Formwork pouring: which design is better. Do-it-yourself formwork for the foundation: step-by-step recommendations on how to make formwork We mark the formwork for the foundation with our own hands

Installation of the formwork of floors may differ in different parameters, which is characterized by the type of product and the peculiarity of the work. In this article, we will consider the types of formwork for floors, and also describe detailed instructions for installation.

Types of products for overlapping

All work on the installation of formwork for ceilings is intended for the construction of buildings or houses in a monolithic way. When carrying out work, it is important to adhere to the rules and recommendations in order to ensure the strength and stability of the structure. Formwork installation technology should be carried out by workers or specialists in this field.

Before moving on to the installation of floor formwork, it is important to consider the parameters and types of this type of product. There are such types of structures:

• on wedge forests;
• formwork on cup scaffolding;
• on bulky bowls;
• formwork on telescopic props.

For telescopic racks made of steel, formwork is used when the ceiling height is not more than 4.6 meters. When erecting a structure of greater height, it is important to use volumetric formwork. In this case, the installation is intended for monolithic slabs made of reinforced concrete, with a height of 20 meters and a thickness of up to 70 cm. For this type of formwork, it is necessary to use vertical posts, inserts, jacks, crossbars and other connecting elements. All installation and dismantling works are not complicated.

Features of the installation of telescopic slab formwork are fixing the tripod in the base, which supports the entire structure. At the same time, the installation technology is carried out using special shields. They are made of plywood, which has waterproof properties. In fact, plywood boards are solid items for formwork assembly.

Another type of construction is carried out on wedge scaffolding, which is used for the installation of floors of a multi-storey building. They can be used for other purposes, however, instead of plywood, scaffolds are laid on them and ladders are fixed, which is necessary for lifting workers. Wedge scaffolding has a design prototype that consists of horizontal and vertical racks. They can be connected at different angles, which will allow you to perform high-quality work on difficult sites.

The technology of installation of ceiling formwork on cup scaffolding consists in installing a structure in the form of a frame. This method differs from the previous one in that the option of connecting the racks must be done using the cup method. This will allow you to install at the same level from 1 to 4 parts in 1 bowl.

Features of the assembly of formwork for beam ceilings

The technology for mounting the formwork of the ceiling involves the use of beams made of reinforced concrete. They carry out the main load of the building. Therefore, formwork is important not only for floors, but also for the beams themselves. Work must begin after the installation of the columns is completed.

First of all, the beams are fastened into special grooves, which are located in the formwork structure of the columns. After that, you can proceed with the installation of telescopic racks, however, it is important to remember the allowable heights. All supporting elements are recommended to be installed on tripods, which are fastened with crossbars, which will increase the stability of the beam ceiling.

Next, they proceed to the installation of the formwork walls, which are important to fasten together and the bottom, using special fasteners. An additional element of strengthening is the flooring of wooden beams. Under them, it is also important to install telescopic racks for the formwork of the slabs. The last stage of work is the installation of panels on the sides of the formwork and the laying of the reinforcing frame. In this case, it is necessary to additionally check the following aspects:

• final formwork adjustment procedure;
• checking the level of floor beams and other elements;
• establish the presence of sags or deflections that are important to eliminate.

Features of installation of formwork without monolithic beams

The formwork installation scheme using this technology can be compared with the features of the installation for beam ceilings. However, this method is simpler, since there is no need to install additional fences, they are designed for pouring monolithic beams. You should be aware that for the assembly of formwork it is important to adhere to the requirements and rules that determine the installation distance of the support posts.

• The installation step should be no more than 2 meters if the ceiling height is up to 230 mm.
• A step of 1.7 meters is used for floors with a thickness of 28 cm.
• If the overlap is about 320 mm, then it is advised to install racks every half a meter.

During installation work, it must be remembered that the distance between the racks described above has the maximum performance. Therefore, the step between the supports is recommended to be slightly reduced. Plywood, plastic and other building materials can be used as panels for the construction of the formwork of slabs. It is important to know that in order to obtain a good quality surface, it is important to use laminated products. If you plan to use plywood, then it is important that it is moisture resistant.

Features of installing polystyrene formwork

This installation scheme has some nuances that are important to remember when installing the formwork. The design scheme is designed for certain cavities, which are intended for the formation of load-bearing beams from reinforced concrete. This will reduce the amount of work. At the same time, in all details of the formwork there are special niches through which various communications can be laid, such as sewerage, water supply, electricity.

Approximate scheme for creating formwork for monolithic floor from expanded polystyrene does not present certain difficulties, so that 2 or 3 people can participate in the process of work. It is advised to start the installation technology with the installation of racks and load-bearing beams.

It is important to know that the direction of the beams must be perpendicular to the position of the shields and the perforated metal profile, which will strengthen bearing capacity. If it is necessary to carry out the necessary communications through the formwork, then it is possible to cut an opening in the wall, while it is important to seal the joint area.

Features of dismantling work

The parameters for dismantling the formwork may depend on various factors, which are determined by some regulatory and design documents. In this case, the implementation of the deadlines depends on several factors:

• brand of concrete used;
• time of year when installation work is carried out;
• thickness and overlap parameters.

