Technology for installing formwork under the installation opening. Formwork for the foundation: types, methods, materials

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Not a single construction site is complete without concreting, and where there is concrete mortar, there is formwork. The design used in manufacturing deserves special attention. After all, the quality of the foundation for the house largely depends on its reliability.

Pouring formwork can cause the following problems:

expansion during concreting;
partial destruction;
local leaks concrete mixture.

To avoid this and find out what to make a structure from reliably and cheaply and what the requirements are, take advantage of the practical experience of experts at the FORUMHOUSE website.

What to make formwork from

The quality of the design largely depends on what material it is made from. The formwork is made from: laminated plywood, OSB boards, DSP sheets, flat slate, non-removable polystyrene foam sheets. It's even in use old furniture, as well as “used” pallets.

But the undisputed leader is ordinary wood.

How to make a structure from boards

Forum members advise how to make formwork panels. To assemble horizontal panels, it is recommended to use edged boards measuring 100x25 mm and 150x30 mm, and for vertical panels, use timber 100x50 mm, resting him against the shield with his edge.

The vertical installation step is transverse (beam 50x100 mm) - from 70 to 100 cm. To make the formwork more rigid, two 50x100 mm beams are installed horizontally on each side, top and bottom.

With a well-thought-out design and competent execution, the strength of boards of these standard sizes is sufficient to withstand the pressure of large volumes of concrete mixture on the walls of the structure.

When choosing boards for this design, you must immediately consider the option of their further use. Because formwork for the foundation will require more than one cube; it is irrational to use boards only once. In order for the boards to remain “industrial wood” after dismantling, it is necessary to protect them from direct contact with concrete.

How to attach the film

Before concreting, the inside of the structure is lined with a durable polyethylene film for formwork, which must be secured with a stapler. Construction is best done using self-tapping screws. In this case, it can be easily disassembled, minimizing damage to the formwork boards.

Dmitrievich-50 member of FORUMHOUSE

After dismantling the formwork, I put a 30x120 mm board on the sheathing. Before this, I cleaned the surface of the boards from staples. The main thing is to disassemble everything carefully.

UKSUS70 FORUMHOUSE member

Installation of formwork is a very important and crucial stage of foundation construction. Formwork is a system of vertical floors assembled from panels.

Formwork panels are made from various types durable materials. Vertical panel floors, combined into a single structure, form an impenetrable form for liquid concrete.

Thanks to your design features, formwork can take any geometric shape. This allows you to build a foundation for a wide variety of layouts. load-bearing structures building.

Types and properties of formwork

The formwork is installed using removable panels. In some cases, the installation of formwork from permanent elements is used. Fixed panels play the role of an integral load-bearing part of the foundation. Plates made of various polymeric materials are used as material for permanent formwork panels.

Installation of formwork from permanent slabs is often used when laying a slab foundation.

Wooden formwork panels are suitable for private construction

For example, fiberglass and polystyrene boards serve not only as vertical formwork panels, but also as insulation for the foundation. To prepare the foundation formwork, you need to correctly assemble the panels and carefully check the connection of the fastenings of the vertical formwork floors.

The formwork installation technology depends on the material of the vertical floor panels. Formwork comes in various types:

Board formwork;
Construction plywood panels;
Metal shields;
Polymer and foam boards.

Formwork structure made of boards and plywood

Properly connected panels should not have any gaps between them. To fasten wooden panels, a system of ties, spacers, slopes, clamps and stops is installed.

The installation of the formwork structure must be carried out in such a way that its internal surface does not have any protrusions, but is smooth and even. The developed standard technologies for assembling board or plywood formwork for foundations recommend using boards and plywood with a thickness of at least 10 mm for panels.

Plywood with a thickness of at least 10 mm is attached to the timber frame

If the foundation has a large width, then the lateral pressure of concrete can be withstood by boards made of boards with a thickness of 30 to 40 mm. The frame of the shields and stiffening ribs are prepared from wooden beam cross section 40x60 mm. Fasteners for enclosing structures are made from the remains of boards and timber. Other suitable materials are also used.

After installing wooden or plywood panels, carefully check the surface of the formwork for cracks and irregularities. If any are found, they need to be eliminated.

First, boards and plywood are cut to the size of the panels. Boards or sheets of plywood are laid on the laid out bars. Then all the elements are connected with nails or self-tapping screws. The finished planes are framed with timber and stiffening ribs are attached to them.

Trenches are dug using markings made using string and wooden pegs. At the bottom of the trenches I arrange an underlying layer of sand, gravel or crushed stone.

