Foundations and their types. Types of building foundations and features of their construction. Monolithic columnar structures

Different types of foundations different characteristics. Therefore, it is important to understand whether the chosen technology meets your requirements.

A foundation is a structure buried in the ground that transfers loads and impacts from a building (structure) to the foundation (stratification of soils that absorbs pressure from the structure). They are:

Most of the listed structures are concrete. Their significant prevalence is due to the fact that many are confident in the reliability of concrete, as well as in the fact that it retains heat well and allows one to avoid expensive and labor-intensive additional measures for insulating the floor, communications, finishing and insulating the base.

Concrete foundations by construction method:

monolithic (constructed on site from reinforced concrete);

prefabricated (built from ready-made reinforced concrete elements);

combined (constructed from ready-made factory elements and concrete mortar).

Traditional concrete foundations is opposed by the younger technology of constructing foundations from screw piles.

In this article we will talk in detail about the advantages and disadvantages different types foundation.

Reliable and economical, as it does not require additional waterproofing work. Suitable for buildings that do not have a basement, and the walls are made of light materials: houses made of timber, SIP panels, frame-panel houses, gazebos.

The pillars are installed along the perimeter at all intersection points of the external and internal walls of the building and at the corners of the external walls. The distance between the columns can vary from 1.2 to 2.5 meters, depending on the load on the foundation. Strapping beams are installed on top of the pillars. If the distance between the pillars is more than 2.5 or 3 meters, then beams made of metal or reinforced concrete are installed on them. The required cross-section of the pillars depends on what material they are made of: concrete pillars, brick pillars have a cross-section of about 40 centimeters, stone pillars - about 60 centimeters.

Columnar foundations are:

monolithic;

Monolithic ones are used when the depth of occurrence groundwater is more than one meter. They dig holes or drill holes in the ground using special equipment. The posts are equipped with a reinforced bandage so that they do not get damaged when the soil moves. For the same purpose, formwork is installed around the columns. The area between the pillars is covered with gravel or crushed stone.

Precast post foundations are used in wet areas such as wetlands. They are produced in advance. These are reinforced concrete pillars that are connected to a base plate. For their manufacture, reinforcement (metal rods) and wire are used.

Strip foundations are most often used in individual house construction. This technology is simple, but it is characterized by high consumption of materials, as well as significant labor intensity of the process itself. In fact, strip foundation- This is a reinforced concrete or concrete strip that is located around the perimeter of the entire structure. It is laid under all load-bearing external and internal walls of the building. The width of the tape depends on the loads transmitted from the ground structure.

This type of foundation is used for structures made of heavy materials: houses made of stone, brick, concrete, expanded clay concrete and slag concrete. It is also suitable for buildings with a basement, ground floor or garage.

There are two types of tapes:

monolithic;

Monolithic ones can withstand enormous loads and are suitable for structures of any shape. To build them, a trench is dug in which formwork is installed. They are reinforced, and then the concrete mixture is laid, producing concrete strips, the width of which is usually about 60 centimeters.

When constructing a prefabricated strip foundation, a different technology is used. Concrete or reinforced concrete blocks are laid on the mortar and tied with strong wire. The prefabricated structure is erected quickly, but still remains strong and reliable.

The disadvantages of the “tape” include:

the dependence of the quality of the structure on the size of the building (the larger it is, the more difficult it is to make a reliable “tape”);

due to poor ventilation, increased humidity occurs, which leads to rotting of the lower crown wooden houses and joists on which the floor is attached;

the service life of a strip foundation may be reduced due to corrosion of the reinforcement, and under certain conditions the concrete itself is susceptible to sulfate corrosion;

when making a reliable foundation, it is necessary to bury the tape beyond the depth of soil freezing (more than 2 m), which leads to a significant increase in its cost;

the difficulty of organizing proper quality control of the work performed (use of low-quality concrete, lack of reinforcement, etc.);

it takes a lot of time for complete shrinkage;

high price.

Slab foundation

A slab or solid foundation is a monolithic reinforced concrete slab without empty cavities, poured over the entire area of the building.

To install it, you need to dig a pit (its depth is determined by the characteristics of the soil at the construction site and the designed structural solutions of the foundation), into which sand and gravel are then poured, forming a sand and gravel cushion. Formwork is installed, reinforcement is carried out, and concrete is poured over the entire area.

Slab foundations are used in cases where the load from the building is high, and also when the soil underneath is weak. They are designed in the form of a flat or ribbed slab with the ribs located under load-bearing walls or columns. Solid foundations ensure uniform settlement of the building and protect basements from groundwater back-up.

The advantages of the slab are high load-bearing capacity, which is achieved thanks to large area, which reduces the pressure on the foundation and allows work to be carried out in difficult soil conditions, as well as the possibility of any redevelopment due to the uniform distribution of loads.

At the same time, a solid foundation has the following disadvantages:

high price;

a ventilation problem can cause rotting of the elements of the lower part of wooden buildings;

the need for high-quality waterproofing;

the difficulty of organizing proper quality control of work performed;

It takes a lot of time for complete shrinkage.

Pile foundation is a complex of piles combined into a single structure that transfers loads to the foundation.

According to the method of deepening into the ground, piles are:

Driven or pressed - reinforced concrete, wood and steel, driven into the ground without drilling it or into leader holes using hammers, vibratory hammers, vibratory hammers, vibro-impact and pressing devices, as well as reinforced concrete shell piles with a diameter of up to 0.8 m, deepened by vibratory hammers without excavation or with partial excavation and not filled with concrete mixture.