As a rule, in the summer it will be possible to remove the formwork after 3 or 4 days, but continue construction works only recommended after 3 weeks. In winter, the drying time of concrete is extended, which depends on wet and cold weather. The essence of formwork dismantling lies in the simplest disassembly of parts. If the design has special falling heads, then the dismantling process is greatly simplified.

Also, the use of such details will allow to partially carry out the work, but it is possible to simultaneously remove the formwork of the slabs, photos of which can be seen on this site. You can determine the time for the removal of the structure if you calculate the level of concrete strength, the indicator of which should be from 70 percent.

How to make a formwork for overlapping: step by step instructions

In a similar situation, we will consider the features of the construction of formwork for monolithic ceilings. They are often used in today's construction. If in the course of work to use quality materials, made according to the latest technologies, this will reduce the weight of the structure, load parameters, which will reduce construction costs.

Provides quality work correct installation formwork, because pouring and forming the foundation is not a complicated process. As a rule, builders use several options for using formwork, some of which offer to purchase a finished structure, while others prefer to do everything themselves.

It is important to know that the formwork for the floor slab is made in this way: a frame is assembled from vertical racks, which are fastened together with special crossbars. They are nailed perpendicularly to the transverse beam, on which the plywood flooring is laid. It must be laminated and moisture resistant, which forms the bottom of the formwork. To carry out the work, it is necessary to prepare the following materials:

• support posts, which are bars with a section of 120x120 mm to 150x150 mm;
• beam crossbar and beam transverse - has the form of an edged board, the cross section of which is 160-180x50 millimeters;

• braces, which are a board that has a thickness of 3 cm;
• flooring, moisture-resistant plywood is used, the thickness of which is 1.8 cm.

For such work, it is not necessary to purchase expensive materials made from coniferous trees, which is very uneconomical, so several alternative options can be distinguished:

• use lumber that is intended for the truss system;
• use previously used products that were previously used in construction;
• preference for materials that are made from low-grade tree species, such as softwoods.

To carry out the work, it is necessary to make a calculation of the formwork of the slabs, namely, to establish the required number of supporting elements, which are racks. So, when assembling the formwork, it is important to consider the steps for placing the rack. All parameters and distances were indicated in this article.

Step-by-step instructions for mounting the formwork:

1. Considering the thickness of the floor, we recalculate the steps between the beams, thus forming the first row. To do this, you need to drive a longitudinal beam into special grooves with nails into the upper ends of the support posts. The approximate depth of the half-groove should be equal to the crossbar. This will provide the desired load on the support. Further, we fix the ends of the longitudinal beam to the wall.

2. In the same way, it is necessary to assemble the second row for the formwork. The base for the structure must be strong and even. To do this, it is advised to put a board under the supports, the thickness of which should be about 5 cm.

3. Perpendicular to the longitudinal beam, we attach a transverse beam with a set distance of 60 cm. Next, we install support posts, the verticality of which is checked with a plumb line.

4. Using the same technology, you need to install the remaining rows in order to create a frame of the desired parameters.

5. It is important to level the horizontal bars using a building level, while the height of the racks is easy to adjust.

6. It is important to fasten all racks together using braces. They can be attached with nails, while their position must be diagonal. At the same time, you need to ensure that the entire frame of the racks is strong enough and reliable for further work.

8. It is important to keep the ends of the floor from freezing. Thus, masonry must be made around the perimeter, for example, from aerated concrete blocks. For brick walls it is necessary to lay out four rows of brickwork, the thickness of which is 12 cm. And it is recommended to insulate the outer side with foam.

10. Filling concrete mortar. It is recommended to dismantle the formwork after 20 days.

Formwork installation scheme for different types overlapping represents the performance of a large amount of work, the implementation of which will require huge costs. Of course, the formwork can be built with your own hands, or you can purchase a new design. In this case, all costs will be the same.

Slab Formwork: Installation Instructions, Construction Portal

Construction of houses The installation of floor formwork can differ in different parameters, which is characterized by the type of product and the peculiarity of the work. In this article, we will look at

The construction of any monolithic objects, whether it is a residential building or an industrial building, is not complete without wall formwork. This design is necessary for the construction of walls and ceilings.

Manufacturers offer many variations to solve problems of any complexity, one of the most popular is the formwork of the Gamma series.

Formwork material

An important characteristic is the material from which the wall formwork is made. The calculation of the required amount of concrete depends on this, as well as its weight, strength, cost, installation and finishing. Formwork is made from:

reinforced concrete;

Each of the materials has its own advantages and disadvantages. Metal formwork is widely used in industrial construction (withstands high pouring speed). However, it is very heavy, its installation requires the use of special equipment.

The form of expanded polystyrene is light, it serves as an additional insulating layer. However, the low strength of the material complicates construction (for example, a concrete pump cannot be used for pouring).

Wood, chipboard and plywood are also easily deformed, but at the same time they provide easy and quick installation. Plastic is sensitive to negative temperatures, but durable and sealed. The main area of ​​​​use is private construction (if you need to make a shallow foundation or a light building with your own hands), because. their installation does not require special skills.

