Foundations for houses are the best advice. Which foundation is better: choosing together

Which foundation is better for a house built with your own hands in a suburban area depends on the characteristics of the building, the quality of the soil, and climatic conditions.

The choice of foundation depends on the level of groundwater and the depth of soil freezing, whether there is a slope of the soil on the site or nearby reservoirs and ravines.

Thinking about how to choose the foundation for the future building, the owners land plots they turn to specialists for advice and often make decisions depending on their financial situation, forthcoming costs and the ability to do most of the work with their own hands.

Varieties of designs

When deciding which foundation to choose for building a house on a suburban area, it is necessary to determine exactly what material the building will be erected from.

Everything existing species foundations for a home have their own advantages and disadvantages. The selection criterion can be not only the cost of work and materials, but also the time that will have to be spent on preparing and performing all the manipulations, the need to attract construction equipment and much more.

Most land owners base their choice of the type of foundation on the ability to do all the work on their own, but everyone is interested in:

• which foundation is cheaper;
• the most reliable foundation;
• simple foundation.

Which foundation is better to start building without fear of significant material costs and being completely confident in its reliability and durability, they decide depending on what material the building will be erected from, and on what soil it will be located.

When thinking about how to make a cheap skeleton for construction, you should pay attention to the cost of the materials used, their quantity, and the method of delivery to the object.

According to many builders, the answer to the question of which foundation is the cheapest can be an estimate drawn up for the construction of various foundations.

You can choose the type of foundation based on data on the quality of the soil:

• heaving;
• flowability;
• freezing depth;
• groundwater level.

All foundations have characteristic differences, positive and negative sides, but the most common in the construction of private houses are:

• tape;
• slab;
• pile.

What kind of foundation is needed for a house depends on the level of load that the foundation has to withstand.

This, in turn, is determined by the quality of the building materials used to build the walls:

• wood (logs, beams, boards, shields);
• stone;
• brick;
• adobe;
• foam or gas block.

It is important to take into account the height of the basement and other details, and therefore the choice of one of the various options for foundations is most often trusted by a professional.

A budget option

In an effort to build a cheap foundation with your own hands, you need to make an estimate and find out all the upcoming costs. To find out this will help a special calculator, which you can use by contacting the office construction company or by obtaining the necessary information on the Internet.

A strip foundation for a house is recognized as economical, reliable and durable, the construction of which can be carried out from a wide variety of materials, even if it is necessary to use concrete blocks, brick or stone.

Builders are well aware of the types of strip foundations, the creation of which does not require the involvement of special equipment or specialists:

• monolithic;
• made.

This is an excellent base for a block house. To create it, you will need to clean the area for the house, make markings, dig trenches for the tape, build a pillow of sand and gravel at the bottom, assemble and install the formwork structure.

The strength of such a base is provided by a frame connected from reinforcing bars. This structure must be assembled separately, installed on the bottom of the trench and filled with concrete. Such foundations take time to shrink. It will take at least six months to wait for the start of construction.

Considering the various types of foundations, the advice of experienced craftsmen will help to determine which foundations are of the highest quality and affordable in terms of prices. In their opinion, the simplest and most inexpensive, one might say, the budget option for a frame house is a skeleton built on piles. This is not only the best and cheapest foundation in comparison with other types of bases, but it is:

• quite easy to manufacture;
• durable;
• durable;
• used on the most weak soils, loams. For more information on the most economical type of base, see this video:

This rather cheap type of base for a country building is chosen as one of the most durable and reliable.

To create it, you will need to prepare pits, install formwork in them, reinforce with reinforcement and pour concrete.

Another type of piles is metal screw. Such a foundation can be easily built independently without the use of construction equipment.

It is more difficult to cope with driven piles, but it is quite possible to perform these works in a short period of time, having built a high-quality supporting structure for a country house located on any soil.

Expensive and durable

If low price materials is not the most important selection criterion, then the choice will fall on the slab base.

It will cost more, but its durability and other technical characteristics will ensure that the homeowner is absolutely satisfied with all the qualities of the foundation.

The main advantage is the even distribution of the load over the entire surface of the monolithic concrete slab.

To create it you will need:

• prepare a site and a pit of the required depth (it is 50 cm higher than the thickness of the slab itself);
• make sand filling, having done a good tamping and checking the horizontalness with a level;
• the next layer is fine crushed stone, covering the entire surface to be poured;
• a layer of waterproofing, which will require the use of roll materials; roofing material is laid with an overlap and fixed with bitumen brought to working condition;
• before we fill the pit with concrete, it will be necessary to carry out high-quality reinforcement using reinforcing rods with a diameter of 10-12 mm.

