Do-it-yourself foundation formwork: step-by-step recommendations on how to make formwork. How to make a formwork for a strip base yourself - a step-by-step video instruction Correct formwork for a country house

Using monolithic technology, an entire building can be constructed. The formwork around the house is assembled for the construction of the blind area. It is a strip of concrete that surrounds the building.

It is being built at the last stage of the construction of the building, and if this was not done on time, then it is possible to build a blind area during the operation of the house. Moreover, the work on its construction is not particularly difficult.

Appointment of the blind area

We will figure out how to make the formwork around the house, if you plan to do the work yourself. First of all, it is worth clarifying the purpose of this construction. In fact, this is just a strip of concrete, it is located close to the walls of the building and surrounds it.

The main function of the structure is to protect the foundation. Incorrect production of blind area or its complete absence can shorten the life of the building. The blind area around the house is constructed for the following purposes:

• protection basements from the ingress of melt or rainwater;
• somewhat reduces the depth of freezing of the soil in the protected area, which has a beneficial effect on heat conservation;
• gives the building a finished look, it looks more neat and solid.

It is extremely important to make the formwork around the house correctly, therefore if you plan to carry out the work yourself, you need to carefully study the technology.

Formwork materials

If you decide to make the formwork yourself, then at the initial stage it is worth choosing the material. Several options are possible, including:

• Concrete mortar. Minimum thickness the concrete layer is 50 mm, but the optimum thickness is from 70 to 100 mm.

Advice! When making a blind area around the house with your own hands from a solution, you can use large pebbles for decoration. The stones are laid close to each other or at a distance to individual elements did not touch each other.

• Crushed stone. This option is allowed if the soil waters are deep enough.

Advice! For filling the blind area, you can use expanded clay, pebbles or gravel. Stones can be used in the same fraction or in different sizes.

• Paving stones. Concrete paving stones can be bought ready-made or made by yourself. Paving stones may have different shape and color. The gaps between the individual elements are filled with sand.

Most often, blind areas are made of concrete. Construction is carried out quickly, necessary materials are available, the work is easy to do on your own.

Formwork calculation

As usual, construction begins with calculations and a project, this element is built, in accordance with the requirements of SNiP. Primary requirements:

• the formwork should go in a continuous tape without gaps and breaks;
• a gap is left between the basement of the building and the concrete tape to compensate for thermal deformations. This gap is filled with an elastic sealant;
• it is important to ensure the drainage of water from the house, therefore, the concrete tape is made with a slope. The slope should be between 1 and 10 percent. As a rule, the slope is two to three centimeters for each meter of the track width;

• the width of the formwork is determined depending on the type of soil, but it must be at least 1 meter;
• when determining the width of the tape, the size of the roof overhang should also be taken into account, the blind area must be wider, at least 20 cm;
• the outer edge must be flat, the presence of any curvature is not allowed;
• the presence of defects - cracks or depressions must not be allowed. Moisture can seep through these defects or plants germinate, which will contribute to the destruction of the structure.

Formwork installation

It is better to start the installation of formwork around the house in warm time of the year. Before the beginning construction works it is necessary to prepare the site and carry out the markup. The marking is carried out with the help of pegs, they are driven into the corners of the building and the twine is stretched between them.

Advice! To prevent the germination of plants, it is recommended to water the prepared area with a special solution.

• chipboards;
• moisture resistant plywood;
• steel sheets;
• non-removable formwork options use forms made of expanded polystyrene reinforced with fiber additives.

But most often boards are used; for assembling the frame, it is recommended to take a bar with a section of 30 by 60 mm. The formwork installation rules are quite simple. It is necessary to drive the prepared boards or strips of plywood along the perimeter of the markings made.

Supports are used to strengthen the structure. The same boards are installed across with a step of about 1 meter. These elements will help create expansion joints. Next, you need to lay a layer of waterproofing and pour a layer of sand 5 cm thick.

The poured sand is spilled with water and rammed to increase the density of the backfill. The second layer of backfill is crushed stone, this layer also needs to be tamped, but already without moisture. When backfilling is performed, a slope must be formed from the walls in order to ensure water drainage.

