Material for foundation formwork. Installation of formwork for strip foundations

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 construction:

Removable, which is dismantled after the solution has completely dried. This formwork is assembled from separate 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 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 requires the purchase of already ready set to carry out 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 required thickness 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, buildings for utility purposes) 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 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-story 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, monolithic flooring is most often used. 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 cross 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 carry out accurate calculations. It is important to determine the required number of racks, the spacing 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 support posts(strictly vertical).

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 of 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.

Almost everything existing species strip foundations can be poured using only formwork - an auxiliary structure, which is often made from scrap material. It serves not only to ensure constant dimensions of the base, but also gives the foundation even correct forms and reduces consumption concrete mortar. Plus, it can be removed, moved to another construction site and used more than once.

Types of structures

The construction of an auxiliary structure made of wood, metal or other materials involves the use of rigid structures interconnected and capable of supporting the mass of concrete, but some types also provide excellent thermal insulation characteristics of the house. Various types of materials are used to construct formworks; let’s stop and first look at the types of formworks for strip foundations:

Removable (collapsible). These are wooden, less often plastic and metal shields, which are assembled in the form of a constructor, provide reliable connection elements and tightness of seams. In most cases, the calculation of the quantity necessary materials done on the spot when necessary. After use, you can remove and reapply. You can make it yourself from wood.
Fixed. This is a disposable design, made from polystyrene foam, and serves as the main thermal insulation layer. Needed when the building area is limited. Thanks to reinforcement with special supports and spacers, the foam plastic can withstand heavy loads, does not deform, and do-it-yourself assembly is done like a construction set from factory elements. It cannot be removed; it is necessary to calculate the panels for each specific construction. Various materials can be used, but most often polymer products.
Combined. Here wood is simultaneously used as outer layer formwork, and polystyrene foam as insulation. After pouring the foundation outer part The structures can be removed, while the insulation remains embedded in the concrete.

Several years ago, builders preferred to use removable formwork for strip foundations, since it is reusable and can be rented at affordable price. Moreover, many companies and small firms produce such formwork with their own hands and then rent it out at an affordable price. It is worth noting that it is difficult to erect the formwork correctly, according to all standards, taking into account the technical characteristics of the materials used, as well as the possibility of expanding the base if necessary.

Design elements and material

The formwork consists of several main elements:

Wooden boards of rectangular or square shape of any size.
Clamps for vertical placement of panels.
Horizontal internal bushings, they are used to ensure the required internal width of the tape and prevent the expansion of the panels
Waterproofing. It prevents liquid from leaking out of the formwork, and also ensures a faster drying speed of the solution.

Formwork for strip foundations can be made from wood. The most affordable and cheap material, the device is simple and anyone can make a frame with their own hands using available tools. For the production of formwork in private conditions, plywood up to 15 mm thick or edged boards 40 mm thick are used. In this case, it is easier not only to construct a strip foundation, but also to carry out the calculation correctly required quantity materials.

Metal factory structures are strong and reliable. They are durable and reusable, but due to their large mass they are difficult to transport. Only experienced builders can install such shields correctly. Tape extension is not allowed.

Plastic formwork or polypropylene foam is lightweight, compact, expensive and versatile. Excellent for the construction of load-bearing walls and ceilings, as well as for pouring strip foundations. Plastic and polystyrene foam are artificial thermal insulation, calculations are made right on the spot, and the panels can be cut to your size. It is also easy to construct a plinth on such a ready-made, flat surface.

Installation of wooden formwork

To produce wooden formwork, it is better to use edged board or wide plywood. Ready-made shields of fixed sizes are made from these materials, then grooves are made on the external contours to connect the shields to each other. All joints are treated with waterproof sealant or polyurethane foam. The moisture content of the wood should not be high, the thickness of the cracks should be up to 2 mm. The height of the shields should not exceed 5-7 cm above the level of the foundation strip. Installing the formwork is quite simple, you can do it yourself:

First, the construction site is prepared.
The dimensions of the formwork are calculated, the appropriate materials are selected and the structures are assembled.
Then the shields are installed on the outside and reinforced with braces, where the main fixation will be the soil or reinforced pillars. The braces are nailed to the boards and installed at intervals of at least 1 m from one another, the minimum permissible distance is 30 cm for thick bases.
Jumpers of a fixed length are secured with nails or corners - this is the maximum allowable width of the foundation strip.
The inner part of the formwork is installed in the same way and tightened with clamps, nails or other fasteners.
The vertical and horizontal position of all shields is checked, the permissible slope angle is no more than 3 degrees, and they must not have deflections or bends. The condition of the surface of the boards should be regulated by slats, a level or a construction hydraulic level. Local deviations for plywood should not be 2 mm, and for boards - up to 3 mm.
After pouring the concrete solution, the formwork can be removed and reused, and the base can be constructed on a flat outer surface.

The correct positioning of the formwork panels can also be controlled using casting threads and wires, as well as fixed type fasteners. If permanent formwork is used, it is advisable to fix it on the inside of the polystyrene foam. wooden planks, install strong hooks in them and connect the fittings flexibly. Then the hooks will tension both surfaces of the formwork and fix them within the specified parameters.

After installation, the inside of the formwork must be covered with roofing felt in several layers so that the concrete does not leak out, as well as to ensure waterproofing of the tape. Waterproofing must be laid from downward slopes, closer to the sand cushion, so as not to tear the layer during concreting. It is better to bend the upper part of the ball of roofing material over the upper edge of the formwork, secure it with clamps or screws, and secure it with a stapler. Then the sheet will withstand the load that will occur when pouring concrete from a concrete mixer.

How to install formwork for strip foundations on unstable soil

Even just digging a trench or pit in loose soil is fraught with some danger due to its possible shift. Therefore, first they make the outer formwork of the trench in order to prevent soil shifts, and only then they equip the inside of the trench.

To protect the labor of workers, a trench is dug at a certain slope of the walls and of sufficient width for convenient installation of shields. Then the formwork is installed, which is often made in several layers, where the intermediate zone is the clamps of the outer edge from the ground and the inner edge from the concrete mortar zone.

To ensure that the formwork stands securely, you can pour a layer of concrete on top of the sand-gravel mixture medium density so that it fixes the shields from the inside. When the formwork is installed on concrete base, then it is better to use special threaded ties. They fix the slabs together, prevent them from spreading under the mass of concrete, and steel bushings are provided inside the formwork.

How to arrange a combined formwork for a strip foundation

Combined formwork pays off when you need to build high building and install thermal insulation on a limited area of the construction site. The design involves a combination of removable and permanent formwork, which you can do yourself, while its design remains quite simple. From the outside - these are ordinary removable plastic or wooden boards, and inside there is a layer of polystyrene foam.

This design carries the advantages and disadvantages of two types of formwork. Some developers spend money and time on thermal insulation, especially when it is necessary to build a foundation without calculations in a short time. The disadvantage of such formwork is that when it comes to waterproofing, it can only be placed on the outer surface, and the inner part of the insulation cannot be removed.

If the strip base is erected on strong soils that are not prone to heaving, then the trench is dug taking into account the thickness of the insulation, as well as the removable formwork panels. In the underground part, the insulation is attached to the walls of the trench, and in the above-ground part - using self-tapping screws. You can also use special mounting dowels and umbrellas, but then removing the insulation during restoration or repair is problematic. If the tape is installed in loose soils, then the insulation is installed completely immersed in the ground, provided that the level of frost heaving in the region is insignificant.

The role of permanent formwork for strip foundations

These are panels made of polystyrene foam, connected to each other by grooves in the shape of a construction set, so they are often made with their own hands according to ready-made drawings. Installed inside reinforcement cage, then filled with concrete. Due to the presence of expanded polystyrene, a thermal insulation and waterproofing layer is simultaneously formed on the surfaces of the tape. This type used when the building area is limited or the burial level is high groundwater. The advantages are obvious:

it can be quickly assembled directly at the construction site and does not take up much space;
it is supplied in a factory configuration, there is no need to calculate the parameters of the panels, they can simply be cut, which cannot be done with wooden formwork;
all external and internal surfaces of the tape remain insulated;
the result is the smoothest outer surface, ready for construction and resistant to frost heaving.

