protected by galvanizing and / or a polymer layer, therefore it does not rust;
in industrial buildings, the material can be left without decorative trim, 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;
the corrugated board transfers the load to the metal frame of the building, therefore, the internal walls do not bear 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 metal scissors, from which formwork of any shape can be created.

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

It looks like an interfloor flooring based on corrugated board from the inside of the building

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

Fixed formwork made of expanded polystyrene

Expanded polystyrene / polystyrene is the most popular material for permanent formwork. Its relevance is explained by such factors as:

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

Examples of polyurethane foam formwork blocks of different configurations

Opponents of expanded polystyrene formwork indicate its danger in case of fire and a low degree of environmental friendliness. Even if you buy materials labeled eco, 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.

Permanent formwork made of magnesite glass

Magnesia glass sheets or LSUs have been used as permanent formwork since the middle of the 20th century for the construction of 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 for glass-magnesite sheets with decorative finishing

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 building structure so much.

Among the advantages of glass magnesite:

multifunctionality: it is suitable for creating foundations, walls, floors, fences, etc.;
high thermal insulation, which is associated not only with the properties of the formwork itself, but also with the advantages of the aggregate (fiber-reinforced concrete grade D250-D320, concrete with expanded polystyrene 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 thickness of walls with LSU formwork will save space inside the house;
the rough surface of the sheets can be easily revetted with clinker tiles, decorative plaster or any other finishing material;
the sheet can be slightly bent if necessary for the construction of a semi-tower or other home decoration (radius of curvature - 3 m).

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

Magnesite glass sheets will come to the yard at all stages of building a house

Magnesite glass sheets, like wood concrete, often form only the inner contour of the formwork, while the outer one is most often built from decorative bricks. As a result, external finishing is unnecessary, and inside there will be a fairly thin layer of putty. The technology is suitable for the construction of 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 DSP formwork (excluding decorative finishes).

Magnesite glass sheets are still produced only in China and Korea, and LSU quality control is also carried out there. There are no domestic analogues for this material.

Instructions for the assembly of pre-fabricated formwork

We will consider the technology of constructing 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 manipulator.

Prepare a pillow under the block foundation by filling and compacting layers of sand and fine gravel. A thin screed should be poured over the pad to simplify the further laying of blocks, as well as to avoid concrete leakage when pouring the foundation.
Sand and gravel cushion must be spilled with a thin layer of concrete before installation
Pull the thread along the trench and lay the first layer of blocks on the pillow, being careful 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 reason may lie in the unevenness of the pillow. In this case, the row must be disassembled and a more even base made.
Due to the correct geometry of the blocks, the foundation tape is even and clear
Connections between walls should be provided with special blocks of slightly longer length. If there are none, a recess should be made in the universal blocks, as in the picture. This will ensure a secure adhesion of the perpendicular foundation strips.
At the junctions of the inner and outer walls, you need to put special corner blocks
Place metal or fiberglass reinforcement in the slots of the blocks. For low-rise construction, two parallel rods are enough, but if necessary, you can arrange three.
The blocks have special grooves for reinforcing rods
At the junction of the walls, the rods should 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
When the length of the rod is not enough, it can be extended by tying a new rod with a special thin wire. It is advisable to make 2-3 dressings in different areas of the overlap.
Tie the reinforcement with an overlap of 15-20 cm
Place the second row of concrete blocks exactly on top of the first. Do not allow even small deviations, if necessary, adjust the position of the block with a mallet.
Install the second row of hollow blocks on top of the first
Pour the prepared formwork with 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
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 individually at a distance of 1.5 m from each other
After the concrete has dried, start building up the foundation. Install and tie up the reinforcement, assemble two new rows of blocks and fill the formwork with concrete. Continue this way until the foundation reaches the height you want.
New reinforcement is installed on top of the concrete screed
The last row of foundation blocks is poured until a flat horizontal surface is formed. While the concrete is still wet, it can be smoothed with a small board or long plastering trowel.
The foundation is ready for the construction of the walls of the future home

A foundation made of concrete hollow blocks for a private house according to the described technology is assembled 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 full and hollow reinforced concrete blocks and monolithic with temporary formwork

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

Making permanent formwork with your own hands

Let's consider the process of creating a permanent formwork from sheet materials with independent cutting using the example of EPS (extruded polystyrene foam).

