Pouring the foundation into a fixed formwork with your own hands. We make fixed formwork

Registration: 23.07.12 Messages: 1.682 Acknowledgments: 2.699

House of Friends

Registration: 23.07.12 Messages: 1.682 Acknowledgments: 2.699 Address: Cheboksary

Strip foundation: Casting concrete into the ground + fixed formwork made of XPS (Penoplex)

Unfortunately, all the materials of the TS on Yadisk were not available, I had to clean up the links ...
I suggest that participants upload all information to the forum ... as well as to Diaries and Albums ...
Hello!
When studying reinforcement, I created my own topic -
The reinforcement is divided into longitudinal and transverse. Longitudinal - this is a long reinforcement laid along the foundation wall. Transverse - this is reinforcement laid across the foundation wall. Transverse is vertical and horizontal. I had transverse reinforcement (vertical + horizontal) represented by bent clamps from reinforcement d = 10 mm. Clamp installation step 0.5 m.

There were 5 rows in the longitudinal direction: the lower and upper rows each had 3 rods d=16 mm, and the middle rows each had 2 rods d=12 mm. Knitting wire d = 1.2 mm (taken 10 kg at 55 rubles per 1 kg). They bought one crochet hook, one was made by a helper from a piece of 10, another 2 home-made hooks were taken from a neighbor. You can make a hook yourself, it will be even better, more convenient and stronger, the bought Chinese hook was bent. It's a pity there are no photos of homemade hooks left.
When reinforcing, it is necessary to remember the main points of SNiPs regarding the reinforcement of the foundation: 1) The protective layer of concrete, it must be at least 5 cm. This means that the reinforcement should not be adjacent to the walls of the trench. On the sides of the trench and on top, the reinforcement should recede from the edge of the foundation by 5 cm. From the bottom - 7 cm in the absence of a concrete cushion and at least 3.5 cm if there is one. 2) When the height of the MZLF is more than 70 cm, it is necessary to lay not only the lower and upper rows of longitudinal reinforcement, but also the middle rows of longitudinal reinforcement, which do not bear loads, are not working rows of longitudinal reinforcement, but are constructive. It is enough to make the middle rows of longitudinal reinforcement from reinforcement d = 12 mm if the wall is more than 3 m in length and only along the side faces of the foundation. That is, for the middle rows of the longitudinal, 2 rods from the 12th reinforcement are sufficient. 3) To anchor the reinforcement in the adjacent adjoining wall, it must be bent at the ends, or if the length of the rod (standard 11.7 m) does not allow bending, is a bit short, then additional L-shaped corners can be used to strengthen the anchoring. 10 bends very easily, 12 bends with one hand, 16 bends for 3-4 seconds with 2 hands with full effort. The structure for bending the reinforcement is boiled on a garden water tank, shown in my video clip J The length of the reinforcement for anchoring is 40 diameters of the reinforcement, if the concrete of the foundation is grade M250 (this is the grade of concrete at least recommended by experts for the foundation). That is, for example, for reinforcement d \u003d 16 mm, the length of the reinforcement for anchoring \u003d 16 * 40 \u003d 64 cm. From this figure, you must subtract the length of the reinforcement, which has already been anchored at the corner. For me it was 45 cm, i.e. 64 - 45 = 19 cm. I had to bend the 16th at corners of at least 19 cm according to the rules.
Fittings: 10, 12th, 16th in total with delivery for 36,000 rubles, there are still many 10s left for the foundation for the garage next. year.
8. We install the top row of Penoplex inside the formwork, screw it in with self-tapping screws 7 cm long outside the formwork. Screw them in from the outside, because then you have to unscrew them. It is better to stick to a certain system, for example, the lower self-tapping screw under the upper one, because then, after sprinkling the formwork outside with earth, it will not be easy to find these self-tapping screws. If the base is less than 60 cm and, in addition, there is a slope on the site, like ours, then the bottom of the top row of the EPPS can be nailed into the ground, only carefully and if the top of the trench allows (dug by hand) J
9. Installation of sleeves in a trench for future sewer and water pipes. We bought a plastic red pipe with a diameter of 200 mm and a length of 1 meter for 650 rubles. They made 2 sleeves from it, where the sewerage will pass. How the sewerage will go, he calculated in advance what slope the pipes will go and what adapters will be installed, fully visualized the entire sewerage system in his mind, thought out how the sewage system will go in relation to the rooms and where it will go to the septic tank on the street and got the depth and location of the sleeves. There is a lot of information on the topic on the forum, you can find it.

