How to make a formwork for the foundation: step by step instructions. Do-it-yourself formwork for the foundation: step-by-step recommendations on how to make formwork How to make formwork for the foundation

The blind area around the house is a strip located around the entire perimeter of the room. Its main role is to divert surface water from the foundation, thereby protecting it from moisture. She is important element in construction and the final stage. The blind area is done after all the work performed. If you want your foundation to last for a long time, you must definitely do it right. An improperly made blind area can add a lot of problems in further construction, but you can avoid them by reading this article.

Blind area around the house

The main functions of the blind area

• Decorative completion of the building, it makes the house look more solid and attractive;
• The blind area protects the foundation of your building from water leakage;
• Reduces freezing of the soil, which favorably affects the warmth in the house.

How to make formwork around the house yourself

Anyone can make a formwork around the house with their own hands, having necessary material and tools. After reading everything necessary advice, you can make the formwork yourself. The main thing to know is that improperly made formwork will adversely affect your entire construction site.

Determine the width of the blind area

In choosing the width of the blind area, you need to pay attention to the roof of your house. The blind area should not protrude significantly beyond the level of the roof so that precipitation does not flow onto it. The recommended width is 60-100 centimeters. With this width, it will be comfortable for you to walk and it will waterproof the lower part of the building.

Step by step guide

1. You need to decide on the material. The most practical material is boards or plywood. They are easy to use and do not cost much.

2. We turn to the choice of construction formwork. You should choose between removable and fixed formwork. They differ from each other in that one will need to be disassembled after construction works, and the second is not. Both types use practicality and convenience among all developers.

3. When you decide on the material and type, you need to start marking. To do this, a projection is made from the edge of the building with the help of a plumb line. The resulting line must be fixed with a mark and add 30 centimeters. Now our markup is ready.

4. According to our received markup, removed upper layer soil about 25 centimeters deep.

5. The most important stage is the installation of formwork. We begin to mount and strengthen all prepared materials along the perimeter of the formwork. To ensure that our design is strong and reliable. It is necessary to correctly place the driven pegs and supports, if the position is incorrect, our formwork may become unsuitable for further concrete pouring.

6. When this work is done, it is necessary to fill up a layer of sand about 5 centimeters and pour in plenty of water. A layer of rubble is poured on the sand with water. These steps you have taken will help ensure a well-made formwork, ready to use, which can be poured with concrete.

Materials and tools for construction

For construction work, you need to stock up on tools and materials. Doing all the work with your own hands will be impossible if you do not have required set for the builder. It should be noted that poorly selected material will adversely affect the outcome of the construction.
The list of necessary tools and building materials:

1. Shovel for soil preparation;
2. Cement, sand and crushed stone for concreting;
3. Level and tape measure for precise measurements;
4. Boards or plywood for the manufacture of formwork;
5. Trowel and spatula;
6. Saw, hammer and nails;
7. A wheelbarrow for transporting material will greatly facilitate the work.

Basic rules for the blind area

The direct role of the blind area is to protect concrete from water, which means that it should be laid with a slight slope. It is done so that the water that has fallen on the blind area is glass to the bottom. It should be understood that if the level of the blind area is incorrect, its protection will decrease. All work with the arrangement of the blind area should be done before the first frost. The blind area is made strictly around the entire perimeter of the building; gaps in it cannot be strictly made. Even the smallest gaps will affect the quality.

How to prepare the mortar and pour the formwork

Blind area concreting

Preparation of a solution for pouring is the most important stage for the construction of a blind area. It needs a very strong cement-based mortar of at least grade m 300. In the street aggressive environment a bad solution will quickly deteriorate. It is undesirable to save on cement, quality and durability depend on it. It is necessary to hammer the solution in proportions of 1 share of cement to 3 shares of sand. It is advisable to add frost-resistant additives when preparing the solution during the winter period.

Before pouring, it is necessary to mark the slopes, which will be fixed from the house parallel to the wall. Using a level, you need to check the formwork lines. For a more accurate level, you need to fix the threads. They will serve to help you when pouring concrete.

