How to fill the foundation under the house - tips, schemes and ways to save. Strip foundation: how to do it yourself What to use for the foundation

When building a house, it is important to pay attention to its foundation. All the load will be concentrated on it, and if the center of gravity is not powerful enough, the building may skew and all the work will be in vain. Before starting construction, you should decide: what is needed for the foundation of the house? The answer to this question can be varied, for this you need to make calculations and decide which one will be the most basic site.

What calculations need to be made?

Before you directly start building a house, you need to draw its plan and make a professional calculation. First of all, the weight of the future structure is determined. To find out this figure, you need to add up the dimensions of the most significant parts of the house. They can be floors, walls and partitions, all interior decoration, windows, doors, stairs, ceilings and roofs.

The weight is calculated for each structure separately, this is influenced by the materials chosen by the owner and the size of the building. To make it easier to make calculations, it is necessary to draw up a graph of the entire room, break it into several figures and add up the area of ​​\u200b\u200beach of them. The resulting figure must be multiplied by the specific gravity of the source material from which the entire structure is made.

It is worth considering that in winter, the load on the foundation can increase significantly due to snow accumulated on the roof. When calculating, it is required to independently determine the snow impact in your region, since the amount of precipitation everywhere occurs with different values. For those who live in warm regions, such a calculation is not mandatory.

When planning a building, it is recommended to immediately decide how much furniture will be in it. Each object in the house can also cause a certain effect on the center of gravity. If there is a lot of furniture in the house, then you should take the figure with a margin. The result obtained will indicate the weight of the house along with the furniture.

An important indicator is the soil that is on the site, the softer it is, the more powerful the foundation needs to be made. All results of the area of ​​the house, together with the objects in it and the snow load, must be divided by the estimated area of ​​\u200b\u200bthe foundation. The figure that will be obtained during this action is the specific pressure. A powerful structure can only be poured if this value is less than the resistance of the soil.

To determine what kind of foundation is needed for a house, you need to know exactly the load. It also takes into account what the frame will consist of and how much the owner plans for it to stand. In total there are many types of foundations for the building. All of them differ in the method of construction and cost.

Strip foundation

The tape frame, most often, is assembled by hand. Many solutions can be used as a material. For example, built from:

• Rubble stone or rubble concrete;
• Concrete or reinforced concrete.

In addition to the mortar, in order to fill in the pledge for the future structure, the following materials and tools will be required:

• formwork boards;
• shovel;
• hammer and nails;
• fittings.

This area is suitable for structures with heavy walls. To build such a frame, you need to spend a lot of money. First of all, you will need to dig trenches that will repeat the shape of all load-bearing walls. One strip can be up to 80 centimeters. At the same time, it is worth considering that you need to leave additional space for formwork and reinforcement.

There are two types of tape frame: monolithic and prefabricated. The first option is more powerful, as it is able to withstand the heaviest loads for several decades. To make such a pledge for the building is quite simple, you need to lay out the formwork and make a reinforcing bundle in it. Concrete mixture is poured into the resulting cells. After it has completely hardened, you can proceed to further work.

The prefabricated foundation consists of powerful elements pulled together. They can be concrete or reinforced concrete blocks. The connection of each part is carried out using the strongest steel wire. Despite the fact that the pour structure is simple, such a pledge can last more than a hundred years. However, this type is more suitable for structures of a simple form.

Column Foundation

From the name of this base, you can guess that it consists of separate pillars. Such a procedure is one of the most popular, since it does not require large financial resources for the purchase of material and physical costs. Such a pledge is more suitable for small objects, with light walls that do not have a basement. Pillars can be made from the following impurities:

• Rubble stone;
• Rubble concrete;
• concrete blocks;
• Ceramic brick;
• Zheleznyak.

Each post must be installed in the place where the corner of the house or the connection between two floors will be located. They are also located along the perimeter of all walls, at a distance of about two meters from each other. The greater the weight of the house, the smaller the gap should be. Column foundations also come in two types - prefabricated and monolithic.

The monolithic base is poured only if no water is observed at a depth of about 1 meter. There is a special instruction for its creation:

If the land on the site is damp, then a prefabricated frame should be preferred. Most likely, the question will arise about what is needed for the foundation of the house? Its most important part includes reinforced concrete pillars. The main difference of such a structure is that each element is interconnected by a base plate, and metal wire is used as reinforcement.

Tiled Foundation

The base is a solid or lattice platform. Reinforced concrete or beams can happen as the main component. It is worth considering that such a center of gravity should have a size corresponding to the area of ​​\u200b\u200bthe future building. It is one of the most powerful, as its advantage is not only the ease of creation, but also the ability to withstand both vertical and horizontal loads. However, many people deny themselves this pleasure because of the high cost.

There is a certain technology for pouring the slab:

1. First of all, you need to take care of the preparation of the mixture. The most economical option is to mix concrete. It is advisable to use special equipment for this purpose - a concrete mixer.
2. Work begins with leveling the ground and removing vegetation from it.
3. Formwork can be laid out on a flat surface.
4. The last stage of the procedure is the pouring of concrete.

It is worth considering that all materials should be close, and the work should be done as quickly as possible. It is unlikely that it will be possible to create a foundation in one day. If the break in work takes less than 12 hours, then concrete can be poured in small layers. In the event that the gap takes longer, you need to wait until one strip is completely dry, after which you can only apply the second.

The thickness of the platform is determined during the planning of the building, depending on its weight. As a waterproofing, you can use rolled material, which is attached to the formwork. First, before work, you need to take care of the communications wire, if any. It is advisable, after the structure is completely filled, to cover it with a special film for even drying.

basement with basement

People who want to have a basement in their house often think about whether it is necessary to insulate the foundation of the house. The material for this purpose can be chosen arbitrarily, but it is recommended to use foam. It is very important to decide where to post it. If protection from external factors is required, then this is done from the outside. If necessary, insulate the basement itself, it is laid from the inside.