Shell piles are reinforced concrete, driven by vibratory hammers with soil excavated from their cavity and filled partially or completely with concrete mixture.

Rammed - concrete and reinforced concrete, installed in the ground by placing a concrete mixture in wells formed as a result of forced displacement - squeezing out the soil.

Drilling rigs are reinforced concrete, installed in the ground by filling drilled holes with concrete mixture or installing reinforced concrete elements in them.

Screw piles - consisting of a metal screw blade and a tubular metal shaft with a significantly smaller cross-sectional area compared to the blade, immersed in the ground by screwing it in combination with indentation.

According to the conditions of interaction with the ground, the following are distinguished:

rack piles - piles of all types that place a load on the dense layers of soil beneath them;

hanging piles - piles of all types, resting on compressible soils and transmitting the load to the foundation soils with their side surface and lower end.

A pile foundation is suitable for soils with poor stability, if you need to distribute a large load on them, or in areas where there is concentration large quantity groundwater. The use of piles makes it possible to transfer this load from the upper layers of the soil to deeper ones, which are more dense.

The advantages of pile foundations include a significantly lower level of shrinkage and a relatively low price. But the construction of such a foundation is a complex process that requires a whole range of work, the quality of which is difficult to control.

The main disadvantage is the need to use special machinery and equipment that are used when laying the piles themselves. This factor can be eliminated if you use a foundation made of screw piles.

A foundation made of screw piles is one of the types of pile foundations, which at the same time are not characterized by its most significant disadvantages, which we discussed above.

Pile-screw structures do not require excavation work; they can be erected at any time of the year. They are quite economical and do not require shrinkage time.

We discussed the quality of screw piles and their installation in the articles “” and “”.

To start any capital construction, you need to decide on the type of foundation on which the object will stand. This choice depends on many factors: the type of building, the material of its walls, the number of storeys, soil properties, the depth of groundwater, and the amount of funding for the project. In order to do right choice, you need to know what types of foundations there are and their application.

Even in ancient times, people noticed that the construction of buildings must be done on a solid and durable basis. Depending on the natural conditions In each region, each region has developed its own traditions regarding foundation construction. Today, humanity uses several types of foundations, both in private and large-scale industrial construction. These include:

Columnar.
Tape, which can be monolithic or prefabricated.
Slab.
Pile.

They all have their own characteristics and scope of application. Each has both advantages and disadvantages, which should be known to everyone who plans to engage in the construction of any capital project.

Columnar types of foundation

If you plan to build a wooden or frame house With lightweight design, which will not have a basement, then this type of foundation seems to be the most suitable. Its significant advantage is its low cost compared to other types. After all, it requires the least amount of material, and labor costs are small. For a long time, this foundation has been used for the construction of houses made of logs and timber. The first load-bearing row of the frame and the floor beams were placed on the pillars.

By design, columnar foundations are divided into wooden and stone (brick). Wood foundations have been popular for many centuries in regions where there are forests with massive trees. Today it can also be used, for example, for the construction country house in order to save money. Making such pillars is not difficult. To do this, open pits are dug into which wooden chairs made from the butt of pine or oak with a diameter of at least 25 cm are installed vertically. In this case, the butt should be facing down.

For greater stability, the lower part of the posts is often rested against a different solid base or additional reinforcing elements are made. This increases the supporting area, which makes such a foundation more reliable. A concrete slab or a wooden structure in the form of a cross with struts is used as a support. In some cases, this support is made of liquid concrete. To do this, the pole is immersed in the solution by 15 cm and fixed vertically. After the monolith hardens, the column will hold tightly. A wooden cross is made by fastening two 70 cm long bars crosswise. It is connected to the post with a tenon joint for greater strength.

The number of chairs depends on the area of the structure being built and the weight of the building. In any case, they should be installed at corners and at intersections with load-bearing walls. Additional columns are made, if necessary, based on the calculation for each ton of weight of the structure, one column with a support area of at least 490 mm2, if the bearing capacity of the soil is normal 2 kg/cm2. The pillars in the pit are covered with sand in layers and compacted. For more long term services, wooden structures are burned and coated with tar or waste.

Wooden poles have a significant drawback - their fragility. No measures will allow the use wooden foundation for decades. If you use brick or stone to construct a columnar foundation, then this drawback can be successfully avoided. The construction of a stone columnar foundation is carried out using rubble masonry. At the same time, it is done in mandatory ligation of sutures. Granite stones, broken bricks or rubble stones are used as filler. The masonry is made of iron ore brick. Ordinary red and sand-lime bricks are not used for this purpose, as they are destroyed by moisture. IN as a last resort, they make good waterproofing for it.

If you start construction on a wetland, then it will be impossible to build either a wooden or stone foundation on it. In this case, the solution would be to install a prefabricated columnar foundation. The elements of such a foundation are made in advance by rigidly fastening the pillar to a concrete flat base. The pillars themselves are made of reinforced concrete with reinforcement. You can also install asbestos pipes, which are filled with reinforcement from scraps of old pipes or wire and filled with concrete. Their surface is coated with bitumen. Cement grades M300 and M400 are used for pouring. Such a foundation can be made locally by drilling wide wells and installing pipes in them, followed by pouring concrete.

Columnar types of foundations need to be installed in dry soils. They are not suitable for areas where there is a significant surface slope, as misalignment may occur. You should not choose this type of foundation if you plan to build a house with a basement or ground floor.

