Fastening of the foundation formwork. Independent production of formwork for strip foundations

Modern construction develops with an emphasis on quality in the shortest possible time and at low material costs.

This approach makes it possible to build houses in an extremely short time, as well as to make housing affordable for the majority of the population.

This directly affects the turnover of capital, and also makes it possible to interest the buyer, because we live in an era when we want to get a high-quality result in the shortest possible time, and not wait for finished housing for years. Now there is a tendency to use it only as a facing material.

Formwork for the construction of walls and casting from, make it possible to build a reliable frame of a house on one floor, within a week. For comparison, a brick structure will need to spend twice as much time and money.

When performing formwork erection in a building where there are already ceilings on the ceiling, experts advise constructing racks with fastening of the upper formwork elements in the ceiling. Often this method is used in the construction of high-rise buildings, but with minor modifications it is also suitable for low-rise construction.

For independent use, wood shields with 200 x 50 cm will fit. The principle of their installation is the same as in metal ones. The main task is to put it exactly horizontally. Work with wooden formwork for walls is faster in time, but the process of building walls itself delays for a longer period when compared with metal ones.

Installation of brick wall formwork

Brickwork is also used as a permanent formwork for walls. The building into which the concrete is poured is constructed of silicate and facing bricks. At first glance, it may seem that this technology is very costly, both in terms of money and labor. But, nevertheless, it has its advantages and is used quite often in practice. This method guarantees obtaining a reliable frame and warm walls at the same time at the exit.

In order for the concrete solution under pressure not to spread the brick form, it is necessary to lay a kind of partitions through 3 rows vertically and 4 - 5 bricks horizontally. A certain gap of the structure, which is adjacent to the brick for cladding, is laid with an insulating material, more often all use expanded polystyrene foam. The unoccupied space is poured with a mixture of grade 200 concrete.

Foamed polystyrene foam makes it possible to compensate for the pressure of the concrete mass, and after the structure shrinks, the material expands and fills the remaining gaps. The cast frame made of concrete perfectly holds the brickwork, creating all the conditions for excellent. Very often, in order to reduce the cost of facing bricks, which are not very cheap, the outer walls are revetted in halves, which are cut lengthwise.

The house starts from the foundation. Making it with your own hands is not difficult, experts say and give their advice on the step-by-step installation of formwork - a key element of the future foundation of the house. An article, as well as photos and videos, will help you understand the recommendations.

In order for the concrete support of the building to become strong and monolithic, the builders came up with formwork.

It can be temporary or permanent, made of wood or polymers, but its main tasks remain unchanged:

• create and maintain the shape of the above-ground part of the concrete strip foundation;
• be as smooth as possible from the inside in order to minimize subsequent finishing work on the surface of the structure;
• cope with the loads when pouring and compacting concrete mortar;
• quickly assemble and disassemble;
• if necessary, isolate concrete from soil and other negative factors.

In order for the installation to go smoothly, and you do not have to solve unexpected problems, before starting work, you must make sure that there are five main conditions:

1. The soil on which the base is poured must be completely free of debris and various impurities.
2. The panels on the inside should have as flat and clean surface as possible in order to reduce finishing work.
3. The formwork fasteners must withstand the pressure of the concrete and not deform.
4. Maximum contact between the shield components is required to prevent leakage. For this, the clarity of the geometry of the edges of the structure is important.
5. If the shuttering boards are reused, it is necessary to clean the entire working surface from the remnants of the previous mortar.

Attention! Modern formwork is classified into two categories: removable and non-removable. In addition, it differs in the type of material used: wood, plywood, metal, expanded polystyrene, etc.

Removable formwork: time-tested installation

Mount, pour, hold and remove - this is a short recipe for installing removable formwork. Its most popular variety - wooden - is as old as the concrete foundation. It is not difficult to make such a formwork. Shields are made outside the construction pit from boards and sawn timber of the required dimensions. The boards are edged, since it will be necessary to fit them tightly to each other.

Attention! Slots up to 3 mm in timber formwork are considered the norm. As a result of preliminary wetting, the boards will swell and the distance will decrease. If the slots are larger, up to 10 mm, they must be closed with tow, and the very large ones must be filled with slats.

The structure is fastened with the help of vertical posts (most often - from a bar). It is recommended to place them at intervals of about 1 m. Bars can be placed more often if the boards are thin. It is also important that the length allows them to hold tight.

It is better to sharpen the bars at one end, then they will easily enter the ground. To fix the formwork panels at the same distance, wire twists, struts, frames, wooden ties are taken.