Dismantling the formwork

After assembling the formwork, reinforcement is laid inside and the grout is poured. After pouring the concrete, allow time for it to harden. The exposure time depends on the climatic conditions.

At high temperature it is necessary to additionally spill the poured concrete and cover it with polyethylene so that the solution dries evenly. When the concrete hardens, it will be possible to disassemble the assembled formwork, first removing the supports, and then the main boards.

So, concrete formwork is assembled for the manufacture of a concrete blind area. The purpose of this structure is to protect the foundation. Therefore, it must be done without fail. You can do the work yourself. For the manufacture of formwork forms, most often boards and bars are used, but other materials can also be used.

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

Features and functions of the blind area

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

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

The blind area performs several functions at once:

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

The following materials can be used for this coating:

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

Rules for the execution of formwork and blind area

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

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

Necessary materials

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

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

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

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

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

More expensive and quality option blind area devices - laying monolithic concrete slabs or reinforced slab products. But such materials cannot be used on heaving and clayey soils, as well as with a high GWL, since the structure can quickly deform.

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

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

Formwork technology

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

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

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

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

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

Performing coverage

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

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

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

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

From an engineering point of view, no specialist will be able to calculate the formwork absolutely precisely: too many variable objective and subjective factors affect the structure.

Let's name just a few of them.

1. The quality of the lumber. In nature, there are no two completely identical boards. The strength of sawn timber depends on malformations, the number, nature and specific location of the knots, etc.
2. Indicators of concrete. Concrete can have a different consistency in terms of viscosity, it depends on the proportions and characteristics of the fractions used during preparation. In addition, the loads on the formwork vary with the speed of pouring the concrete, the ramming method and the availability of reinforcement.
3. Climatic conditions. At subzero temperatures, the boards have some indicators of physical strength, in summer others. Dry planks can withstand higher forces, but their strength decreases in rainy ones.

Exists building standards, regulating the maximum deflection of the formwork. For the aboveground part of the foundation, the deflection should not exceed 1/400 of the length; for the underground part, the standard is increased to 1/250 of the length. It is difficult for non-professionals to achieve such values. What should ordinary developers do? During the creation of the formwork, you need to be guided by the advice of experienced builders and your intuition. And remember the main rule - it is better to do any formwork with a clear margin of safety, do not rely on "maybe it will withstand". It must be remembered that it is very difficult and expensive to correct violations of the linearity of concrete.

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

Film faced plywood formwork

If the formwork is for 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 bath, you can choose the most cheap option manufacture of formwork.

By design features, the formwork can be:

Manufacturing of removable formwork for a strip foundation

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

Of one universal algorithm there is no formwork manufacturing, each master makes his own changes, taking into account the specific material, characteristics of the foundation and personal preferences. We will only talk about one of the many options.

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

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

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

Step 2. Formwork installation.

Lower the shields carefully into the trench. Prepare ground pegs and corner posts. In our case, props need to be done on both sides approximately every 50 ÷ 70 cm.

To Bottom part shields did not move during fastening, fix it with small pegs or insert spacers of appropriate length between opposite shields. Then you do not need to take them out, let them remain in the concrete.

The photo shows the props of the shields

Step 3. Drive in the pegs in the corners of the trench and pull the rope between them. The height of the rope must 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 align the foundation strip manually after pouring.

Step 4. Drive the pegs into the bottom of the trench under the level or plumb line, the driving depth depends on the characteristics of the soil, but in any case it should exclude their horizontal movements.

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

Step 6. Install horizontal spacers between the boards. 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 expanding force of concrete, they only serve to facilitate the installation of the formwork.

Step 7. Measure the required formwork width in the upper part, connect two rows of panels together wooden slats to size. This connection will prevent the formwork from deforming during the pouring of the 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 through two with a drag together to prevent the shields from swelling under the weight of the concrete. Wire with outside parties fixed to the vertical crossbars, twisted with a slight tension - the walls of the basement part of the foundation will turn out to be even. During the dismantling of the formwork, the wire is simply cut off and remains in the concrete.