Various types of strip foundation

This is perhaps the most common type of foundation. It is used in the construction of almost any buildings and structures, especially in private construction. The parameters of such a foundation depend on the mass of the structure and the properties of the soil. The convenience lies in the fact that the walls of such foundations are solid and can serve as the walls of basements or the ground floor.

There are several types of strip foundations: prefabricated, rubble, monolithic and panel. All of them are made using different technologies, but the common thing is that they resemble a ribbon lying on the ground. That is, it is a continuous base without gaps. It is worth dwelling in more detail on each of them.

A prefabricated strip foundation is made of reinforced concrete blocks that are fastened together. They are very heavy, so lifting equipment is required for construction. For these purposes they release reinforced concrete structures width 300, 400 and 600 mm. Before constructing the foundation, 10 cm of concrete preparation is made. The first row of blocks is already placed on it. The elements are fastened together by pouring the solution into the technological grooves available on each product. The second row is laid on top of the first using mortar like brickwork. This dressing is observed in all corners. The joints are coated with a solution.

If the bearing capacity of the soil is insufficient, a support for such a foundation is made from special foundation blocks, which come in widths from 800 to 2800 mm in increments of 200 mm. It is not advisable to use a block prefabricated strip foundation in houses where there will be ground floor, since the joints will freeze. Or you need to produce high-quality, and therefore expensive, waterproofing.

Another type of strip foundation is rubble. Its use is permissible for the construction of buildings up to 2 floors. Such a foundation is poured into trenches facing the walls. Rubble stones measuring 25–30 cm in size are placed on the compacted bottom. The gaps between them are filled with crushed stone, compacted with a tamper, after which the whole thing is filled with concrete mortar. Such a foundation should rise 15 cm above the ground and have a width greater than the width of the walls. The base of such foundations for normal soil is made 60 cm wide. If the soil is loose and has a low density, then the area needs to be increased even more.

A monolithic strip foundation is poured entirely from cement mortar, which includes cement, sand, crushed stone and water. Usually take three parts sand to one part cement. The bottom of the trench is compacted and filled with crushed stone. After this, the solution is poured. A formwork made of wooden panels is erected over the above-ground part. The width of such a foundation should also be greater than the width of the building walls. The shields are connected with bars to avoid their divergence. Reinforcement connected to each other is placed inside the formwork. Then the entire volume of the formwork is filled with mortar to the required height and the upper plane is leveled horizontally. All surfaces of such a foundation must be waterproofed.

Today there is another one new way strip foundation devices. It is applicable for wooden houses with a basement. The construction uses foundation panels with a thickness of only 260 mm. They have a cellular structure filled with insulation. The concrete itself contains water-repellent additives, which makes waterproofing unnecessary. The production of such panels is made to order for any type of structure.

In addition, there are foam structures with concrete poured inside. This is the so-called permanent formwork. The foam plastic remains as if put on the foundation, which provides its thermal protection for a very high level. The advantage of this design is that there is no need to construct formwork. It is enough to place foam plastic forms in the trench and fill them with concrete. Such structures are closed from above finishing materials. Since polystyrene foam is very afraid sunlight, then this must be done as quickly as possible.

Slab foundation

This type of foundation is a solid monolithic slab made of concrete. It is done in cases of high groundwater levels and on weak types of soil with uneven compression. The slab is laid ready-made, manufactured at the factory, or it is poured on site using scrap metal, fittings, wire and similar things. To do this, remove the soil to the underlying hard rock, compact the bottom of the pit and fill it with sand to 5–7 cm. Then compact it again and lay the reinforcement as evenly as possible, so that it does not rise above the upper level. Pouring is done in one go, preferably from a concrete truck.

A slab foundation is very reliable, but its disadvantage is that it is impossible to build even an underground space under it, not to mention a basement. The advantage of this type of foundation is that it is possible to lay a floor on it, installing insulation and screed. There is no need for additional lags here.

Pile types of foundations

There are three types of pile foundations. All of them are buried into the ground to a great depth, and connected from above with grillages, forming a solid frame. Post piles are driven or pressed into dense continental rock. In private construction, a depth of 4–6 m is sufficient. Hanging piles do not reach these layers and are driven into compacted soil. Screw piles are made from metal pipes with a screw at the end in the form of a screw. They are not driven into the ground, but screwed in like a screw. Piles are usually made of reinforced concrete or steel. The main disadvantage of a pile foundation is the need for pile driving equipment. This type of foundation is the only one possible in frozen and moving soils.

A plinth is built on any type of foundation. The walls are starting to be laid on top of it. Most often, the base is made of brick for waterproofing. The base is always slightly wider than the walls and narrower than the foundation. The main function of the plinth is to protect the walls from dampness and provide ventilation in the basement. In addition, this design allows you to build floor joists. Waterproofing at the foundation can be vertical or horizontal. It provides protection against moisture penetration into earth walls.

Knowing the features of all types of foundations, you can easily decide on the choice of the most suitable one for your home. It should be said that the most expensive types are monolithic foundations, as they require a large amount of material. Columnar and screw piles are cheaper than others, but they have restrictions on the type of soil. When choosing one type of foundation or another, you need to remember that it is the basis of the building, and the safety and durability of the entire structure depends on its quality.

Foundations and their varieties are selected depending on the type of structure being built on them. Each type of foundation has its own not only design features, but also the nuances of application. The factors for choosing one foundation or another are:

Characteristics of the soil, namely its bearing capacity. In other words, the ability to withstand certain loads.