According to experts, it is recommended to insulate the frame from the outside. First of all, it will protect it from freezing, moisture penetration and exposure to temperature changes. In addition, the insulation will give the center additional reliability. A positive quality is the fact that it will be warm in the basement.

First of all, it is necessary to dig out the very first layer of the structure. Then it is necessary to treat it with a special agent to remove contaminants. The first applied layer is responsible for waterproofing; bitumen can be used as it. Next, you need to apply insulation, after which you can level the surface and complete the ground work.

When building a house, it is advisable to remember that thermal insulation and waterproofing are two important indicators. It is necessary to remember this during the construction of the facility. It is easier to do the insulation immediately than later. If the house is built for living in all seasons all year round, you should make the highest quality foundation.

The foundation is the most critical structure in the construction of buildings and various structures. Why is a foundation needed? The foundation perceives the entire load from the structure, including the weight of all structural elements from which the building and structure are being built. The functions of foundations are to absorb and evenly redistribute this load on the foundation and soil.

Therefore, the foundations must be strong enough, have structural stability, durability, be individual for each structure, economical. The calculation for the construction of foundations should be carried out by the design institute, based on the category of soil, bearing load, terrain, availability of groundwater, material, etc.

According to the type of material, foundations can be:

• rubble- rubble masonry is performed with dressing of seams (vertical) on a cement, complex mortar.
• rubble concrete- are carried out in a wooden formwork (form) from concrete of a grade above M75 (with the addition of pieces of rubble stone to its mass). These two types of foundations are labor intensive and are used where rubble is a cheap local material.
• concrete and reinforced concrete foundation structures can be monolithic or prefabricated.

The labor intensity of the last foundations is much lower than rubble and rubble concrete.

According to the way of working under load, the foundations are divided into:

• tough, which perceive only compressive stress. On this basis, rubble, rubble concrete and concrete are classified as rigid foundations.
• flexible which also resist tensile forces. Reinforced concrete foundations are flexible.

The main types of foundations

• strip foundations - located along the entire length of both external and internal walls, a number of columns (in some cases).
• solid foundations- are a reinforced concrete slab made of a monolith under the entire spot of the structure, used for particularly heavy loads and insufficiently strong foundation soils.
• columnar foundations located under free-standing supports of columns, pillars, sometimes under walls.
• pile- are immersed in the ground, transferring all the loads from the structure to the base.

The lower surface of the columnar and strip foundations, which rests on the base, is the sole of the foundation. Its dimensions are calculated depending on the existing loads, as well as the standard soil resistance at the base. The top surface of the foundation is a cutoff.

The distance from the surface of the earth to the mark of the base of the foundation is called the depth of the foundation. The latter depends on the depth of the soil, which can serve as a reliable foundation.

However, under all conditions, in order to prevent the soil from bulging out from under the foundations under the weight of the load, its depth should not be less than 0.5 m from the level of the planned ground (for non-basement buildings) or from the level of the basement floor.

Wooden structures must be erected above the ground, to eliminate contact with the ground, whether it be a house, a bathhouse or a log house. Under the internal walls and pillars of heated buildings, the depth of foundations is taken regardless of the freezing depth, but not less than 500 cm.

We examined the topic of why a foundation is needed, got acquainted with what materials it is made of, with the main types of foundations, how these structures work under load. Now you have an idea and can choose the right foundation for your building. Good luck.

Kirill Sysoev

Calloused hands do not know boredom!

Content

In housing construction, one of the main structures is the foundation for the house, which can only be chosen taking into account the soil and the load from the object itself. These are the main factors influencing the choice of one or another option. For a private house, several types of foundations are suitable at once. All of them differ in the type of construction, materials used and their price, installation technology. The foundation project is the basis of the entire future home, so the choice of a specific type must be taken seriously. This will help you information with photos and videos below.

Types of foundations for a private house

The main classification that describes what kind of foundations there are for building a house takes into account their design and the weight for which they are designed. In its pure form, tape, columnar, monolithic and pile stand out. In some cases, combinations are used. For example, tape around the perimeter of the building with pillars or piles in the center. It all depends on the magnitude of the load that the foundation experiences from the private house itself.

Tape

The strip foundation owes its name to its appearance. These are tapes dug into the ground, which are supported by slabs. They perceive the weight from the overlying structures and transfer it to the ground. More often, such tapes are performed around the perimeter of the building and at the location of the load-bearing walls. There are two options for how to properly build a foundation - monolithic and prefabricated. In the first case, formwork is constructed, after which concrete mortar must be poured into it, and in the second, individual elements are used, for example, foam blocks, rubble concrete, rubble stone or foam concrete.

Columnar

The cheapest option is columnar. It requires a minimum of materials. The structure itself is a pillar, immersed to a certain depth or a concrete mixture. The latter is immersed in advance in a drilled well. For one-story cottages, this option is considered optimal, especially if it is light wooden. An inexpensive columnar foundation for a house can also be monolithic or prefabricated. In the first option, you need to dig wells into which concrete is poured, in the second, they collect pillars from blocks or brickwork.