The basic rules for installing a canal that you will need when calculating:
A) The sleeves should be 2 times wider than the duct pipes.
B) Pipes from the kitchen, shower, bathroom d = 50 mm are laid with a slope of not more than 3 cm per 1 meter of pipe.
IN) Pipes from the toilet bowl and the outlet pipe to the septic tank d = 110 mm are laid with a slope of not more than 2 cm per 1 meter of the pipe.
G) Make all transitions from horizontal to vertical with corners of 2x45 degrees or 3x30 degrees.
D) The last pipe of the canal that goes to the septic tank must be straight.
In accordance with these rules and pipe distances for your project, obtain the depth and location of the sleeves. I bought a cross, 45-degree corners, assembled this whole structure in order to find out how much deeper the pipe will go from the second floor after the junction with the vertical riser. The sleeves are fastened with pieces of reinforcement rods 10-ki, showed the sleeves in his video.
For water pipes, the most important thing is to lay them below the freezing depth. If I officially have a freezing depth of 1.6 m in the republic, then it is necessary to lay a pipe at a depth of 1.8 m (at least). A neighbor laid at a depth of just over 1 m, trusted the "specialists" from the poor man's company. Last year, the repair of frozen pipes cost him a large sum + hemorrhoids + lived for some time without water in the winter.
My water pipe will enter the house above the foundation from the heated boiler room adjacent to the house, so I did not lay a sleeve for it.
We poured concrete grade M250, 48 cubic meters on September 27, 2013. By this time, the rains had so washed away the ground around the trench that even we, in galoshes and boots, were stuck in the mud while working. It was possible to forget about the mixers loaded with concrete that will drive up to our trench. A loaded mixer of 6 m3 weighs 32 tons, 8 m3 weighs 36 tons. I had to order a concrete pump. Well, this is our personal mistake, you have good information from someone else's experience, so I think the cost of a concrete pump truck can not be considered a total cost. This pleasure cost 3000 rubles. for 1 hour. The owner assured that it would not work in less than 6 hours. Although the capacity of the machine is 120 cubic meters per hour. J I understand that everyone has their own business. Such a car costs 14 million rubles.
What can you advise to those who will also hire a concrete pump truck?
A) Arrange with the concrete supplier for a continuous delivery of concrete. Not just - “Yes, yes, of course, everything will be in the best possible way”, but a written contract, which states that every time a downtime, for example, more than 30 minutes, a certain amount is charged from the supplier. penalty. My waiting for mixers with concrete cost me 3000 rubles. per hour J The concrete pump driver said he could pour my foundation in 1.5 hours, but that's the way it is. In addition, you need to order a car for at least 4 hours.
B) Buy for all jamshuts that will spin next to the concrete pump supply pipe: safety glasses (can be found in the kit from punchers, drills), cheap disposable surgical bandages, rubber gloves. The jet of concrete is so strong that splashes of concrete fly into the eyes, mouth, hands dry from concrete, fingernails hurt.
IN) Position the concrete pump truck with its back to the approaching mixers.
But filling with such equipment, of course, is very easy. It is not necessary to row the concrete with shovels, it pours evenly right up to the top of the plinth. It is better to agree in advance with the driver so that he immediately moves the pipe where you say. And the problem of all self-builders pouring into the ground, “will the trench collapse or not” disappears. By the way, the work of jamshuts is also not cheap. And they need at least 5-6 people, because the amount of work is large. The time given for unloading the mixer is 40 minutes. The next hour of downtime of the mixer while you work costs 1200 rubles.
1 m3 of concrete M250 cost 3600 rubles. (3450 for 1 m3 + 150 for anti-frost additives) The cold weather came and we decided to play it safe by ordering an anti-frost additive for concrete. Delivery of one mixer with a size of 6m3 costs 2500 rubles. 196,400 rubles were spent on concrete with delivery by 6-cube mixers (8 machines). I took 49 cubic meters, as taught on the forum, that is, my calculated volume + 1 m3 in reserve. As a result, he poured exactly 48 cubes, and poured the rest in front of the house - a platform for the arrival of car J
That's all, if there are questions on the construction of this type of strip foundation, not covered in this article and the links to the forum topics, as well as not disclosed in Andrey Dachnik's book "MZLF", write - I will try to answer J