Pouring is done in one day with careful tamping. After completing the work, it is necessary to protect the surface of the slab from drying out or excess moisture. This will require plastic wrap or a thick layer of sawdust. Concrete gains strength within a few days, but it is finally ready for use no earlier than a month later. For detailed arguments for choosing a foundation for a country house, see this video:

Selection features the right foundation consist in the fact that before starting work you need to carry out geological survey, determine the quality of the soil, establish the value of the future load and decide whether the owners of the site are able to perform all the work without the participation of specialists.

At the design stage, the question arises, which foundation is better to choose for the future home. The solution to this issue is important for the developer. The cost of the foundation foundation of a structure can be one third of the total estimated cost construction, so you need to choose the most reliable and durable foundation. When determining the best foundation, the owner of the future home should always be guided by the compliance of the price and quality of the foundation.

The main factors determining the choice of the foundation

Consider the main conditions that affect the choice of the foundation for the house. The properties of the subsoil are determined by its composition, the level of groundwater and the depth of soil freezing.

Soil composition

According to their bearing capacity, soils are divided into three groups:

Weak soils

Peaty, sandy and clayey soils are considered weak soil bases. For example, peat bogs are so unreliable that they often avoid the construction of any structures.

Clay soils are generally prone to swelling. Heaving, that is, a sharp increase in the volume of the soil under the influence of moisture saturation, can cause the foundation structures to be pushed out to the surface of the earth. In the same way, frozen soil layers affect the supporting structures of the structure.

Weak sandy soils do not have a high bearing capacity and can contribute to subsidence and destruction of the foundation of the house. On soils of this type, pile foundations are laid with a grillage, monolithic reinforced concrete slabs, both resting on piles and without them.

Rocky foundations and rocky soils

Rocky foundations are the strongest. On such soils, strip monolithic and prefabricated reinforced concrete foundations are erected. Columnar supports with a grillage also perfectly serve as a reliable foundation for buildings on such soils.

Dense soils

Dense soils are formed from bonded rocks that can withstand heavy loads and are immune to heaving.

On dense soils, monolithic and prefabricated reinforced concrete foundations are mainly erected, and columnar foundation supports are also widely used. Dense soils are reliable and acceptable for all types of foundations.

The depth of soil freezing and the level of groundwater

These two factors determine the depth of the foundation. To create a reliable foundation for the structure, the depth of the foundation is determined below the freezing soil layers and below the groundwater level.

When building low-rise houses from lightweight structures, the foundation is made shallow above groundwater, but below the depth of soil freezing.

Guided by the calculated value of the load from the house on the entire supporting area of ​​the foundation, the type of foundation, its dimensions and configuration are determined.

If several types of foundations can be applied to an object under construction, then the decision which foundation is best done based on the cost of its construction and reliability.

The main types of foundations

Strip foundations

In terms of depth, strip foundations are shallow and deep foundations. Shallow tapes are used mainly in the construction of low-rise buildings from lightweight structures (foam blocks).

In other cases, foundation strips are laid below the water table, creating powerful base structures with high bearing capacity. Strip foundations are either monolithic reinforced concrete or precast concrete strip.

Strip monolithic reinforced concrete foundations

Monolithic reinforced concrete foundation is one of the most common types of foundations for buildings and structures. The device of such a supporting part of the house requires large costs for the production of earthworks and reinforcement works, as well as for the installation and dismantling of the formwork. All this is justified by the great strength and high load-bearing capacity, which makes it possible to erect multi-storey buildings from heavy structures.

What is the best foundation to lay on dense soils? The solution to the issue, of course, will be made in favor of the construction of the strip foundation.

The question of which foundation is better for a house with a complex configuration of walls in the plan will also not raise doubts in favor of choosing a strip monolithic base.

Precast concrete strip foundations

Compared to monolithic belts, precast concrete blocks are more economical. Installation of precast concrete blocks does not require labor costs for the installation of formwork, work on reinforcement and concrete pouring of the foundation.

From precast concrete blocks, both shallow and deep foundations are mounted. Precast concrete factories offer a wide range of precast foundation blocks.

What is the advantage of prefabricated blocks over a monolithic base? Installation of blocks does not require the production of time-consuming work on the installation and dismantling of the formwork, as well as on its reinforcement. The construction time of the foundation is significantly reduced due to the absence of time costs for concrete hardening. Reinforced concrete blocks are easy to transport and store.

