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Do-it-yourself formwork for the foundation: step-by-step recommendations on how to make formwork. What to make formwork from: the most effective solutions How to make formwork for a strip foundation yourself

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

The shield base can be made of plastic, metal, plywood or board. With the right approach, even a private developer can install, fix and dismantle it.

Why formwork is needed and its types

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

distributes the pressure of concrete around 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.

For the construction, practical and reliable materials are used, providing additional strength and durability of the base.

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

Removable formwork used in the construction of the base, requiring decorative cladding. Such a frame is completely dismantled after the concrete mixture has completely solidified. The main advantage of the design 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, slabs of expanded polystyrene and hollow blocks of concrete are used. Such materials allow you to create a foundation of a 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 fixed formwork

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

from wood

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

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 build a base of varying complexity and configuration due to the flexibility of the metal;
provides reliable waterproofing protection of the foundation;
suitable for the construction of foundations of tape and monolithic type;
allows you to perform a decorative finish of the base, elevated above the ground.

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

From reinforced concrete

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

Significant advantages of the design: the possibility of reducing the consumption of concrete mix, increased strength and durability.

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

Styrofoam

The most reliable and popular option for the construction of formwork. 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 collapsible formwork

Collapsible formwork is wooden and metal. For the manufacture of wooden structure laminated plywood is used and wooden planks. 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 of plates with a polished surface. Such a 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 characteristics material. The disadvantages are: the complexity of installation and the need to attract specialized equipment.

How to calculate the formwork design

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

For work, a standard board 600 cm long, 10 to 15 cm wide, and 2.5 cm thick is used.

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

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

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

One cube of lumber includes from 40 to 65 boards. To the cost of the formwork material, you should add the cost of consumable fasteners - nails, staples, spacers and reinforcing bars.

Formwork construction on the example of a strip foundation

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

earthworks

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

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

A pillow of sand and small gravel is laid at the bottom to reduce the consumption of concrete mix. Next, the base is reinforced with reinforcing bars.

Assembly of structural elements

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

After finishing preparatory work the frame is poured with concrete mixture according to the level. And if the pouring technology has been observed, in a month you can start the main construction work.

For pouring the foundation, concrete M 150 and 200 is used, with a high GWL (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, the stronger and more reliable the finished formwork.

From the prepared material, a shield is assembled with a height equal to the height of the base.

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

Assembly of formwork for a monolithic slab

Formwork installation for monolithic foundation is carried out according to the following scheme:

Installation of vertical supports - telescopic legs made of metal or wooden logs with a diameter of up to 12 cm. The distance between the supports is 100 cm, the distance from the racks to the wall is 22 cm.
Installation of fixing crossbars on supports to provide additional reinforcement of the formwork. To do this, you can use channels, longitudinal bars 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 and installation vertical elements designs.
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 a flat surface of the concrete base.

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

Many experts recommend entrusting the construction of foundation formwork to professional builders who are able to put into practice any technically complex project. But this does not mean that the 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.

Formwork is a structure made of shields, spacers and stops, which serves to give shape to concrete and reinforced concrete products. If we talk about construction, then this system is necessary when pouring a foundation of any type, but the largest structures are needed when constructing a tape monolithic foundation. Formwork is also used when creating reinforcing belts in masonry walls from building blocks. In the same buildings, a reinforced belt is often needed at the top to create a solid base for attaching the roof system. It is also formed using formwork. This design will also be needed when pouring concrete paths or concreting blind areas, and for some other types of work.

Removable and non-removable

According to the principle of use, the formwork can be removable (collapsible) and fixed. As the name implies, the removable one is disassembled after the concrete gains strength above the critical one (about 50%). Therefore, it can be used multiple times. Depending on the material, the same kit can withstand from 3 to 8 pours, industrial options can be used several dozen, and some hundreds of times.

Removable formwork is dismantled after the concrete has gained 50% strength

Fixed formwork becomes an inseparable part of the foundation. Such systems began to be used relatively recently. They are made mainly from extruded polystyrene foam. Blocks of different configurations are produced, which are interconnected using locks and metal studs. From the blocks, as from the constructor, the necessary form is typed.