To attach the formwork, you must choose only high-quality reinforcement

After this, the enlarged elements are installed in the design position and the installation of fasteners begins. Support boards are placed along the formwork installation line, the pointed lower ends of the support beams rest against the ground, and the upper ends hold the formwork.

Fence walls are placed along the entire perimeter of the marking, securing them with evenly distributed fasteners. The panels are connected to each other by pieces of timber using nails or self-tapping screws. The opposite walls of the fence are connected with U-shaped clamps. Clamps are made from boards and timber.

Such structures prevent the formwork walls from breaking apart under the pressure of the poured concrete mixture. On the outside, slopes are installed from timber, the pointed part of which rests on the ground and the other end supports top part shield

Removed board panels can be disassembled into boards and beams, then they are used for other work. Dismantled plywood sheets can be used again to construct a foundation at another facility.

Combined formwork

Combined formwork is installed in loose soils. For the above-ground part of the foundation, the formwork is prepared from boards or plywood. Underground enclosing structures are made of non-removable polystyrene slabs, asbestos-cement sheets and pipes.

Installation of formwork structure made of metal panels

When installing formwork, it is necessary to strictly observe the verticality of structures

Metal panels are factory-made structures. The frame and stiffening ribs are made of a metal profile. The area of the boards does not exceed 3 square meters.

For small foundations, small-panel metal formwork is used. Metal fencing structures are made of steel sheets with a thickness of 1.5 to 2 mm.

Metal structures of this type are reusable shields. The formwork can be used as an adjustable fence.

The metal planes are fastened together with bolts. Where standard fences do not fit into the overall laying of the formwork, the dimensions of the panels are adjusted using gas cutting and welding. Quick-release connections for fencing elements are made from rolled profiles.

Reusable metal structures require special care. After the next use of the boards, structures and elements are thoroughly cleaned of concrete using metal brushes and special steel scrapers.

Before each use of inventory fences, all metal surfaces and parts that come into contact with the liquid solution are lubricated special means. The lubricant ensures easy separation of the panels from the hardened concrete, which allows you to keep the surface of the monolith smooth and without cracks.

Installation of formwork structures made of other materials

Fiberboard and particle boards are used as formwork for foundations. Formwork made from these materials is successfully used for the construction of columnar and other types of foundations.

Fences for pouring foundations are made of foam plastic and polymer slabs. As a rule, such structures are non-removable. They are left in the ground as part of the building's foundation.

General requirements for formwork work

The entire internal surface (bottom and walls) of the formwork is lined with a waterproofing film. Waterproofing will prevent cement laitance from seeping into the soil. Subsequently, the film will protect the foundation from the effects of ground moisture.

Properly applied technology for connecting parts of the fence will eliminate the violation of the verticality of the formwork walls and ensure a horizontal position of the concrete surface. After finishing pouring the foundation, its upper horizontal surface is covered with film or other waterproof material. This will protect the monolith from evaporation of moisture from its surface until the concrete solution has completely hardened.

During installation of structures, you must constantly monitor their verticality, using a level and plumb line.

The fencing elements are dismantled after the bearing capacity of the base monolith has been fully achieved. Before removing the shields, they are tapped with a rubber hammer. This allows you to remove the formwork without much effort.

Watch a video of how the formwork structure is dismantled.

Conclusion

The formwork forms a foundation of such width that load-bearing walls and the edges of the floor structures rest on it. Reinforced concrete slabs are used as flooring.

Reinforced concrete beams, wooden logs and metal beams. It is important that the surface of the foundation is strictly horizontal, which will ensure a high-quality fit of the floor structures.

This will ensure proper distribution of the load on the horizontal surface of the base of the building. A variety of types of enclosing structures allows the developer to choose best option formwork for the construction of its foundation.

No specialist can calculate the formwork absolutely accurately from an engineering point of view: too many variable objective and subjective factors influence the design.

Let's name just a few of them.

Quality of lumber. In nature, no two boards are completely identical. The strength of lumber depends on developmental defects, the number, nature and specific location of knots, etc.
Indicators of concrete. Concrete can have different consistency in viscosity, it depends on the proportions and characteristics of the fractions used during preparation. In addition, the loads on the formwork vary depending on the speed of pouring concrete, the method of compaction and the presence of reinforcement.
Climatic conditions. At sub-zero temperatures boards have some physical strength indicators, and different ones in summer. Dry boards can withstand higher forces, but in rainy conditions their strength decreases.