Advice. Instead of nails during installation, it is better to use self-tapping screws. The structure assembled on them is easier to disassemble, because it will be enough to simply unscrew them, and not unbend, as is the case with nails. It is necessary to knock down the boards so that the heads of the nails (screws) are on the inside of the formwork.

The final step in the installation of wooden formwork is to secure the panels in the trench using spacers: wooden stakes or bars. After pouring and tamping, the concrete is cured in the formwork for up to two weeks, until it hardens and gains strength. After that, the structure is dismantled. Plywood formwork is installed according to a similar principle.

Attention! It is advisable to isolate the removable formwork from concrete with special compounds against the adhesion of materials.

Permanent formwork for foundations: a new word in construction

In recent years, the removable structure has been replaced by a structure using polymer formwork, which, after pouring concrete, becomes part of the future foundation. It gives it additional properties, protecting it from water and keeping it warm. Additional properties of permanent formwork made of such a material: ease of assembly (somewhat reminiscent of a constructor or a puzzle) and, as a result, geometric harmony of parts. Certain types of polymer formwork have a reinforcing mesh that reinforces the foundation.

Of the minuses - the cost of such a foundation is higher than that built with the help of boards. However, the game is worth the candle when it comes to what is being built for decades and for yourself. Permanent formwork can also be made of galvanized profile sheet - in the finished foundation, it will protect the concrete surface, and its waves will serve as stiffeners. In addition to such a metal structure, a removable "belt" of stakes from a bar is required.

Around any building, or rather along its perimeter, a blind area is necessarily equipped. This coating protects the building from the destructive effects of melt and sedimentary water, which can erode the soil under the base of the house and lead to its subsidence, as well as destroy the base structure. This important protective element around the house is made of concrete or asphalt concrete. In order to complete the blind area, you need to erect the formwork. At first glance, this is not difficult to do, but there are some nuances that must be observed in order for the blind area to have the correct slope from the walls of the building. In our article, we will tell you how to make formwork around the house.

Features and functions of the blind area

Externally, the blind area looks like an ordinary concrete or asphalt path, which is tightly adjacent to the walls of the building and encircles it around the perimeter. The width of this coating is normalized by SNiP and can be at least 1 m. It should be remembered that the outer edge of the blind area should protrude beyond the boundaries of the roof overhang by at least 200-300 mm.

Important: the installation of this protective coating is carried out after finishing facade work has been done on the house.

The blind area performs several functions at once:

1. When snow melts or rain falls, precipitation can be absorbed into the ground near the house and cause the destruction of the foundation structures or flooding of the basement. Much more precipitation collects around the house, as it actively flows from the roof of the building and its walls.
2. Thanks to the blind area, the soil around the building does not freeze to such a great depth as in places of open soil. Thanks to this, the basement or basement room becomes warmer, which affects the temperature throughout the house.
3. In addition, frozen soil can also adversely affect the base structure. This path near the building protects building structures from frost heaving forces, which can lead to base movements and cracking of the building walls.
4. The presence of a neat blind area around the house increases its aesthetic qualities.

The following materials can be used for this coating:

• Concrete is most often used, since it is the most affordable material that you can prepare yourself. To pour concrete, you need to properly equip the formwork. That is why in our article we will look at the intricacies of this process.
• You can also make a blind area from paving slabs.
• Around large public, apartment buildings and shopping centers, the blind area is made of asphalt.

Rules for the execution of formwork and blind area

Before getting down to work and starting to make the formwork near the house with your own hands, you should remember a few simple rules that will allow you to do everything at the highest level:

1. If the work will be carried out in hot weather, then the surface of the formwork and concrete (after pouring it) must be periodically moistened with water. Due to this, dried wood will not absorb moisture from the concrete, thereby reducing its strength. Wetting and covering the concrete in the first few days after pouring will prevent moisture from evaporating too quickly and unevenly, which can lead to surface cracking.
2. In order to correctly determine the width of the blind area, the slope, the depth of its laying and design, it is important to take into account the geological and climatic features of the construction area. Observing this rule, you will make a high-quality and durable blind area.
3. It is better to arrange this covering around the building before the onset of cold weather.
4. This protective concrete product should enclose the entire house in a continuous strip. That is, there should be no breaks and areas of unprotected soil in the coating. Otherwise, through such uncoated gaps, water will easily seep into the ground and cause the destruction of the base structure.
5. An expansion joint is necessarily made between the blind area and the basement of the house, since these structural parts cannot be connected to each other. The width of the temperature gap is 2 cm. The seam must be closed with a sealant so that water does not seep into it.
6. The slope of the coating should be at least 10 ppm from the walls of the house, that is, 1 cm of slope per meter of width.