Monolithic slab

The most expensive and reliable is the slab foundation for the house. It is a monolithic surface, slightly buried in the ground or lying on it. The thickness of the slab can vary from 0.3 to 1 m. For stability, it is reinforced with metal rods with a diameter of 12-25 mm. The slab is used for very high loads from the number of storeys (usually more than 2 floors) or weak soils. The plate evenly distributes forces over its entire surface. She happens:

1. Monolithic. The most common option is when the entire area under the building is poured with concrete mortar up to 50 cm thick, depending on the calculated mass.
2. Caisson. Suitable for light buildings - wooden or metal frame or from gas blocks. This is a lightweight and economical option.
3. Swedish plate. Used in the construction of SIP-panels or frame. Only suitable for well-drained soil.

on stilts

A bit similar to a columnar pile foundation for a house, but it is more expensive. It is used on unstable soil or when strong soil is located very deep - sand, quicksand, with a close location of groundwater. Even significant weights are easily transferred to the piles, which are united by a grillage on the surface. They can be wooden, metal, concrete with reinforcement. According to the principle of deepening piles can be:

• screw - twist into the ground;
• driven - they are hammered with a special hydraulic hammer to failure;
• stuffed - concrete is poured into a pre-drilled well;
• pressed in - pressed in by hydraulic pumps.

What is the best foundation

It is difficult to determine exactly which foundation of the house is better. Everything depends on the mass, i.e. building height, soil type and budget. The most common and frequently used is tape. It is also suitable for buildings with a basement and will withstand even heavy loads well. Slab is better to use in case of large volumes. Piling is mainly used in case of insufficient strength of soils occurring at the construction site. Columnar is best used for light structures, for example, small wooden summer cottages.

How to choose

It has already been said above what determines the choice of foundation for the house. These are a number of factors, each of which is important to consider. The presence of groundwater and its level, the depth of soil freezing, and whether a basement is planned under the project are affected. Some even have to do the math. Others can often be found on the Internet - the depth of freezing for a particular region. You can also find out from organizations involved in construction. This is especially true for soil types and the location of groundwater.

Groundwater availability

One of the first factors affecting the laying of foundation structures is the groundwater level (GWL). To determine it, at least 4 wells are drilled at the corners of the proposed structure. Their depth should be 50 cm lower than the expected level of the sole. The complexity of the choice will be only with a high occurrence of water. It will require backfilling, waterproofing material, drainage and insulation. The basis itself is chosen as follows:

• at GWL below 1.5 m - a shallow slab or tape;
• above 0.5 m - only pile, and it is better from screw piles, because they are cheaper;
• below 0.5 m - an unburied slab, columnar, is suitable.

Soil freezing depth

It is equally important to determine the freezing of the soil. The foundation sole must lie below this level. This will help to avoid the lifting of structures due to frost heaving of the earth. Moreover, for unheated premises, the freezing value increases by 10%, and for heated premises it decreases by 20-30%. It is measured from the ground level or the basement floor, if such is provided.

Foundation and soil types

Only a professional geotechnician can accurately tell how to determine the type of soil. But this can also be done according to the characteristic features of the soil at the construction site. In any place, almost always several varieties of soil lie at once. Of these, the main ones are:

1. Rocky or clastic. This is a rock mass, it does not swell and does not freeze, but it is difficult to build a structure on it, but it can be shallow.
2. Sandy. Sand particles of different sizes are not prone to heaving, are easily compacted, but require preparation to strengthen the walls of trenches and pits.
3. Clayey. The most difficult due to the high rate of heaving. In most cases, only piles are suitable here.
4. Dusty clayey. The bases are not at all suitable for pouring, as they freeze and swell strongly.

Foundation calculation

To properly build the foundation, you will have to make several calculations. The first of these is called the collection of weights. It is necessary to determine the mass of all structures that will be located above the ground. Based on this value, the optimal basis is selected. Next, you need to define a few more values. This is the area and depth. The latter is determined depending on freezing. These are the main recommendations describing how to calculate the foundation for a house.

House weight calculation

The first task is to determine the weight of the house. It takes into account many values, so it is better to use a special online service. It's called the Home Weight Calculator. There, you will only need to enter the characteristics of the future structure that you will find in the project. In addition to a quick calculation of values, the calculator will also offer you a sequence of calculations with a detailed explanation of all steps.

Calculation of the area of ​​\u200b\u200bthe foundation

Instructions on how to calculate the area of ​​\u200b\u200bthe foundation depend on the type of structure chosen. For tape, it is necessary to calculate the length of the entire tape - this is the perimeter of the building. Further, this value is multiplied by the width of the base, as a result, the area is obtained. In general, it is calculated as follows - S \u003d yn * F / y c * R 0. The values ​​​​used in the formula:

• S is the desired area (cm2);
• yn = 1.2 – reliability factor;
• F is the design load on the base, i.e. weight of the building (kg);
• R 0 - design soil resistance at a laying depth of 1.5-2 m.
• Another value in the formula y c is the coefficient of working conditions:
• 1.0 - for plastic clay, stone walls of the building;
• 1.1 - for plastic clay, but under wooden or frame walls;
• 1,2 - weakly plastic clay, soil - silty sands;
• 1,2 - coarse sand, long structure;
• 1.3 - fine sand, any structures;
• 1.4 - coarse sand, non-rigid structures or rigid, but long.

How deep should the foundation be?

Taking into account the freezing of the earth, the depth of the foundation for the house is determined. The soil has a high or low heaving index. In the first case, the sole is located below the estimated level of ground freezing. In the second option, it can have a height of 0.5-1 m. On coarse sand or rocky ground, a laying depth of about half a meter is allowed.

How to calculate materials

The construction of the foundation is the calculation of the materials themselves. It will be necessary to determine the amount of concrete mix, reinforcement and piles. In some cases, the volume of the required brick is also calculated, for example, for a columnar foundation. The data obtained will help to avoid unnecessary expenses. Including transport. In addition, it generally reduces the construction time of the structure.