Fold the sheets into pieces corresponding to the width and length of the tamped trench. From the remains, cut out strips for the sides with a height of 20-25 cm. The total length of the sides should correspond to the double perimeter of the trench + 20% for overlapping at the corner points.
It is possible to cut sheets of expanded polystyrene not only with power tools, but also with a hand hacksaw
Place the sheets in the trench so that the sides are on the XPS layer and not touching the ground. Fasten the sheets in the corners by piercing the material with the plastic ties of the SVT system.
When laying EPS sheets in a trench, try to minimize gaps
Place the halves of the plastic ties between the vertical sheets and fasten them together. If the system does not snap tight enough, tighten the connections with pliers.
Plastic ties are easy to install by hand
Install reinforcing bars above and below the horizontal braces. To keep the metal in the thickness of the concrete, place pieces of expanded polystyrene under the rods. Special grooves on plastic ties will help maintain the same distance between the reinforcement bars throughout the entire foundation.
Both metal and fiberglass reinforcement rods are suitable for reinforcement.
Tie the twigs 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 thin wire, welding is not allowed
Build up the foundation with whole sheets of EPS, having previously attached narrow strips of the same material to them using plastic clips. Place the prepared sheets as shown in the figure. When installing, pay attention to the location of the grooves and ridges on the sheet.
We begin to increase the height of the foundation
Attach vertical sheets to each other with ties, install and tie the reinforcement using the technology described above. You should get at least two plastic-reinforcing belts, approximately at a distance of 10 cm from the upper and lower edges of the sheet.
Plastic spacers between the plates are installed in the same way
Attach the locking plate to the sharp ends of the plastic ties and cut off the ends that remain free.
The protruding tails of the screeds are easy to cut with nippers
Fill the reinforced formwork with cement-sand mortar. You can use your own concrete mixer to prepare concrete, but you will need a lot of mortar. If you doubt that you can fill the entire foundation in a day, it is better to use the services of an industrial concrete mixer tank.
Fill the finished foundation with concrete
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 EPSP sheet.
The upper plane of the concrete layer must be at the level of the outer formwork layer

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

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

When giving preference to one of the options for fixed formwork, consider not only your financial capabilities and labor costs, but also the purpose. For example, in areas with swampy soil, blocks based on wood chips should not be used, 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 a warm house without unnecessary financial costs.

Features of the choice of formwork

Before making the formwork for the strip foundation, you need to evaluate the range of building materials on the market for the corresponding products. In addition, the formwork can be rented, this can be the only right solution. If you are building your own house, then this option is not entirely suitable, it acts as an exception in the case when fixed formwork is purchased. Considering all possible options, the manufacture of formwork is the most acceptable option. This implies the possibility of using the material that will form the basis of the structure during further construction work.

Materials for the manufacture of formwork

If you are wondering how to make a formwork for a strip foundation, then you need to decide what materials will be used in the process. A common option for this is plywood is used, among other things, it is worth using a laminated variety of this material, since it can withstand pouring more than once. If an edged board is used, then it is preferable to make shields.

The peculiarity of self-production of formwork

When assembling panels using edged boards, it is necessary to take into account that there should be no gaps between the elements, this is exclusively the flow of the solution.

Elements of different lengths and widths can be used, when assembling, it is preferable to use nails, and in order to strengthen the shields and prevent them from diverging, cross-members should be used. If you are thinking about how to make formwork for the foundation, the step-by-step instructions presented in the article will allow you to do the work correctly. The shields must be knocked down from the inside, and from the back the nails must be bent. Taking into account the dimensions of the future foundation, it is possible to calculate the distance between the crossbars of the shields, this will eliminate deformation. Among other things, when making the formwork, you need to take into account the height of the future structure. The higher the base, the thicker the formwork bars should be. This also applies to cross members. At the next stage, you can start assembling the shields, the quality of the foundation will depend on the performance of these works.

If you are seriously thinking about the question of how to correctly make the formwork for the strip foundation, then you need to take into account that screws can also be used for fastening, which is the most common option. Highlighting the peculiarity of screws, we can say that their use involves holding them in wood, this fastening is considered the most successful for installing formwork. It is characterized by durability and reliability. It is necessary to correct the position of the formwork elements using a level and a square. The verticality of the panels can be checked with a simple building level, while the water level should be used to check the overall level of the structure.