Soils are distinguished: rocky/stony (do not change characteristics under the influence of moisture, changes in temperature), sandy (are weakly frozen, are well compacted, compacted), clay (deeply freeze and swell, can liquefy with abundant moisture), peat (drained swamps, reservoirs), loams, sandy loams (a mixture of clay and sand particles, their behavior depends on the balance of these components), gristly (a mixture of clay, sand and small stones, quite reliable).

Freezing depth– largely depends on the type of soil. After all, the more it is saturated with water, the stronger the swelling. Such ground movements (particularly in spring) can push out the foundation and affect its rupture in the horizontal and vertical directions.
Type of building being built– its weight (walls, ceilings), static/dynamic loads, other features, for example the presence of a basement, cellar.
Groundwater– the depth of the foundation depends on their level (determined by geotechnical research, such as drilling wells).

Now knowing about the features of choosing a foundation for a house, you can move on to the main types of foundations.

It should be noted that for the construction of a private house, four main types of foundations are traditionally considered:

Columnar.
Tape.
Pile.
Slab.

Columnar foundation

The structure of such a foundation is a system of rubble, stone or brick pillars. The supports are erected in increments of approximately 1.2 to 2.5 meters under the most critical points of concentrated loads of the future house (intersections of walls, corners, places where heavy boiler equipment is installed, etc.). In order to combine the free-standing pillars into a reliable structure, strapping beams are laid on top, thus creating a finished foundation.

Separately, we can note the columnar foundation using the (very popular today) TISE technology. Its essence lies in the construction of wells in the places where the supports are installed, their reinforcement and filling with concrete. Such foundations are also called monolithic columnar foundations. The lower part of the support (sole) has an extension.

Features of a columnar foundation:

Suitable for light soils that are not subject to strong heaving and movement (especially in the horizontal plane). It has proven itself well in heaving soils provided they are deeply frozen.
Great solution for low-rise construction(timber houses, frame houses, panel houses).
Affordable cost, minimal labor costs (compared to other types of bases)
There is no need for waterproofing.
Used for houses without a basement.

A reliable, inexpensive foundation, actively used in suburban construction.

Strip foundations

The name of the foundation fully corresponds to the visual representation of its structure. This is a reinforced concrete strip laid under all internal and external load-bearing walls of the house. The construction of such a foundation requires a larger volume of excavation work and consumption of building materials when compared with a columnar analogue.

There are:

The main advantages of strip foundations: versatility (suitable for almost any soil and type of building), as well as the possibility of constructing a garage, basement, cellar and subfloor.

Pile foundation

This type of foundation is suitable for soft soils, when it is necessary to transfer the load from the building to denser layers. Also, pile foundations are actively used for the construction of houses on terrain with slopes and significant unevenness. Of course, you can bring in soil and prepare the site for construction. However, using piles will be cheaper.

Structurally, the foundation consists of free-standing piles, the heads of which are connected by a beam (grillage). By immersing each pile to the calculated depth, you can easily obtain an even horizontal plane of the grillage for building walls.

Piles are:

Slab foundation (Swedish plate)

Massive and powerful foundation for the construction of brick, log, block houses. This type of foundation is also called floating and can be used on almost all soils (including peat, clay and with a high degree of heaving). A monolithic reinforced concrete slab is cast on a “cushion” to the size of the house or slightly larger. When the soil moves, the foundation “floats”, which preserves the integrity of the structure.

Separately, we can note the modern slab foundation– USHP (Swedish stove) or insulated Swedish stove. The peculiarity of the base is its insulation with polystyrene foam (side edges, bottom), laying of communications in the thickness of the slab, as well as a “warm floor”. Thus, the USP simultaneously represents: a foundation, a heated subfloor, and the ceiling of the first floor. You can immediately build walls on the slab, and upon completion of construction, lay the final floor covering.

In conclusion, I would like to note that the foundation is the base, the basis of the house. You should not save on its construction.

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If the foundation is chosen correctly, any structure will last long enough. Knowing the types of foundations for a private house and their distinctive features, it will be possible to choose a suitable option for a one- or two-story building. We invite you to get acquainted with the most common types, their advantages, selection criteria, as well as instructions for making your own device.

The construction of every private house begins with the foundation

The main purpose of any foundation is to take on the weight of the erected structure with subsequent transfer of the load to the soil mass located under the base. Therefore, it is very important to decide on the type of future foundation at the design stage. The choice is made taking into account the characteristics of the structure being built. The weight of the house is of particular importance.

The choice in favor of the pile type is made when building a private house on quicksand, sand, and loose soils. The special design of the base makes it possible to transfer significant loads to weak soil and makes it possible to build a private house with a lot of weight.

Piles can be:

Pressed in. To deepen these supports into the ground, special hydraulic pumps are required;
Printed. Formed directly on construction site. A well is pre-drilled into which concrete is poured;
Hammering. Such supports are driven into the ground using a special hydraulic hammer. Driven structures are used when the structure is erected in an open area. If there are other buildings near the construction site, there is a high risk of them being damaged by the shock wave created;
Screw. The most expensive option, allowing use on any soil. During installation, they are screwed into the soil.

Advice! If there are dilapidated buildings near the construction site, you should give preference to pressed or pressed supports.

The main disadvantage of a foundation on stilts for a private house is its high cost. Installation is often performed using specialized equipment.

If the installation of a pile screw foundation- this is absolutely not for you, we recommend using the services of professionals. For example, a company engaged in the construction and restoration of foundations on screw piles for country houses, bathhouses, piers, moorings and any structures that require a strong and durable foundation.

Related article:

It is quite possible for any more or less competent builder to make such a structure. Its advantages and disadvantages, features of installation and finishing - all this is discussed in our material.