Large developers prefer to work using removable structures, which also include Gamma formwork. Depending on the purpose, it can be used to build:

round structures (columns, pillars);

floors.

The calculation of the required volume of concrete is carried out taking into account the type of formwork.

Advantages of removable structures

If we are not talking about one-time construction, prefabricated large-panel or panel formwork - best option due to these advantages:

Versatility. Components (special fasteners, rotary elements) allow you to create structures that are complex in shape.

1. Installation of removable formwork

   The main components are the block and fastening elements (). Depending on the type of construction (panelboard, large-panelboard), the block can be from 90 * 60 cm to 330 * 120 cm in size. The calculation of the required size of the shields is carried out taking into account the scale of construction. For construction small house, or conventional shield formwork with blocks of 1.5 * 1 m. - the best option.

   Panel formwork is easy to assemble with your own hands, installation does not require the use of special equipment, and various components allow you to assemble a structure of any shape. This makes it indispensable for pouring the foundation or erecting walls and floors of a one-two-story building.

   The frame of the shield is made of metal profile(high carbon steel or aluminum alloy). The shield is made of plastic or plywood, in some cases it is provided with a reinforcing material. Installation of additional stiffeners guarantees the strength of the structure.

   A significant advantage of the fixed form is its cost and easy installation. The construction of monolithic houses with this design minimizes labor costs. Whether the installation of other structures consists of the following steps:

   • a corner block is mounted and walls are erected;
   • installation of door and window openings;
   • concreting is carried out (each stage of pouring is performed after the previous layer has solidified).

   Features of large-panel formwork

   Large-panel formwork Gamma has, in addition to the listed elements, the following components:

   

   inside corner to make a corner block;

   hinged shields, with which you can form internal and outside corners any radius;

   arc-forming element, to obtain a rounded section of a wall or ceiling;

   ties that rigidly fix the shields to each other.

   Also, to facilitate work at height, the kit can be supplied with scaffolds for workers, which are easily attached to the block at the level of any floor. Components can be purchased as needed, the calculation of the required quantity will be done by specialists.

   Large-panel formwork is used in the construction of large-scale facilities, therefore, special requirements are imposed on it. The block must withstand high pouring speed, and its rigidity must ensure the ideal geometry of the walls and foundation. This is achieved through the following design features:

   shield made of solid-rolled profile;

   a special lock that allows inserting additional sheets up to 10 cm thick between the shields (to strengthen the structure or additional thermal and waterproofing);

   fastener elements simultaneously tighten and fasten the shields to each other;

   the block is covered with a special, protective coating ( powder paint), such an external finish helps to prevent corrosion.

   To date, adjustable removable formwork Gamma is the most optimal solution in terms of price-quality ratio.

   Application of wall formwork (video)

   The choice of formwork for various objects

   They are mainly used in the construction of the foundation of small objects (cottage, garage) with their own hands. Installation in a trench and pouring are carried out manually. For heavy structures, the foundation and walls are strengthened by reinforcement. External and exterior finish possible immediately after the concrete has set.

   Fixed EPS formwork has become a popular solution for the construction of small private houses. The thermal insulation properties of expanded polystyrene can significantly save the cost of heating the room. In addition, the decoration of such a building (both inside and outside) is not particularly difficult. Majority finishing materials(drywall, facing boards, lining, veneer) are easily attached to expanded polystyrene sheets.

   Removable panel formwork can be installed to build a shallow strip foundation, in which case it acts as a basement. Wooden or - the best solution for the price, since a shallow foundation does not imply the use of complex structures. It is easy to assemble and disassemble with your own hands, using improvised tools.

   Large-panel formwork (for example, Gamma 330) is used in the construction of multi-storey buildings, industrial facilities etc. At the same time, due to its configuration, it is easily transformed into a form for floors, supporting elements. The accompanying documentation indicates possible assembly schemes and the calculation of the necessary elements.

A well-prepared pad and excellent quality concrete are worthless if the foundation formwork is poorly made. It is clear that the accuracy of the geometry of the base plate or tape depends on many factors, but first of all on a serviceable and durable frame for pouring concrete. Therefore, in addition to a normal cushion, concrete and reinforcement, to install formwork under a good quality foundation, you will most likely need to buy a normal sawlog and not collect the slab from the nearest storerooms, even if it is a one-time formwork.

The main elements of the formwork for the foundation

The standard arrangement of the form for pouring the foundation involves the use of the following materials:

• Marking cords and stakes, guide boards. Boards and stakes will need to be sewn to the pillow at the bottom of the trench, after which side panels and foundation formwork fasteners can be installed;
• Edged board, at least 30 mm thick, and timber with a section of 50x50. The amount of sawlogs required for the assembly of sideboards is calculated based on the depth of the foundation, the width of the tape and the dimensions of the perimeter;
• Side struts, supports, spacers and ties for foundation formwork, studs, plastic wrap, steel corners and nails are bought with a margin, it is better not to use old illiquid assets.

For your information! The best fasteners for wooden formwork are ordinary hardened self-tapping screws, from 35 to 70 mm long. They cost more, but the quality of fixation is an order of magnitude better, especially since the danger of splitting a board or plank is eliminated.