Amount of concrete

It makes no difference whether you decide to order work on the construction of the base or mount it yourself, it will not be superfluous to estimate the required volume of concrete. It is very easy to do this. The calculation is carried out according to one simple formula. You need to take the area value already calculated above, multiply this number by its height. The result will be the volume of the structure. This is how much concrete is needed for the foundation.

Armature and wire

It is somewhat more difficult to calculate the amount of reinforcement. It all depends on the type of foundation itself, the type of soil and the weight of the building. The larger the last factor, the thicker the reinforcement should be. It should occupy at least 0.001% of the cross section of the base of any type of structure. This applies to ribbed reinforcement. Smooth is only a binder, so it will need 1.5-2 times less. Wire for knitting reinforcement is taken at the rate of 20-30 cm per connection.

Calculation of the number of piles

To calculate the pile foundation, you will need the value of the required area calculated above. In the formula, it is the main value. It must be divided by the cross-sectional area of ​​​​one pile. The result will be their number. For example, the required area is 6 m2, and the cross section of the piles is 0.3 m2, then the following is obtained - 6 / 0.3 \u003d 20. The result is that 20 piles are required.

How to make a foundation

In order to properly build the foundation for the house, it is important to step by step markup, then build the formwork, after which it will be possible to pour the concrete mix. These steps are also suitable for a prefabricated structure. Only instead of pouring the solution, you will need to lay all the elements in a certain order. Formwork is required only for columnar, tape and slab types. The pile is mounted without it.

markup

Even before the start of earthworks, they mark the corners and sides of the building according to the drawn scheme. This will require simple materials and tools - a rope, cord or fishing line that would be visible against the background of the earth. You also need to stock up on a tape measure and pegs to mark the corners. Step-by-step instructions on how to mark the foundation:

1. Drive one peg into the base corner of the building, any of your choice.
2. Further, in the direction of one of the walls, measure 4 m. Drive in another peg, connect it to the previous one with a rope.
3. Then go to the adjacent wall. From the first peg, measure 3 m in its direction, drive in another peg, connect them.
4. Measure the distance between the unconnected pegs - it should be 5 m (the rule of the golden triangle, or Pythagoras).
5. Adjust the position of the pegs so that the sides are equal to 3, 4 and 5 m.
6. Next, stretch the rope to the required length of the walls. In the same way, make other right angles.

How to fill

The next stage after marking is pouring the foundation. It is better to place the concrete mixer in close proximity to the place of its device. It is necessary to pour everything at once or so that the number of layers of concrete does not exceed two. Each of them must be sealed, for example, with a reinforcement bar or with a special vibrator. At the end of the work, the finished structure is covered over the entire area with a layer of film or roofing material to protect it from weather factors. The design strength of concrete is gaining after 28 days.

formwork

In private construction, the installation of temporary formwork is more often used. It plays the role of a base in the construction of a tape, slab or columnar. For its installation, you can use second-rate wooden bars and boards. They make special shields that are installed around the perimeter of the trenches. For connection use nails or self-tapping screws. After installing the panels, you need to make clamps that give the formwork rigidity. The shields themselves are additionally supported by slopes.

Foundation price

The cost consists of the price of all materials used. They can only be checked with manufacturers. The costs will also apply to preliminary work - excavation of the soil, delivery of materials and possible additional labor. Approximate prices for the Moscow region are shown in the table:

Name of works or materials	Price, rubles
Mechanized digging of a trench 50 cm wide per linear meter
Dumping a cushion of crushed stone and sand per linear meter
Imported concrete mix (M300), 1 m3
Concrete laying work, 30% of its cost
Fittings, 1 rod with a diameter of 14 mm
Work on the installation of one rebar
formwork
chipboard 12 mm, per 1 m2;
bar 50x50 mm;
self-tapping screws;
installation work, per linear meter.
Total for 1 running meter
	5142*L, where L is the length of the foundation

Video

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Even a person who is far from the topic of construction is clear that the top layer of soil, which turns into slurry in spring and autumn due to the abundance of moisture, cannot serve as a basis for construction. It is necessary to provide support on a more reliable surface, for which the building is equipped with a recessed part - the foundation. But what should be this very foundation for the house? There are not one or two options, let's deal with this issue in detail.

What is the best foundation

Acquaintance with the varieties of foundations will be more meaningful if you first determine the criteria for choosing this design. So, a good foundation should:

1. Have as little cost as possible.
2. Provide such a specific pressure on the soil, which would not exceed the bearing capacity of the latter. It is obvious that the specific pressure on the ground with the same mass of the building will be the smaller, the larger the area of ​​​​the base of the foundation.
3. Have a service life not less than the resource of the building.

Understanding this, you can proceed to the study of varieties of this constructive element.

Foundation types

If the solid soil lies relatively shallow, columnar foundations are usually used.

The cheapest option, which is an ordered group of pillars. They must be installed in the corners of the building and in other places where load-bearing walls intersect, and if necessary, also along the walls with a certain step, which depends on the configuration and weight of the building.

The columnar foundation is used on solid soils for buildings of small weight

The area of ​​​​support of the columnar foundation is small, therefore it is erected only under light buildings: frame houses, wooden or built from foam blocks (in this case, a belt of reinforced concrete or rolled metal is laid on the pillars). With a significant mass of the structure, the specific pressure on the ground will be excessively large. It should also be noted that it is impossible to arrange a basement in a house with a similar foundation.

According to the material used, columnar foundations are divided into:

• wooden;
• stone;
• brick;
• reinforced concrete.

Wooden

This is an outdated technology, but due to its cheapness, it may turn out to be quite appropriate today, for example, when building a country house or a barn. The lower part of pine or oak trees with a diameter of 25 cm or more should be used, which is installed with the root part (called the butt) down. As a bioprotection that prevents decay, mining, tar and modern antiseptics are used.