After these simple manipulations, you can start pouring the solution itself. It should turn out thick and you need to pour it continuously. The freezing process must be monitored.

After pouring the concrete and drying it, it is required to cover it with a film for 48 hours. This procedure is done so that the moisture that concrete needs does not evaporate. If the poured concrete does not have moisture, the work done is in vain. It will deteriorate and start to crumble.

It is explained by its high reliability and ease of construction. Even a person who does not have much construction experience can easily fill in a garage or fence site. Knowledge about formwork installation will never be superfluous and will allow you to correctly calculate the required amount of material for pouring. Therefore, today we’ll talk about how to make formwork for strip foundation.

The term "formwork" refers to a special construction barrier, with the help of which the molded concrete is poured. In the process, the liquid solution is poured into the prepared mold, vibrated special devices for compaction and removal of air bubbles leading to internal destruction, and left to harden.

At the same time, the formwork allows you to give the future foundation various forms and configuration, and also, when performed with a certain accuracy, allows you to get a flat horizontal surface of the strip foundation, ready for masonry work.

Formwork types

According to the classification, the formwork can be divided into several groups: by material, manufacturing method, removable or non-removable.

Metal formwork fencing is highly reliable, able to withstand a large volume of poured concrete, and assembled in the shortest possible time. The assembly of any necessary figure, be it a square or a rectangle, is carried out in a few elementary operations. Special fasteners allow you to slide and push apart metal sheets, Giving required volume for filling. The disadvantages of this type include high cost. This equipment is mainly used at large construction sites and in specialized construction teams whose profile is pouring foundations.

For people who need formwork for a single use, it is perfect wooden version. The assembly process takes more time compared to the metal counterpart, but the cost of the raw materials used is several times lower.

There is also the option of fixed formwork, which are blocks of expanded polystyrene into which concrete is poured. This type of formwork is also a heater for the foundation. This tool is installed in the required place, poured into the cavity, after which the entire system remains in place. The foundation of this kind is one of the most even and confidently holds the palm in the budget rank.

Budget formwork

If at a construction site there is an acute question of what to make the formwork for the foundation as cheaply as possible, then the cheapest way to create such a structure is to use old doors. This method ideal for small volumes of pouring, allows you to reduce manufacturing costs by several times. Assembly and adjustment has some difficulties, since the bulges of the doors do not allow you to fill in an absolutely even foundation right away, but this problem is easily fixed. A huge advantage of the door formwork is the solidity of the structure, which reduces the cost of spacer material.

Do-it-yourself formwork

The first step, before starting work on the formwork itself, is to prepare land plot. After digging the trench, you can calculate the required material. Using sheets of glued wood of medium thickness will allow you to assemble the structure to the required dimensions as quickly as possible. The use of boards is possible, but this method has several disadvantages:

• low accuracy of the side surface of the foundation with the final result;
• high probability of breakthrough of the solution with excessive pressure on one area;
• long build.

If you decide to build a formwork from boards, then you need to use an edged board with a thickness of 40 mm or more to carry out the work. Boards with less thickness can easily sag from the pressure of concrete, which will negate all efforts and costs. Boards with too much thickness will lead to unnecessary costs, although bearing capacity formwork will not be affected. Therefore, which board to use for formwork, each builder decides for himself, based on the budget and on specifications future foundation.

As a rule, the internal cavity of the formwork made of boards is covered with a layer of greenhouse film, which prevents concrete from flowing through the gaps between the boards.

When using sheets, the load is distributed evenly, which avoids excessive pressure in specific areas. An important component is a sufficient amount of spacer material. Let's talk more about it.

Special fixtures and stops, which will support the formwork from the outside and pull it together from the inside, will help to avoid destruction of the structure. As a rule, to strengthen the formwork of the strip foundation, studs are used, which are installed inside the formwork, fixed from the outside with nuts and serve to keep the structure from concrete pressure from the inside.

The second element for strengthening the formwork are jibs, which are installed outside in increments of 1-1.5 meters along the entire length of the formwork on both sides. These supports give additional stability to the entire formwork.