Step 8. In turn, put the supports of the shields, 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 an emphasis. Check the position of the shields on the rope at all times. If you have correctly installed the internal spacers of the formwork, then it will not change its position during installation and fixing. If you see mistakes, correct them immediately. It happens that some pegs wobble in the ground - you no longer need to rely on them. Drive in new ones next to them and fix the inclined spacers to them. At the junction of the shields, you need to put a board and always a support.

Step 9. In the upper part of the formwork, you need to insert pieces plastic pipes for ventilation ducts and technological holes in the strip foundation. No pipes at hand - make ordinary wooden boxes, then they will be removed and the holes will get better.

Step 10. Check again that the foundation formwork is correctly positioned and firmly fixed, problem areas need to be corrected immediately. The formwork should stand firmly, should not stagger even under great efforts.

Everything, concrete can be poured. 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 with plenty of water every day. The fact is that the strength of cement depends on the moisture content and the drying time of the concrete. If the 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 manufacture is almost the same as those described above. It is only necessary to make the size of the shields immediately according to the size 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 of reinforced monolithic slabs are made for baths built on waterlogged soils or soils with very low bearing characteristics. In most cases, the dimensions of the bath do not exceed 4x4 meters. It is quite difficult to pour a large monolithic slab on your own; you are unlikely to be able to achieve its ideal horizontal performance.

Step 1. Level the surface of the ground as much as possible, fill and compact sand pillow 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 into the corners of the future monolithic slab pegs, pull the rope. Place boards under the rope, secure them with pegs. Drive the pegs into the ground firmly. Place the formwork with the letter "P", so it will be much more convenient to feed and level the concrete, you will not have to step over the formwork every time. When concreting, do not forget about reinforcement.

Step 4. When until the end concrete slab there will be about one meter left - install the last plank, level it, secure it in position and continue pouring concrete.

Video - Box slab foundation

Video - Layout and formwork for a monolithic slab

Video - Formwork and reinforcement strapping of a monolithic slab

Now there are several issues to consider regarding the use of additional materials for the manufacture of formwork.

Instead, you can take roofing material, roofing felt, thick waxed paper or other materials. The use of these materials for upholstering formwork panels is encouraged. Why?

The film must be installed with inside formwork. Secure it with a stapler to prevent sagging or slipping.

Prices for plastic wrap

polyethylene film

Metal tie rods

If you have them, use them for health, if not, you should not buy specifically for the foundation of the bath. 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; under the nuts, be sure to place large diameter washers and pieces of boards.

Prices for tie rods

tie rods

Fixed formwork

New technology for pouring foundations and erecting walls, characterized by excellent performance characteristics and, unfortunately, the same high price indicators. Significantly speeds up the construction process, plays the role of not only formwork, but also insulation. It is often used for the construction of monolithic earthquake-resistant reinforced concrete buildings. Bearing walls are not only durable, but also insulated.

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

1. Made of highly durable expanded polystyrene foam. Represents 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 again assembled and the next one is poured.

   

2. Concrete fixed formwork... Made from durable concrete, lateral surfaces blocks have spikes and grooves for a strong connection to each other. The walls are held in place by bridges. Such formwork can be used both for pouring foundations and for erecting monolithic reinforced buildings. The reinforcement does not fit, the vertical rods are inserted into the holes, and the horizontal ones rest on special stops.

   

3. Wood concrete. It can be in 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; fittings may be inside. The panels are assembled on screeds installed inside the concrete. The front surfaces of the screeds are in 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 bath. Baths do not need an insulated foundation, and the basement visible part will get off with ordinary decorative materials.

Foamed polystyrene foam prices

expanded polystyrene foam

Possible consequences of poor-quality formwork

Let's say right away - all the consequences of an 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. Consider three possible options for the consequences of marriage in the construction of formwork.

Option 1. The swelling of the formwork became noticeable during the pouring of the concrete. Stop work immediately and call all assistants for help. Use a shovel to push back the concrete where the formwork swells. To prevent the concrete from floating back, nail at some distance the transverse boards along the entire width inside the formwork. Keep in mind that the concrete will gradually fill the groove and work must be done quickly. Throw concrete more than 1.5 meters from the emergency location.