Fixed formwork becomes part of the foundation - it is also a heat insulator

The non-removable formwork made of expanded polystyrene not only gives shape, but at the same time is thermal and hydro insulation, and also has soundproofing properties. It costs a lot, but immediately solves many problems, and the time spent on building the foundation is significantly reduced.

There is another type of fixed formwork - hollow concrete blocks. They also have different configurations - wall, corner, with a radius, etc. They consist of two or three walls and several jumpers holding the walls in a certain position. They are connected to each other with locks, reinforced with rods.

formwork requirements

Since this whole system is created in order to give shape to concrete and reinforced concrete products, it must be strong and elastic enough to withstand the pressure of the mass of liquid concrete. Therefore, rather serious requirements are imposed on the materials for formwork in terms of strength. In addition, the assembled panels must have a smooth and even inner surface: it forms the foundation walls, and hydro- and / or thermal insulation materials are then fixed to them. It is easier to attach them to flat (at least relatively) surfaces.

Removable construction materials

In construction organizations, there are metal structures assembled on studs and bolts. In private construction, formwork panels are made of boards, moisture-resistant plywood and OSB. Wooden blocks are used as stops and spacers. Nobody bothers to make a metal structure, but it is very expensive and unprofitable for a one-time use.

When building a cottage or country house most often used shields from boards. Any species can be used, both coniferous and deciduous. It is better to take an edged one: the solution should not ooze through the formwork, and this is unrealistic to achieve with an unedged board.

What does the formwork for strip foundation look like in section

With a foundation height of up to 1.5 meters, the formwork board must have a thickness of at least 40 mm. Shields are fastened with bars of section 60 * 40 mm or 80 * 40 mm. If the height of the foundation is large - it is deep - such bars will not be enough to hold the mass of concrete. At a height of more than a meter, you need to use a bar of 50 * 100 mm or more. For assembly use nails or screws. Their length is 3/4 of the total thickness of the board and bar (for the above dimensions 60-70 mm).

Formwork is also made from plywood. There is even a special formwork, laminated with paper with synthetic impregnations. The coating has increased resistance to aggressive environments, which is liquid concrete. This material is marked with FSF (using formaldehyde glue).

The thickness of plywood for formwork is 18-21 mm. Shields are assembled on a metal or wooden frame. The wooden frame is made from a bar 40 * 40 mm, fasteners need to be used shorter - 50-55 mm. When using plywood, it will be easier to work with self-tapping screws: nails are hard to hammer.

Construction of formwork panels made of plywood and OSB

OSB is used for this purpose infrequently, but this option also takes place. The thickness is about the same: 18-21 mm. Structurally, it is no different from plywood shields.

Select the dimensions of the sheets of these sheet materials based on the dimensions of the required formwork panels - so that there is as little waste as possible. Special surface quality is not required, so you can take low-grade materials, which are usually called "building".

Decide for yourself what to make the formwork for the foundation: it depends on the prices for these materials in your region. The usual approach is economic: what is cheaper is used.

Do-it-yourself formwork for a strip foundation

The most voluminous is the formwork for the strip foundation. It follows the contours of the house and all load-bearing walls on both sides of the tape. When constructing a more or less large building with a large number of partitions, the cost of foundation formwork materials will be very significant. Especially with deep foundations.

Shield design and connection

When assembling the formwork with your own hands, it is important to make the shields strong: they will need to hold the mass of concrete until hardening occurs.

The dimensions of the formwork panels vary and depend on the geometry of the foundation. The height is slightly higher than the height of the foundation, you determine the length of each shield yourself, but usually it is from 1.2 to 3 m. It is inconvenient to work with very long structures, so the optimal length is about 2 m. The total length of the entire formwork should be such that they became exactly according to the marking of the foundation (do not forget to take into account the thickness of the shield).

How can formwork for a strip foundation be installed: in a trench dug according to the dimensions of the tape and in a pit in braces

When making formwork from boards, cut several pieces of the same length, fasten with bars and nails or self-tapping screws. When using nails, they are hammered from the inside of the shield, bent on a bar. It is easier to work with self-tapping screws: they do not need to be bent, because due to the thread they provide a snug fit of the elements. They are twisted from the inside of the shield (the one that will be facing the foundation wall).