Formwork for non-standard shapes

Columns, roundings and other structures or their individual elements require a special approach. For these places, it is recommended to use plastic or metal inserts that will retain the intended shape and aesthetic appearance with maximum accuracy. Strengthening with additional spacers will never be superfluous - you completely eliminate the risk of leakage.

Separately, it should be said about the provision of technological holes in the foundation. These holes include vents and leads for communication pipes. For this, special embedded sleeves are made in the formwork from plastic pipes, which then allow to obtain through holes in the foundation.

Conclusion

The foundation is the basis of any structure and the guarantee of its long service life, therefore it is worth treating its preparation and pouring as responsibly as possible. Careless attitude and the use of improper materials automatically reduces the service life by several times. Each owner at the beginning of the construction process wants to end up with a strong and beautiful building that will serve him and his children.

Do not neglect the information from professionals during self-construction. Having an experienced craftsman in the team will help you properly allocate available resources and make a solid foundation for your future home. important detail when pouring is reinforcement - the creation of a grid of metal rods that create a powerful frame for strengthening. Accounting for all the nuances from the choice of raw materials to the process of filling the box with concrete is mandatory to obtain the desired result.

Finally, we invite you to take a look at independent construction formwork for strip foundation:

The construction of a building begins with the foundation. To implement this design, you need to pour concrete into a pre-constructed frame, which is called formwork. It should be as rigid and strong as possible in order to prevent changes in the shape and size of the foundation tape. We will tell you what types of formwork for strip foundations exist, what material the structure is made of and how to properly install it.

What is strip foundation

The most important point in planning the construction of a house is the correct choice of the type of foundation - the main structural element building. An incorrectly designed foundation often causes irreparable consequences during the operation of the building.

The strip foundation is a reinforced concrete strip laid around the perimeter of the building. In this case, the tape is laid under the outer and internal walls, which contributes to the preservation of the shape of their cross section. The technology of the strip foundation device is not particularly complicated. However, compared with the columnar type, the construction of this structure requires more time and building material.

The scope of the strip foundation is quite extensive. It is often used:

• in the construction of buildings with concrete and brick walls from high rate density (more than 1300 kg/cu.m.);
• for buildings with heavy floors (monolithic or prefabricated reinforced concrete);
• when building houses in areas with heterogeneous soil (for even distribution of the load on the walls);
• if the building is planned to equip the basement.

Design requirements

Formwork is a supporting structure that is poured with concrete to form the foundation. Therefore, its material and installation scheme must meet the following requirements:

• Strength. The formwork walls must withstand the pressure of the concrete. In this case, a slight uniform deformation is allowed along the entire perimeter of the building.
• The ability to withstand the temperature and humidity conditions, which is necessary for a thorough hardening of the solution. Formwork should be made of chemically neutral material.
• The absence of gaps between the formwork elements, chips and cracks in the material. In the case of leakage of the solution in the foundation, unwanted voids are formed.
• Compliance with the design dimensions of the calculated data.

Formwork types

When pouring a strip foundation, use different types formwork. They differ structurally, as well as the material from which they are made.

By design, formwork for a strip foundation can be:

• Removable. Before pouring concrete mix shields are assembled and installed, and after the mortar has hardened, they are dismantled;
• Fixed. Such formwork remains in the foundation structure, while serving as a heater;
• Combined, which is a combination of the two previous types. It is a removable structure with a heater laid inside, which, unlike the outer formwork, cannot be dismantled.

Often, removable formwork is used to fill a strip-type foundation, since this option is more economical. However, fixed and combined designs have recently begun to enjoy increasing popularity.

Material for manufacturing

If you decide to do the formwork with your own hands, the right choice will be the manufacture of a frame from lumber. The design in this case will be removable. Wood has sufficient strength, is easy to process, is an environmentally friendly material and is inexpensive. The use of metal or plastic does not make much sense, especially considering that the former is susceptible to corrosion, and the latter does not tolerate low temperatures.