There are building standards that regulate the maximum deflection of formwork. For the above-ground part of the foundation, the deflection should not exceed 1/400 of the length; for the underground part, the standard has been increased to 1/250 of the length. It is difficult for non-professionals to achieve such values. What should ordinary developers do? When creating formwork, you need to follow the advice experienced builders and your intuition. And remember the main rule - It is better to make any formwork with a clear margin of strength, not to rely on “maybe it will hold up.” It must be remembered that correcting violations of the linearity of concrete is very difficult and expensive.

First, you should know for what purpose you need formwork. If you plan to use it repeatedly, you should use special laminated waterproof plywood or knock down standard panels from high-quality edged boards.

Laminated plywood formwork

If the formwork is one-time use, then low-quality materials will be used; under certain conditions, you can use pieces of chipboard, ordinary plywood, or even unedged boards. As a rule, for the construction of a bathhouse, you can choose the cheapest formwork option.

According to the design features, the formwork can be:

Manufacturing of removable formwork for strip foundations

Initial data: the formwork will be made of a removable type along the entire height of the foundation, the material of manufacture will be second-grade edged boards with a thickness of 25 mm.

There is no one universal algorithm for making formwork; each master makes his own changes taking into account the specific material, characteristics of the foundation and personal preferences. We will tell you only about one of many options.

Step 1. Preparing the shields. Take the dimensions of the trench in length and depth. Do not make the shields large - it will be very difficult to work with them; their length should not exceed 3÷4 meters, depending on the height. Make shields from edged boards; you can use the same boards or slats as vertical posts. If you have thin slats, then nail them with an edge.

Practical advice. Never use self-tapping screws to assemble formwork.

Firstly, it takes a long time and to screw them in you need to have a special electric tool.
Secondly, disassembling shields using self-tapping screws is a pain. The holes for the sprocket are clogged with earth or concrete, and “picking” them out is a very thankless and “nervous” job. And self-tapping screws are much more expensive than nails, and for formwork you will need more than one kilogram.
Thirdly, not a single formwork element is tensile; all have a load only in bending or compression. In this case, the nails are not pulled out of the boards; use them calmly. By the way, it is not necessary to take long nails and then bend them “one meter long” from the front side of the shield.

Step 2. Installation of formwork.

Carefully lower the shields into the trench. Prepare pegs for driving into the ground and corner supports. In our case, supports need to be made on both sides approximately every 50÷70 cm.

To prevent the lower part of the boards from moving during fastening, secure it with small pegs or insert spacers of the appropriate length between the opposite boards. There is no need to take them out later; let them remain in the concrete.

The photo shows the supports of the shields

Step 3. Drive pegs into the corners of the trench and stretch a rope between them. The height of the rope should be greater than the height of the above-ground part of the foundation. The fact is that you will not be able to accurately align the formwork along the horizon at a given height; you will have to level the foundation strip manually after pouring.

Step 4. Drive pegs into the bottom of the trench at a level or plumb level; the depth of driving depends on the characteristics of the soil, but in any case it should prevent their horizontal movement.

Step 5. Place one row of shields and temporarily secure them to the vertical pegs. Place the second row and grab it too. Check all markings.

Step 6. Install horizontal spacers between the panels. These can be pieces of metal rods, wooden slats, plastic tubes, etc. The distance between the spacers is about a meter; they are not affected by the pushing force of the concrete, they only serve to facilitate the installation of the formwork.

Step 7 Measure the required width of the formwork at the top, connect two rows of panels together wooden slats to size. This connection will protect the formwork from deformation while pouring concrete. The distance between the slats is approximately 50 centimeters. If you have an above-ground part of more than 50 centimeters, then you need to tie the boards together with a wire to prevent the panels from swelling under the weight of the concrete. Wire with external parties It is fixed to the vertical crossbars, twisted with a slight tension - the walls of the basement part of the foundation will be smooth. When dismantling the formwork, the wire is simply cut off and remains in the concrete.

Step 8 Place the supports of the shields one by one; in the lower part they should rest against the pegs; in the upper part, a small piece of board should be nailed to the shield for support. Constantly check the position of the shields against the rope. If you have correctly installed the internal spacers of the formwork, it will not change its position during installation and fixation. If you see errors, correct them immediately. It happens that some pegs wobble in the ground - you no longer need to count on them. Drive in new ones nearby and attach inclined spacers to them. In place of the junction of the shields you need to put a board and always a support.

Step 9 At the top of the formwork you need to insert pieces plastic pipes for ventilation ducts and technological openings in strip foundations. There are no pipes at hand - make ordinary wooden boxes, then they will be removed and the holes will be straightened.

Step 10 Check again that the foundation formwork is in the correct position and firmly fixed; problem areas should be corrected immediately. The formwork must stand firmly and should not wobble even under great effort.