Columnar foundation

The columnar base consists of pillars immersed in prepared wells or directly into the ground. From above, the individual supports are connected to each other using reinforced concrete beams. Can be used when constructing a structure on stable ground. It can be prefabricated or monolithic. The advantage of a columnar base is its affordable cost. Disadvantages include low strength and difficulty in constructing a basement or basement.

Advice! The columnar type is worth choosing if you are going to build a bathhouse or a small outbuilding.

Slab foundation

The slab base includes a reinforced concrete slab, 0.3 - 1 meter thick, laid to a certain depth on pre-poured concrete or a layer of sand. Additional reinforcement ensures sufficient strength characteristics.

This design allows you to evenly distribute the load. It is used in the construction of a private house on soft soil. However, due to the monolithic nature of this type, many people refuse to use it.

Attention! If the slab foundation will be poured under a private house large area, it is worth taking care of the presence of expansion joints that will prevent cracking of the base due to the resulting stresses.

The characteristics of the foundation can have a serious impact on the duration of operation and maintenance procedures of any structure. It is important to know how to choose a foundation for a house and what factors you should pay attention to. We invite you to get acquainted with the main ones.

Analysis of soil conditions at the site

A full assessment of the soil can only be done through appropriate geological research. Based on their results, the height of the fill layer can be determined, which should be removed before construction begins.

Considering that any soil swells in winter, measures should be taken in advance to uniformly raise the foundation. When building a private house on a site with difficult soil, you can prepare a sand cushion.

The depth depends on the depth of soil freezing: the denser it is or the more moisture it contains, the deeper the freezing will be. As a result, in an area with high groundwater, the foundation is poured to a greater depth or wider.

Attention! The anti-heaving sand and crushed stone cushion makes construction possible on any soil.

Analysis of hydrological conditions at the site

The hydrological conditions of the site determine the requirements for the depth of laying the foundation and the design features of the drainage system. If the site has an unfavorable hydrological regime, the construction of a private house will be difficult. Water trapped between soil particles will cause the soil to deform when it freezes, causing it to bulge upward. Heaving is observed on silty sands, loams and clay.

Calculation of the required foundation depth

The depth to which the laying will be made depends on the characteristics of the foundation on the site. With a high heaving index, the depth should be 0.5 - 1 m greater than the freezing depth. If the soil is not heaving, the base is poured to a depth of at least a meter.

What materials can be used to make a foundation for a private house?

The characteristics of the materials used to fill the foundation largely determine their advantages and disadvantages. Tape base May be:

Reinforced concrete. It is characterized by accessibility and high load-bearing capacity. If the private house being built has heavy load-bearing walls, the reinforced concrete foundation will become best choice. However, it will take some time to form the desired contour;
Rubble concrete. Affordable option. When pouring the foundation, additional gravel, boulders, and broken bricks are added to the concrete. Able to withstand significant loads;
Brick. Formed from clay bricks. It is built on dry soil. Relevant if pouring a monolithic type is impossible for some reason.
From blocks or slabs, laid in a pre-prepared trench and connected to each other using concrete.

The columnar base is made of:

Brick if a two-story private house is to be built from a similar material;
Stone. The foundation can withstand the load of a heavy building;
Tree. Used in the construction of lightweight structures;
Reinforced concrete. Used in the construction of multi-story buildings.

The manufacture of a pile foundation can be done using various materials:

Tree. Wooden piles are relevant for light buildings of small area. For their production, mainly pine is used, processed using special technology;
Reinforced concrete. A suitable option for any private house, including those built using reinforced concrete;
Metal. The base used when it is impossible to use reinforced concrete;
Combinations of several types. It is assumed that concrete and metal will be used together when constructing a private house on difficult soil, for example, swampy soil.

What grades of concrete should be used when constructing a monolithic foundation?

The lower the strength of the solution, the cheaper it costs. However, you should not save on the device. When developing a foundation, a composition is selected whose characteristics will allow it to withstand the operational load. What brand of concrete is needed at a specific construction site can be found in the corresponding section of the project documentation.

For a strip foundation of a private house it will be the best option. It has sufficient strength. With its help, you can form the walls of the basement of a private house through which moisture does not penetrate well.

For monolithic base concrete with lower strength should be considered, since during operation such a base experiences a uniform load. For the pile type, it is worth choosing a more durable composition.

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Rules for waterproofing and insulating the foundation of a private house

It is not enough to simply fill the base, following certain rules. High-quality waterproofing and insulation of the foundation of a private house, carried out four weeks after completion of construction work, will prevent moisture from penetrating from the outside into the private house.

Waterproofing is performed different ways. The most popular option is the formation of a special film. Through it, condensate will be discharged outside, and moisture will not be able to penetrate inside. In order to exclude negative impact moisture should be removed in a timely manner from the foundation of a private house. This can be done by installing a high-quality drainage system and performing drainage work.

Related article:

Composition and features of the production of the substance, its varieties, consumption for square meter, a review of manufacturers, technology for waterproofing foundations with mastic - you will find in our publication.

Thermal insulation of the foundation of a private house, carried out during the construction phase, is most often done outside the building, since in this case it is possible to manage the internal space more rationally. To do this, permanent formwork is installed, to which insulation is attached: expanded clay, polystyrene foam or mineral wool. When choosing the appropriate option, the characteristics of the soil, the area where the private house is located, and a number of additional factors are taken into account.