The most popular lumber for assembling formwork for strip foundations is edged board. The product is preferred due to its precise dimensions, which can significantly reduce the amount of finishing work on finishing the concrete base. As a result, the foundation is obtained as even as possible. Accordingly, the cost of its construction is also reduced. In addition, in view of linear dimensions lumber, it is much easier to assemble the formwork with your own hands, including a set of boards with walls of the required height. In addition, the material can be used repeatedly, which makes it as convenient and cost-effective as possible.

Useful advice: Use boards unsuitable for assembling formwork for roofing or lining subfloors.

As for the type of wood for the manufacture of the frame for the foundation, it all depends on the expected load of the poured concrete solution. The most durable lumber is made from hardwoods. From such boards they make formwork for the foundation in both civil and industrial construction. If super-heavy loads are not expected, then you can use sawn timber from coniferous trees.

Territory preparation

Before proceeding to the construction of the foundation, engineering and geological surveys should be performed in order to determine the type of soil, as well as the depth of laying the future foundation. In this matter, it is better to consult with the employees of the capital construction department in your region. Be sure to find out the depth of freezing of the earth in your area and the depth of occurrence ground water. So, the foundation should lie 0.3 m below the freezing depth and should not reach the level of groundwater.

In order for the foundation and the building itself to last for many years, the concrete base must be designed in accordance with all rules and regulations. Therefore, it is advisable to use the services of a qualified specialist who will help to competently produce necessary calculations. Do not try to design a foundation yourself without basic knowledge in this area. This can cause unpleasant consequences, such as the formation of cracks in the walls, deformation of the base, and so on.

Before designing the foundation, it is necessary to determine the size of the building, the location and thickness of the internal, as well as the load-bearing walls, using the heat engineering calculation of the enclosing structures. The fact is that the wider and heavier the walls, the more powerful the foundation itself should be. Having decided on these parameters, you can proceed to the foundation device, which begins with the marking of the territory.

Plot marking

First you need to clear the site of debris, remove the vegetation layer and level the surface. After that, two U-shaped structures are installed on the site, which are two pegs driven into the ground with a horizontal rail fixed to them. These structures, together with a rope stretched over them, mark the outer edge of one of the walls of the foundation. Next, a second rope with the same U-shaped design is pulled perpendicular to the first. Similarly, the marking of all other external boundaries of the concrete base is performed.

The next step involves the designation of the inner sides of the walls. The ropes should be pulled parallel to those that define the outer edges of the foundation. In this case, the distance between them should correspond to the width of the walls of the future base. After that, it is necessary to measure all corners - they must be straight. If initially it was not possible to make a perfect rectangle, then pull the ropes diagonally and achieve their equality. This way you will get all 90 degree angles.

Following the designation of the location of the main contour, the marking of the inner walls of the foundation is carried out, which will become the basis for internal partitions the buildings.

Excavation

The markup is ready and now you can start developing the soil. Trenches should be dug strictly along stretched ropes. As noted earlier, the depth of laying the foundation is selected depending on the depth of soil freezing. At the same time, the height of the trenches under the internal walls of a heated house does not depend on this parameter and is often 0.5 m.

It is worth noting a few nuances about the shape of the cross-section of the trench under the strip foundation. If the depth of laying the concrete base is less than 1 m, then the walls can be made vertical. In the case of a deeper excavation of the soil, the walls must be made with a slight slope.

If it is planned to build a cellar, then a foundation pit is dug for it at the same stage. To reduce the volume of excavation, it can be placed in any of the corners of the future building, along two walls of the foundation.

Useful advice: The best place for the device of the cellar will be the south side of the house.

Material calculation, necessary tools

When buying lumber for formwork, you need to remember that the boards will be located on both sides of the trench. In addition, the number of strips required also depends on the depth of the foundation and the width of the wooden product. After all, the boards are knocked down with bars into shields, the height of which should be slightly greater than the depth of the trench. Therefore, to determine the number of boards, it is necessary to measure the total length of the trench, multiply it by two, divide by the length of one wooden product and multiply by the ratio of the height of the trench to the width of the board. As for the bars, the step of their location should be no more than 40 cm. Depending on this, the number of required bars is also determined. So, for work you will need the following materials:

• board (humidity - no more than 22%; thickness - 25-50 mm; width - 200-300 mm);
• bars (section 40 * 40 mm; length is equal to the depth of the trench);
• sand;
• nails, screws;
• tow;
• thin rails.