That's it, you can pour concrete. It is recommended to remove the formwork no earlier than two weeks after pouring the concrete. If the weather is hot and dry, the concrete should be watered generously daily. The fact is that the strength of cement depends on the humidity and drying time of the concrete. If water evaporates quickly, then chemical reactions do not have time to end, the reliability of the foundation tape will significantly decrease.

As for the formwork for columnar foundations, the work on its production is almost no different from those described above. You just need to immediately make the dimensions of the boards according to the dimensions of the columns. Of course, the small width and height of the posts greatly simplifies the technology of fixing the formwork in the desired position.

Foundations from reinforced monolithic slabs are made for bathhouses built on waterlogged soils or soils with very low load-bearing characteristics. In most cases, the dimensions of the bathhouse do not exceed 4x4 meters. Fill a monolithic slab yourself large sizes quite difficult, it is unlikely that you will be able to achieve its ideal horizontal performance.

Step 1. Level the ground surface as much as possible, pour and compact a sand cushion at least 20 centimeters thick.

Step 2. Prepare the lumber, you will need edged boards and slats. The height of the formwork depends on the thickness monolithic foundation, in most cases it is no more than ten centimeters. This means that it is quite enough to have boards 20 cm wide and 20÷30 mm thick.

Step 3. Drive pegs into the corners of the future monolithic slab and pull the rope. Place boards under the rope and secure them with pegs. Drive the pegs firmly into the ground. Place the formwork in the letter “P”, this will make it much more convenient to feed and level the concrete, and you won’t have to step over the formwork every time. When concreting, do not forget about reinforcement.

Step 4. When to the end concrete slab approximately one meter will remain - install the last board, level it, secure its position and continue pouring concrete.

Video - Box slab foundation

Video - Marking and installation of formwork for a monolithic slab

Video - Formwork and reinforcement strapping of a monolithic slab

Now we can consider several issues regarding the use of additional materials for the manufacture of formwork.

Instead, you can use roofing felt, roofing felt, thick wax paper or other materials. The use of these materials for upholstery of formwork panels is encouraged. Why?

The film must be installed with inside formwork. To prevent sagging or slipping, secure it with a stapler.

Prices for polyethylene film

polyethylene film

Metal tie rods

If you have them, use them for your health; if not, you shouldn’t buy them specifically for the foundation of a bathhouse. It is advisable to use metal studs on high foundations; they cannot be strengthened with side stops. The studs must be inserted into plastic tubes of the appropriate size; be sure to place washers under the nuts large diameter and pieces of boards.

Prices for tie rods

tie rods

Permanent formwork

The new technology for pouring foundations and erecting walls is characterized by excellent performance characteristics and, unfortunately, the same high price indicators. It significantly speeds up the construction process and acts not only as formwork, but also as insulation. Often used for the construction of monolithic earthquake-resistant reinforced concrete buildings. Load-bearing walls They are not only durable, but also insulated.

Construction companies produce permanent formwork from various materials and with various linear indicators. The specific type of formwork should be selected taking into account the place of its use. There are several types of permanent formwork.

Made from highly durable expanded polystyrene foam. It consists of flat plates or blocks, corner turns, spacers, reinforcement clamps, etc. The thickness of the sidewalls can be from 40 to 100 mm. The process of assembling formwork blocks is carried out in tenons; all dimensions must be checked with a level. Depending on the height of the formwork, concrete is poured in several layers along the entire perimeter of the foundation or wall. After pouring the previous layer, several rows of formwork are assembled again and the next one is poured.
Concrete permanent formwork. Made from durable concrete, the side surfaces of the blocks have tongues and grooves for a strong connection with each other. The walls are held in place by jumpers. Such formwork can be used both for pouring foundations and for erecting monolithic reinforced buildings. The reinforcement is not knitted; vertical rods are inserted into the holes, and horizontal rods are placed on special stops.
Wood-concrete. It can take the form of hollow blocks or flat panels; the front surfaces must be finished; it is used only for the above-ground part of the foundation or walls. The blocks are installed using the dry masonry method; there may be reinforcement inside. The panels are assembled on ties installed inside the concrete. The front surfaces of the screeds have the form of large flat washers; the surfaces of the panels are characterized by high adhesion to all building finishing materials.

It is not economically feasible to use such expensive formwork on strip foundations of a bathhouse. Baths do not require an insulated foundation, and the visible part of the basement is finished with ordinary decorative materials.

Prices for foamed polystyrene foam

expanded polystyrene foam

Possible consequences of poor-quality formwork

Let’s say right away that all the consequences of incorrectly made, installed or fixed formwork are very sad; their elimination requires a lot of effort and money. In the most serious cases, pouring the foundation will have to start from scratch. Let's consider three possible consequences of defects in the construction of formwork.