The use of fixed formwork technology allows in one step to give the supporting base the necessary shape and ensure water tightness, insulation and other necessary functions of the foundation, which are determined both by hydrogeology at the site and by climatic conditions in the construction region.

Fixed formwork for the foundation

This technology of forming the supporting base of the house appeared relatively recently - about 15 years ago and immediately gained popularity among builders and designers. The use of fixed formwork provides new opportunities for the construction of foundations and solid buildings, reduces the number of technological cycle operations and reduces the cost of construction.

Fixed formwork performs its main purpose - the formation of the foundation when pouring concrete - and a number of additional functions: temperature protection, waterproofing and sound absorption.

Photo gallery: fixed formwork of various types

Concrete blocks are an affordable material for fixed formwork with the possibility of reinforcing with row reinforcement. Foam blocks are very light and retain heat well. Fiberboard is an inexpensive and reliable material for fixed formwork. It has all the necessary properties and allows the foundation to "breathe"
Fixed slate formwork is easy to install and creates a solid mold for pouring

Basic requirements for fixed formwork

As noted above, the main difference between fixed formwork is the fact that after pouring concrete, it becomes a structural element of the foundation. The materials used must have sufficient strength to withstand the high pressure of the concrete solution. But at the same time they must perform other necessary functions - to provide waterproofing and prevent heat loss.

Expanded polystyrene and wood concrete meet these requirements to the greatest extent. The foundations made of them do not need additional insulation and have significantly less weight than similar brick devices, which reduces the specific load on the soil base.

The formwork formation procedure resembles the brickwork process, but is performed without “bandaging”. This is possible because the blocks have protrusions that allow them to arrange their adhesion to each other. In addition, the blocks are tightened across the width with screw fasteners, which significantly increase the strength of the side walls.

Blocks for fixed formwork are stacked close to each other and fixed with special grooves

One of the main requirements for fixed formwork is a small gap between their parts (no more than two millimeters) to prevent concrete leakage during pouring.

Another obvious requirement for such devices is high adhesion of the contact layer with the concrete mortar.

Formwork materials: advantages and disadvantages

For the manufacture of fixed formwork, several types of materials can be used.

sheet metal

Depending on the required strength, the thickness of the sheets can be from 0.7 to 4.0 millimeters. The advantages of this material lie in the possibility of forming any transitions, non-standard turns and other formwork configuration elements. Additional tightening parts can be welded to the metal to increase the rigidity of the structure. A protective coating is applied to the outer surface of the sheets, which provides reliable waterproofing of the foundation. The only drawback of formwork made of metal sheets can be considered the high final cost of the product.

Only a steel sheet allows you to build reliable foundations of complex shape.

Cast reinforced concrete blocks

The use of such a formwork is advantageous in that the concrete pouring, when solidified, sets well with the block material related in composition, forming a solid monolithic foundation frame. This reduces the consumption of concrete and reduces the overall cost of the structure. The main disadvantage of this technology is the large weight of the blocks, which is why during installation it is necessary to use lifting equipment.

When solidified, the concrete seizes with the formwork and forms a solid monolithic foundation.

Plywood, wood

Formwork from such materials is simply manufactured and is relatively inexpensive. A significant disadvantage is the limited service life due to the wood's susceptibility to decay processes. Therefore, regular reusable formwork is usually made from wood panels. Waterproof plywood with bakelite binders is often used as a face material on fixed structures.

Wooden formwork is usually dismantled after the concrete has hardened. To ensure the necessary strength, it is strengthened with side supports and screeds.