For the installation of formwork for a strip foundation, you will need tools:

• hacksaw for wood, electric jigsaw or grinder;
• drill, hammer;
• yardstick;
• building level.

After doing preparatory work and the purchase of materials, we proceed to the installation of formwork under the strip foundation. The procedure is as follows:

1. Sand cushion laying. Considering that the weight concrete structure very large, for its uniform distribution on the ground, you need to lay a layer of sand. The height of the compacted and moistened pillow is 150 mm. On a flat and solid base, you can begin the installation of formwork.
2. Installation of guide boards. This procedure must be carried out strictly along the line, so stretch the fishing line along the entire length of the trench in advance. After that, install the guide boards according to the marking, fixing them with pegs and vertical bars from inside. On the outside, in addition to the pegs, install additional stops. After that, check the correct installation of the guide elements using a tape measure and a building level.
3. Shield installation. We attach the boards to the bars and connect them with nails. The procedure is performed from the bottom up.
4. After assembling the shields, we put spacers. As the latter, bars can also be used. As a result of the installation of spacers, the panels should take their final position, that is, the formwork will take the form of the walls of the future foundation.

Properly executed formwork for the strip foundation is the key to the strength and durability of the building

Important: To seal the resulting cracks, use tow or thin slats.

This completes the procedure for installing the formwork under the strip foundation. But there are a few more nuances that should be performed if necessary.

The nuances of work

• If the height of the formwork exceeds one and a half meters, then at the bottom of the trench it is necessary to make a window to remove industrial waste, which in this case can be very large.
• A layer of waterproofing material is laid at the last stage of the formwork installation, before reinforcement.
• If re-use of a collapsible structure is intended, then an oily substance should be applied to its inner surface to minimize adhesion to concrete.

The right strip foundation for the house

Remember, well-executed formwork is a guarantee of ensuring the correct form of the concrete base of the building. Therefore, take this work with all seriousness and follow the technology of erecting a frame under a strip foundation.

We make formwork for a strip foundation with our own hands - the necessary material, calculation, device, etc. with video

Types of formwork for strip foundations. The choice of material, preparatory work and the device of a wooden structure.

Creating a strip foundation for a house is almost never complete without formwork. It gives shape to the concrete structure, prevents the outflow of water from the concrete, makes the surface of the tape smooth so that waterproofing and thermal insulation can be easily done. How to do the formwork for the strip foundation with your own hands?

Requirements

The formwork should create an optimal temperature and humidity regime at which the concrete hardens well and gains maximum strength. An important requirement is the chemical neutrality of the materials used. They must not react with concrete.

If the formwork is removable, it should be easy to remove without damaging the concrete structure.

Formwork types

Formwork for a strip foundation can be

• removable,
• fixed,
• combined.

It is also sometimes allowed to pour concrete directly into the trench without a mold.

Removable

Removable formwork is made of boards or plywood and other panel materials: chipboard or fiberboard. The cheapest material is wood. You can also use a slab, but it must be edged (edged) so that the boards fit snugly together. You can also buy or rent a ready-made set of prefabricated metal, plastic or wooden shields. Whether plastic metal shields allow you to make the concrete surface very smooth or, conversely, textured.

Fixed

Fixed formwork is most often made from extruded polystyrene foam (EPS). She looks like in the photo.

For more strong connection sheets are fastened with plastic ties. At the same time, this form acts as a heater.

Important! EPPS is afraid of ultraviolet radiation, so the foundation needs to be shaded while the concrete is curing.

You can assemble it yourself from polystyrene foam sheets, or you can buy a ready-made kit. It can be standard or collapsible for non-standard buildings. The advantages of the non-removable option are precise observance of the geometry and high speed of work. Minus - it is difficult to evenly concrete the foundation

Removable-non-removable (combined)

This is a combination of removable and fixed formwork. This design is used on loose soils. It consists of two layers: an inner one made of extruded polystyrene foam and an outer one made of a conventional removable deck made of planks.