Wooden poles must be treated with antiseptic impregnations

It is also useful to burn the outer surface of the barrel with a gas burner or blowtorch. Then it will be much less susceptible to destruction and damage by fungus. However, it must be understood that even with the most effective protection measures, the service life of a wooden foundation will be relatively short.

To increase the area of ​​support, under a wooden pole, you can put a crosspiece made of pieces of timber 70 cm long (for reliability, it is connected to the pole in a spike) or a reinforced concrete slab. It is most effective to pour the slab right on the spot and drown the column by 15 centimeters into the still liquid solution - this will ensure its reliable fixation.

Upon completion of the installation, the recess in which the pole is installed is covered with sand with a layer-by-layer rammer (for good compaction, the sand is pre-moistened).

Stone

A more durable and durable option, but at the same time, again, having a completely democratic cost. It is due to the use of untreated natural stone - rubble (limestone, dolomite, sandstone) or granite.

Fragments of 20–30 cm in size are used, which are folded into a pillar with gaps filled with crushed stone and cement mortar (rubber concrete masonry). In this case, you need to remember about the dressing of the seams.

Instead of stone, you can use another cheap material - brick battle.

brick

When building such a foundation, special attention should be paid to the choice of brick: it should be as moisture resistant as possible. Iron brick meets this requirement in the best way. In extreme cases, other types are allowed, but only if treated with reliable waterproofing.

Brick pillars are inferior to reinforced concrete in strength, but surpass wooden ones in terms of service life.

Reinforced concrete

The peculiarity of reinforced concrete pillars is that for their construction it is not necessary to dig a large pit. You can make one or more holes with a garden drill, then install an asbestos-cement or plastic pipe there and pour concrete into it. At the bottom of the excavation, before installing the pipe, it is necessary to make a sand and gravel backfill, and install a reinforcing cage in the pipe before pouring concrete (concrete does not work well in tension). The plastic pipe acts not only as a form for concrete, but also protects it from water. The asbestos pipe must be coated with bitumen before installation.

In the absence of a pipe, a cylindrical shell sewn from roofing material can be used.

Due to the danger of skew, the use of a columnar foundation in areas with a large slope is not allowed.

With a significant mass of the structure (brick house) or low bearing capacity of the soil, it is necessary to increase the area of ​​​​support, so the foundation is built in the form of continuous tapes under all the main walls. The cost of funds and labor increases compared to the columnar counterpart, but it becomes possible to arrange a basement in the house - the foundation tapes will become its walls. In addition, such a base is insured against distortions even with a significant slope of the construction site.

A strip foundation is more expensive than a column foundation, but it will withstand a much heavier house and allow you to build a basement in it.

There are several types of strip foundations:

• monolithic;
• made;
• rubble;
• panel.

Monolithic

It is made directly at the construction site by filling the formwork with liquid concrete. In individual construction, this type of foundation is most often used, since special equipment is not required for its construction.

Today, special foam molds are produced that can be used instead of wooden formwork. The benefit from this solution is twofold:

Styrofoam should be protected as soon as possible with the help of finishing materials from the ultraviolet radiation contained in sunlight, which destroys it.

Made

It is built from prefabricated reinforced concrete blocks, which are installed on a concrete slab. To unite into one whole, the foundation blocks have special grooves, which, after being put in place, must be filled with mortar. It is easier and faster to build a foundation from blocks, but a truck and a crane are needed to deliver and install them.

For buildings of large mass, blocks with an enlarged sole are produced (the product looks like an inverted letter “T”), due to which the specific pressure on the ground is significantly reduced.

Blocks with an enlarged sole are able to withstand very high weights.

The joints between the blocks are prone to freezing, so the prefabricated foundation is not very well suited for houses with a basement.

Rubble

An inexpensive version of the strip foundation, which is constructed in the same way as stone pillars (see above). In terms of strength, it is inferior to a reinforced concrete counterpart, therefore it is allowed for use only with a building height of no more than two floors. Another requirement: the width of such a foundation must be at least 60 cm.

Panel

For the installation of strip foundations under light wooden houses, the owners of which wish to have a basement (a columnar foundation, as already mentioned, does not give such an opportunity), special panels are produced from cellular concrete, the pores of which are filled with insulation.

During their manufacture, water-repellent additives are added to the concrete mix, which eliminates the need for waterproofing the foundation. The thickness of the panels is 260 mm.

The most expensive type of base. These are no longer narrow strips built only under load-bearing walls, but a monolithic reinforced concrete slab completely covering the building. The high cost is due not only to its size, but also to the need to use reinforced reinforcement.

Monolithic reinforced concrete slab - the most expensive of all existing types of foundations

It is necessary to resort to the device of a slab foundation when construction is carried out on weak, unpredictable soil or in conditions of a high level of groundwater. The board provides the following benefits:

1. Reduces ground pressure to a minimum.
2. It turns the building into a single structure, thanks to which it retains its integrity and does not deform in case of uneven subsidence of the soil.

If soil with sufficient bearing capacity is too deep, any of the foundations described will be prohibitively expensive. In such situations, another variety is used - a pile foundation.

Piles are long, strong reinforced concrete or steel rods that are driven into the ground to the desired depth.

The device of a pile foundation will allow you to build a house on soft soils and on quicksand

There are the following types of piles:

The first two varieties are introduced into the ground by impact or indentation. Screw piles do not require the use of pile driving equipment, they can be installed independently. To do this, you need a long lever and a few helpers.