Cement particle boards, arbolite, fiberboard

These materials are similar in properties, since they have a similar composition. They are made from high grade cement and wood chip fillers. For fixed formwork, they are used in the form of ready-made blocks. The main advantages are ease of installation and low thermal conductivity. Among the shortcomings of DSPs are the high weight of products, which creates certain problems both during transportation and during installation.

Styrofoam blocks

Expanded polystyrene is the leader among materials for fixed formwork. The formwork is assembled from such blocks as in the Lego constructor, and the light weight of the products allows them to be moved manually. The delivery set includes accessories that allow you to assemble a support base of any shape. The disadvantage is hygroscopicity and the inability to withstand the simultaneous effects of water and low temperatures.

Expanded polystyrene blocks are the most popular material for fixed formwork. They are easy to install, weigh little and form a solid structure of the desired shape.

Profiled steel sheet

This material (profile "M") is used as a fixed formwork in the manufacture of ceilings. It significantly strengthens the structure and increases the service life of the floors due to the protective coating of the outer surface of the sheet. When using it, you can abandon a continuous strip foundation in favor of pile-slab structures.

Fixed formwork from a profiled sheet is the best option for constructing concrete floors

There are practically no technical shortcomings with this material.

Installation of a fixed frame for the foundation

Before considering the process of installing the frame, you need to decide on the design and dimensions of the support base. To do this, a number of mandatory measures should be taken.

Preparatory work

They are as follows:

Conduct exploratory drilling of several wells to clarify the hydrogeological situation at the construction site. To perform this work, it is better to invite specialists who will take samples and analyze them in the laboratory. The goal is to determine the quality of soils, determine their bearing capacity, as well as the depth of the aquifer. Exploration drilling services will cost 6-9 thousand rubles.
Develop a drawing of the foundation with dimensions based on calculations and laboratory data.
Clear the area where the foundation will be installed from vegetation, including bushes and trees. Removal of plants is carried out not only along the contour of the foundation, but also several meters from it.
Under the foundation, a site is cleared a few meters longer and wider than its design dimensions.
Mark the foundation according to the previously developed drawing. To do this, you can use pegs and construction cord. If it is planned to subsequently install a solid fuel stove in the house, its supporting base is included in the foundation plan and is carried out together with the main building.
The marking for pouring the foundation is carried out using cords and pegs. Be sure to check the equality of the diagonals of the resulting quadrilateral
Dig a trench according to the established markings to the design depth.
Make a drainage backfill along the bottom of the trenches. For this, river sand is used, poured with a layer of about 15 centimeters. A layer of gravel of medium fraction up to 20 centimeters thick is poured over the sand.
Thoroughly compact the drainage layer with a vibrating plate. In this case, the backfill and soil will sink, compensating for the thickness of the drainage layer, and the foundation support mark will return to the design depth.
Drainage backfill consists of sequentially laid layers of sand and gravel 15–20 cm thick each. They need to be compacted with a vibrating plate
Check the levelness of the bottom of the trenches. It is best to use a laser building level.
Lay waterproofing over the drainage layer. Traditionally, ruberoid is used for this.

Formwork assembly

Next, the actual installation of fixed formwork begins. Usually it is supplied in the form of rectangular blocks with ready-made joints between them. When properly assembled, the structure will be a fairly airtight mold for pouring concrete. The delivery set includes tie rods, washers and nuts to them. In addition to the basic elements of the foundation, you need to purchase additional transitional products that allow you to form a foundation of any complexity.

When installing a metal fixed formwork, internal screeds can be made on site. Segments of the desired length are cut with a grinder and welded in the right places inside the formwork. In addition, a “mustache” made of bent wire 5–6 millimeters thick is welded along the inner surface of the steel sheet. On formwork for heavy foundations, the structure can be reinforced with stiffening ribs from steel angles or other profiles.

On concrete blocks, transverse lintels are provided in their design and do not need additional reinforcement. They have grooves for laying longitudinal reinforcement. The transverse ties should ensure the rigidity of the structure so that the side walls do not bend under the influence of the mass of concrete during pouring.