EPPS is attached to the ground on nails 20 cm long, to a tree - on self-tapping screws. This option has its advantages:

• immediately there is thermal insulation from the sides and from the base of the foundation,
• a smooth surface is obtained on which the soil will slide when moving.

Such formwork can be made with insulation only in the underground part or to the full depth.

If the XPS blocks are installed to the full depth, they are placed directly in the trench, before that dowels are inserted into them so that the XPS is securely attached to the concrete. In the upper part protruding from the trench, a formwork of plywood panels is installed, which are fixed with braces and stakes. Before installing the XPS blocks, the trench is lined with a film. XPS is attached to the walls of the trench and wooden shields with nails 20 cm long.

If XPS is installed only in the underground part, a wooden formwork is made in the upper part, into which metal or plastic sheets are inserted to obtain smooth surface plinth.

Concrete preparation

Concrete preparation (podbetonka) is a thin layer of concrete that forms the bottom of the formwork. It has a waterproofing function, does not allow cement milk to go into the ground. However, a footing device is optional. They also make formwork without concrete preparation, especially in private construction. In this case, it is necessary to pour a sand cushion and compact it well. Polyethylene or roofing material is laid inside the formwork. At the bottom, waterproofing must be laid in several layers, it is attached to the wall with a stapler.

To make formwork with concrete preparation, the trench is expanded, and its walls are made in the form of slopes. In this case, boards or plywood boards are installed to the entire depth of the trench and attached to the timber frame.

The shields are pulled together with a metal pin inserted into the tube so that it can be removed. At the ends of the studs, wooden bars and nuts are installed. Such screeds are made at a distance of 0.5 m. Also, the formwork is strengthened with struts and stakes. If the formwork is placed on concrete preparation, then anchors are made in the latter. Also, such formwork can be done without concrete preparation, for example, on loose soil.

Preparatory work

Before you make the formwork for the strip foundation, you need to prepare the site. To do this, it is cleaned of debris, trees, the fertile layer is removed, leveled. After that, the dimensions of the future building are transferred to the site. Careful marking is very important.

Further, trenches are dug for the strip foundation, the depth of which depends on the type of foundation: 50-70 cm for shallow and below the freezing depth for buried. There is also a non-buried type of strip foundation. Usually a trench is dug 10 cm wider than the foundation tape. The bottom of the trench should be flat, this moment is controlled by the level or by the ropes stretched during marking.

A sand or sand and gravel cushion is made in the trench. To do this, a layer of sand is poured onto the bottom, it is moistened and carefully compacted. If the soil is dusty, geotextiles are placed at the bottom of the trench before filling the sand. Also, the pillow is made two-layer: 20 cm of sand and 20 cm of fine gravel. After these preparatory work, you can assemble the form for the foundation.

Manufacture of removable formwork

The load, i.e. the pressure of the concrete on the formwork, depends primarily on the height of the belt. The larger it is, the greater the load on the formwork and the stronger it should be.

Most often, boards with a thickness of 25-50 mm and a width of 10 cm or more are taken, the wider the board, the easier it is to assemble the structure. The shields assembled from the boards are installed in the trench with the help of pegs, strengthened with struts. The struts are made from a bar with a thickness of at least 5 cm and are placed at a distance of 0.5 m. You can also use panel materials:

• plywood.

Connect boards or shields with screws or nails.

Plywood shields are installed on the edges of the trench, reinforced with braces to stakes installed at a distance of 1 m from the edge of the trench. Between the braces should be no more than a meter. In the upper part, the deck is fastened with wooden lintels at a distance of 0.5-1 m. Inside, the form is lined with polyethylene or other waterproofing, which should completely cover the shields and bend outwards. Polyethylene is fixed with a furniture stapler.

You can use both new and used boards. It is important that they are not cracked, it is also necessary to pull out all the nails from them. It is advisable to use boards made of coniferous wood, they must be sufficiently moist (at least 22%).