The pressure on the formwork has noticeably weakened - try to level it. It is very good if you can adjust the jack and use the beams to slowly level the formwork. You can stretch a wire in a place free from concrete and use it to level the bulge. It is very important: do not knock on the formwork with a sledgehammer, in this way you will make it even worse. The vibration will cause the concrete to float downward and further disturb the straightness of the formwork. Level up the shield gradually, without excessive fanaticism. Excessive force can completely break the shield or individual fasteners. The consequences will be very sad. As soon as it was possible to align the shield, immediately fix its position. This time, check the reliability of the props with extreme care.

This case is the easiest, all the others are much more troublesome.

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

What to do if the formwork has shifted

Important. Not everything that is written on the construction forums, however, think with your own head before believing the first advice of the "expert" that catches your eye. Many such "experts" advise to remove the formwork, and while the concrete has not yet gained strength, cut down the hillock with a shovel. This is not advice, but a mockery. Never remove the formwork! It is very likely that the entire foundation will crack. It may not crumble before our eyes, but give almost imperceptible cracks, which will reduce the strength of the structure to almost zero. We noticed the trouble the next day - that's it, the train left. Wait until the concrete has completely hardened, disassemble the formwork, pick up the hammer drill and work "in the sweat of your brow."

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

We hope that from the second time you will understand how the formwork is installed correctly. And to prevent this from happening - read the article carefully again. It is possible and necessary to make your own improvements, but only if you have experience in the construction of at least three different formworks.

Video - Possible consequences of poor-quality formwork. The gap

Conclusion

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

When starting the manufacture of formwork, you need to adhere to two rules.

1. First, you need to know the job. Do not think that everything is very simple, you can "somehow blind" and it "will somehow stand."
2. Second. There is no need to be afraid of any work, but it must be respected. You must always have a vision of operations several steps ahead in your head, you must be able to choose the most optimal from several possible options.

Video - Reinforcement and formwork of a shallow strip foundation

Video - Installation of braces for formwork

The technology of building a private house is complex and consists of a number of individual works... Often, the most important of these is overlooked, which can lead to significant financial loss and anxiety for residents. It is on the manufacture of a foundation blind area, which is more often called house formwork.

The purpose of the blind area and its main parameters

A properly made home formwork is designed to solve a number of problems, the main of which are the following:

1. Protection of the basement of the walls of the house from waterlogging by limiting the amount of water penetrating from the ground surface;
2. Protection of the foundation of the house from waterlogging;
3. Creation of a footpath around the perimeter of the building.

Based on the above, rather strict requirements are imposed on the parameters of the blind area. Its width must reliably block the flow of rainwater from the roof of the house. To do this, the width of the house formwork is chosen 300 mm more than the overhang of the roof edge beyond the plane of the walls. When planning the use of the blind area as a footpath, the distance from the walls to the edge is chosen in the range of 800-1000 mm.

Requirements for the parameters of the blind area

A mandatory element is a small, within 3-7 o slope of the formwork in the direction from the wall of the house to the outside. This is necessary to ensure the outflow of fluid. For a more complete removal of it along the edge of the formwork, it is recommended to install a rainwater drainage system, since making the formwork around the house correctly means providing for all the conditions for its operation.

The depth to which it is recommended to lay the formwork cake should not be less than 250-300 mm. Only in this case it will be possible to make a concrete tape of sufficient strength, reliably preventing the penetration of moisture to the foundation and basement of the house.

Do-it-yourself formwork installation technology step by step

Manufacturing technology of the blind area at home

In progress self-made formwork at home there are several main points to be addressed Special attention... We will tell you more about them in the attached detailed instructions for the implementation of this type of work.

First stage - markup

If there is no formwork for any reason, it must be made as quickly as possible, without waiting for the irreversible destruction of the foundation of the house to begin. We start by marking the tape. To do this, you need to check with the design value of the roof overhang beyond the plane of the walls. If you find given value it was not possible on the drawings, we determine it in a practical way, since it will not work correctly to make the formwork around the house without this.

To do this, you can from the edge of the roof, for example, through attic window, lower with your own hands a strong thread with a weight attached to its end. After the oscillation of the plumb bob stops, it remains only to retreat outward from it the required 300 mm. Having measured the total distance from the walls of the house to the obtained point, we obtain the desired width of the blind area.