Video: how to make a foundation using expanded polystyrene formwork

The bars are installed as the crossbars are placed, starting from the bottom row. Each bar is laid to its full length and fastened to the ties with a knitting wire. The distance between them should be 14-15 centimeters. After assembling the bottom row, the next one is mounted in the same order, and so on along the entire height of the foundation.

Reinforcement of the foundation is made of metal bars fastened with knitting wire

Reinforcement bars should not end or start at the corner or intersection of the foundation strips. In these places they bend or go straight. Vertical racks of reinforcement can be supported by drainage.

concreting

Formwork can be poured with concrete on your own, or it can be done with the involvement of a concrete pump and a team of concrete workers. The choice depends on the size of the foundation and the expected scope of work.

Pouring a large foundation is best done using special equipment.

The casting of the foundation must be carried out continuously. Only in this case it will be truly monolithic and durable.

The filling process takes place in layers until the required height is reached. The next layer is poured according to the previous one before the mortar begins to harden. In this case, the filled layer must be constantly pierced with rods, preventing the formation of air bubbles in the mass of the solution. The best result is the use of special vibrators for sealing the filling. If the foundation is formed intermittently, a seam will inevitably form in it, in the place of which a crack will subsequently appear with all the ensuing consequences.

Video: foundation concreting

Do-it-yourself fixed formwork

You can install the formwork yourself. The main thing is to choose the right material suitable for a specific foundation for the project. It is also important to purchase components for corners, transitions and mates. This may require qualified advice from a hardware store manager.

Mounting order

Before starting the installation of foundation blocks, it is necessary to arrange a foundation for it. This is done by backfilling a gravel cushion up to 15–20 centimeters thick. The layer must be carefully leveled and spilled with water to seal. For foundations for heavy structures, preliminary concreting is carried out with a solution 10–12 centimeters thick.

If the foundation will take heavy loads, a slab of lean (with a reduced percentage of cement relative to sand and filler) concrete is preliminarily poured onto the soil

The second mandatory operation is the waterproofing device. According to the bulk layer, it is made of roofing material or polyethylene. For pre-filling, you can use bituminous mastic.

Before installing the formwork, a waterproofing layer is laid on the bottom of the trench. It can be made from polyethylene film or from roofing felt.

The bottom layer of the foundation is formed from blocks with bottoms. You need to start from the corner, carefully exposing the block. The straightness control is carried out on a pre-tensioned cord between the corners.

Blocks of fixed formwork with bottoms are laid down, starting from the corner

The second and subsequent layers are assembled from blocks with through openings. The orientation of these parts is not difficult, since the blocks are installed in the tongue and groove.
A reinforcing frame is installed inside the assembled formwork
To ensure high-quality filling, you need to complete its first part already at this stage. In this case, the use of a deep vibrator is mandatory in order to avoid the formation of air pockets in the mass of concrete. The "bayonet" method using a pin is not always effective.

The device of further layers up to the design mark in height is carried out similarly.

Making blocks with your own hands

The easiest way is to make blocks of permanent formwork based on concrete. Fillers in this case are wood chips or expanded polystyrene balls in an amount of up to 70% by volume. Concrete is poured into collapsible metal molds. The final formation of blocks is carried out on a vibrating table, then the products in the molds are placed under a canopy until they are ready. The process is lengthy, so the preparation of blocks begins in advance. The long duration of hardening is the main disadvantage of the procedure for self-manufacturing fixed formwork from concrete blocks.

Video: independent production of concrete blocks for fixed formwork

The use of technology for casting foundations into fixed blocks can significantly increase labor productivity during their construction. This eliminates the need to perform other operations, in particular, the installation of insulation or waterproofing. As a result, the seemingly large costs are offset by the rejection of additional expensive work. In addition, carefully designed formwork element designs make it possible to obtain sufficient quality even when performed by unskilled builders.

Concrete foundation blocks

Foundation blocks are special concrete products that are widely used to equip the foundations of various buildings. They act as an alternative solution to traditional methods of creating foundations, since with their help it is possible to abandon the formwork, which allows reducing the consumption of reinforcement, concrete and seriously speeding up the work.