Important! After assembling the formwork, it is necessary to check its strength. It must withstand pushes, kicks. Don't be afraid to break the boards: it's better if you find a weak spot during the inspection phase than if it reveals itself during the pouring of concrete.

Immediately you need to provide channels for pipes and other communications. To do this, holes are drilled in the shields. desired diameter and insert pipes into them.

The formwork should be slightly above the concrete level, which is marked on the boards with a cord. It is possible to make formwork flush with concrete, but it is more difficult for non-professionals.

It is important to control how evenly the shields are installed. This is especially true of the above-ground (basement) part of the foundation. The walls must be strictly vertical, and the upper edges set in the same horizontal plane.

Dismantling

An important question that worries builders is when to remove the formwork? If this is done too early, the foundation may be damaged; if it is done too late, the adhesion of the boards to the concrete will be too strong, in addition, when the wood dries, it will shrink and create tension.

Depending on the air temperature and season, the formwork is removed after 2-15 days, when the concrete hardens. The lower the temperature, the more time you need to wait. The formwork can be removed when gaps appear between it and the concrete. The boards can be reused, for this the formwork is lined with polyethylene or treated with oil or lime milk. Remove the boards from the strip foundation carefully, avoiding blows to it.

Properly made formwork prevents many problems during the pouring and further operation of the strip foundation. Therefore, it is necessary to approach this task responsibly and follow the technology.

The construction of the foundation refers to labor-intensive and expensive processes, in individual construction the only way save is the performance of all work (or their individual stages) on their own. In particular, this applies to the formwork device when pouring tape-type bases, with the right approach and studying the video instructions, even a non-specialist will carry out its installation, fixing and removal. The material of shields and supports can be any: plastic, metal, moisture-resistant plywood, boards. Wood is used most often due to reasons of economy, ease of assembly and fitting to the desired dimensions.

On the preparatory stage the foundation is marked, its perimeter is calculated. The formwork is placed on even and compacted layers of a drainage pad of sand and gravel. Shields and supports are assembled in advance, the gap between digging a trench and installing them should be minimal, otherwise the walls will begin to crumble, and rain moisture will accumulate at the bottom. It is easy to calculate the required number of boards or plywood for formwork under a strip foundation, it is enough to know its area. Up to 90% of supporting structures in private construction are made of wood, their thickness depends on the mass of poured concrete and the purpose of the building. The minimum for timber is 50 × 50 mm, plywood - 10 (subject to its support), boards - from 22.

Construction technology step by step

Consider the standard instructions for building formwork with your own hands in stages (more recommendations can be found in):

1. Drawing up a scheme of the foundation, selection and calculation of the material.

2. Knocking down shields. The boards are sawn into pieces of the same size, fastened to the timber with nails or self-tapping screws, with hats inside. Deviations in level are inevitable (they do not exist except when using plywood), but it is important that they do not exceed 2-3 cm. Gaps and cracks are unacceptable: large ones are clogged with thin slats, small ones - with tow. This step is easy to do by yourself, the help of another person is required only with limited strings.

3. Lowering and fastening the formwork panels to each other. The method of fixation depends on the variety: removable ones are twisted from the outside, non-removable ones (from expanded polystyrene, fiberboard or other DSPs) - as it will be more convenient. Corners require special attention.

4. Installation of spacers (wooden bars or pieces of plastic pipes at reusable formwork between panels with a length equal to the width of the strip foundation) and fixing the structure from the outside with supports sawn at an angle of 45 °, the second end of which is buried in the ground.

5. Checking the strength and deviations from the markup. Final fixation, sanding the lower section. Designation of the line border of the upper edge of the base.

6. Flooring inside the waterproofing film. This stage is optional, but it is recommended to carry out in the presence of gaps between the boards and in order to facilitate the removal of the formwork. When working with boards made of plywood, plastic or metal, the inner surface should be lubricated with oil.

7. Pouring and distribution of concrete inside the foundation formwork: in layers, but without significant interruptions, compacting every 20 cm and leveling the upper edge with a trowel. With properly selected boards and reliable fixation, the structure does not bend under the weight of the solution and remains motionless when air is forced out. It is this condition that allows you to get a stable foundation.