Option 1. Swelling of the formwork became noticeable during concrete pouring. Stop work immediately and call all helpers for help. Use shovels to remove the concrete where the formwork is swelling. To prevent the concrete from floating back, nail transverse boards at some distance along the entire width inside the formwork. Keep in mind that the concrete will gradually fill the hole; work must be done quickly. Throw concrete at a distance of more than 1.5 meters from the emergency site.

The pressure on the formwork has noticeably weakened - try to level it. It is very good if you manage to adapt the jack and use the beams to slowly level the formwork. You can stretch a wire in a place free of concrete and use it to level the convexity. Very important: do not hit the formwork with a sledgehammer, this way you will make it even worse. The vibration will cause the concrete to float down and further disrupt the straightness of the formwork. Level the shield gradually, without excessive fanaticism. Excessive force may completely break the shield or individual fastening elements. The consequences will be very sad. As soon as you manage to level the shield, immediately fix its position. This time, check the security of the supports with special care.

This case is the easiest; all the others cause much more trouble.

Option 2. Displacement of the formwork was noticed only on the second day.

What to do if the formwork has moved

Important. Not everything that is written on construction forums is true; think with your own head before believing the first piece of advice from an “expert” that catches your eye. Many of these “experts” advise removing the formwork, and while the concrete has not yet gained strength, cut down the mound with a shovel. This is not advice, but mockery. Do not remove the formwork under any circumstances! There is a very high probability that the entire foundation will crack. It may not crumble before your eyes, but may give almost imperceptible cracks, which will reduce the strength of the structure almost to zero. We noticed trouble the next day - that’s it, the train left. Wait until the concrete hardens completely, dismantle the formwork, pick up a hammer drill and work hard.

Option 3. The formwork or part of it fell while pouring concrete. The most unpleasant situation. What to do? Scratch your smart head “silently and with a smile,” remove the concrete, clean the site and start all over again.

We hope that from the second time you will understand how to install formwork correctly. To prevent this from happening, read the article carefully again. You can and should make your own improvements, but only if you have experience in constructing at least three different formworks.

Video - Possible consequences of poor-quality formwork. Gap

Conclusion

Many articles on the Internet begin with the words “the foundation has a great influence on the strength of the building.” This is true. But then you can read that “everyone can do it,” that “there is nothing complicated here,” etc. This is not true. Don't waste your time reading such advice. Think about why the earnings of professional experienced builders are several times higher than the earnings of engineers? Because a professional builder not only has theoretical knowledge, he has tried all the “scientific” recommendations with his own hands.

When starting to make formwork, you need to adhere to two rules.

First, you need to know the job. You shouldn’t think that everything is very simple, you can “somehow mold it” and it “will somehow stand.”
Second. There is no need to be afraid of any work, but you must respect it. You should always have a vision of operations several steps ahead in your head, you should be able to choose from several possible options the most optimal.

Video - Reinforcement and formwork of shallow strip foundations

Video - Installation of braces for formwork

One of the first stages of construction of structures for various purposes is the installation of formwork. Often this process remains without due attention. But already at the stage of preparation for pouring it becomes clear that not everything is as simple as first thought. The formwork installation instructions will help you assemble the frame.

Types of formwork

There are three types of design:

Removable, which is dismantled after the solution has completely dried. Such formwork is assembled from individual parts. The result is a collapsible structure that can be dismantled and reused. Among the advantages of this type of formwork are ease of installation and the possibility of reuse, which significantly reduces the financial costs of construction.

Fixed, respectively, one that cannot be dismantled. Installation of formwork of this type is carried out mainly from expanded polystyrene or polystyrene foam. It remains part of the structure being built. And at the same time it acts as insulation.

“Floating” formwork is typical for the construction of a monolithic foundation, which is immersed in the ground. It is a shield assembled from boards, which is slightly higher in height than the planned concrete structure. The shield is lowered into the pit and attached to its walls. Cardboard or roofing felt is rolled out on top of it.

There are also several types depending on the purpose:

Wall formwork. Its installation is carried out for the construction of vertical structures and walls.

Horizontal, which is used for installing foundations and floors.

Curved, which allows you to fill parts of unusual shapes.

Installation and dismantling of each type of formwork has its own characteristics. You need to know them to perform quality work.

Advantages of permanent formwork

Installation of permanent formwork involves purchasing a ready-made kit for performing the work. All that remains is to assemble the structure and install it. This leads to a number of advantages that formwork of this type has:

short deadlines for completing work;

ease of installation;

low weight of the structure;

resistance to fungus and mold;

fire safety;

low cost.