The first and last bars are fastened from the edge at a distance of 15-20 cm. Between them, at a distance of 80-100 cm, additional ones are placed. To make it convenient to install formwork panels, two or three bars (along the edges and in the middle) are made 20-30 cm longer. They are sharpened and driven into the ground during installation.

Approximate dimensions of formwork panels made of edged board

Plywood or OSB boards are assembled on a bar frame. When assembling, it is important to strengthen the corners well. In this design, they are the most weakness. You can strengthen them with metal corners.

Do-it-yourself formwork installation

If the shields were made with several elongated bars, they must be placed along the stretched marking cords. The difficulty lies in the fact that at the same time you need to expose in a vertical plane. For fixing, you can use bars clogged at the mark and set vertically. When installing, set the plane of the shields close to these bars. They will be both support and guides.

Shields with extended transverse bars are easier to install

Since the bottom of the trench or pit must be flat (compact it and level it to the level), it should be easy to set the shields horizontally. Try not to hammer them too much: it will be easier to level them later. Lower one of the corners to the level of the bedding. There should not be a gap, the solution should not flow out. Having achieved a snug fit, take the building level, apply along the shield and hammer the second edge with a hammer until the upper edge is set horizontally. You are already setting up the next shield relative to the installed one: they must be at the same level and in the same plane.

If the shields are made without long bars, at the bottom of the pit, along the marking line of the tape, a bar is fixed, which will serve as a stop. The shields are attached close to it, then fixed with the help of slopes and struts.

Strengthening - braces and stops

In order for the formwork not to fall apart under the mass of concrete, it must be fixed from the outside and from the inside.

Braces are installed outside. Supports should be at least a meter apart. Particular attention should be paid to the corners: they put stops in both directions. If the height of the shield is more than 2 meters, then one belt of stops is not enough. In this case, at least two tiers of spacers are made: upper and lower.

Outside the formwork put stops and braces. With a high height, they are made in several tiers. Pay attention to the thickness of the support beam

It is also necessary to stabilize the distance between two opposite shields. To do this, use studs made of reinforcement with a diameter of 8-12 mm, metal gaskets and nuts of the appropriate diameter. Studs are installed in two tiers: above and below, at a distance of 15-20 cm from the edge.

The length of the studs is approximately 10-15 cm longer than the width of the tape. There are two options:

Both ends of the reinforcement are threaded. Then each stud will require two metal sealing plates and nuts.
On the one hand, the hairpin is bent and flattened, a thread is cut with an arc. In this case, one nut is needed (there are still two plates).

The internal distance between the shields, equal to the design width of the tape, is fixed using segments plastic pipes. Their inner clearance should be slightly larger than the thickness of the studs.

How to make spacer studs in formwork

The assembly goes like this:

Holes are drilled in both shields with a long drill.
A piece of pipe is installed between them.
The pin is being threaded.
Metal plates are installed (they will not allow the hairpin to break the shield material).
Nuts are tightened and tightened.

You need to work together, and better - three of us. One inside between the shields installs tubes, and one person for installing studs and tightening nuts.

When removing the formwork, first unscrew the nuts and remove the studs, then dismantle the slopes and stops. Released shields are removed. They can be used further.

How to spend less

A lot of material is spent on the manufacture of formwork for a strip foundation: the boards form the entire strip on both sides. At great depths, the flow rate is very high. Let's say right away: there is an opportunity to save money. To make only part of the formwork and pour not everything in one day, but in parts. Despite popular belief, this will hardly affect the strength of the foundation (if you know the secrets), and you can save decently. You can divide the foundation either horizontally or vertically.

Filling with layers

With a large depth of laying, it is more profitable to fill in parts horizontally (in layers). For example, the required depth is 1.4 m. You can break the pour into two or three stages. With two stages, it will be necessary to make shields 0.8-0.85 m high, with three - 50-55 cm.