If you decide to install the formwork under the foundation on self-tapping screws, stock up on an electric screwdriver and a pair of replaceable batteries, and the supply of self-tapping screws can be washed with kerosene, this will help to properly fix the material without distortions in the wood.

Forget about laminated chipboard and steel tubular frames, this type of reusable formwork cannot always be correctly installed on its foundation. If you like a steel, aluminum or plastic frame, then immediately hire a team of workers who can properly assemble and install it according to your requirements.

Correctly assemble and install the foundation formwork

In the vast majority of cases, builders prefer to assemble side panels, struts, bring the entire set to the foundation trench, and only then assemble - install the finished parts according to the markings.

The best option would be the following order of work:

Transfer all the characteristics and dimensions of the future foundation to the exact formwork sketch, if necessary, check the dimensions of the trench and correctly increase the width at the places where the struts are installed:

1. Assemble the side panels from the edged board. For conventional formwork under MZLF, you will need to install a shield 60-70 cm high. Length at correct selection material does not greatly affect the quality of the formwork and, as a rule, depends on the possibilities of transport;
2. We cut the spacers from the beam and mark the places for their installation on the shields, notches in the foundation trench will help to correctly install the bars so as to withstand the desired width of the tape;
3. We make required amount struts, they will need at least one pair per meter of shield length.

For your information! In some cases, craftsmen prefer to make and install struts directly when installing side panels in a trench.

It remains a little - to hammer in the support stakes according to the markings, install the shields and fix them correctly, taking into account the readings of the building level and plumb line.

How to put the foundation formwork on the ground

The most important stage of the formwork installation has always been and remains the process of adjusting the position of the posts and shields relative to the marking lines. First of all, along the stretched cords, you need to install and hammer in a number of marking stakes, better made from scraps of the board used to assemble the side shields. A flat peg is cut at least 20-30 cm longer than the vertical posts of the formwork boards.

Each such stake must be installed on the bottom of the foundation trench, while the side plane and height of the stake are aligned in the direction of the marking cord and the vertical plumb line. It is necessary to install the marking stake very reliably, if necessary, make an external support.

For your information! It is very important to correctly install and securely fasten the marking stakes, all further assembly of the formwork is done quickly enough.

The next step is to install the outer formwork panels. From the outside, the shields will be based on marking stakes; on the inside, it will be necessary to install temporary fasteners from the same pegs hammered in a checkerboard pattern with marking ones, as in the photo. After leveling the shields with self-tapping screws, we grab them to the marking racks.

Next, we install the inner perimeter of the side panels, temporarily fix the inner row with the help of spacers and struts. We check and adjust the position of the shields according to the building level, stretched marking cords and a vertical plumb line, after which we connect the upper boards of adjacent shields with planks.

Final operations

After tuning and fitting individual elements formwork for marking and the dimensions of the foundation, you will need to perform another important element - to fix and strengthen the base of the side formwork panels. It is on the lower part of the side surface that the maximum bursting load occurs, therefore, each shield from the bottom, from the outside, must be hemmed with a beam or a bottom board, it is advisable to do this at the stage of assembling the shields, since it is not very convenient to hit nails at an angle, squatting in a trench . Installed struts usually hold the sides, but do not prevent deformation of the bottom, so installing wedges in the bottom is vital.

Along the hemmed bottom board, wedge-shaped pegs are driven into the ground every 60-70 cm, their task is to fix the bottom part of the formwork and prevent the shields from dispersing under the pressure of concrete.

At the final stage, experts recommend covering the wooden formwork with a coating or laying it out with a thick plastic film. A properly laid coating will protect the formwork tree, water will be absorbed less, and after the concrete has set, it will be quite easy to remove the boards.

Concrete pouring, planking and formwork removal

Integrity and resistance of the formwork to hydraulic load from liquid concrete largely depends on the ability to carefully pour the concrete solution into the mold. You can correctly regulate the pouring process by rearranging the guide troughs, through which the solution flows into the mold. The main thing is that after pouring the foundation, the mortar should flow evenly throughout the formwork, gradually increasing the level of the poured mass.

Sometimes a situation arises when the lower and middle boards bend under the pressure of concrete. There is no catastrophe in this if it does not affect the overall dimensions and position of the formwork, although, according to all the canons, such a defect must be eliminated. If there is a threat of separation of the board or deformation of the entire plane of the shield, then urgent measures must be taken to strengthen the surface and the specific board. Firstly, additional self-tapping screws are cut in and reinforcing struts are installed correctly. Secondly, it is necessary to wrap or hammer a pile half a meter from the bend, install a car jack horizontally, and through a steel plate or thick wooden board gently press the defect. Calling all those present to help will not be entirely correct, there is little sense from them, just one competent assistant with a jack and a pile is enough.

It will be correct to remove the formwork after pouring for the strip foundation in a week at an average air temperature of at least 15-17 ° C; in cold weather, the period before disassembly must be doubled. In order to properly disassemble the structure, you will first need to remove the struts, pull out the wedges along the bottom board and knock down the upper planks that tighten the shields. If a film or roofing material was laid, it is enough to carefully drive a few wedges into the gap between the shield and the foundation tape.