Along the perimeter of the house, retreating to the required distance, we mark the formwork of the house. To do this, drive in wooden pegs or pieces of steel reinforcement 250-300 mm long in the corners and tie them with a strong nylon cord. If the walls of the house have complex shape, this must be reflected in the territorial formwork markings.

Stage two - earthworks

For further work it is necessary to prepare a pit inside the marking with a depth of about 300 mm. To do this, using bayonet shovel cut and remove the soil, folding it around the perimeter of the working area or distributing it over the territory of the site.

Preparatory earthworks

Fulfill given view DIY work alone is quite difficult. It is better to invite several assistants or you will have to spend on hard physical labor from several days to a couple of weeks, depending on the availability of free time.

After the trench required size will be ready, its bottom must be carefully leveled while maintaining the required slope from the walls of the house outward and tamped manually using the simplest devices or a vibrating plate.

Stage three - installation of blind area formwork and filling

Along the edge of the finished recess, it is necessary to install a limiting formwork from coniferous boards with a thickness of 25 mm installed on the edge. Their width should be 3-5 cm greater than the depth of the trench. For stability, the boards are fastened with spacers and slopes to the outside of the soil around the house. Similar boards are installed across the future blind area with a step of about 1 meter. They will act as expansion joints when the formwork is filled with your own hands.

Installation of formwork and filling the bottom of the blind area

Next, a layer of waterproofing is laid on the bottom of the trench and a layer of clean sand about 5 cm thick is poured. Then it must be moistened by sprinkling with a simple watering can or from a watering hose. Wet sand is compacted to increase its density. The second layer of backfill consists of medium fraction crushed stone, which is also tamped dry, without preliminary moistening. We recommend placing a layer of geotextiles between the layers to prevent their mixing and grass sprouting, since it is necessary to make the formwork around the house as efficiently as possible.

Stage four - installation of the reinforcing frame

In order to pour concrete with your own hands into the formwork in accordance with all the rules, it is necessary to make and lay a reinforcing frame in the trench. It is a mesh of wires or rods with a thickness of 6-8 mm. In hardware stores, you can purchase ready-made parts of a standard size.

Otherwise, the reinforcing frame can be made by yourself. To do this, you need to purchase several tens of meters of steel wire and cut a sufficient number of pieces along the width of the formwork. Similarly, we cut segments according to the distance between the boards installed transversely. Through an equal distance, the rods are tied together with a steel knitting wire.

It is advisable to lay the reinforcing mesh not directly on the crushed stone layer, but to raise it a few centimeters. Pieces of bricks used as linings can help with this.

The fifth stage - making concrete and pouring the formwork

The main material used for assembling the formwork at home with your own hands is concrete mix... You can prepare it yourself using the simplest electric concrete mixer. Without this device it can be rented for a small fee.

The second option for obtaining concrete in the required quantity is purchasing it at the nearest concrete plant. You can calculate the required volume based on the geometric parameters of the tape and the simplest mathematical formulas by multiplying the width of the blind area by the perimeter of the house and the depth of concrete pouring.

The mixture obtained in one way or another is distributed at the site of the future formwork of the house with their own hands, pouring out buckets or directly from the automatic mixer. The main task in this case is to provide the concrete surface with the required slope from the walls of the house, since it is necessary to correctly make the slopes of the foundation at an angle of 3-7 o. For this it is used building rule or a plaster float.

The do-it-yourself blind area is left for several days until the concrete completely hardens and hardens. During this period, it is advisable to cover the tape with a thick cloth, avoiding over-drying it is recommended to moisten it, especially on hot summer days.

The final stage is finishing the formwork of the house

Having completed the pouring of concrete, it is necessary to lay this or that type of coating on the tape, since it is necessary to make the formwork around the house not only correctly, but also beautifully. For finishing the blind area, the following types of materials are used:

Various finishing of the blind area of ​​the house

• Asphalt;
• Paving slabs;
• Natural stone.