Columnar foundations

Columnar supports are placed in the plan on the line of load-bearing walls, in the corners of the house perimeter, as well as in places where loads from various internal technical equipment of the house are concentrated.

Columnar supports can be shallow and deeply buried. Support pillars can be used instead of strip foundations. Supports are placed with a step of 1.5-2 meters. When comparing the strip base with the support pillars, the economy of the arrangement of columnar supports is noticeable.

The savings lie in significantly less excavation and no formwork. However, one should not forget about the costs of installing the grillage. All doubts about the choice of the type of foundation will be resolved by a comparative technical and economic calculation.

Slab monolithic foundation

Monolithic reinforced concrete slab can act as an independent supporting structure buildings, and play the role of a pile foundation grillage.

Such structures are erected on soft soils. A reinforced concrete slab has a high bearing capacity, but is an economically expensive structure.

Piles

The main purpose of the piles is to transfer the load from the building through the soft soils to the denser soil layers.

The most common types of piles:

• Reinforced concrete piles;
• Bored supports;
• Casing;
• Shell piles;
• Metal screw supports;
• Wooden supports.

Reinforced concrete piles

Reinforced concrete piles are manufactured at the plant. The markings for the installation of piles are made on the bearing lines of the load-bearing walls, in the corners of the structure and in places where vertical loads are concentrated. Reinforced concrete supports are installed using piling equipment.

Bored piles

Reinforced concrete pipes are installed in drilled holes. Reinforcement cages are installed inside the pipes. Then it is poured with concrete with layer-by-layer compaction. Bored piles are used in densely built-up areas. In such places, the pile driver can cause unwanted deformations in the bearing layers of the soil. All this can adversely affect the foundations of nearby buildings and structures.

Bored piles are mainly used in industrial construction.

Casing pipes and shell piles

Casing pipes and shell piles are used in the construction of large industrial facilities... Installation and assembly of supports of this type is possible with the use of high-tech equipment.

Screw piles

Screw piles came to civil engineering in the second half of the last century from the military industrial sphere. For the rapid formation of a reliable base for small structures, they are indispensable. Developers apply screw piles not only on soft clay soils, but also on dense soils.

Small screw supports are installed by two people by rotating the pipe using a lever. A lever in the form of a pipe is threaded through a hole in the upper part of the support and, by the efforts of two workers, a rotational translational vertical movement is given to the pile.

Watch a video detailing the pros and cons of screw bases.

The pile foundation is prepared in 5-7 days, depending on the size of the construction field.

Wooden supports

Wooden poles with pointed ends are driven into the ground with a hand tool or a copra. Most often, wooden piles are used in the construction of light outbuildings.

Before you start building a house with your own hands, it is worth asking the owners of neighboring houses about the foundation structures of their buildings. Such information will help you make the best choice of foundation for your home.

We will send the material to you by e-mail

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 offer you to get acquainted with the most common types, their advantages, selection criteria, as well as instructions for the device with your own hands.

The construction of each private house starts from the foundation.

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

Types of foundations used in construction - analysis of the pros and cons

The base to be installed can have various designs. We offer you to get acquainted with the most popular types of foundations used in construction and their distinctive features.

The choice in favor of the pile type is made when building a private house on quicksand, sand, loose soils. The special design of the base makes it possible to transfer a significant load to soft ground and makes it possible to erect a private house with a large weight.

Piles can be:

• Impressed. To deepen these supports into the ground, special hydraulic pumps are required;
• Stuffed. Formed directly on construction site... A well is pre-drilled into which concrete is poured;
• Hammered. Such supports are driven into the ground using a special hydraulic hammer. Driven structures are used when the structure is being erected in an open area. If there are other structures near the construction site, there is a high risk of damage from the shock wave;
• Screw. The most expensive option that can be used on any soil. During installation, they are screwed into the soil.

Advice! If there are dilapidated buildings near the construction site, it is worth giving preference to rammed or pressed supports.

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

If the installation of a pile screw foundation- it's 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, baths, piers, piers and any structures that require a strong and durable base.

Related article:

Any more or less competent builder is quite capable of making such a structure. Its advantages and disadvantages, installation and finishing features are all about this in our material.

Column foundation

Columnar base consists of pillars immersed in prepared wells or directly into the ground. From above, the individual supports are interconnected using reinforced concrete beams. It can be used when erecting a structure on stable ground. It can be prefabricated and monolithic. The advantage of a columnar base is its affordable cost. The disadvantages include the low strength and complexity of the construction of a basement or basement.