Foundation design

The design phase always begins with a study of the soil at the construction site in order to assess its bearing capacity, compressibility and groundwater level. This work must be carried out by specialists of a licensed organization, who will make their decision after analyzing several samples taken with a special drill.

Building at random, even with data on soils in neighboring areas (if one of the neighbors has already ordered such a study), is highly discouraged, since the geological situation in your area may differ from that available nearby.

Soils are different, but in general they all represent different combinations of just two extreme forms:

And here are the intermediate forms:

• sandy loam: contain only 5-10% clay impurities;
• loams: clay occupies from 10 to 30%.

Both varieties can be light, heavy and dusty. Obviously, the closer the soil is to clay, the more problematic it is in terms of construction.

Such an important characteristic as heaving depends on the content of clay in the soil. It is directly related to the ability to retain moisture: the more water will be in the soil by the onset of frost, the more it will increase in volume when this water freezes. If the freezing of the soil extends below the base of the foundation, the latter will be subjected to an extrusion effect from below.

Thus, the depth of the foundation depends on the heaving:

Parts of the foundation located under the internal walls can be deepened by 0.5–0.6 m, regardless of the type of soil.

When building on heaving soil, the depth of the foundation can be reduced in two ways:

1. By warming the soil, due to which the depth of its freezing will decrease. A wide strip of insulation is laid around the building, capable of bearing the load without deformation. The best option is extruded polystyrene foam. A cheaper, but less effective analogue is expanded clay.
2. By replacing heaving soil to a freezing depth with sandy soil. The width of the backfill should slightly exceed the transverse dimension of the foundation.

As for the bearing capacity of the soil, it depends on many characteristics:

• particle size and cohesive force between them;
• the size and nature of foreign inclusions;
• coefficient of friction between particles;
• the ability of the soil to erode and dissolve;
• compressibility and loosening of the soil.

The bearing capacity of the soil is determined by specially developed methods.

All of the above applies to the most common loose soils. In addition to them, there are rocky soils, which are a very reliable foundation for construction.

Rocky soils are characterized by high strength, so they arrange non-buried strip or pile foundations.

Foundation calculation

Design and calculation of foundations should be carried out in accordance with the requirements of SNiP 3.02.01-87 "Earth structures, bases and foundations". Before performing calculations, it is necessary to determine a number of parameters.

Required support area

It is determined by the formula: S = M / P, where M is the mass of the entire structure, including the foundation (kg); P is the bearing capacity of the soil (kg / cm 2).

Required compressive strength of the material

The same formula is applied, but in a slightly modified form: P \u003d M / S f, where M is the mass of the above-foundation part of the structure (kg); S f - the area with which the structure rests on the foundation (cm 2).

It is advisable to make the margin of safety small, since the more durable the material is, the more expensive it is.

Other inputs

When performing calculations, the depth of the foundation is determined. We have already talked about how this is done. In addition, they do:

• reinforcement calculation;
• calculation for possible uneven subsidence of soil, etc.

The technique is quite complicated, so professional civil engineers should do this work.

What kind of concrete should be used

For the construction of the foundation, heavy concrete is used. When choosing, you need to pay attention to the following characteristics:

Concretes with P3 and P4 mobility are considered optimal for pouring a strip foundation. In the first case, when laying, it is imperative to use a vibrating plate, in the second, its use is highly desirable. Concrete with a mobility index of P5 is too fluid and is not usually used for such purposes. Concrete P2 can only be used under the condition of a rare arrangement of reinforcement, the use of a vibrating plate is mandatory.

Today, there are quite a lot of enterprises engaged in the production and delivery of ready-mixed concrete (RCH). However, practice has shown that there are many dishonest among them, so you need to choose a supplier very carefully. Just in case, it is recommended to order concrete 1–2 steps higher in grade strength than required by calculation.

Well, the most reliable option is to make concrete yourself. To do this, you need to carefully study the technology (there are many publications on this topic on the network) and rent a concrete mixer with a drive - a solution prepared in a trough by stirring with a shovel is 40% less durable.

Foundation construction

We will consider the construction process using the example of the most popular variety - strip foundation. Here are the steps it consists of:

1. Marking: the outlines of the future foundation are usually marked with pegs driven into the ground and a cord stretched between them. There are no difficulties here, but you need to remember one subtlety: a marked 4-gon should have equal not only opposite sides, but also diagonals (a sign that all angles are equal to 90 degrees).

   The marking of the future foundation is made using a cord and pegs (or special chairs)

2. Digging a trench: excavation should be carried out to a depth below the design mark of the base of the foundation, since a sand and gravel cushion will be laid under it.
3. Pillow device: this structural element consists of two layers: from below - sand, from above - gravel or crushed stone. The thickness of the layers is 10 cm each. The pillow excludes the flow of water to the foundation from below due to the capillary effect (crushed stone and sand are draining materials and, due to their flowability, evenly distribute the load from the foundation to the ground).

   The pillow under the foundation is a collection of carefully compacted layers of sand and gravel (or crushed stone)

4. It will be more reliable to lay a preparation of lean (with an increased percentage of sand and gravel relative to cement and water) concrete 15–20 cm thick without reinforcement or 6–10 cm with reinforcement on top of the pillow.
5. Formwork installation: it is assembled from sheet wood-shaving materials, plywood or boards. The structure must be strong enough not to collapse under the weight of rather heavy concrete, so it is reinforced with supports throughout its entire length.

   Wooden formwork must be reinforced with side supports before pouring concrete.