It is necessary to lay the selected covering on cement mortar or special construction moisture resistant adhesives... In this case, the formwork of the house will not only efficiently drain water from the walls and foundation, but will also become a decoration of your home.

Formwork is a form for placing concrete. During its installation, a system of supporting and forming structures is used, which should ensure the characteristics of a concrete structure, according to project documentation... Formwork for casting strip foundation presupposes adherence to specific building codes, the most important of which are the requirements for tightness, strength, rigidity and compliance with the design geometric shape... There are a number of standard technological techniques that can provide all the necessary specifications formwork and optimize the cost of its construction.

The choice of formwork design depends on the shape and design parameters of the strip foundation, soil characteristics, characteristics of the material used and factors external environment... According to the terminology and definitions, the following types of formwork can be used for the strip foundation:

• Removable formwork, the design of which provides for the possibility of disassembling it into its constituent elements after the concrete has hardened.
• Permanent formwork, the elements of which are part of strip foundation and may have additional functions thermal insulation, waterproofing, decorative and protective purposes. A set of modular elements reduces installation time and does not need to be removed after the concrete has hardened.

If the soil does not crumble and has sufficient hardness and viscosity, then a formwork device is allowed, providing for concrete casting directly into the trench of the strip foundation, which can reduce the consumption of material for the device of forming and supporting structures.

Expanded polystyrene, foam and foam concrete blocks can be used as non-removable elements and taken into account when determining the design section of the strip foundation. Plastic or metal shields are used to obtain a smooth or textured surface of the plinth walls, which can reduce finishing costs. The most affordable material for formwork is wood.

Wooden formwork

Wood, plywood of waterproof grades, fiberboard and chipboard are the most affordable and least expensive material that allows you to make formwork yourself. Small-panel formwork made of boards is capable of withstanding up to 15 cycles, subject to technology requirements. The thickness of the boards from which the boards for the foundation (deck) are made should be 4-5 cm, and their width - at least 15 cm. suitable varieties wood for these purposes are conifers with a moisture content of at least 22%. The gaps between the deck boards should not exceed 2 mm. Before pouring concrete, it is allowed to treat the installed boards with water to swell the wood and reduce the crevice gaps. Panels made of plywood, chipboard, or fiberboard can withstand up to 30 casting cycles.

Installation of wooden formwork strip foundations using the walls of the trench as a mold for pouring concrete.

A small-panel collapsible structure made of boards, or plywood, installed along the edges of the trench, is the simplest type of wooden formwork that you can do yourself. The concrete is poured directly into the trench dug in clay soil... Depending on the material and the presence of non-removable elements, this design may have the following options:

Plywood formwork

Plywood deck. Plywood shields (3) are installed on the edge of the trench, which are reinforced with braces (8) to stakes (4) located at a distance of at least 1 m from the edge of the trench. The step of the braces must be made no more than 1m. The upper cuts of the shields are fastened with wooden bridges (6) with a step of 0.5-1 m. Permissible deviations the geometry of the plywood panels should not exceed 2 mm per 1 m of the formwork length. Edge strings of cast-off (7) are installed along the top edge concrete pouring (5). Waterproofing material made of PVC or EPDM (2) is laid on a sand cushion (1) compacted at the bottom of the trench. Its edges should completely cover the ground walls and shields, with a bend along their upper edge and secure fixation with a furniture stapler.

Plank formwork

A deck made of planks (3) is fixed at the edge of the trench. To strengthen it, braces (8) and stakes (4) are used, according to the scheme (Fig. 2). The gap between the boards should not exceed 2 mm. The installation of this structure is similar to the installation of a deck made of plywood panels.

Fully insulated formwork

The use of fixed EPS blocks for the entire depth of the strip foundation formwork, and a deck made of plywood panels. In blocks of expanded polystyrene (12), before installation in the trench, the installation of facade dowels (10) is performed. After the concrete has hardened, the dowels securely fasten the EPSP panels to the walls of the foundation. Plywood panels (3) are installed on the edge of the trench and secured with slopes (8) and stakes (4). The upper edges of the boards are fastened with wooden jumpers (6), installed 0.5-1 m apart.