How to strengthen the foundation of a private house

If during the operation of the building the base shrinks or becomes deformed. In this case, it will be possible to strengthen the foundation of a private house by choosing one of the following methods:

Installation of additional screw piles, which are located along the entire perimeter of the building at a distance of 1.5 - 2 m from the walls. Extension beams are used to connect the base and piles. If the structure is light, the old foundation can be replaced with new screw supports;

Construction of a concrete frame. To do this, the foundation of a private house is completely excavated around the entire perimeter, permanent formwork made of sheet metal is installed, and concrete is poured. Quite often, this method is used to strengthen the foundation of a private house with your own hands;

Use of bored piles. To do this, holes are drilled directly into the body of the base, followed by the development of a well to a certain depth, depending on the characteristics of the soil. A reinforced frame is installed in the cavity, then it is filled with concrete. After the solution has completely hardened, the bored piles and the old foundation work as a single unit, ensuring uniform distribution of the load and transferring it to the deep soil layers.

Attention! Before choosing the optimal method, it is worth carrying out engineering and geodetic surveys on the site, which will confirm or refute the need to strengthen the foundation.

Instructions for laying foundations for a private house

Those who decide to install the foundation for a private house on their own will definitely need detailed instructions, describing the order of execution. If available, you can see the list of necessary equipment and tools that will be required to complete the work.

DIY strip foundation: step-by-step instructions

For those who want, who want with their own hands, step-by-step instruction includes the following steps:

Photo	Description of work
	Along the contour of the future private house and under the load-bearing walls, a trench of sufficient depth is dug, inside which permanent formwork is installed.
	To ensure sufficient strength, a reinforcing frame is installed
	Concrete of the selected grade is poured. Using a vibrator will ensure better concrete shrinkage.
	The solution is poured to the very top and left until completely dry.

DIY pile foundation

To install a pile foundation with your own hands, you must first mark the area. After this, the work is performed in the following sequence:

Photo	Description of work
	A sufficient number of piles and tools that may be required when performing the work are prepared.
	A piling machine is supplied to the work site.
	Piles are driven into the ground. Their spatial position is carefully controlled.

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Choosing the right foundation is a task even more important and responsible than building the house itself. After all, the durability of the entire building will depend on the strength, stability and reliability of the foundation. That is why we will dwell in detail on what types of foundations there are, in what cases they are used and on what soils.

To choose the right foundation for your home, you need to consider a number of factors:

Structure and condition of the soil at the site. Which foundation to choose is largely determined by the initial conditions of the site. There are heaving soils that, when freezing or other changes in atmospheric conditions, can move and expand, squeezing out the structure. TO heaving soils include clay, sandy loam, loam, and peat bogs. There are also non-heaving soils that can serve as a fairly solid foundation for a foundation. These are sand, gravel and rocks.

Groundwater level. If water is nearby, it can have a very negative impact on many types of foundations.
House weight, material, from which the walls will be built.
Features of the house architecture: the presence of a basement or ground floor.
Landscape features: Flat or sloping terrain.

An important nuance is also the financial component. Typically, at least 25% of the cost of constructing the entire house is spent on building a reliable foundation. And this is quite justified, given how important the strength and durability of the foundation is. It is strongly not recommended to save on materials for the foundation; this can lead to bad consequences in the future.

So, below are the most common types of foundations for a house, cottage, bathhouse, garage, extension and other structures.

Strip foundation

The most common on this moment The type of foundation is a strip foundation. It is a tape that runs under all load-bearing walls. In addition to the fact that the foundation strip is located around the entire perimeter of the house, it can also be under internal walls or important heavy elements, such as columns.

Depending on the type of materials used, a strip foundation can be:

Rubble.
Concrete.
Rubble concrete
Reinforced concrete.
Brick.

Also he may be monolithic or prefabricated For example, a foundation made of prefabricated concrete or reinforced concrete blocks is used if the construction of a house is planned to be completed in a short time during the summer months before the onset of rainy autumn or winter. In this case, there is no need to wait for the concrete to gain strength. A foundation made of ready-made blocks can immediately serve as the basis for the construction of walls after installation.

But I would also like to note that a non-monolithic strip foundation has less strength, since the joints of concrete blocks are a weak point. Water can seep into them, the joints do not withstand bending stresses well, even if reinforced with mesh, so it is likely that the foundation will rupture at the junction of the blocks.

Monolithic foundation is arranged using formwork. Rubble and rubble concrete foundations are made in regions where rubble is a local, cheap, common material. The width of a rubble foundation is usually 0.6 m if the masonry is made of torn rubble, and 0.5 m if the masonry is made of rubble slabs. The laying of rubble foundations is carried out on concrete mortar with mandatory ligation of vertical seams using reinforcing mesh.

Monolithic concrete and reinforced concrete foundations are the most common. Their width can be smaller than rubble ones, from 35 to 50 cm, depending on the thickness of the building walls and the bearing capacity of the soil. Typically, the width of the foundation is taken to be 20% greater than the width of the wall.

A strip foundation can serve as the basis for such buildings:

Brick house (made of red or sand-lime brick).
Reinforced concrete house of medium weight.
House made of stone.
Log house.
House made of aerated concrete.
Block buildings.
Garages, bathhouses, extensions, fences, etc.

Advantages of a strip foundation:

Possibility of arranging a basement or ground floor.
Withstands quite heavy loads from heavy 2-3-story buildings.
You can install heavy floors made of concrete slabs.
Relative ease of construction, all work can be done independently.

The disadvantages of a strip foundation include the cost of materials: cement, crushed stone, sand and reinforcement. But the end result is worth it.