Also, permanent formwork is both a layer of insulation and consists of foam blocks that are easily connected to each other. In this case, the inner wall is thinner than the outer one. Thanks to this it is achieved high level thermal insulation.

Construction of permanent formwork

The finished panels are attached to the corner bars using self-tapping screws or nails. The fastening must be reliable. As the concrete expands, the pressure on the board will increase, which can lead to cracking of the boards. The main thing is that the block itself remains on the outside. Parallel to the assembled structure, another row is assembled at a distance from the future wall. The result should be a frame around the entire perimeter.

A layer of crushed stone or sand is poured into the finished formwork box. This will protect the solution from loss of moisture, which will go into the ground. The formwork installation technology provides protection against mortar leakage through existing holes. To do this, the boards are covered with film or roofing felt, which are fastened with screws or staples using a stapler.

All work must be carried out taking into account the level. It is very important. At each stage, the evenness of the structure in height, length and vertical is checked (especially important). Two rows of shields must run strictly parallel to each other.

Basic elements of formwork

Removable formwork, which is assembled independently, consists of the following elements:

The deck, which is flat shield, which is the enclosure of the entire form. The structure must be strong enough to withstand the pressure of the solution. Therefore, it is made from plywood or edged boards 4-5 cm thick.

Scaffolding that supports the structure. They hold the walls, preventing the mortar from squeezing out the deck. Scaffolding is made from pine bars or boards (2.5-5 cm).

Fasteners are all the parts with which all structural elements are twisted: wire, clamps, ties, hardware, and so on.

The deck is most often assembled from boards 15 cm wide, which are connected in several rows using nails (driven from the inside, bent from the outside) or self-tapping screws (they are screwed in from the inside). The distance between the boards should not exceed 3 mm. The shields are fastened together with additional strips.

A simpler option for making a deck is to use moisture-resistant plywood 1.8-2.1 cm thick.

Installation of formwork

The frame will be installed level and level if the site is properly prepared in advance. It is marked using cords stretched between pegs. The sand cushion is filled in and compacted. If necessary, a pit is prepared.

Installation of formwork occurs in the following sequence:

The perimeter should be marked with vertical guides (wooden blocks, metal corners or pipes).

It is necessary to place the finished panels along the guides, maintaining the required distance between them (it is equal to the required thickness of the foundation).

Securely secure the deck. Support it from the outside with inclined beams (1 strut for each meter of deck).

Connect the panels together with 5x5 cm bars.

Cover the inside of the formwork with film (roofing felt).

Foundations up to 20 cm high do not require serious construction. For them, bars driven into the ground are enough.

Installation of wall formwork

The process of constructing wall formwork is more complex. In this case, small-panel and large-panel formwork are distinguished.

The first option is suitable for the construction of small buildings (country houses, utility buildings) and partitions between rooms. In this case, small-sized plywood panels are used.

Installation of large-panel formwork is typical for the construction of buildings with high heights. For work, use sheets of metal or large sheets of plywood.

To install the walls, prepare a foundation into which reinforcement is inserted. A two-row formwork frame is assembled around it. When using regular plywood, the joints are coated with glue or sealant. Currently, there is special plywood for formwork on the market. Its individual sheets are connected using the tongue-and-groove principle, which does not require additional sealing.

Types of floors

The installation of floor formwork depends on the type of floor itself. The following types of structures are distinguished:

On large bowls. Used for structures with high heights. In this case they use vertical racks, jacks, inserts, crossbars and other elements for connecting individual parts.

On wedge scaffolding, which is used for multi-storey buildings. Instead of plywood panels, scaffolding is installed.

On cup-type scaffolding. This type involves mounting a frame. The racks are connected to each other using the cup method.

On telescopic bowls. Suitable for cases where the ceiling height is less than 4.6 m. It is based on tripods that support the entire structure. Boards made of moisture-resistant plywood are laid on top.

Slab formwork

Currently most commonly used monolithic ceiling. Using his example, we will analyze the process of installing formwork.

For formwork, vertical posts are used, connected to each other by crossbars. They are attached at right angles to bars running in the transverse direction. A plywood panel is laid on these cross beams, which is the bottom of the formwork.

To perform this work, the following materials are used:

stand - timber with a cross section of 12-15 cm;

crossbar and transverse beam - edged board 16-18 cm wide and 5 cm thick;

braces - board 3 cm thick;

flooring - moisture resistant, 1.8 cm thick.

Before starting work, it is necessary to make accurate calculations. It is important to determine required amount racks, the pitch of their placement and other indicators.