Conclusion

All forms of timber formwork are built according to the same scheme, therefore, having mastered the most complex tape version, you can, without hesitation, correctly assemble and install the form for piles, MZLF or slab foundation. The biggest problem when assembling the form of any type of foundation will be the problem of correctly assembling the structure for steps, a furnace or an extension of a complex structure. Any of these elements will require a lot of time to come up with and install a frame of the desired shape and size.

Confirmed by many decades of observation, research and technology refinement.

The construction technique of this type of bases has been worked out to the smallest detail, which makes the appearance of errors unlikely.

All possible problems arise only with the independent construction of the foundation by people who do not have experience and appropriate training.

Most mistakes are made at the preparation stage, when creating the elements of the tape design.

Consider one of the important stages of construction - the assembly and installation of formwork.

A formwork is a form for pouring concrete. Represents shield structure made of wood, plywood or polymer materials, forming a container in the form of a concrete strip. It is built right at the casting site, according to the dimensions specified in the project or working drawing.

In most cases, the exhibition is made from edged boards, but there are also more specialized designs designed for reusable use. The main requirement for formwork is strength, the ability to withstand the loads that occur when concrete is poured and hardened.

In addition, the tightness of the form is important, preventing the concrete from flowing out and eliminating unproductive material loss.

Kinds

There are various types of formwork.

The type of construction and installation differ:

• Small and large shield. The most common type.
• Block. Used for filling wells, columns, etc.
• Volumetric adjustable. Used for parallel casting of vertical and horizontal surfaces.
• sliding. Moves as the concrete sets for further pouring.
• horizontally movable. A type of sliding formwork for pouring horizontal structures.
• Climbing. It is used for tiered concreting of vertical structures.
• Fixed. Concrete or polystyrene blocks are used, from which the wall is assembled, and the internal cavity is poured with concrete. The technology is relatively new and not yet widely used.

Of the listed options, mainly panel types are used, since the rest of the structures are intended not so much for strip foundations, but for general construction work.

There are varieties according to the level of heat saving:

• Insulated.
• Heating.
• Special.
• Uninsulated.

The choice of type and material for formwork is made at the stage design work and is based on engineering calculations.

Most projects of private houses consider only wooden formwork due to the ability to assemble any size, but there are other solutions.

What material is used

Formwork can be created from various materials:

• Wooden.
• Plywood.
• From polystyrene foam.
• Metal.

In addition, options are available in synthetic fabrics or rubber. Wooden structures predominate because they are cheap, can be used repeatedly and in different sizes.

Reusable molds are designed for mass production of castings of the same size and configuration, so they are made from stronger and more durable materials.

advantage wooden structures is low cost and versatility, but their assembly time is much longer than that of plywood or metal ready-made shields.

How to calculate quantity?

The easiest way to calculate is to use an online calculator. In the appropriate boxes, enter your own data - the height of the tape, the total perimeter multiplied by 2, and the type of material.

The result is the amount of wood in cubic meters. This is convenient, since the usual calculation is made according to the area, which is then converted into cubic meters.

For those who do not trust the online calculator, the calculation method is useful:

1. The perimeter of the tape is calculated.
2. Divided by the length of one board, we get the number of shields.
3. The width of the shield is selected according to the height of the tape (usually, a multiple of the width of the boards).
4. The number of boards in each shield is calculated.
5. Multiplied by the number of shields.
6. The result is multiplied by 2.

In addition, it is necessary to calculate the number of slats needed to create the crossbars and stops. It is determined by the product of the total number of shields by the number of planks of one shield.

NOTE!

Any calculation method is quite approximate, so it is recommended to purchase 10-15% more than it turned out when calculating.

What is the best board to use

For the assembly of formwork, the most common material is usually used - edged pine board. It is recommended to plan the working surface of the boards, but this is not always possible, therefore most often the boards are assembled from unplaned boards.

An important issue is the degree of moisture content of the lumber. In this case, the use of a dry board is not necessary, and sometimes even undesirable. The formwork keeps the array wet for a long time, which is periodically watered all this time.

Dry lumber begins to actively absorb moisture, swells and increases in size, which causes individual boards to be squeezed out of the plane by a shield.

The thickness of the boards used to assemble the shields ranges from 25-40 mm. The higher and wider the tape, the thicker the boards must be in order to withstand the loads during pouring and the pressure of liquid concrete on the walls.

Mounting order

Formwork is created in stages:

1. Cut vertical cross bars. Their length is 40-50 cm longer than the calculated width of the shields, since they will have to be driven into the ground. To do this, one end is pointed for better entry.
2. Board preparation. They are cut to length (if necessary) and stored on a flat surface. Optimally - close to the trench, so that you do not have to carry ready-made shields for long distances.
3. The crossbars are laid out in increments of 0.8-1.2 m. The top cut is aligned along the line.
4. Build shields. First, attach the top board, then attach the rest as tightly as possible. Nails or screws are used.
5. Shields are lowered into the trench, aligned along the axes and dimensions. The pointed ends of the vertical planks are driven into the ground until the horizontal boards come into contact with the bottom of the trench.
6. Shields installed in parallel interconnected by crossbars defining the thickness of the tape. Their role is sometimes performed by U-shaped clamps assembled from wooden bars.
7. From the outside additional inclined struts are installed, excluding the extrusion of shields when pouring concrete.