If the foundation has a great depth, it can be poured in two or three parts, divided vertically into approximately equal shares

The order of work is as follows:

The formwork is set up from the short panels made, the reinforcement is knitted for the entire required volume.
Concrete is poured according to the height of the formwork.
After 7-8 hours after pouring, it will be necessary to remove the top layer from the entire surface of the tape with a trowel. When vibrating concrete, cement milk rises. As it hardens, it becomes brittle and brittle. It is this layer that will need to be removed. As a result, the surface will be uneven and rough, and this will improve adhesion (adhesion) with the next layer of concrete.
At a temperature of +20°C, after three days the formwork can be removed, the boards cleaned and fixed higher. When removing the shields, take out the studs. Tubes can be left in concrete. They have already become part of the monolith. Sometimes they are taken out, and the holes are filled with mortar.
Raise the formwork higher and pour it again.

The shield is simply installed on the already "grabbed" concrete, and rests against the edges of the trench, but at a different level

When installing the second (and third, if necessary) tier, the shields find a little on the already filled area, covering the tape from the sides. In this case, the lower row of studs usually serves as a stopper and emphasis. Therefore, when installing them, put them all on the same level from the bottom edge of the shields.

The fittings are already connected, the internal studs are cut. It remains only to put the other tubes, put the studs back in place and put the outer stops and braces. It does not take much time to install the next layer of formwork.

Why does this method not affect the strength of the foundation? Because the strength of concrete is not taken into account in the calculation. She goes to reserve. In addition, the load in strip foundations is distributed along the long side. And there are no gaps in length. So the foundation will stand for a long time.

vertical division

The second way is to split the plan vertically. The foundation can be divided into two or three parts. Only you need to divide not exactly “along the line”, but to space the joints a certain distance.

In the part of the building selected for installation, install the formwork with “plugs” in those places where the part to be installed ends. Inside the installed part, knit a reinforcing cage. In this case, the bars of longitudinal reinforcement must extend beyond the formwork by at least 50 diameters of the reinforcement used. For example, a 12 mm bar is used. Then the minimum outlet outside the formwork will be 12 mm * 50 = 600 mm. The next rod is tied to this release, and one by one they will go to these 60 cm.

One important detail: when breaking the plan of the house into parts, make sure that the “pieces” poured during this period end at different levels (see the picture).

The second way is to divide the plan into several sections (they are marked in different colors in the figure)

Fill the assembled area with concrete. As in the previous method, after 7 * 8 hours it will be necessary to beat the solution, but already on vertical surfaces. Take a hammer and remove the sidewall plug, beat the cement-sand mortar down to gravel (near the formwork there will most likely be a layer of mortar without aggregate). As a result, the surface will be chipped, which is good for adhesion with the next portion of the solution.

These methods can be safely used in private construction: they are practiced in the construction of monolithic multi-storey buildings, and there workloads on concrete walls and the foundation is incomparably larger.

There is another trick. Everyone says that boards or plywood can then be used in auxiliary work. In practice, it turns out differently: it is impossible to cut wood or plywood soaked with cement. In addition, it becomes dirty and rough, and it is also unrealistic to clean and polish it: it does not “take” any grain. So, in order for the wood (and plywood, if not laminated) to remain usable, the front of the shields is covered with a dense film. It is fixed with a construction stapler and staples. If it is damaged, replacement takes very little time. Formwork improved in this way gives an almost perfectly flat foundation surface, which facilitates subsequent work on hydro- and thermal insulation.

Do-it-yourself formwork for a strip foundation: fixed and removable, how and from what to make, establish ways to save

One of the stages in the construction of a strip foundation is the manufacture of formwork - a system of shields that give shape to concrete. At self construction it can also be made by hand.

If you decide to build your own house for permanent residence or a country house, a holiday cottage, you cannot do without the construction of formwork during the construction process. Even if a prefabricated block foundation is chosen for the house, its design still requires the pouring of reinforced monolithic belts, at least one belt above the prefabricated foundation. It is possible to do without formwork, perhaps, only when erecting a light frame or wooden house on screw piles.

The question of what to make and how to put the formwork at different stages of construction is asked by many developers. Because in order to obtain a solid building, the pouring of its constituent elements must be of high quality. To do this, you need to properly install the formwork and make proper reinforcement inside it.

Before you put it, you need to prepare a place for it. This means that earthworks associated with digging a pit or trench should already be completed, the necessary backfilling and tamping of sand and gravel under the foundation base has been made.