Installation instructions for floor formwork

The work instructions include the following steps:

Longitudinal bars are attached to the top of the racks, the second end of which is fixed to the wall.

The second row is assembled in the same way. To do this, a 5 cm thick board is laid under the supports.

Cross beams are laid in increments of 60 cm.

Install the support posts (strictly vertically).

The racks are connected to each other by braces.

Sheets of plywood are laid on the cross bars, leaving no gaps.

The ends of the ceiling are protected by masonry made of blocks or bricks.

A frame is assembled from reinforcement. At the same time, if necessary, space is left for communications.

When all the work is completed, the concrete can be poured. The formwork is removed after 3 weeks.

Conclusion

Installation of each type of formwork involves the use certain materials. If boards are used, they must be new. Rotten old boards may not withstand the load and break. Plywood must be moisture resistant or laminated.

All work must be performed in accordance with the calculations made. This is especially important for the installation of formwork for ceilings and walls.

Advantages and disadvantages of the design. Types of formwork. Permanent formwork for foundations, walls and ceilings.

Many experts advise using this particular type of plywood when assembling formwork with your own hands. For walls, a slightly different technology is used, but for the foundation this option is the most acceptable. Another advantage of FSF is that it can be used several times. It is not recommended to cover the interior parts of the room with such plywood.

Before the beginning installation work required to carry out standard calculations. These include determining the amount of material needed and finding its final cost. It is important to consider the type of raw material that will be used to make the formwork. OSB boards, plywood, chipboard, boards - all these materials have different prices.

OSB formwork is most often used in private construction, since this material is not suitable for large projects due to its poor resistance to moisture. Calculating the number of boards is very simple. To do this, first of all, it is necessary to divide the perimeter of the planned foundation by the length wooden part. Next, you need to divide the height of the base by the width of the wooden board.

Expanded polystyrene blocks for formwork are very quickly installed

The last thing to do is to multiply the two values obtained earlier. The result will correspond to the number of boards that will need to be purchased. Experts recommend adding a small margin (about 10%) to the calculated data.

Note! One cubic meter of boards can hold an average of 40 to 65 products.

In order to determine the cost, you need to multiply the price by the number of cubic meters of lumber required to install the formwork for the foundation.

Other expenses should be added to the resulting figure. For example, to assemble a forming structure, a certain amount of timber will be required. Wooden spacers are also used to strengthen the formwork. The cost of purchasing additional materials can in some cases amount to 40–50% of the total price of plywood sheets and boards. The final cost calculation also includes the costs of purchasing tools and elements that will be used to fix the individual components of the formwork.

Before starting the assembly of a removable forming structure, it is necessary to purchase the appropriate tools and materials, and it is also worth preparing the area that has been designated for installation of the foundation. The most common is the strip base. To make removable formwork you will need the following materials:

Before starting the construction of formwork, it is necessary to purchase the appropriate tools and materials

Counting materials for organizing formwork strip foundation is carried out based on the dimensions of the future foundation. It is necessary to take into account several requirements to correctly implement the forming design. The height of the formwork assembled from plywood must exceed the level of the base by 50 mm. Spacers are installed at a strictly defined distance from each other (700-1000 mm).

It is important to remember that there should be as many stakes as there are side supports. The shields in the corners are fixed together. For this purpose, side jumpers are used. When organizing formwork, a dense film made of polyethylene material is used. It should cover everything inner part fencing. Before you begin, it is recommended to watch training videos on how to properly make a foundation.

Preparing the place where the base will be cast includes several types of work. First of all, you need to dig a ditch in the ground. The trench must correspond to the designed depth. In this case, it is required that the width of the ditch have a margin of 10 cm greater than that of the future strip base.

Next, you need to level and compact the soil at the bottom of the trench. Then the walls are leveled. One of the most important conditions When pouring the foundation, it is necessary to organize a special cushion of gravel and sand at the bottom of the ditch. Standard width this layer is 10-15 cm.

The most commonly used material for formwork construction is boards

Note! Not all buildings require the organization of the foundation using a forming structure. In some cases, it is possible to pour the foundation without formwork. This foundation is suitable for various types of temporary buildings. The technology of such construction takes into account digging a trench, laying polyethylene and reinforcement.

In soil that has a high density coefficient, a trench is made corresponding to the width of the concrete strip. Moreover, the formwork in this case should be located above the soil level.

Installation of a removable structure most often takes it into account reuse. If this is not necessary, then you can purchase a non-separable polystyrene foam form. Doing this work on your own is quite difficult. To do this, you need to draw up a competent project and strictly follow the instructions for organizing the base formwork. Let's look at each stage of the work in more detail.