The inner surface of the formwork should be lined with plastic wrap to ensure tightness and prevent concrete from flowing out. No matter how neatly and tightly the formwork is assembled, the loads during pouring are very large and occur abruptly.. The shields diverge slightly, which leads to the appearance of cracks. The film saves material and prevents waste.

Installation of removable plywood formwork

Plywood allows you to get sealed panels with a flat and smooth surface. For a one-time you can get by with the cheapest pine plywood, but for reusable formwork it is recommended to choose more durable birch plywood, impregnate it with drying oil or purchase laminated plywood (the best option).

The thickness of the sheets is chosen based on the height of the formwork, but not less than 10-12 mm. Usually plywood 14-18 mm is used.

Assembly order:

1. Plywood panels are cut to size.
2. The frame of the shields is made from wooden bars (50 by 50 mm). It is a edging located on the outer (non-working) side of the shield. It is not necessary to connect the planks to each other, but they are firmly attached to the plywood sheet. For fastening, nails, self-tapping screws or metal studs are used (for large shields).
3. Pegs are driven into the trench, designed to stop the shields.
4. Finished shields are placed in a trench, their position is leveled. The distance between the parallel panels is fixed by transverse struts, which are subsequently removed before pouring.
5. Separate panels are interconnected to obtain continuous formwork walls. The joints are sealed as tightly as possible, when cracks appear, they are immediately sealed.
6. U-shaped clamps are installed on top of the shields with a step of about 1 m, which hold the shields from extrusion during pouring.
7. It is recommended to line the inside with polyethylene to seal the formwork and improve the concrete setting. The plywood will remain clean and can be reused or reused for other purposes.

NOTE!

After purchasing the material, it is necessary to inspect it and apply a layer of drying oil on the entire surface and end sections. This will help facilitate the dismantling of the formwork and save it for reuse.

How to assemble from Styrofoam

In this case, the formwork is not subject to dismantling, being first a mold for casting, and subsequently a layer of insulation. Ready-made blocks of extruded polystyrene foam and additional elements for them are used - jumpers, details for longitudinal connection, etc.

All of them are commercially available and purchased in advance in the right quantity, which greatly simplifies assembly and allows you to get a strong and airtight outer cocoon for the concrete tape. The technology was invented a long time ago, but for various reasons it was not used, it is only now beginning to gain popularity.

Nevertheless, the results suggest good prospects for the technique.

Formwork assembly is simple. The blocks are interconnected according to the principle of the constructor, fixing is carried out using jumpers. The assembly process, in addition to creating a mold for pouring, combines insulation and sound insulation, which reduces the overall time of work and simplifies the work as a whole.

The fewer operations, the less the possibility of errors or technology violations.

The main disadvantage of the technique can be called the high cost of polystyrene blocks, which increases the cost of.

This is the main factor hindering the spread of technology.

Installation of removable formwork with insulation

Do-it-yourself installation of this type of formwork is carried out according to our own method:

1. The trench has a width equal to the thickness of the tape plus a double layer of insulation. Usually extruded polystyrene foam is used. The insulator sheets are installed on the edge vertically and fastened with nails 20 cm long directly to the walls of the trench.
2. Before installing the heat insulator on the reverse side, facade dowels are installed over the entire area. Their ends pass through the material and protrude into the trench in order to ensure a high-quality connection between concrete and insulation after pouring.
3. Wooden formwork is installed along the edge of the trench, forming a continuation upwards of its walls. The heat insulator is attached to it in the same way as to the ground - with nails, only of a shorter length. The technique for creating shields is common, the only difference is the installation not inside the trench, but along its edges.
4. Pouring concrete ensures tight contact of the tape with the insulation, the absence of gaps and the tightness of the insulation layer. After the concrete has hardened, the wooden formwork is dismantled, and the heat insulator remains on the concrete surface. Taking into account the specifics of the material, it is necessary to install a protective layer of the plinth sheathing to exclude mechanical effects on the insulator.

Perform dismantling wooden shields Care must be taken not to destroy the polystyrene foam plates.

Installation of fixed formwork

In addition to polystyrene foam, concrete is used to make fixed formwork. Hollow blocks are produced from it, which are assembled like parts of a designer, forming a hollow wall of the desired size.

After that, concrete is poured inside, filling the voids and forming a monolithic solid wall. This technology appeared earlier than polymer fixed formwork, but, due to various reasons, is not widely used.

The creation of such an external frame allows you to solve a number of problems with rigidity, tightness of connection with concrete filling and finishing work. and can be produced without waiting for the final hardening of concrete.

Savings appear building materials, since there is no need for conventional formwork.

The method of assembling the formwork is simple and does not raise questions. Blocks are installed in the prepared trench on the waterproofing layer, a layer of waterproofing is applied to the side surfaces, after which the concrete is installed and poured.