Necessary materials

• unedged or edged board;
• panel formwork can be made of chipboard (chipboard);
• moisture-resistant plywood or oriented strand board (OSB) is also suitable for these purposes;
• some types of formwork that take serious loads are made of steel and aluminum alloys;
• permanent formwork is made of expanded polystyrene, reinforced with fiber additives.

To perform the formwork of the blind area, an unedged board or plywood sawn with strips is suitable. Since the poured concrete can slightly expand the formwork structures, bars with a section of 30x30 are used as supports and a supporting frame, from which a solid structure is made.

Important: for the manufacture of a protective coating around the house, removable formwork is usually used, which is dismantled after the concrete has set.

It is equally important to correctly determine the material for making the blind area. The covering can be made of compacted crushed stone, but in this case it is necessary to equip a good drain from the roof so that the flowing precipitation does not erode the fragile crushed stone coating.

Slightly better and more durable than crushed stone coatings, there will be a blind area made of cement mortar laid on top of compacted crushed stone. This option provides better protection of the base of the house from destruction by melt and sedimentary waters. And it is this option for arranging the blind area that provides for the implementation of formwork.

A more expensive and high-quality version of the blind area is the laying of monolithic concrete slabs or reinforced slab products. But such materials cannot be used on heaving and clayey soils, as well as at high GWL, since the structure can quickly deform.

In the case of making a concrete blind area, you will need the following tools and materials for work:

• crushed stone, sand and cement;
• polyurethane sealant for sealing expansion joints between the coating and the house;
• reinforcing mesh;
• nails, screws;
• roofing material or plastic wrap;
• edged (unedged) boards or plywood strips along the height of the poured coating;
• level, rule;
• spatula, bayonet shovel;
• container for mixing concrete.

Formwork technology

After you decide on the material for making the blind area, calculate its width and the required slope, you can start working:

1. First of all, it is necessary to mark the future coverage around the house. To do this, the estimated distance recede from the walls, pegs are hammered in the corners and the fishing line or cord is pulled.
2. After that, within the marking along the perimeter of the building, a fertile soil layer 20 cm thick is removed. The soil at the bottom of the resulting depression is carefully leveled and rammed.
3. Now they start assembling the formwork. First, a frame is made from a bar. For this, bars with a height slightly higher than the thickness of the coating to be performed are fixed at the corners of the recess in the soil. Further, along the stretched fishing line, the same bars are installed with a step of 50-100 cm. For greater rigidity, the bars are fastened together with longitudinal bars. Wooden elements are connected with nails or self-tapping screws.
4. After that, we attach an unedged or edged board to the frame made of a bar so that the bar is on the outside of the structure, that is, on the side of the concrete pouring there is a solid flat surface of the boards. We fasten the boards to the frame with nails.

Attention: to prevent concrete from seeping between the boards, the gaps between adjacent elements should not be more than 0.3 cm.

1. So that after pouring the concrete, the formwork structure does not burst and deform, oblique spacers are attached to the frame from the outside. The installation step of such spacers is 50 cm. We attach the spacers to the frame bars using self-tapping screws or nails.
2. To make it easier to remove the formwork after pouring and hardening of concrete, its inner surface can be covered with a dense polyethylene film or one layer of roofing material. This material will perform other additional functions:
   • will not allow moisture from the concrete to be absorbed into the formwork boards, thereby reducing the strength of the concrete coating;
   • in the presence of significant gaps between the formwork boards (especially in the case of using unedged boards), the coating will not allow the concrete to flow into the cracks.

1. Along the walls of the house, it is necessary to install an edged board with a thickness of 2 cm and a height slightly higher than the height of the covering in this place. It is not necessary to firmly fix the board, since after the concrete hardens, it will be removed. With the help of this board, we will create the required temperature gap between the coating and the walls of the house.

Performing coverage

After the formwork is assembled, you can start making the concrete cover around the house. In this case, the following sequence of actions is adhered to:

1. First, a sand cushion with a height of 10 cm is made. The sand layer is leveled, moistened with water and rammed.
2. After that, a layer of crushed stone with a height of 10-15 cm is made. It is also carefully rammed. At the same time, one should not forget about the necessary slope of the blind area from the walls of the building, therefore, already at the stage of performing the crushed stone pillow, you can take care of creating a slope.
3. A reinforcing mesh is laid on top of the crushed stone.
4. Now you can start pouring the concrete solution. You can use a factory mix or make your own.

Important: in order for the coating to have a sufficiently high strength and not to crack over time, concrete must be poured at one time, without long interruptions in work.