The key disadvantage is the cost of permanent formwork, since it is produced in a factory from expensive materials and cannot be removed. For each individual construction, it is necessary to re-calculate the dimensions of the slabs.

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 starting installation work, standard calculations are required. 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. Procurement costs 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

The calculation of materials for organizing the formwork of a 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. The 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 the entire inside of the fence. 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 a foundation is the organization of a special cushion of gravel and sand at the bottom of the ditch. The standard width of 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 into account its 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. The fence is then leveled 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 polyethylene film. The edges of the canvas are fixed using 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, the plywood panels should be tightened 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 form may result, which will subsequently negatively affect technical specifications grounds. 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. Solid base The fence guarantees the protection of the site from entry by 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 the points corresponding to the installation of 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. WITH similar work Even a person with no relevant experience can handle it. 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, used machine oil is most often used. 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 the support posts are installed from timber and the panels 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. Wooden blocks are used for this purpose. 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 amount of materials needed. Before assembling this structure, it is recommended to study all possible video materials on this topic.

Wood formwork

Metal formwork

Permanent formwork

Inspect the wooden materials prepared for the construction of formwork for unevenness and contamination.
The installation of the structure must be strictly level;
The fastenings must be fixed very tightly, since if this condition is not met, deformation of the future foundation may occur;
When constructing formwork, it is worth checking the surface for the absence of cracks and gaps.

Conclusion

We build a house from foam blocks with our own hands
Floating foundation
DIY foundation formwork
Foundation for a stove in a bathhouse

When constructing a monolithic foundation, it is very important to correctly position the formwork - the structure must create a rigid shape with given geometric dimensions.

The strength and reliability of the foundation support of the building directly depends on the accuracy of the alignment. This article is all about how to correctly set up the formwork for pouring foundation supports.

Which one to choose?

Permanent formwork

There are removable and non-removable formwork designs. For a monolithic foundation, it is usually made of wood, plywood or metal. Fixed forms for the foundation are made from sheets of expanded polystyrene. Expanded polystyrene is not dismantled after hardening concrete mixture– the layer serves as additional insulation for foundation supports (this manufacturing method is most suitable for areas with cold climates).

Assembly of foundation formwork is necessary when concreting monolithic building structures– a reinforcement cage is installed into it, a concrete mixture is poured, which, when hardened, gives the foundation structures the necessary shape and rigidity. Clearly positioned formwork panels help maintain the monolithic reinforced concrete foundation in the dimensions specified by the design.

Making wooden shields

Wooden formwork

Formwork made from wooden boards must be adjusted as much as possible, achieving minimal gaps between two boards so that the concrete mixture does not leak out of the box through existing cracks. Formwork forms must be as smooth as possible and free from flaws, in which case finishing the foundation walls will be very easy to perfect.

Wooden formwork is made in the form of an oblong panel; during installation, the elements are fastened together using metal fasteners (nails and self-tapping screws). Wood is chosen coniferous species, planed edged boards with a thickness of 25 mm and a width of up to 150 mm are ideal.

The racks and frames of the form for a monolithic foundation are made of wooden blocks - these elements ensure the stability of the panels during pouring of concrete mortar.

It is very important to use lumber for the manufacture of formwork high humidity– this is necessary so that the wood does not absorb moisture from the concrete solution, which will greatly deteriorate the quality of the hardening concrete solution.

Installation Rules

Pouring the foundation

When installing, it is very important to follow the existing building codes and rules - this will help to pour strong and reliable foundation from monolithic reinforced concrete:

It is not allowed to install the support posts of formwork panels on excavated or bulk soil, it is necessary to ensure the reliability and stability of the structure, for which, on problematic soils, it is necessary to place cuttings of boards under the support posts.
The panels must remain in an unchanged position for quite a long time, taking into account the impact on them of the mass of concrete poured into the structure, therefore wooden formwork can be strengthened by installing braces, racks and supports.
In subsidence and heaving soils, the mold is mounted on special foundation edges buried below the freezing point of the soil.

Installation work

It is convenient to mark the formwork on the building site using pegs and stretching a construction cord or fishing line over them. It is very important to remember that the foundation should be 10-15 cm wider than the walls. Each action should be checked by level and laser level- this way you can ensure the most even arrangement of the formwork panels.