EPS blocks are joined together using special locks that ensure tightness. The correct pouring height of the strip foundation is determined by the edge strings of the cast-off (7). The height of the plywood boards must be made 5-7 cm above the level of the foundation pouring (5). The waterproofing film (2) is laid along the entire depth of the trench with a slight overlap and fixed with a bend to the upper edge of the panels using a furniture stapler. At the bottom of the trench, a sand cushion (1) with a height of 20 cm or more is rammed.EPS blocks are attached to plywood boards and soil walls of the trench using nails 20 cm long (9). The upper ends of the EPS blocks are fixed to the transverse lintels using self-tapping screws (11), which can be easily dismantled when the time comes to remove the formwork.

Formwork with insulation in the underground part

The use of EPS blocks as non-removable underground formwork elements and smooth (textured) metal or plastic sheets to provide the required surface qualities of the basement. EPPS sheets (12) are installed under the cut of the trench, and the deck (3) is covered with nasty sheets (11) to give the surface of the basement walls the desired texture.
When using fixed EPPS blocks (URSA, Penoplex, Dow, BASF) with a thickness of 5 cm or more, a lighter version of a lattice deck is allowed, which saves building materials.

Installation of wooden formwork for trenches with slopes, or for strip foundations with concrete preparation

If the soil does not allow pouring concrete directly into the trench, or concrete preparation is required to install the foundation, then the wooden formwork is installed to the entire depth of the trench, the width of which increases by 2 times the foundation cut, and the walls of the trench are made in the form of slopes.

It is best to install water-resistant plywood grades as a material for the deck (9), but it is also allowed to use boards with a thickness of 4-5 cm and a width of 15 cm. timber(10). To tighten the shields, a special device is used, consisting of a metal tube (5) installed between the shields. A threaded rod is inserted into the tube, at the ends of which bars for support, nuts, or threaded plates (4) are installed, with which the shields are tightened. Threaded ties are installed at a distance of 0.5 m from each other. Edge strings (7) are used as guides when installing the shields. With the help of spacers (3) and braces (11), the vertical stability of the structure is ensured. The stakes (12) for supporting the braces are driven in at a distance of at least 1 m from the edges of the trench.

The formwork can be installed either on a sand bed (1) or on a concrete preparation in which anchors are equipped (2). According to table 1 of the formwork quality indicators (), the vertical error of the structure should not exceed 5 mm for each meter of height. Irregularities per meter of length shall not exceed 3 mm for a deck made of planks and 2 mm for a deck made of plywood panels. It is necessary to remove supporting and shaping wooden structures without the use of shock loads.

Errors arising during the installation of the formwork

If the developer is faced with the task of correctly making a strip foundation with his own hands, then it is necessary to take into account typical mistakes that can be done by builders without relevant experience:

• The lack of sufficient distance between the support stakes and the edges of the trench can lead to the collapse of its walls during the pouring of concrete into the formwork and the loss of structural integrity.
• The use of loose wedges for leveling the side panels using braces and stops creates a threat of their collapse when performing work on vibration impact on concrete poured into the formwork.
• The use of materials whose strength and elasticity characteristics are insufficient to resist the pressure of the poured concrete, or errors in the design of the supporting elements can lead to an unacceptable displacement of the foundation axes with respect to the design position.

Reducing the cost of manufacturing formwork

To reduce the amount of material required for the installation of the formwork, you can use the method of stage-by-stage pouring of the foundation. The formwork is assembled in a separate section of the tape and reused when pouring in the next section. At a positive temperature and average air humidity, a break between the stages of pouring for a period of 3-4 days is allowed, necessary for the partial hardening of concrete.

Depending on the availability of material, the pouring process can be broken down both along the length of the tape and in height. To ensure a sufficient level of adhesion between the areas of the foundation located one above the other, it is necessary to remove the layer of laitance that accumulates on the upper edge of the lower tier before starting the next pouring cycle. To ensure reusability of the material, plywood panels, or the deck surface assembled from individual boards, can be wrapped with plastic wrap, or pre-treated wooden elements adjacent to concrete, lime milk.

In order to correctly make a good formwork for pouring a strip foundation with your own hands, it is necessary to strictly observe building codes and correctly use proven technologies.

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