First of all, it is necessary to make shields, which are the main forming elements. Nails are used for fastening. The height of the shields should be slightly higher than that of the base (about 10 cm). In order to understand the features of assembling the forming structure, it is recommended to study the corresponding photos and videos. The formwork for the foundation is strengthened with your own hands using wooden stakes. As mentioned above, their pitch is approximately 70-100 cm. The distance from the foundation to the stakes should be approximately 1 meter.

Next, you need to place the shields along the edges of the ditch and connect them to the stakes, using special jumpers. Then the fence is leveled in a vertical plane, for which you will need to use a building level. After this, the structure is fixed to the mow.

In some cases, it is possible to pour the foundation without formwork

At the next stage, the internal cavity of the formwork is covered with dense plastic film. The edges of the canvas are fixed using a construction stapler. Next, you will need to place a reinforcing grid in the intermediate space. When installing formwork for a strip foundation with your own hands, you may need to add reinforcement under wooden supports, the height of which is 5 cm.

Note! Before starting pouring, it is necessary to organize passages for communications. Round sleeves are used for this.

After laying the reinforcing grid, you should tighten plywood panels using wire. It is worth noting that if the foundation has rounded areas, then in this case you will need to bend the plywood to achieve the desired shape.

During the assembly of the forming structure, it is necessary to comply with certain dimensional requirements. All possible deviations from the norms should be taken into account. Otherwise, an unstable shape may result, which will subsequently negatively affect the technical characteristics of the base. So, there are special requirements for the manufacture of formwork.

How to make a foundation correctly? It is important to remember that the deviation of the panel structure in the vertical plane should not exceed 5 mm per 1 meter of height. Quite often, inexperienced craftsmen make the mistake of placing boards in areas that have a natural slope of the ground. The top formwork board in this case should be positioned strictly horizontally. Repeating the tilt is strictly prohibited.

Wall formwork is not yet widely used in construction

There are also clear restrictions on the displacement of the forming structure from its original position. The maximum permissible displacement is 15 mm. When installing boards, you need to take into account that the differences between them should not exceed 3 mm.

How to install formwork on an area with loose soil? In this case, it is necessary to make a wider ditch, on the sides of which additional spacers need to be arranged.

If desired, at the stage of assembling the formwork, you can insulate the future foundation. To do this, use any suitable inexpensive material(for example, foam). In this case, the trench expands in accordance with the thickness of the insulating material.

In the case of organizing a foundation without formwork, suitable reinforcement is selected in the ground from which the lattice is constructed. It is not recommended to use this technology if the soil on the site does not have sufficient density.

When installing permanent formwork, it must be remembered that the most important criterion is its tightness. If we neglect this, then the thermal insulation qualities of the non-demountable structure will be greatly reduced.

The forming structure is used not only for pouring the foundation of residential and commercial buildings. The need for formwork is also present when installing some protective structures. A strong fence base guarantees protection of the area from unauthorized persons.

The construction of a fence is not complete without pouring the foundation.

In this case, before installing the formwork, you will also need to carry out some preparation. The first step is to mark the perimeter of the future structure. Then the soil is prepared, which involves removing vegetation, stones, debris and other obstacles that may interfere with the installation of formwork under the fence.
Next, you can start digging a trench. It is worth considering several rules. At points corresponding to installation supporting elements(pillars), the depth should reach 80 cm. The same figure for spans is 50 cm.

Note! After organizing the trench, you need to pour sand and gravel into it to prepare a special cushion .

How to build the formwork for the foundation of the fence yourself? Complete at home this device not so difficult. Even a person who does not have relevant experience can cope with such work. To organize the forming structure under the base of the fence, you should follow a step-by-step algorithm of actions.

The first step is to strengthen the waterproofing qualities of the wood from which the formwork will be made. For this purpose, waste is most often used machine oil. Next, vertical stakes are installed. The distance between them should be at least 50 cm, but not more than 1 meter.

A foundation is needed even for a fence made of corrugated sheets

Then installation is carried out support posts from timber and the shields are fixed to them. For fastening in this case, use ordinary nails or self-tapping screws. At the next stage, it is necessary to tighten the shield fence with wire and install the reinforcing mesh.

After installing the reinforcement, the upper part of the frame is fixed. For this purpose they use wooden blocks. In the corners there are brackets that perform a fastening function. At the final stage, you will need to seal the cracks in the structure. This completes the installation of the formwork for the base of the fence.

Independent installation of formwork for the foundation of a residential or commercial building requires serious preparation. In addition to drawing up a plan, you should calculate the quantity necessary materials. Before assembling this structure, it is recommended to study all possible video materials on this topic.

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