In private construction, depending on the climate, the bearing capacity of the soil, the proximity of water to the surface, they use different types foundations:

tape - the most popular in construction;
slab - for wet, heaving soils;
pile - for soils with a large freezing depth.

The rest of the foundations, such as pile-grillage, TISE, ribbed slabs, are obtained by combining these basic structures. Formwork for all types of foundations can be installed using and combining the same assembly and fastening technologies as for the first two.

If piles are used in the foundation, this simply adds a few steps when the time comes and. It will be necessary to properly fasten the reinforcement of the grillage and piles by welding or tying wire, as well as to make a temporary addition of sand with waterproofing along the upper edge of the piles, which is removed after the concrete has set and the formwork has been removed.

If not ready-made piles are used, but their casting is supposed, asbestos-cement pipes or roofing material are used as formwork, which are lowered into the well along with reinforcement.

Wooden structures for pouring the foundation

Strip foundation formwork without monolithic concrete preparation: a) small-panel removable formwork made of plywood panels; b) small-panel removable formwork from boards; c) small-panel removable formwork made of plywood panels with fixed formwork elements made of expanded polystyrene sheets; d) small-panel removable formwork made of boards with a smooth plastic or steel sheet and underground fixed insulation.

Traditionally, wooden boards or boards are used for formwork. If you follow SNiP, the thickness of the board should be at least 40 mm. When the walls of the formwork are under strong pressure, which can arch thin boards. As a result, the foundation on the sides will be convex. But it is not so much its appearance that is important, but the amount of wasted concrete. Therefore, it is important not only to install the formwork in compliance with all dimensions, but also to choose the right thickness of the material for its manufacture.

In practice, for a tape narrow (20 - 30 cm above ground level) foundation, a board 25 - 30 mm thick is often used. But at the same time, the formwork walls are reinforced with vertical bars with spacers nailed every m and a half. This design is made in the form of a rectangular triangle of boards, one leg of which is nailed to the wall of the formwork, the other lies on the ground, resting against a clogged wedge, and the third board (hypotenuse), relying on the same wedge, presses the formwork. It is better to put such slopes on the outside of each wall. Between themselves, the walls are pulled together by jumpers along the upper edge of the formwork.

If the formwork is completely installed in the trench, the thickness of the boards does not play a big role, sometimes Chinese polymer-coated plywood is used instead.

In the manufacture of formwork for the slab, the same slopes are used, installed along its perimeter. But the thickness of the boards for the walls, as well as with a large width of the strip foundation, needs to be increased.

So that there are no air bubbles in the concrete that reduce its strength, pouring is usually done with a vibrator. The impact of vibration on the walls of the formwork can disrupt the fastening of simply wedged elements, which can lead to its destruction and concrete leakage. Therefore, all slopes, struts and jumpers between the walls are connected using self-tapping screws. Such fastening is more reliable than on nails.

In order for the edges of the strip foundation to be even, the markings must be made not from the center of the tape, but by pulling the cord along the level on each side. You can also determine a right angle with a shoelace using the Pythagorean theorem.

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How to save money on construction

Boards are not cheap, it can be unprofitable to spend extra money on buying wood for large-volume formwork.

But you can use existing boards, just use them correctly, wisely.

For example, boards with a thickness of 50 mm can be used first on the formwork, then on the installation of the ceiling. It is better to immediately treat them with an antiseptic so as not to stain the boards with concrete, the formwork is lined with plastic wrap on the walls. The same method will allow you to use one formwork several times.

Formwork of foundations for columns: a - rectangular, b - stepped; 1 - stop bar, 2 - covering shield, 3 - spacer, 4 - mortgage shield, 5 - wire tie, 6 - mounting nail, 7 - stakes.

When calculating the foundation for tension, concrete is not taken into account, only reinforcement, so nothing bad will happen to the design properties of the structure if it is poured 2 or 3 times. The concrete of the first pour can be allowed to set, but not completely, 3 - 4 days will be enough. Then the formwork can be safely rearranged and continue pouring further. For better adhesion, the edges of the concrete do not need to be made even, it is better to make additional notches with a hammer.

In this case, it is desirable to somewhat space out the joints of the foundation, where the first pour ends and the next one begins. To prevent breaks in the pour from being located on the same line on adjacent walls, one wall is poured longer than the other.