1. The mortar to be poured must be thick enough to be applied in a thicker layer against the walls of the house, thereby creating the necessary slope. The correctness of the fill is checked using a level. The surface is aligned with the rule.
2. In the process of hardening in the first days, the concrete surface is wetted with water and covered with plastic wrap.
3. After removing the formwork and removing the board, which is laid along the walls of the house, the resulting temperature gap is filled with polyurethane sealant.

Monolithic construction is at the forefront of all technologies today. And this is quite natural, because in most cases it is more economically justified. In the field of foundations, concrete materials are very beneficial as they allow pouring foundation structures of almost any shape and size. But in order for this to be possible, it is necessary to use formwork.

In the design documents, formwork is given a separate place. It is customary to make formwork drawings especially for foundation work, describing in detail the specification of formwork panels and their standard sizes, connecting elements, fasteners, etc.

This is done in order to be able to imagine how much of this inventory is needed for foundation work. When the size of the foundation changes, the formwork equipment also changes.

The very first formwork, like the modern one, was made from wood-based materials. It was wood, due to its processing ability, that made it possible to quickly draw the outlines of a mold for pouring and assemble it from individual elements together. Today there are two main types of formwork:

• Detachable- the most common type of formwork used in construction. Depending on the size of the element to be concreted, a variety of materials are used for its manufacture. Preference is given to moisture resistant ones, which allow this inventory to be used repeatedly. The individual panels of the removable formwork are interconnected by various elements - ties, bars, gaskets, etc. This makes it possible to make a continuous formwork structure of almost any length. With the help of type-setting boards, you can make various forms of formwork. At the end of the work, the panels of the removable formwork are dismantled;
• Fixed- often used for foundation work, and allows you to save on dismantling work. It is made from expanded polystyrene foam (PSB). This formwork has a closed shape, is not afraid of frost and changes in humidity.

The smoother the shuttering boards, the easier it is to place them in place as accurately as possible and without gaps. It is this shortcoming that can subsequently lead to unnecessary costs for trimming the plane of a monolithic element, changing its dimensions and violating the integrity of the form.

Materials for removable formwork

For the production of formwork, a wide variety of sheet materials are suitable that can withstand the shape when concrete is poured. The most commonly used materials are the following:

How to make do-it-yourself shields for strip foundation formwork

Foundation shields are made in such a size that they could be easily moved and installed in place. Due to the nature of the material and the need for its leveling, wooden formwork panels are rarely longer than 3 meters. If there is a need for large sizes, it is not particularly difficult to connect several shields to each other.

The creation of a panel formwork from wooden planks for a strip foundation can be divided into the following stages:

Shields made of sheet materials such as plywood, OSB-3 orOSBs are made in a similar way. It is much easier to work with these materials, especially when the farm has an electric jigsaw, with which they are cut to size. Bars-stakes on them are also fixed at a given interval.

Panel formwork calculation

Engineering calculations for panel formwork are based on the dimensions of the foundation element, the amount of concrete mix. Further, tensile loads are calculated, taking into account the operation of the vibrator. And after that, the thickness of the walls of the formwork panel is displayed. Documentation on the requirements and calculations of the formwork for the foundation is described in the updated version of GOST R 52085-2003 “Formwork. General technical conditions ". The number of boards, determined in cubic meters, is calculated using a very simple formula:

Q = (A * B * D) * 2, where

BUT- board thickness;

IN- foundation height;

D- the perimeter of the foundation tape.

Foundation works are fundamental in modern construction. In most cases, it is more rational to make a monolithic foundation, because it is affordable for money, and is considered the most durable and practical of all known. But for its construction, it is extremely important to equip an accurate and economical formwork.

With low construction requirements, the formwork is made from scrap materials, saving money on this inventory, at the same time risking nullifying all efforts in this matter. There are times when concrete, due to insufficient stops, weak shields squeezes them out, violating the integrity of the structure. Work has to be redone anew, wasting time, energy and money. That is why the manufacture and arrangement of formwork for the foundation should be taken seriously, and made in accordance with all the rules and standards of the construction business.

This video is about the installation of removable formwork for various types of foundations. It reveals in detail all the nuances of the manufacture of wooden panels, their exposition at the site of the foundation, describes the reinforcing, spacer and tightening elements, methods of fastening. This video also describes the preparatory work before starting concreting the foundation.

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 varying 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 a 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

Collapsible 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 selected 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 base 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. 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:

1. 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 posts to the wall is 22 cm.
2. Installation of fixing beams on supports to provide additional formwork reinforcement. To do this, you can use channels, longitudinal beams or I-beams.
3. Installation of the frame in a horizontal position on the installed crossbars, while its dimensions must correspond to the dimensions of the future foundation.
4. Height adjustment of supports and installation of vertical structural elements.
5. 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 foundations 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.