Many craftsmen, before making the formwork for the strip foundation, also think about how to carry out the dismantling work. These manipulations can be carried out very simply. In order to facilitate the performance of these works, the surfaces of the boards must be wrapped in paper, which must be pre-treated with oil.

Features of the manufacture of removable formwork

Before making the formwork for the strip foundation, it is worth considering that it can be non-removable; in this case, you can use not only wood, but also aluminum, as well as steel sheets, as a material, and you can combine them. Quite often, a coating based on polyvinyl chloride is used, which facilitates the process of mounting and dismantling the formwork. Steel formwork is used, as a rule, for the construction of complex structures. In this case, a monolithic formwork is being erected. In order to facilitate the process, you can use metal frames into which wooden boards are inserted.

Formwork requirements

If you will independently form the formwork for such a structure, it is important to know, because otherwise, mistakes cannot be avoided. If it is necessary to provide as small a gap between the elements as possible, the removable formwork should have less adhesion to concrete. If, during molding, gaps from 1 to five 5 mm were formed, then they must be removed with the help of tow. If the slots formed have a more impressive width, then slats must be driven into them. In order to tie the walls of the formwork, wire rod can be used.

If you are thinking about how to correctly make the formwork for the foundation, then you need to remember about arranging the sand preparation, it must be formed so that the thickness is 150 mm.

Materials for the use of permanent formwork

If you yourself will make the formwork for the foundation, you need to know how to do it yourself. If you decide to perform permanent formwork, then you can use wood concrete or expanded polystyrene. The first version of the material is made using the technology of mixing wood raw materials in the form of chips and mortar. If you use this type of formwork, you get walls that are already thermally insulated. This will allow you to get a structure that is much cheaper than brickwork, among other things, it will take up less space. Polystyrene foam, although considered a suitable material for formwork, is not entirely safe.

Features of the construction of permanent formwork

In order to carry out work using expanded polystyrene or wood concrete, the blocks must be connected by means of special locks that are provided on the products. The technology will be used the same as that used for the construction of a brick wall. It will be necessary to insert reinforcement into special grooves, which will give additional rigidity to the structure, after that it will only be necessary to pour concrete. Such formwork is used, as a rule, in the construction of houses with a small number of floors.

One of the most important stages in the construction of any building with your own hands is the arrangement of the foundation. It is a concrete base that accepts the load from the weight of the constructed object. The service life of the entire building depends on the durability of this product, therefore it is important to observe the correct technology in its manufacture.

A tape-type foundation has good performance characteristics, which is equipped around the perimeter of the building being erected from heavy building materials, such as brick and monolith. The required geometric shape of the strip foundation, which serves as a support for the load-bearing walls, is given with the help of formwork, into which the concrete mixture is poured.

The strip foundation is ripe - the formwork can be removed

Purpose of formwork for the foundation

The formwork for the foundation is a box-type structure consisting of shield rails and fastenings in the form of longitudinal and transverse struts and corner stops. Its main purpose is to give the concrete base the form provided for by the construction project.

Formwork is necessary in order to build a foundation of any type, but it reaches the largest dimensions when arranging tape bases. The structure must have sufficient elasticity and strength to withstand the pressure of the concrete solution poured into it. For this reason, the building materials for its assembly are selected taking into account the indicated characteristics.

Choosing the type of formwork: removable or non-removable?

The huge variety of formwork types that exist today can be divided into two large groups: removable and non-removable types. Removable formwork can be used multiple times, non-removable - once. The choice is made depending on the operational requirements.

Fixed formwork has its advantages, but foundation waterproofing will not work

Building structures erected using fixed foam formwork have excellent sound absorption and heat conservation characteristics. They are caused by polystyrene foam blocks remaining on the outer surface after the concrete mixture poured into the cavity of the blocks has hardened. This technology can be used both in the construction of private houses and in the construction of buildings up to nine stories high.

The fixed option is not used for buildings with a basement floor, since in this case it is impossible to perform a full waterproofing of the foundation.

The elements of the removable formwork, after the concrete mixture poured into it has hardened, are dismantled and can be reused. In this case, the surfaces of the foundation become available for waterproofing. Wood formwork, used in the arrangement of the foundations of small houses, has a limited number of applications, but its cost is also low. Metal formwork, which is most commonly used in industrial production, has a much longer service life.