The formwork under the slab is usually set immediately around the entire perimeter, but it also requires less material. If a ribbed slab is poured, inside the formwork, part of the area of \u200b\u200bthe pit is laid out to the required height with foam plastic so that the gaps between such sections form ribs. Styrofoam remains under the stove as a heater.

Sometimes the ribs are poured separately, filling the space formed between them with compacted sand and crushed stone, and a slab is cast on top. In this case, the strip formwork technology is used first, and then the slab formwork.

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Reinforcement of the assembled structure

If necessary, install fittings inside it and do not forget about the ventilation device and the laying of water and sewer pipes.

Formwork of strip foundations: a - rectangular with a height of up to 200 mm, b - rectangular with a height of 200 to 500 mm, c - rectangular stepped with a height of up to 750 mm, d - fixing the guide board, e - wooden clamp (detail), e - steel clamp ( detail); 1 - spacer, 2 - stakes, 3 - side shield or side board, 4 - pressure boards, 5 - struts, 6 - clamps, 7 - guide board.

First, the reinforcement grid is installed. Some prefer to assemble it right on the spot. Therefore, often vertical bars are simply stuck into the ground, and they begin to knit longitudinal and transverse reinforcement to them. But it is more convenient to pre-make a simple template from improvised materials, where the reinforcement bars are attached at a certain distance. You can first connect the horizontal elements of each belt, then add vertical rods or collars and assemble the lattice along the length of the longitudinal rods.

After that, you can continue to assemble the frame already inside the formwork. Longitudinal working reinforcement bars must be knitted with an overlap, which is at least 40 bar diameters, i.e. if the bar is 12 mm, an overlap of at least 48 cm must be made. The thickness of the working reinforcement is calculated by the designer when designing the foundation, its rods must be ribbed.

It is also important to correctly fix the corners of the reinforcing cage so that the structure works as a whole, there are no chips and cracks in the concrete at the junction of the foundation walls. Simply tying cross rods together at the corners is a big mistake. It will be correct to bend the rods themselves or use additional rods of the same diameter, bent at an angle and connected to the main ones.

It can be used for fastening reinforcement and welding, but this weakens the reinforcement itself and requires additional costs for welding equipment.

The finished frame must also be properly installed inside the formwork. The distance from the metal to the base and side walls of the formwork must be at least 50 mm so that the rods are securely hidden by concrete. For this, ready-made plastic reinforcement clamps are used; in extreme cases, stones or fragments of brick can be placed under the grate.

Diagram of a reinforced slab foundation.

It is usually carried out in two belts. The number of belts is determined by the thickness of the cast plate. In this type of foundation, all the rods are working, therefore only ribbed reinforcement from 10 to 16 mm in diameter is used. When laying, the maximum distance between adjacent rods of more than 40 cm is not allowed, usually the step between the rods is 20 cm.

If the slab design provides for more than one belt, then the distance between the belts is determined depending on the thickness and stiffness of the reinforcement used. To fasten the belts together, reinforcement bars of smaller thickness are used, since they practically do not experience vertical loads.

To connect the reinforcement bars to each other, they are knitted with soft knitting wire, as well as with. The thickness of the wire can be from 0.7 to 1.5 mm, the main thing is that it should not be hardened. If fiberglass reinforcement is used, which is not yet very common, plastic clamps or ties are used for knitting.

Reinforcement should also be installed on pads to provide the necessary distance from the metal of the rods to the edge of the concrete surface.

Formwork is a kind of form for a 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 effort on dismantling works, as well as to insulate and / or strengthen 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 deterioration 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

Advantages	Minuses
Ease of erection, the final result is less dependent on the skill of the workers (compared to self-made removable formwork).	In houses with fixed formwork, it is often observed high humidity, which forces to equip a powerful ventilation system.
Good heat and sound insulation (compared to buildings made of brick and reinforced concrete slabs).	The impossibility of construction in the cold season, since a large mass of concrete hardens poorly at low temperatures.
Ease of carrying out finishing works due to the flat surface of the formwork without cracks and differences in wall thickness.	The need for additional wetting of 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 strikes.
The durability of buildings with reinforced concrete formwork is 300 years or more.	Difficulty in dismantling during alteration and reconstruction, especially if the filling was reinforced with metal rods.
The technology is suitable for the construction of buildings of any size and number of storeys, from summer houses to shopping malls.	In case of fire, the formwork material can release harmful substances.
Minimization of construction waste (compared to construction technology with removable formwork).	With insufficient or incorrect external processing of polystyrene foam blocks, water, insects, and small rodents can get into the walls.