Advice! The columnar view should be chosen if a bathhouse or a small outbuilding is to be built.

Slab foundation

The slab base includes a reinforced concrete slab, 0.3 - 1 meter thick, laid at a certain depth on a 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 ground. However, due to the monolithic nature of this type, many refuse its device.

Attention! If the slab foundation is poured under private house large area, it is worth taking care of the presence of expansion joints, which 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 the procedure for servicing any structure. It is important to know how to choose a foundation for your home, 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 made 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 the winter, measures should be foreseen in advance to evenly raise the foundation. When building a private house on an area with difficult soil, you can prepare a sand pillow.

The depth depends on the depth of freezing of the soil: 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 made wider.

Attention! The anti-heaving sand-gravel cushion makes it possible to build on any soil.

Analysis of hydrological conditions at the site

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

Calculation of the required depth of the foundations

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 foundation 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 for pouring the foundation largely determine their advantages and disadvantages. The tape base can be:

• Reinforced concrete. Differs in availability and high bearing capacity. If the private house being built has heavy load-bearing walls, the reinforced concrete foundation will become the best choice... However, it will take some time to form the desired contour;
• With rubble concrete. Available option... When pouring a foundation into concrete, gravel, boulders, and broken brick are additionally added. Able to withstand a significant load;
• Brick. Formed from clay bricks. Built on dry ground. Relevant if filling a monolithic view is impossible for some reason.
• From blocks or slabs laid in a pre-prepared trench and connected to each other with concrete.

Columnar base is made of:

• Bricks if a two-story private house is to be erected from a similar material;
• Stone. The base is able to withstand the load of a heavy building;
• Wood. Used in the construction of easy structures;
• Reinforced concrete. Used in the construction of multi-storey buildings.

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

• Wood. Wooden piles are relevant for light structures of a small area. For their manufacture, mainly pine, processed using a special technology, is used;
• Reinforced concrete. A suitable option for any private house, including those built using reinforced concrete;
• Metal. The basis to which they resort when it is impossible to use reinforced concrete;
• Combinations of several types. It involves the joint use of concrete and metal when building a private house on difficult soil, for example, on swampy soil.

What grades of concrete to use when constructing a monolithic foundation

The lower the strength of the solution, the cheaper it is. However, you shouldn't skimp on the device. During development, a composition is selected for the foundation, the characteristics of which will allow it to withstand the operational load. What grade of concrete is needed at a particular 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 a monolithic base, concrete with a lower strength should be considered, since during operation such a base experiences a uniform load. For a pile look, it is worth choosing a more durable compound.

Related article:

Rules for waterproofing and insulation of the foundation of a private house

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

Waterproofing perform different ways... The most popular option is the formation of a special film. Through it, condensation will be discharged outside, and moisture will not be able to penetrate inside. To eliminate the negative effects of moisture, it should be timely from the foundation of a private house. This can be done by installing a high-quality drainage system and performing drainage work.

Related article:

The composition and characteristics of the production of a substance, its varieties, consumption for square meter, an overview of manufacturers, the technology of waterproofing the foundation 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 carried out outside the building, since in this case it is possible to more rationally dispose of the internal space. For this, a permanent formwork is mounted, to which insulation is attached: expanded clay, polystyrene or mineral wool. When choosing a suitable option, the characteristics of the soil, the location of the private house 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 foundation shrinks or deforms. 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. Outrigger beams are used to connect the base and piles. If the structure is light, the old foundation can be replaced with new screw supports;

• Concrete cage device. For this, the base of a private house is completely dug out along the entire perimeter, a permanent formwork made of sheet metal is installed, and concrete is poured. Quite often, in this way, they perform the strengthening of the foundation of a private house with their own hands;

• The use of bored piles. For this, pits are drilled directly in the body of the base, followed by development of the well to a certain depth, depending on the characteristics of the soil. Reinforcement cage is installed in the cavity, then it is filled with concrete. After the mortar has completely hardened, the bored piles and the old base work as a whole, ensuring uniform distribution of the load and its transfer to deep soil layers.

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

Instructions for the construction of foundations for a private house

Those who decide to carry out the construction of the foundation for a private house on their own will definitely need detailed instructions describing the order of execution. If available, you can familiarize yourself with the list of the necessary equipment and tools that will be required to perform 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
	A trench of sufficient depth is dug along the contour of the future private house and under the load-bearing walls, inside which a permanent formwork is installed.
	To ensure sufficient strength, a reinforcing frame is installed
	The concrete of the selected brand is being poured. The use of a vibrator will allow for better concrete shrinkage.
	The solution is poured to the very top and left to dry completely.