Materials for removable formwork

The most expensive formwork material is sheets made of metal with a thickness of one to two millimeters. They are easy to bend at any angle, creating a structure of the most complex geometric shape. To increase its rigidity, reinforcing bars can be welded to metal sheets. The disadvantages of such formwork are its heavy weight and significant cost.

Beams, edged boards, plywood or OSB are common materials for creating formwork

The most popular formwork material is wood in the form of boards, plywood or OSB boards. The advantages of wooden structures include ease of installation without the use of special tools and their affordable cost. The disadvantages include the need to perform work on reinforcement with stops and struts. Formwork from boards and plywood sheets is often used in the construction of private houses.

At the same time, OSB formwork is distinguished by its durability due to the good moisture resistance of the material.

What else can a concrete fence be made of? Instead of OSB, it is, of course, possible to use ordinary chipboard, but it swells from moisture and will serve only once.Do-it-yourself formwork for a house can also be built from available tools at hand, such as old doors, sheets of slate and other materials that can really be connected without gaps in their side surfaces. The only advantage of this solution is its low cost. Several options for arranging removable formwork

There are much more negative sides. These include:

increased complexity of installation work;
the possibility of a leakage of concrete mix;
low characteristics of the bearing capacity of the structure;
the need to equip additional fasteners.

This kind of structure can only be used in the construction of small buildings. In capital construction, formwork made of such materials is not used.

We mount the formwork for the strip foundation with our own hands

Do-it-yourself installation of removable formwork for a strip foundation involves a large amount of work. The tape of the concrete base is located along the perimeter of the constructed building, repeating the contours of its load-bearing walls on both sides.

If the structure is large enough, the financial costs for arranging the foundation will be very significant, especially if it is significantly buried in the ground. For the manufacture of removable formwork in private housing construction, boards, plywood and OSB boards are most often used. You do not need to use special tools to work with these materials.

Assembly and connection of shields

When performing installation work on your own, it is important to make shield fences with good strength, they must withstand the pressure of the concrete mass. Several edged boards of the same length are fastened with threaded fasteners or nails. The optimal length of the assembled board is about two meters, with a longer length, it is difficult to work with the boards.

Edged boards are ready for formwork installation

When assembling the formwork, the bars into which the nails are driven are located at a distance of fifteen to twenty centimeters from the edges of the shield and every meter of its length. In the middle and at the edges, vertically longer and sharpened slats are packed vertically in order to bury them in the soil during installation.

Panel construction based on plywood or OSB

Plywood and OSB panels are mounted on a prefabricated timber frame. The illustration shows the construction of a panel made of plywood. In this case, it is convenient to use sheets with dimensions of 1525x1525 mm, which are sawn in half. The finished shields are connected to each other using bolts and nuts through the holes in the side bars.

Installation of formwork in the pit

Before installing the formwork in the pit, the site is marked with the help of pegs and a rope stretched between them. The bottom of the pit is covered with compacted sand. The work is done as follows:

vertically arranged pegs indicate the perimeter of the formwork installation;
shield fences are aligned along them, the distance between them must correspond to the width of the foundation strip;
through each meter of length, panel fences are supported from the outside by inclined stops;
the joints of the shields, if necessary, are additionally reinforced with wooden bars;
pipes are installed in the upper part of the fence to create technological holes in the foundation;
all parts of the structure are carefully strengthened, they should not stagger even when significant efforts are applied.

The higher the foundation and the formwork, the more fasteners will be required

The easiest way is to install shield fences with rails, which are vertically sharpened from below, located on them. They sink into the ground, and the shields are leveled using a building level.

Fixing shields

The formwork must withstand the pressure of the concrete mass poured into it, therefore, the structural elements are strengthened with supports every meter of its length. The braces in the corners look in two directions, so they need to be given special attention and work carefully at this stage. If the height of the backboard fence exceeds two meters, the props are installed in two tiers, with a significant height of the backboards, the reinforcement is performed in several rows.

Formwork reinforcement options depending on the height of the foundation

The internal distance between the opposing structural elements, equal to the width of the foundation strip, is stabilized by means of studs made from a rod and pieces of plastic pipes. Spacer rods, which are threaded rods at the ends, are installed in the formwork as follows:

a piece of plastic pipe is placed between the opposing formwork panels;
a hairpin is threaded into it through the drilled holes;
on the inside, metal washers are installed to protect the formwork from damage;
from the outside, nuts are screwed onto the thread.