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 specific 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.

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 during production. 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 reapply a protective compound (grease, mastic, paint) on the places damaged by temperature.

Powder coating of metal sheets is 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. The finished walls are 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 construction projects, 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 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 flakes from water, and laminated plywood repels the concrete mixture and never forms with it monolithic wall, 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 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 back 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 of 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 roundings, 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 for fixing drainpipe clamps 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 forced ventilation and fight 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.

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

Fixed formwork made of corrugated 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 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, due 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 of polystyrene formwork point to its fire hazard and 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 - great option for the construction or reconstruction of 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 bricks. As a result exterior finish turns out to be unnecessary, and inside there will be a thin layer of putty. 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.

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
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.
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 junction of internal and external walls you need to put special corner blocks
Lay metal or fiberglass reinforcement in the slots of the blocks. For low-rise construction, two parallel rods are sufficient, but if necessary, three can be arranged.
The blocks have special grooves for reinforcing rods.
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
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
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
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.
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
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
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 filled 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).

Dissolve the sheets into fragments corresponding to the width and length of the compacted trench. From the remains, cut out strips for sides 20–25 cm high. The total length of the 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
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
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
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.
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
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
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
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
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
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 thermal conductivity. In this case, you can quickly build warm house without extra financial costs.

Features of the choice of formwork

Before you make a formwork for a strip foundation, you need to evaluate the range building materials on the market for the relevant products. In addition, the formwork can be rented, this may be the only right decision. 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. If we consider everything 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.

Formwork materials

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

Feature of self-manufacturing formwork

When assembling shields using an edged board, it must be taken into account that there should be no gaps between the elements, this is only the flow of the solution.

You can use elements of different lengths and widths, it is preferable to use nails when assembling, and in order to strengthen the shields and not allow them to diverge, you should use crossbars. If you are thinking about how to make a formwork for the foundation, step-by-step instruction presented in the article will allow you to do the work correctly. The shields must be knocked down from the inside, and the nails must be bent from the back. Given 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, in the manufacture of formwork, it is necessary 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 crossbars. At the next stage, you can begin to assemble 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 properly make a formwork for a strip foundation, then you need to consider that screws can also be used for fastening, which is the most common option. Highlighting the peculiarity of the screws, we can say that their use involves conducting in wood, this fastening is considered the most successful for the installation of 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 a hydraulic level should be used to check the overall level of the structure.

Many craftsmen, before making formwork under strip foundation, they also think about how to carry out the dismantling work. It is very easy to carry out these manipulations. In order to facilitate this work, the surfaces of the shields must be wrapped in paper, which must be pre-treated with oil.

Features of the manufacture of removable formwork

Before you make a formwork for a strip foundation, it is worth considering that it can be fixed, as a material, you can use not only wood, but also aluminum, as well as steel sheets, and you can combine it. Quite often, a polyvinyl chloride-based coating 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. At the same time, 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. When it is necessary to provide as little as possible the gap between the elements, 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 eliminated with the help of tow. If the formed slots have a more impressive width, then they need to drive the slats into them. In order to connect the walls of the formwork, you can use wire rod.

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

Materials for the use of fixed formwork

If you yourself will make formwork for the foundation, you need to know how to make it yourself. If you decide to perform a fixed 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 will get walls that are already thermally insulated. This will allow you to get a design that is much cheaper. brickwork, among other things, it will take up less space. Expanded polystyrene, although considered a suitable material for formwork, is not completely safe.

Features of the construction of fixed formwork

In order to carry out work using polystyrene foam or wood concrete, the blocks must be connected using special locks that are provided on the products. The technology will be used the same as that used in the construction brick wall. It will be necessary to insert reinforcement into special grooves, which will give additional rigidity to the structure, after which 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.