DIY pile foundation

To complete the installation of the pile foundation with your own hands, you must first mark the site. After that, the work is performed in the following sequence:

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

Article

Building a foundation is one of the main stages in building a house. In this case, the developer needs to answer the main question: which foundation to choose?

An improperly constructed foundation can cause destruction of the building. Therefore, it is necessary to choose carefully.

The main purpose of the foundation is the uniform perception of the load of the house and its structural elements, the transfer of the load to the foundation.

Depending on the method of support on the ground and the shape, foundations are divided into the following types:

• tape;
• columnar;
• pile;
• slab.

After studying the material and consulting with specialists, you can choose the appropriate type of foundation and save your time and money.

Strip foundations

This type is most often used in individual construction... As a material for you can choose rubble concrete, rubble stone, brick, concrete, reinforced concrete.

Strip foundations are commonly erected in basement homes and buildings with heavy walls. This type of foundation is installed around the perimeter of the house. Its device requires a large number of materials and labor costs. Despite the laboriousness, such foundations are technologically quite simple. If you plan to build a house with a basement, warm underground, garage and basement, then it is recommended to choose a strip foundation.

Strip foundations are monolithic and prefabricated. Which one to choose depends on a number of factors.

When building strip monolithic bases, manually or with an excavator, they dig a trench 50-80 cm wide. The width of the trench should be about 10 cm higher than the width of the foundation itself on both sides. This is necessary for the device of the formwork, to which the reinforcing strapping is made. Next, the concrete mixture is placed in it.

The main advantage of monolithic tape bases is the ability to withstand significant loads. Such bases can be used in the construction of buildings of various shapes.

Foundation masonry from different materials: a) natural stone; b) cobblestone; c) crushed stone and brick; d) brick; e) clay.

Prefabricated strip bases are reinforced concrete or concrete blocks laid on mortar and tightened with strong steel wire. Such a foundation is durable and quick to erect. Its service life is up to 150 years.

This type is used for the construction of buildings of simple shapes, since the building blocks require trimming for the implementation of complex architectural tasks.

Prefabricated strip bases are impractical for the construction of buildings with a basement, since the presence of horizontal and vertical joints significantly reduces water resistance. And the device for additional waterproofing requires additional costs. The construction of such foundations on deep-freezing ones is economically unjustified, since it requires an increase in the amount of work.

Such bases are suitable for construction:

• houses with several floors, except for houses whose walls are made of piece materials, such as reinforced concrete panels, bricks;
• houses with a deep basement used for swimming pool, sauna or parking.

Back to the table of contents

Columnar foundations

The main structural elements are the pillars. Their construction requires almost 2 times less material and labor costs than the construction of tape bases. This type of base is ideal for the construction of cottages without a basement with light frame, cobbled, panel or chopped walls.

As a material of manufacture, you can choose rubble stone, rubble concrete, concrete blocks, solid ceramic iron ore brick.

The posts are installed at the corners and intersections of the outer walls. The pillars are placed with a step size of 1.5-2.5 m along the entire perimeter of the building. The strapping beams are placed on top. If the distance between the separately standing columnar bases is more than 2.5-3 m, it is necessary to lay massive reinforced concrete or metal randbeams.

The minimum cross-section of the posts depends on the material of manufacture. For example, pillars made of concrete, buta-slab or rubble concrete should have a cross-section of 40 cm.Masonry from natural stone - 60 cm, pillars of brick - up to 38 cm.

Formwork design for strip foundations.

Columnar bases are divided into prefabricated and monolithic. Which type to choose depends on the specific conditions.

For its construction, holes are manually dug in the ground or drilled using special equipment. The posts must have a reinforcing strap. It is needed to prevent the collapse of the column during seasonal ground movements. Formwork is also required, which can have a round or square shape. It is necessary to provide for a gap between the walls of the pit and the formwork of at least 10 cm, which will avoid the deforming effect of ground movements on the post. After removing the formwork, sand or fine gravel is poured into it.

Prefabricated columnar bases are intended for damp and wetlands. They consist of reinforced concrete pillars and base plates. Wire and metal rods are used as reinforcement.

This type of base is usually not used in the construction of houses with a basement and basement. It is not used on uneven terrain due to the possibility of tipping over by the side pressure of the soil.

but given type the foundation is the cheapest. It is most effective at heaving soils with deep freezing. On moving soils, such foundations are unstable to tip over.