8. Formwork dismantling - depending on the brand and the time of concrete hardening, but not earlier than 3 days. Private developers remove it after 70% hardening - that is, after 2 weeks. The main sign of the admissibility of such an operation is the appearance of a gap between concrete base and formwork. You should not do the work yourself, especially when removing large supports.

After that, they proceed to the next stage of erecting a strip foundation with their own hands: waterproofing, if necessary - insulation, backfilling with soil. A slightly different (simpler) scheme of actions is observed step by step during the installation and operation of non-removable forms of formwork recommended for construction in areas with heavily frozen soils in winter. Structures with walls made of expanded polystyrene or DSP reduce the load on the foundation and give it stability. They are easy to assemble on their own, but unlike ordinary wooden ones, they remain in the ground (points 8 and 9 of the above instructions are skipped).

If the height of the strip foundation exceeds 2 m, it is advised to make formwork panels from solid materials, and not knock them down from boards. In this case, square structures are considered the strongest; when installing too long, the requirements for the number and reliability of stops and internal struts increase. With a deep foundation, due to the increase in costs, it is worth considering the option of renting formwork.

Contacting specialists (at least consulting) is required when building on loose soils. In addition to increasing the number of supports (with a standard step of 0.9-1 m), it is recommended to combine materials, for example, upholstering formwork boards from the inside with plywood. The opinion of professionals is also important when organizing vertical and lateral supports with a significant rise of the belt over zero mark the latter variety is in some cases even screwed to the walls. The standard maximum is 15 cm above the ground level, when it is exceeded, the formwork for the future base is supported from all sides.

When choosing an internal waterproofing, two factors are taken into account: the budget and the size of the aggregate fractions in the concrete. It is not recommended to use roofing felt for these purposes, it is inferior in flexibility to polyethylene (especially in winter). Most often, the choice is made between thick film and moisture-resistant plywood, the second option is optimal when working with heavy coarse-grained concrete.

Rules for uneven ground

The above instruction implies the laying of a standard strip foundation; when working on a slope, the process becomes more complicated. In this case, the base is made stepped, in the very lowest point the formwork is made higher, at the top the tape should rise above the ground. The bottom is required to be even under any conditions, by analogy, layers of sand and larger aggregates are gradually filled up and compacted, it is recommended to fill in a layer of lean concrete.

This type of foundation on a slope will be appropriate when building a house made of heavy bricks (but with differences of more than 1 m, the costs increase unreasonably, it is not allowed to exceed the height of the tape at the lower point by more than four times its width), for light buildings, a pile-grillage type is considered a good alternative. The formwork for pouring a hanging grillage is distinguished by the presence of a bottom and additional supports (the weight of the concrete is directed to it, and not to the ground).

Bug Propagation

Violations of technology when installing formwork for a strip foundation include:

• Use of an uncut or oversized board. From evenness inner surface and the absence of gaps depends on the correctness of the cement hydration process. Serious deviations or gaps lead to the flow of the solution, the solidification of the tape with uneven walls (more susceptible to groundwater later on).
• Installation of formwork for the foundation of overdried wood (for similar reasons). In this case, raw boards are preferred.
• Errors in choosing thickness and width. It is wrong to use plywood without deck support, as well as knocking down too thin boards.
• Removal of the formwork ahead of time, rough dismantling (tearing off with force).
• Installing formwork on uneven ground.
• No internal spacers at the start of concreting. Exists important rule: all wooden elements are removed as the formwork is filled with concrete. It is permissible to leave only reinforcing screeds made of tin inside the tape.

Ignoring the rules is fraught with bending structures and overconsumption of concrete, leakage, the formation of uneven walls and difficulties in further finishing the strip foundation. The involvement of specialists is required if concreting is necessary in winter, work is carried out on difficult soils, and installation time is limited.

Incorrectly assembled formwork from boards can be strengthened - it is enough to beat it from the inside with moisture-resistant plywood. If you want to reuse the supporting and shield structures, the removed shields are washed, leveled and dried.