It is possible to position the formwork correctly only by using a level, which should be used to periodically check for possible displacement of the panels during installation.

You can start installing the boards only on level ground, securing each board with scraps of reinforcement and wooden support pegs. The panels are secured from the inside with reinforcing rods - after concreting, the reinforcement will serve as an additional reinforcement element to impart vertical rigidity. Watch the video on how to install formwork without mistakes.

The lower edges of the formwork panels should rest completely on the upper surface of the ground, and adjacent elements should have the closest possible fit to each other.

The side panels are tightened using special ties made of timber, which are strengthened on top of the formwork panels from above. Screeds are installed every 0.5 - 1.0 meter.

How to correctly level formwork panels

Usually the formwork rises 30 cm above ground level; it is very important to set the panels as level as possible so that there are no differences in height on the surface of the foundation. All formwork installation operations should be checked for level. It is very important to level the upper edge of the formwork, for which a stake is driven in the center of the building, on which the zero mark of the foundation is marked. Then, using a tubular level, marks are placed on the surface of the formwork panels or stakes. Concrete should be poured into the structure in accordance with the marked risks.

When the concrete mixture hardens and gains strength, the panels can be dismantled, usually 14-15 days after pouring the concrete.

When installing formwork for the foundation, it is better not to slack in the work, otherwise the durability of the built house will be at risk.

How to align formwork using a laser level?

Using a laser level, the formwork is placed simultaneously along the entire perimeter. The device at a distance with high accuracy projects vertical and horizontal lines visible to the eye, determining the shape of the future structure.

Possibilities of laser levels when constructing formwork

Bubble levels allow for significant error. The use of hydraulic ones is possible only in the positive temperature range. Due to the high resistance in the tubes, it takes a long time for the liquid to reach the level. Just marking out a complex foundation can take a whole day.

It’s a completely different matter when the formwork is set using a laser level. This is especially true for models capable of projecting a 360° beam. It is enough to install such a device inside the future foundation, and we will be able to place the formwork anywhere. Several workers can start work at once without crowds. The docking of the shields will occur flawlessly.

Speaking of foundations of complex shapes, with inclined planes and edges, setting up formwork without a laser level will require painstaking and lengthy calculations and making a model of the future structure.

Laser level for home use

Professional equipment is expensive and has great functionality. For reference household Inexpensive rack and pinion models are sufficient. For advanced owners of country real estate who are actively developing their homestead farming and arranging the local area, it makes sense to opt for more expensive structures with a self-leveling mechanism. Unlike rack laser levels, where installation is carried out along an air bubble, here spatial coordination is built into the program. The self-leveling option does not allow the slightest deviation of the beam from the base projections. You can learn more about modern models of laser levels on the website www.laserbuild.ru.

Using a laser level to level formwork

Let's consider the possibility of using a laser level using the example of constructing formwork for a strip foundation. Professional approach consists of preparing shields that are installed in a trench, leveled and nailed together. Sequencing:

we set the level to the height of the future foundation and, by projecting a beam along the perimeter of the trench, we determine the required width of the shield;
After manufacturing the formwork walls, they are installed sequentially. We focus on the projection of the beam. We perform the leveling with pads under the bottom edge of the boards;
After installing the shields horizontally, we check the verticality of the planes. Regulation is made by spacers inside the formwork and upper ties;
After checking, the design is rigidly knocked down. If necessary, reinforcement is knitted and side slopes are attached.

It is also possible simplified version setting up the formwork, when the beam is projected onto the finished formwork. In this case, the beacons are transferred inside the structure. A wire is stretched along them, serving as a guide when pouring concrete.

How to set up formwork for a strip foundation

Reliability and rigidity, the qualities that formwork must meet, and of course, the zero-level form must be ideal. Therefore, for the geometry of the formwork, a deviation of no more than 2 mm and 3 mm is allowed for the joint gaps between the parts of the system. So today we will talk about how to set up formwork from boards for a strip foundation.

Construction device

Formwork made of wood, due to its cost-effectiveness, is the most used option for installing a strip foundation. For the manufacture of formwork, boards and bars are used, and plywood and fasteners can also be used.