There are two options for strip foundations in terms of depth: shallow and recessed.

Laying depth shallow foundation usually does not exceed 50 - 60 cm. It can be built on soils that can serve as a solid foundation. These are non-heaving sand, crushed stone soil and rocks.

It is also important to know the groundwater level. If it is below the soil freezing level, then you can also build a shallow foundation on clay soil and loam.

A shallow strip foundation is perfect as a foundation for light frame structures, garages, extensions, fences, and wooden houses. Although for a one-story brick house You can also make a non-buried base.

The technology for arranging a shallow foundation can be described as follows::

A trench is dug 70 - 80 cm deep and 50 - 60 cm wide.
The bottom of the trench is compacted.
A 30 cm layer of crushed stone is poured onto the bottom and compacted, and then a 10 cm layer of sand is also compacted.
Formwork is installed inside the trench, the top of which should rise 30 - 50 cm above ground level.
The walls of the future foundation must be protected from the influence of water, so a waterproofing material - roofing felt, glass insulation or any other rolled material - is attached to the bottom of the trench and to the walls of the formwork.

Placed inside the formwork reinforcement cage from a rod 8 mm thick.
Concrete solution is poured on top.
The concrete is compacted using a vibrator.

The crushed stone layer should not be neglected, as it serves as a kind of shock absorber. A well-prepared cushion of crushed stone and sand will eliminate the occurrence of local subsidence.

Important! This foundation option is not suitable if the site is uneven and has height differences, as well as for heavy stone buildings.

A brick shallow strip foundation is a conventional brickwork made of baked bricks that do not absorb moisture. It can be equipped for wooden houses, extensions, garages and other light structures.

The depth of the so-called buried foundation is below the freezing level of the soil. This depth differs in different regions and ranges from 70 cm to 1.5 m or more. It can be built on any solid soil, if the groundwater level is below the freezing level of the soil.

Recessed strip foundations can be made on such soils:

Sand.
Clay.
Loam.
Sandy loam.
Rocky soil.

You cannot make a strip foundation if:

Groundwater is high. The foundation will freeze and collapse.
Large elevation changes.
Swampy soil. There is an exception here though. If the peat layer is not too large, up to 1 m, then it is removed to the full depth to a solid bedding base.
Loose, fragile soil.
The soil freezes too deeply. It is not practical to spend money on building such a deep foundation. For example, if the freezing depth exceeds 2 m, it makes sense to choose a different type of foundation.

On insufficiently strong soils, you can make the tape wider and deeper. But this is only if the soil is of average fluidity and there is still strong soil at the bottom of the trench.

The technology for constructing a buried strip foundation is no different from constructing a shallow foundation. The only difference is the depth of the trench and the fact that the material consumption is much greater: more reinforcement and more concrete will be required. Technological openings for pipelines and vents are also provided in the foundation walls.

The buried foundation is strong enough to withstand heavy stone buildings: brick, concrete, etc. That is why it is so popular among the residents of our country.

Columnar foundations are used in cases where the construction of a heavier strip foundation is impractical. For example, if the building is light and the load on the foundation is less than the standard. The columnar foundation consists of pillars with a pitch of 2.5 - 3 m, located along the entire perimeter of the building under the load-bearing walls and under the internal partitions and the intersections of the walls. A grillage must be placed on top of the pillars, which can be made of concrete, timber or channels.

The pillars themselves can be concrete, rubble, rubble concrete, brick and wood. The depth of the pillars is usually taken equal to the depth of soil freezing.

Columnar foundations can be used for:

Wooden houses.
Frame and panel houses.
Extensions.
Lightweight houses made of aerated concrete.

Important! A columnar base is not suitable if you plan to make a basement, ground floor or garage in the house. But this is an ideal option if the site has a slope. Then the pillars are buried to dense soil.

Also note that a columnar foundation can be used in cases where laying a strip foundation is not economically feasible. For example, if the depth of soil freezing is 4 - 5 m. In such cases, they equip columnar base with reinforced concrete grillage.

Wooden pillars are used for the construction of foundations extremely rarely, since they are short-lived. Before installing them in a well, the wood is treated with various waterproofing materials and anti-mold impregnations. Once treated, wooden poles can last a maximum of 30 years. Typically, a wooden base is equipped for light wooden structures, such as bathhouses, sheds, and gazebos.

The technology for constructing a columnar foundation can be described as follows::

Wells are drilled under the pillars to the required depth plus 20 - 30 cm. The diameter of the well is 25 cm.
A 20 cm layer of crushed stone and a 10 cm layer of sand are poured onto the bottom.
After that, rolled roofing material is lowered into the well, which will serve as both formwork and waterproofing for the pillars. Also sometimes used are blanks in the form of steel or asbestos-cement pipes. The upper edge of such formwork should rise above the ground by at least 30 cm.
A reinforcement cage made of rods 10 - 12 mm for vertical load-bearing and 6 mm for horizontal ones is lowered inside the well. The reinforcement should rise 20 - 30 cm above the formwork if you plan to make a reinforced concrete grillage.
Then concrete is poured into the wells and compacted with a vibrator.

A concrete grillage can be installed on top of the pillars, wooden beam or steel channels. In the technology of arranging a columnar foundation, it is extremely important point ensure that the top edges of the pillars are horizontal so that they form a flat plane.

The dimensions of a columnar foundation depend on the material from which they are made. For brick, the width of the pillars should be 50 - 55 cm. For reinforced concrete, 25 cm is enough. Wooden logs are taken 25 - 28 cm in diameter. When arranging a rubble concrete columnar foundation, a width of 50 - 60 cm is taken.