The procedure is simple and allows you to significantly speed up the creation of a solid foundation.

How to further strengthen this device?

The weight of concrete is very high, and the loads on the formwork during pouring can destroy it or create gaps through which the concrete will flow out. For strengthening, additional elements are used that reinforce the walls and take on the load from the weight of concrete.

Usually, at a distance of about 50 cm from the outer surface, stakes are driven into the ground, to which inclined stops are attached. In addition, horizontal stops are laid from below, tightly inserted between the stakes and the lower edge of the shields.

As a result, a number of additional fasteners are formed, which increase the stability of the formwork and protect it from destruction.

When to remove the formwork from the strip foundation?

Dismantling of the formwork is traditionally done 10 days after pouring. R Various technological options allow earlier or later dismantling within 5-15 days, which is due to the size and thickness of the tape - the larger it is, the longer the exposure time in the formwork.

When dismantled in more than early dates extreme care must be taken as the corners or edges of the tape can be easily chipped off.

Useful video

In this video, you will learn how to properly make a formwork for a strip foundation:

Conclusion

Formwork is an important and critical element in creating a strip foundation. It is necessary to treat its assembly with the utmost care and accuracy, without neglecting any stages or elements of technology.

The quality of the filling and the entire foundation to a large extent depends on how reliably and firmly the form is assembled. It is better to spend a little extra time and get the best result, since the fate of the entire building depends on it.

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Any construction of buildings provides for the mandatory installation of floor slabs, which can be either purchased ready-made or made directly at the construction site. In this case, the latter option is very popular, since it is considered less expensive. To do monolithic slabs independently, the creation of a special design is required - the formwork of the floors.

Device

Monolithic overlap is one of the main elements of the structure, which increases the performance of the building and makes it durable. Its installation begins with the assembly of the formwork, which allows the concrete to keep its shape and immobility until it hardens. Slab formwork is considered to be a complex building structure, which usually consists of such elements.

• Base nodes. This wooden bars having the form of telescopic racks. In order to evenly and correctly distribute the dynamic load on this element, the distance between them should be accurately calculated. With the help of such supports, formwork is assembled for pouring monolithic slabs with a height of not more than 4 m. Often, additional or starting racks are also used in the construction of structures. They are made of a metal profile and are fixed to each other with special fasteners (cup or wedge). Thanks to such supports, it is possible to build formworks up to 18 m high.

Racks, which are usually used when mounting formwork in high-rise buildings, consist of three elements: a unifork, a vertical support and a tripod. Unifork is the upper part and serves, as a rule, to fix the working surface. It is often also referred to as a "support fork". This element is produced from four tubes ( square section), which are welded at the corners, and metal plates with a thickness of at least 5 mm. The tripod (skirt) is designed to ensure the stability of the rack and allows it to be securely held horizontally. In addition, the tripod also takes on part of the main load when pouring concrete.

According to the standards, during the construction of ordinary residential buildings, it is allowed to use racks to install an auxiliary structure following sizes: 170-310 cm, 200-370 cm. If it is planned to build a private house outside the city, then you can get by with supports of a typical size of 170-310 cm, they are placed in increments of 150 cm.

• Base. It is made from sheet material, which is most often used as sheets of plywood, metal profiles and shields from boards. To increase the strength of the structure, it is recommended to use a material with high moisture resistance.

• Metal or wooden beams. These elements are placed perpendicular to each other. For the construction of formwork, it is necessary to choose beams with increased rigidity, since the retention of the mass of concrete and the strength of the formwork itself depend on this.

Formwork for slabs can be made various kinds, it all depends on the type of support, the thickness of the concrete pour and the height of the structure.

Advantages and disadvantages

Slab formwork is considered an indispensable building element. However, they have both advantages and disadvantages. Therefore, before you build them, it is important to consider all the characteristics. The main advantages of formwork include such moments.

• Ensuring high strength monolithic slabs. Unlike conventional prefabricated structures, they do not have docking zones and seams.
• The ability to implement non-standard projects, since such formworks allow the production of ceilings of various shapes.
• Exclusion of displacement of floors in the transverse and longitudinal direction. Monolithic slabs acquire additional rigidity.
• Easy installation. It is possible to create formwork on your own without the use of special equipment, which significantly saves construction costs.
• Possibility of multiple use. Climbing formwork is used to cast hundreds or more of monolithic slabs. This is financially beneficial.

. As for the shortcomings, they are few.

• Compared to the use of ready-made slabs, the time costs are greater, since additional construction and dismantling of structures is required. Besides, building process takes a little longer because you have to wait until concrete pouring will gain strength.
• The need for strict adherence to the entire technology of manufacturing and pouring concrete. This is difficult to do, because concrete is poured in large quantities.

Kinds

Slab formwork intended for concreting monolithic slabs can be of several types, each of which differs in assembly technology and technical specifications. Most often in construction use the following type of structures.