6. Inside the formwork, roofing felt must be laid on top of the sand and gravel cushion. It makes sense to wrap the wood elements from which the formwork is assembled with polyethylene. Then they will not deteriorate from contact with concrete and can be used later for other tasks.
7. Reinforcement and installation of products: the reinforcing cage is installed taking into account the fact that the greatest tensile forces during bending occur at the surface itself. That is, the working belts must be located at the upper and lower faces of the future foundation, but in such a way that the reinforcement is protected by a layer of concrete 30–40 mm thick. When reinforcing, two important rules should be observed: reinforcement cannot be welded - only tied: at the welding point, it loses strength and becomes brittle; corners and other points of intersection of the tapes must be reinforced not with two straight intersecting rods, but with one L-shaped one, and each part of it must have a length of at least 30 cm.

   In the corners of the reinforcing cage, solid rods are used, bent at the required angle

8. For the installation of ventilation holes (air vents) at their locations, pieces of plastic pipe must be attached to the reinforcement, resting their ends against the walls of the formwork. To prevent concrete from seeping into the pipe, it is filled with wet sand. Similarly, holes are mounted for passing through the foundation of engineering communications.

   In the frame of the foundation, special air holes are arranged. They are needed for ventilation and removal of excess moisture seeping from the soil.

9. Pouring concrete: it is highly desirable to pour all the concrete in one go. In this case, it is necessary to ensure the exit of all air from the mass of the solution, otherwise voids will remain. This is best facilitated by a special tool - a vibrating plate. If it is not available, the freshly poured solution is densely pierced with a reinforcing bar or a shovel.

The influence of weather conditions on the quality of the fill

Concrete pouring is best done in moderate weather - not hot and dry. During heavy rains, this operation is better to postpone. But an unfortunate incident often happens: filling the formwork with concrete mixture is in full swing, and it began to pour from the sky like a bucket. In this case, it is better not to interrupt the pouring, but the trench must be covered with plastic wrap. We gradually open separate small sections, pour concrete - and immediately return the shelter to its place.

It is especially important to exclude the ingress of precipitation into the concrete mix in late autumn, when night frosts are quite real. If rainwater is allowed to flood the concrete, the result will be disastrous: the monolith will turn into a fragile substance that will crumble from a slight blow.

Waterproofing

As we already know, after the installation of the formwork, the pillow is covered with roofing material. This is a horizontal waterproofing that will protect the sole of the foundation from moisture. The same material or similar (roofing, polymer film) should be glued with mastic on the sides, not only outside, but also inside.

The inner and outer surfaces of the foundation tape must be covered with waterproofing material

External side (vertical) waterproofing must be protected from mechanical damage, since soil (during freezing and seasonal movements) and groundwater will exert pressure on it. In addition, it can be damaged when backfilling the trench. Such protection can be a heater or a brick wall. If for some reason they cannot be installed, you need to at least stick the waterproofing in several layers.

Instead of finishing with roll material, plastering can be applied.

Places for laying engineering communications through the foundation must be sealed with liquid glass or mastic.

Today, special silicone-based compounds are produced that make the concrete surface non-wettable. They eliminate the capillary effect in the pores, due to which water is absorbed. They are called water repellents. Water-soluble varieties can be added to the composition of concrete, producing volumetric hydrophobization.

Materials based on organic solvents are applied to the surface, while they impregnate the concrete by 1–2 cm. True, it must be borne in mind that hydrophobized concrete has low adhesion, so it will be impossible to stick anything on it.

Warming

All building structures, except for the roof, should be insulated from the outside, otherwise, being isolated from the warm interior space, they will freeze and thaw more often. In the case of the foundation, it is necessary to select such a heater that could withstand pressure from the soil when it freezes or moves. These requirements are met:

• extruded polystyrene foam (possesses the best thermal insulation properties);
• expanded clay;
• sawdust concrete.

Expanded polystyrene sheets are installed very simply: they are glued to the waterproofing, and then they are also screwed with dish-shaped dowels (the cap has an increased diameter). Special sheets should be used with end configurations that allow seamless installation. If ordinary sheets are used, the seams between them must be sealed with mounting foam.

Sheets of extruded polystyrene foam retain heat well and reliably protect the waterproofing layer from destruction

blind area device

To prevent atmospheric moisture from penetrating into the soil adjacent to the foundation, a concrete strip 1 m wide is arranged around the house. It is done as follows:

Finishing the foundation of the house

To finish the above-ground part of the foundation, special materials are produced that differ from wall ones in increased strength. The most popular are:

Plinth panels and siding are screwed to the crate, stone slabs are attached to mortar or glue.

Video: do-it-yourself construction of a strip reinforced concrete foundation

It must be remembered that the foundation is one of the most critical parts of the building. Therefore, it is highly desirable that its design and construction be carried out by specialists. If you still intend to do it yourself, perform each step with the utmost diligence and care, paying particular attention to the technology of concrete preparation.

The construction of the foundation is the most important stage in creating your home, since the reliability of the future structure depends on it. It is the poet who, before starting work, needs to learn about all the features of such work. But first, you should choose the type of foundation on which the house will be installed. In certain circumstances, you can build a house without a standard foundation with your own hands.

Strip foundation

Before pouring the foundation of a house, it is necessary to consider the features of different types of foundations. The most common are tape structures. This type of base is the most common. It has several advantages:

• the ability to build a foundation with your own hands;
• low cost of materials;
• possibility to create a basement;
• base strength;
• durability.

It is worth remembering that such a foundation cannot be laid on heaving soils that are prone to flooding. You can find out about the type of soil on the site from organizations that are engaged in geological exploration. Only after that you can begin to create the foundation for the house with your own hands.

Important! Finding out the data on the depth of water is worth not only to create a house foundation, but also in order to properly plan the creation of a well or well.

It is worth remembering that laying such a foundation for a house is a complex process, but with careful attention to each stage of creating the foundation, you can do everything yourself.