Variety columnar foundations, or rather, a combined type of foundation is a column-strip foundation using TISE technology. It is also called a pile-grillage or pile-column foundation.

IN Lately this type of foundation has gained widespread popularity; it is installed even under heavy stone houses in regions with cold winters and deep freezing of the soil. Time will tell how durable they are. In the meantime, they are recommended to be used in cases where the arrangement of a strip foundation is too expensive.

The essence of a columnar strip foundation is that the pillars are lowered below the freezing depth of the soil, and a grillage in the form of a strip foundation is built in the top layer of soil.

The correct foundation using TISE technology is built like this::

The top fertile soil is removed, then a trench is dug as for a strip foundation with a depth of 50 cm.

At a distance of 1.5 - 2 m from each other, holes with a diameter of 25 cm are drilled for the pillars. Depth 1.5 m or equal to the depth of soil freezing in the region. The pillars must be located at all corners of the building and at the junction of walls.
At the bottom of each well, an expanded heel with a diameter of 40 cm is made.
The heel is filled with concrete solution.
Then formwork in the form of a roll of roofing material or asbestos pipe is lowered into the well.

A reinforcing frame is inserted inside, its upper edge should rise above the ground to the entire height of the future foundation.
Along the perimeter of the trenches, wooden formwork is installed, in which technological openings are provided for pipes and communications.
A reinforcing frame is inserted inside and connected to the frame protruding from the wells.
After all the reinforcement elements are connected to each other, you can begin to pour the concrete solution.

First, the pillars are poured and the concrete is thoroughly compacted using deep-hole vibrators.
Then the tape is poured without interruption and the concrete is also compacted.

After pouring, concrete gains strength within 28 - 30 days. After this time, construction can continue.

It is not recommended to install a column-and-strip foundation in swampy areas or on peat bogs.. During operation, it is possible that concrete pillars will separate from the foundation strip or the entire support will become distorted. But if the soil is dense, a foundation of this type can save a lot of money.

If the site has weak, easily compressible soil, a pile foundation is installed. Also, if reaching hard soils of a natural basis under peat bogs is impractical due to their large depth - 4 - 6 m, a pile foundation is driven as the foundation for the building.

Besides everything else pile foundations It is allowed to equip buildings on solid soils if it is economically justified.

According to the method of transferring and distributing loads on the ground, two types of piles are distinguished:

Hanging piles do not reach the hard soil of the natural base. They seem to hang in light compressible rock and transfer loads to it along their entire vertical surface. Typically the end is a screw thread that holds well in the ground.
Standing piles or riser piles pass through soft soils to a solid foundation and rest on it with their ends.

According to the arrangement method screw piles divided into driven and stuffed. Driven piles“hammered” into the ground using special heavy equipment; simultaneously with driving the pile, the soil around it is compacted, which ensures greater reliability.

Driven piles are installed on the construction site using the same technology as pillars for a columnar foundation.

Piles can be concrete, reinforced concrete, metal and wood.

A screw foundation is usually made of steel piles with a thread at the end; they are screwed into light soil. A grillage is installed on top, the material of which depends on the weight of the structure and the material of the walls. For a wooden house, a grillage in the form of an embedded beam is sufficient.

Pile and pile-screw foundations can be constructed on peat soils, in cases where the site has a strong slope, on quicksand, swamps, and subsidence soils. Indicators for using piles as a support are low strength, porosity and excessive soil moisture on the site.

Slab foundation for a house

A solid or slab foundation consists of slabs under the entire area of the building. It is installed in cases where the load from the building is significant, and the foundation soil is weak and cannot withstand it. For example, if a site on a drained swamp, soft porous peat is not able to support the weight of a house, it will shrink and move under its weight. If you build a strip foundation, there is a high probability that it will simply break or skew, and part of the house may fail.

The good thing about a slab foundation is that it will move and “travel” along with the foundation soil. The house will remain intact.

The technology for arranging a slab foundation can be described as follows::

A pit is dug across the entire area of the building. The depth of the pit depends on whether you plan to make a ground floor and basement. Let's consider the option without a basement. In this case, the depth of the pit should be 50 cm.
The bottom of the pit is carefully compacted.
Then pour a 20 cm layer of crushed stone and compact it.
Then a 10 cm layer of sand is also compacted.
A layer of waterproofing material is spread on top, the edges of which are placed on the walls of the pit.
Formwork is installed around the perimeter of the pit. The height is usually no more than 20 cm above ground level.
A reinforcing frame made of 12 - 16 mm rod is installed inside the pit. It takes a lot of material to make it.

The reinforcement frame must be located in the thickness of the concrete, so chairs 3 cm high are placed under it.
Concrete is poured. There must be no interruptions, so a mixer with ready-made concrete is ordered to the site.
The concrete is compacted using vibrators.

Slab foundations are sometimes called floating foundations, as they are able to move with the soil. They can be built on the following foundations: clay, subsidence soils, marshy areas, quicksand, peat soils, heaving soils. On solid foundations, a slab foundation is unprofitable.

In conclusion, I would like to give a few recommendations. If there is high groundwater in the area, it is better to equip a slab foundation, a shallow strip foundation or a pile foundation. If the water level is so high that even a shallow foundation is likely to get wet, then it is necessary to provide high-quality drainage around the house and drain the water into a drain or well. It is highly undesirable for a reinforced concrete foundation to get wet. Soil is considered dry if the groundwater level is below the soil freezing level. As a rule, in such cases you can equip any foundation.