Stationary (non-removable)

Its main feature is that after the solution hardens, it is not removed. Stationary formwork consists of sheets of thermal insulation and layers of waterproofing material, so they provide the building with additional warmth and protection from moisture. Upon completion of concreting, fixed structures are transformed into one of the elements of a reinforced concrete structure. These structures have a number of advantages: they simplify the implementation installation work, reducing labor costs, and give the structure decorative look because they are made from modern materials.

Removable

Unlike the previous type, these structures can be dismantled after the concrete has completely solidified. They are in greater demand than stationary ones, because they are characterized by low price and easy installation. Many builders rent removable formwork, as this reduces the cost of assembling the structure and quickly completes the concreting process.

collapsible

This type of formwork is divided into several classes and differs in the level of complexity. So, for example, when building horizontal planes, a simple (frame) formwork is recommended, but if it is planned to erect buildings of complex shapes, then a three-dimensional (large-panel) structure is suitable. The assembly of such elements is carried out from moisture-resistant plywood, profiled sheet, foam plastic, polystyrene foam and expanded polystyrene.

In addition, sliding formwork is sometimes used for the construction of small and large modules. It is installed vertically. The type of construction is chosen in construction, depending on the complexity of the project.

Technical requirements

Since the formwork for floors is responsible for the further strength of monolithic blocks, it must be erected in accordance with established building codes, taking into account all technologies and rules. The following requirements apply to this design.

• High margin of safety. Each constituent element of the structure must withstand not only the reinforcing cage, but also the weight of liquid and hardened concrete.
• Safety and reliability. During the reinforcement and pouring of the mortar, the workers move along the base, so it must be rigid and exclude any vibration. Otherwise, monolithic slabs may get defects, which in the future can lead to emergencies. Construction tables also help to eliminate damage to the integrity of the structure, on which you can also move during construction work.
• Long service life. This primarily concerns the collapsible and removable type of formwork, which are used in construction multiple times. To create a monolithic floor, it is recommended to install formwork made of durable material that will withstand subsequent operation after dismantling.
• Load resistance. Since concrete is poured superficially and with a recess, its mass creates increased dynamic loads on the formwork. In order for the structure to reliably withstand them, it is necessary to correctly select its material of manufacture in advance and prepare a plan for the foundation slab, which complements the formwork drawing and the slinging scheme.
• Have a fast installation. Today, there are many supporting parts and ready-made sections on sale that allow quick assembly of structures.
• Possibility of disassembly. After the solution has hardened, the formwork, consisting of several elements, can be dismantled for further use. This process should be quick and easy.

Do-it-yourself installation

The installation of formwork for overlapping is considered a responsible and complex process, so if you plan to assemble it yourself, you must have some experience and comply with all the conditions of technology. Many builders prefer to purchase ready-made monolithic slabs; only jacks and workers are required for their installation. The only thing is that construction equipment is not always available in use and in hard-to-reach places she won't be able to work. Therefore, in such cases, monolithic blocks are best done by hand. To do this, it will be necessary to strengthen the formwork, after which concrete is poured. In more detail, the construction process is as follows.

• At the first stage of work, accurate calculations should be made. For this, a design is carried out and an estimate is drawn up. In the project, it is important to take into account the strength of the formwork so that it does not crack under the weight of the concrete solution. In addition, a layout of the slabs is made, taking into account the configuration features of the future building, the brand of concrete and the type of reinforcement. So, for example, for the construction of an ordinary residential building, the width of the spans in which will not exceed 7 m, you will need to make a solid ceiling with a thickness of at least 20 cm.
• The second stage is the purchase of all necessary materials. This is the basis for the formwork, supporting and fasteners.
• The next step is to assemble the formwork itself. Its installation should begin after the walls have been erected, when their height has already been set. For horizontal pouring, two types of formwork can be used: ready-made (purchase or rent, it requires only assembly) and fixed. In the first case, it is recommended to choose a structure made of durable plastic or metal, it can be reused after completion of work. The set of such formworks usually includes sliding supports that allow you to hold the ceiling at a certain level. They are very easy and fast to install.

In the second case, you will have to assemble the formwork with your own hands from plywood and edged boards. It is recommended to take plywood with increased moisture resistance, and it is best to choose edged boards of the same size, this will save you from adjusting them in height in the future. First of all, a foundation is being prepared for monolithic slabs. In the event that gaps appeared between the elements during the assembly of the formwork, then additionally fit waterproofing material. You can also make a structure from corrugated board. It is much easier to work with it and this material eliminates the formation of gaps.

Great attention should be paid to the choice of plywood. It is advisable to purchase laminated or glued sheets with increased moisture resistance and a thickness of 18 to 21 mm. Such material is made from several layers of wood veneer, each of which is laid across the grain. That's why this species plywood is durable. Installation of plywood sheets must be carried out in such a way that their joints fall on the crossbars, in addition, after the formwork is assembled, not a single seam should be visible.

The installation process should begin with the installation of supports that will support the future monolithic block. As racks, both sliding metal elements and homemade logs are well suited (they must have the same thickness and height). The supports must be placed in such a way that a distance of 1 m remains between them, while the distance between the nearest supports and the wall should not exceed 20 cm. Then the beams responsible for holding the structure are attached to the supports. They additionally install a horizontal formwork.