Product elements

The main parts of wooden formwork for the foundation are:

The deck is shaped like a shield and is made of boards or sheets of plywood;
The fasteners used are: screws and nails of various sizes, as well as the wire necessary for fastening various elements;
Scaffolding struts, posts and frames providing lateral stability.

When choosing wood for making formwork, you should check it for bending, since the panels must retain their shape under high loads from concrete, and the boards must bend.

For the manufacture of formwork, the best option would be planed 25 mm boards, preferably coniferous wood, this wood has high elasticity and strength. When assembling panels, it is necessary to use edged (edged) boards, this will reduce the gaps.

For formwork, it is advisable to use boards with a width of up to 150 mm and high humidity. Dried wood will draw moisture from the solution, and this will disrupt the natural course of hardening and affect the quality of the concrete.

Installation of formwork

Having completed excavation, and having installed waterproofing material at the bottom of the trench, we proceed to the manufacture of shields, for which we can use available materials.

Making shields

To do this, cut three-meter boards are connected to each other with wooden blocks, for fixing which you can use screws or nails. The bars should be installed at intervals of no more than 1 meter. One end of the block should have a pointed base to make it easier to drive it into the ground. When installing the bars to the shield, you should remember that the pointed ends should be directed in one direction.

The formwork parts are fixed with nails, which are located with heads on the inside of the foundation, this will allow you to obtain a foundation with smooth walls and will facilitate dismantling work.

Installation of formwork panels

The formwork must protrude at least 30 cm above the ground. To ensure High Quality For formwork, wooden panels must be securely fastened, since when pouring the concrete solution will exert high loads.

Ready-made panels are mounted along the entire perimeter of the foundation base. To fasten the shields, boards and bars are used, from which clamps are made. The clamp has a U-shape, its vertical parts are made of a bar with a cross-section of 40 mm, and for the vertical part you can use a 25x50 mm board.

To add strength, jibs are installed in the clamps. For successful assembly, it is necessary to choose the correct length of the bars, taking into account that it should be equal to half the height of the shield. Installation of clamps is carried out at each bar that fastens the panels. When installing shields, you should strictly observe the location of the structure in the vertical and horizontal planes.

To make supports (struts), boards are used, which are installed at an angle to the connecting bars and are additionally supported by pegs. To fix the support to the beam, you can use both nails and screws. The length of the strut depends on the height of the shield and is taken to be the same.

The main requirement that the entire structure of wooden formwork must meet is the absence of large gaps between the boards. The presence of cracks will allow cement to leak, and as a result, the foundation structure will have irregular shapes.

Perfect wooden formwork may have gaps of no more than 3 mm; such gaps, when pouring the solution and soaking the wood, will quickly disappear.

If, after manufacturing, the formwork has a large number of cracks, they must be eliminated; for this, you can use roofing material or plastic film. These materials are installed on the inside of the formwork and fixed with nails or a construction stapler.

When installing the formwork, the reinforcement is being installed at the same time. After installing and fixing the formwork, its horizontalness is checked using a level. It would be useful to check the fastening of each structural element and compliance with the design dimensions.

After repeated inspections, you can begin pouring concrete.

How to place formwork under the foundation

In order to create a concrete or reinforced concrete structure The construction of formwork is always required initially. This is a temporary structure that acts as a kind of form for pouring mortar, which, when dried, becomes the foundation. And here the question arises: “How to correctly set up the foundation formwork and not make large quantity mistakes?" Here you need to show care and responsibility, having studied everything necessary rules and nuances. You can also try setting up the foundation formwork based on the videos you have watched and provided by experienced professionals.

Types of formwork

Foundation formwork is divided into two main types:

Removable, removed after the concrete mixture has completely hardened. For the manufacture of such a structure, wooden boards, shields, or metal elements are used.
Fixed ones remain with the mortar for the entire existence of the future building.

But designs also differ in the type of material used to construct them. There are metal and wooden structures. That is why, before placing the formwork under the foundation, it is necessary to finally decide on its type and the material used for this. To make the task easier, it is worth familiarizing yourself with each option in detail.