Production features

Our company "Concord Concrete North-West" is engaged in the production of fixed formwork from concrete blocks in accordance with the latest French technologies. The technique consists in the use of hypervibrocompression, due to which it is possible to achieve excellent concrete density indicators, which makes it possible to give the blocks strength like stone materials.

An important advantage of the technology is environmental safety. To prepare the mixture, clean sand, cement composition, quartzite, and also water are used. At the same time, harmful additives and slag are not included in the mass.

The porous structure allows to achieve a low percentage of water absorption. Dry-pressed concrete does not have capillaries that promote the movement of liquid, which gives decent frost resistance. A small capillarity provides excellent waterproofing properties, since water does not rise up. In France, such bases are not subjected to additional moisture isolation procedures.

Areas of use of foundation blocks

Creation of foundations for buildings.
Basement construction.
Construction of swimming pools.
Arrangement of retaining walls.

Advantages of our products

Opportunity to refuse formwork.
High speed and ease of installation without the use of special lifting mechanisms.
Achieving flawless foundation geometry.
Reducing the cost of rebar and concrete by 30%.
Seismic resistance.
Reducing earthworks.
Compliance with applicable environmental standards.
High adhesion to various materials.

Buying blocks for the foundation

The company "Concord Concrete North-West" is independently engaged in the manufacture of foundation blocks and offers the most favorable conditions for cooperation.

Contact our experts to get answers to your questions and order quality products that meet modern requirements. We carry out delivery of products across St. Petersburg and the Leningrad region.

Formwork is a structure made of panels, spacers and stops, which serves to give concrete and reinforced concrete products a shape. 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 la. 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, 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.

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 fixed formwork made of expanded polystyrene not only gives shape, but also simultaneously serves as 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, boards are most often used. 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.

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 - he - 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.

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).

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.

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 weakest point. 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.

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.

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 pieces of plastic pipes. Their inner clearance should be slightly larger than the thickness of the studs.

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 with a height of 0.8-0.85 m, with three - 50-55 cm.

The order of work is as follows:

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 down 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 the workloads on concrete walls and foundations are incomparably greater.

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.

Today, building technologies are progressively developing and improving every day. Innovative developments penetrate into all technological stages of the construction of various buildings. Of course, a special area of construction, where new materials and methods are especially relevant, is the creation of foundations.

Any building (residential building, office complex, etc.) after drawing up and accepting an engineering project begins with the construction of a foundation. In the old fashioned way, it is still quite often made with formwork from wooden panels or boards, however, current technologies allow the regular use of innovative methods, among which fixed formwork from various materials is considered the most promising.

Let us consider in more detail the types, features, application, assembly of fixed formwork for the foundation and a lot of other thematic information.

Fixed formwork - general information

Fixed formwork is an erectable mold structure used in modern construction during the construction of the foundation or load-bearing walls of some buildings.

Outwardly, it looks like a single, strong structure made of blocks or panels. After the assembly of the structure, a cement-sand mass is poured into its interpanel space, which, after solidification, forms a concrete-frame monolithic foundation.

Advantages of fixed formwork

The use of monolithic formwork during construction, which allows you to create a strong, reliable foundation (or walls), has many worthy advantages:

– accelerating the process of laying materials and building the necessary structures;

- lightening the overall weight of the structure due to the possibility of reducing the wall thickness;

- providing excellent sound and heat insulation;

– fixed formwork can be used in almost any construction project – typical one- or multi-storey residential buildings, complex retail and office structures, unusual sports and entertainment facilities, etc.;

– it is possible to use modern materials for such formwork (for example, wood concrete, armoponel, expanded polystyrene) in any climatic conditions – there are no restrictions;

- decorative function - the formwork can have a structured or molded front surface, which will allow not to use additional decoration of the facade with special tiles or panels.

Disadvantages of fixed formwork

The most significant disadvantages of the considered construction technology include the possibility of its use only for the construction of foundations. There are, of course, technologies for low-rise wall construction using fixed formwork, but they are very expensive.

Read also: How to protect yourself from noise: soundproofing an apartment

For example, it is possible to build up walls above the foundation using lightweight glass-magnesite formwork, which is filled with a special foamed concrete mortar. This is how a maximum of two-story houses with foam concrete base walls are created. Such construction is very expensive due to the high cost of materials and the hiring of special equipment with experienced specialists.