Foundation on pillars

This type of foundation for the house is chosen if the site is located on heaving soil, if the freezing point is deep enough. A strip base on moving soil quickly deforms, and poles can be used for several decades.

The advantages of the described type of foundation for the house include:

1. High speed of work. If there are several workers, it is possible to create a columnar base in just a few days.
2. Saving money. Due to the fact that a small amount of material is spent on the creation of pillars, you can save a large amount.
3. Ability to do all the work yourself. At the same time, there is no need to attract heavy construction equipment and hire workers.
4. The ability to install a house on unstable ground, the freezing depth of which is quite large.

When choosing this type of foundation, it is worth remembering that the marking sequence is similar when creating a strip base.

pile foundation

The choice of pile foundation is carried out in several cases:

• if the soil is plastic and contains clay;
• when the content of dust particles in the soil with a small amount of lime and clay;
• if the ground is floating.

Often the use of piles is due to the fact that the site is located on heaving soil. Also, such a foundation for a house can be created in a situation where it is not possible to spoil the natural landscape. In addition, piles are often installed to reduce the construction time of a house.

The advantages of a pile foundation include:

• lower cost of foundation creation;
• reduction of construction time;
• the possibility of refusing to carry out "wet work".

It is worth noting that a house on a pile foundation can stand for the same length of time as buildings on other types of foundations.

Disadvantages of a pile foundation:

• an increase in the cost of design work;
• on piles it is necessary to install a horizontal bundle of wood, metal or reinforced concrete structures;
• difficulties during the creation of the foundation when taking into account the non-standard landscape.

Before building a foundation of this type, it is necessary to take into account all the features of the site and consult with professionals.

Strip base marking

Having chosen a strip base for the house, it is necessary to correctly mark the site. Many site owners prefer to entrust such work to professionals. This is due to the fact that this work requires the accuracy of all actions. When creating markup with your own hands, you need to consider a few points:

1. The width of the base should not be more than the width of the walls by 20 cm.
2. During the design of the foundation, it is necessary to plan in advance exactly where the windows and doors will be. This is necessary in order to make reinforced concrete reinforcement in certain places.
3. You also need to determine the axis of the building. To do this, the first corner is measured first, and then the remaining corners of the future foundation are measured along it. The correctness of the angles can be checked by measuring the diagonals, which should be equal.

It is worth remembering that even ground is not important for the strip base, but when installing it, it is necessary to observe a horizontal position. If the marking of the foundation with your own hands is done correctly, the foundation will be durable and reliable.

trench digging

After creating the layout of the foundation for the house with your own hands, you need to dig trenches for the strip base. If a pile foundation has been chosen, wells are drilled at this stage. The walls of the trench being created are reinforced with boards, which will serve as formwork for the strip foundation.

When creating trenches, it is worth remembering that their bottom should be below the freezing level of the soil. The minimum possible distance between these levels is 20 cm.

It is worth remembering that before pouring the strip foundation, it is necessary to create a sand cushion. After falling asleep, the sand is rammed and spilled with water. It is worth remembering that waterproofing tape material is laid on top of the sand.

Reinforcement

Since the building puts a lot of stress on the foundation, the cement mixture alone cannot support it without reinforcement. Reinforcing elements do not allow the material to deform under the action of compressive forces.

As the "skeleton" of the foundation, metal rods are used, connected to each other by wire. The foundation must contain both vertical and horizontal reinforcing elements. The binding of elements is carried out using metal wire or welding.

Pouring concrete

During the creation of the base, it must be remembered that the mortar must be made immediately before pouring into the trench. If a ready-mix is ​​ordered, it is delivered to the site in a concrete mixer. If the solution is made independently, one part of cement should be mixed with three parts of sand and five parts of crushed stone, which is of medium size. It is important to choose purified sand.

Concrete must be poured evenly around the perimeter. During pouring, care must be taken to ensure that voids do not form in the solution. Their appearance can lead to the fact that the structure will be unreliable and the foundation will crack when the house is installed. After pouring, the concrete should be compacted using a vibrating plate or similar device. In the summer, the set of strength of the foundation lasts about a month. To make a durable foundation for a house with your own hands, you must follow all the rules described.

How to strengthen the old foundation

If during the inspection of the basement you notice that it has cracks or depressions, it is necessary to start strengthening the foundation, since such signs indicate that the base has begun to collapse.

To determine whether the destruction has begun, it is necessary to stick a paper tape across the crack. After that, you need to observe her for two weeks. If after this period it remains intact, this will indicate that the foundation is not destroyed. Such a defect can be repaired by pushing chipped bricks into it and pouring concrete.

If the tape breaks, this will be a sign of the destruction of the base. It is worth remembering that you can only strengthen the base yourself. It is possible to completely repair the foundation only with the use of expensive equipment.

For reinforcement, you will need the following materials and tools:

• shovels;
• metal or asbestos-cement pipes;
• gypsum plasters that will act as beacons;
• cement mortar;
• wooden planks.

First, beacons are installed on the cracks, the date of installation is recorded on them. If the gap occurred quickly, it is necessary to dig a hole next to the foundation, the slope of which should be 35 degrees. Digging takes place to the depth of the bedrock.

After that, a pipe is inserted, the diameter of which is approximately 15-20 cm. Then a concrete solution is poured into the pipe. If the solution does not leave within 2 hours, the filling stops. Resuming the filling in this case can be continued after two days. This process must be repeated at least three times. After that, beacons are again installed on the cracks. If they break again, the described steps must be repeated. A repaired foundation can last a long time.

Having considered all the information provided on how to make a foundation with your own hands (video and photo), you can perform all the steps without involving professional builders.