Spacer sleeves and sleeves of holes for communications

When dismantling the formwork, first of all, the nuts are unscrewed, then the studs are pulled out and the stops and braces are removed. Shield boards can be reused. It is difficult to disassemble the formwork if self-tapping screws were used to fix its elements. Their heads are clogged with dirt and it is very difficult to unscrew them.

As soon as the structure is ready, concrete can be poured into it. Read about that in a special article.

Features of arrangement of round formwork

In the case of a rounded building facade, the question arises of how to make a round formwork for its base. The easiest way is to put a formwork for a round-shaped foundation made of factory-made metal elements. However, this possibility is not always present.

It is convenient to install a round formwork with your own hands from a metal profiled sheet. Such material easily takes the desired shape in one direction and withstands well the load of the mass of concrete when pouring the foundation.

After the concrete has hardened and the profiled sheet is dismantled, a surface of the corresponding shape will be obtained. It can be treated with coating waterproofing, but roll-up will not work.

Most often, round-shaped removable formwork is made using bending sheets of plywood or metal. In this case, it is important to correctly mark the round part of the foundation. To do this, a metal pin is hammered into the center of the corresponding circle and twine is tied to it. Two knots are tied on the twine in accordance with the outer and inner radii of the future formwork. Now you can set any point on a round section of the foundation and drive a support bar with a cross section of at least 50x50 mm into the ground.
Installation options for round formwork made of various materials

Support beams are installed on the inside and outside of the circular formwork, taking into account the thickness of the plywood. The distance between them along the perimeter is the smaller, the smaller the bending radius and the lower the strength of the sheet material, but not less than 50 cm. On the inner side of the formwork, plywood sheets bent in place are attached to the supports with self-tapping screws.

It is better not to use nails, as they are difficult to hammer through the plywood into loose support bars.

The reinforcement of the formwork is carried out using stops and braces, as described above. Examples of a circular design are shown in the photo. In order to equip the foundation for round walls, it is possible to use a large number of small-sized fencing elements. In this case, the inner shields are made shorter than the outer ones. It is convenient to determine their size by performing a sketch of the formwork on a scale. The panel construction is stronger than curved plywood and is preferable for large foundations.

Let's calculate the amount of required materials

The required amount of material for arranging the formwork with your own hands is determined as follows. The length and height of the concrete base known from the design documentation must be divided accordingly by the length and width of the boards to be used. By multiplying the numbers obtained, their number is determined, which is necessary for the construction of a particular formwork. In addition to the planks, you need to purchase wooden beams and spacers. Their cost can be up to half the cost of purchasing boards. It is necessary to take into account the additional spending on studs and fasteners.

Useful properties of plastic wrap

It is not possible to make a shield fence without slot gaps at all, and the concrete mixture seeps out, dirtying the formwork elements. Polyethylene film or roofing felt, fixed on the inner side of the formwork, perfectly protect the surface of the boards from contamination with the concrete mixture, not only from the inside, but also from the outside of the structure.

The use of these protective materials greatly facilitates and speeds up the dismantling work. If it is necessary to remove the formwork panels prematurely, the concrete surface of the foundation is not damaged. Wood panels are not exposed to moisture and can be reused.

Also, the surface of concrete is covered with plastic wrap or roofing felt if it is necessary to take a short break from work or upon completion of casting. They prevent the formation of a hard crust on the surface of the material and retain the moisture necessary for the curing of concrete.

We rearrange the shields and fill the foundation in parts

Pouring the foundation in parts provides for a vertical or horizontal arrangement of butt joints. With their vertical arrangement, the concrete base is separated by partitions. After the concrete mixture has hardened in the first section, the partition is removed and rearranged to the length of the next section. Thus, the entire perimeter of the base is filled.

Pouring the foundation piece by piece with vertical division

With a horizontal arrangement of butt joints, partitions are not installed. Most often, this method is used when arranging tape-type foundations. The concrete strip is divided in height into several parts and sequentially poured with layers of concrete mixture until it reaches the ground level. Docking seams cannot be placed on the reinforcement belts, they must be above or below their level.