Types of fixed formwork

It was previously noted that fixed formwork, depending on the project, can be built from many different materials. The most commonly used are the following varieties:

1. Expanded polystyrene with internal voids- the material is presented in the form of layers (lamellar plates), connected into a single structure by means of special jumpers. The structure being erected resembles a "Lego" constructor, in which blocks are connected into a variety of large shapes. As a result, after pouring the cement-sand mass, a monolithic polystyrene concrete is formed, which needs external (external) and internal finishing. The cladding is mainly necessary to protect the material.

2. Armopanel– presented in different versions – Paroc, expanded polystyrene or Rockwool, covered on both sides with a metal arm mesh. During installation, concrete is poured between the panels under pressure. Upon completion of the solidification of the solution, peculiar "sandwich panels" are formed, which are particularly durable. This construction technique is considered as low-budget, providing excellent performance.

3. Fixed decorative formwork- This is a structure characterized by the presence of a finished outer cladding. Its assembly is carried out by the method of seamless laying of special blocks.

Important! In this version of fixed formwork, you need to put some kind of heat-insulating material (polystyrene foam or mineral wool layers) between the walls of the structure!

After the formwork is prepared, the concrete mixture is poured into it. The result is a monolithic, insulated concrete structure with a decorative finish.

4. Arbolite (wood concrete panels or blocks)- These are slabs consisting of sawdust mixed with wood chips and cement. The formwork is assembled using screeds, long self-tapping screws and nails. Often, when building in a cold climate, a heat-insulating polystyrene foam liner is installed in it. Then they put reinforcement or other metal rods and pour concrete-sand mortar into the prepared structure.

The external surface requires decorative finishing with clinker, facade plaster, siding or natural stone. From the inside, you can finish with drywall or plaster mixture.

Read also: The technology of arranging the "wet facade" in the house (photo). Advantages and disadvantages of a wet facade

Learn more about polystyrene formwork

It is worth stopping and considering the polystyrene version of fixed formwork, since it is it that is used most often in construction today.

The key reason for its demand is the simplicity and ease of installation of polystyrene foam boards. The work absolutely does not require the involvement of qualified specialists or any equipment. Block wall elements are firmly fastened together, and then concrete is poured into the formed space.

Various communications are laid in pre-foreseen technological openings. With this installation technique, an insulated reinforced concrete wall with a monolithic structure is obtained.

This design does not require additional sound or heat insulation, since polystyrene foam perfectly performs such functions. In addition, the surface of this material does not absorb moisture and does not pass water vapor through itself at all. For a monolithic foundation with a fixed polystyrene formwork, adverse weather is not terrible.

The advantages also include the resistance of expanded polystyrene to cracking and thermal structural expansion - that is, this technology can be used to build houses in hot, seismic regions.

The structure of fixed formwork assembled from expanded polystyrene boards is simple and consists of the following parts:

- plastic ties;

- steel (galvanized) L-shaped hooks designed for strong fixation of plastic ties;

— external and internal facing decorative plates. They are made of concrete mix and have a beautiful external structure.

General principles and features of fixed formwork installation

The construction of the foundation using the technological method of fixed formwork is not difficult, although it consists of several successive stages, which are characterized by specific features. Let's consider them in detail:

1. Land preparation at the construction site

The created monolithic foundation, in direct dependence on the functional purpose of the building under construction, can be directly laid on level ground or in a dug trench. Although, regardless of the chosen method, during installation, under the lower surface of the foundation, a sand and gravel “cushion” should be filled, more than 11.0 cm thick. Such a carefully compacted layer effectively compensates for the expansion of the soil and small displacements of its layers with changes in temperature or groundwater level changes.

2. Installing the fixed formwork structure

Since the process of construction (design and installation) of fixed formwork is very simple, especially from polystyrene foam material, it is accessible even to untrained workers. The main thing is that the employee has minimal skills in construction and technological production.

Non-removable formwork made of lightweight materials is installed according to the principle of a children's designer or classic brickwork.