When erecting columnar foundations, problems arise with the construction of the basement, since it is necessary to arrange a concrete lintel between the pillars.

Merits columnar bases are:

• less laboriousness in construction compared to other foundations;
• profitability.

Disadvantages of Columnar Bases:

• the need for a basement device;
• low stability in moving soils;
• the need to limit their use in the construction of buildings with heavy walls on sandy-clay soils.

Back to the table of contents

Slab foundations

They represent a solid or lattice slab of special prefabricated cross-reinforced concrete beams or monolithic reinforced concrete. They are usually erected over the entire area of ​​the building. Their use is optimal for heaving, unevenly compressed and collapsing soils. Because of this, the slab foundation is called floating.

It is most suitable for clay-sandy soils with a water level of less than 1 m from the surface and during construction multi-storey buildings on clay-sandy soil. Such bases can withstand vertical and horizontal ground movements.

Are:

• ease of construction;
• the possibility of construction in subsiding, heaving and moving soils.

The disadvantages include the relative high cost.

Back to the table of contents

Pile foundations

They consist of individual piles covered from above with a beam or concrete (reinforced concrete) slab. In individual construction, they are used extremely rarely, since their construction is laborious.

Pile foundations are intended for houses on soft soils when it is necessary to transfer significant loads from the structure to dense deep soils.

They are made from steel, wood, concrete and reinforced concrete. They can be combined. Piles, lowered into the ground in a completely finished form, are called driven piles. Piles made in channels drilled in the ground are called rammed piles.

By the type of behavior, they are distinguished:

• rack piles, which have solid ground under them and transmit pressure to it;
• hanging piles, which are used for deep burial of solid soil.

Timber piles are economical but rot quickly in wet soil. Their service life does not exceed 10 years.

Lifetime reinforced concrete piles reaches 150 years. They are intended for the construction of multi-storey buildings.

To the merits pile foundations relate:

• less shrinkage;
• economy in comparison with other types due to the reduction in material consumption;
• possibility of application on soils with low bearing capacity.

Their disadvantage is the need to use special equipment during installation.

Back to the table of contents

Determination of the depth of the foundation

It is important to correctly determine the depth of the foundation.

What should be the level of the depth of the bookmark, first of all, depends on the specifics of the relief. If the building is without a basement, then the depth of the laying will depend on underground utilities, the nature and magnitude of the loads.

Foundations are subdivided into:

• buried (profile);
• shallow (shallow).

Profile foundations are mounted below the level of soil freezing. Shallow concrete foundations are installed at a depth of 50 cm.

Profile foundations are used in the construction of heavy structures made of brick or wood, clad with brick. Therefore, the cost of such a foundation is comparable to the cost of the house itself. Shallow foundations are optimal for the construction of timber frame or lightweight panel houses, garages and outbuildings.

When choosing the type of foundation, it is necessary to take into account the type of soil prevailing on the site. This can be determined by a geotechnician.

It is determined by the magnitude of the load under the influence of which the soil settles. The deformation of the soil occurs not only from the load, but also from temperature changes. When freezing, groundwater expands and pushes the base up. Each type of soil has its own draft, therefore the final decision on the choice of the type of foundation is made after carrying out geological procedures.

Back to the table of contents

Determination of the depth of soil freezing

For unheated rooms, the freezing depth is taken 10% more than the average. The depth of freezing is measured from the ground, in an unheated building with a basement - from the level of their floor. For heated premises, the freezing depth will be less by 20-30%.

A foundation erected below the freezing depth cannot guarantee protection against the effects of frost heaving.

To reduce the likelihood of deformation, the following methods are used: reduce the side surface of the base, give the base a trapezoid shape with a narrowing upward, fill its sinuses with non-porous soil, create a side surface using a material with a low coefficient of friction.

It is influenced by the level of groundwater. It is determined by carrying out special engineering and geological studies by drilling pits, soil samples and chemical analysis of water. On construction sites wooden houses the depth of the wells can be up to 5 m. If a brick or stone house is being built, then the depth of the wells will be 7-10 m. At the same time, it is necessary to drill at least 4 wells in the corners of the house.

When choosing the type of foundation, the main factors are the design and purpose of the house.

In the case of building a brick cottage, you need to decide on the height of the house and the thickness of the walls, the presence of a garage, basement and utility rooms. For such a cottage, it is recommended to lay out a strip foundation with a depth corresponding to the type of soil. Walls made of reinforced concrete blocks and panels are erected mainly on strip foundations. The use of slab foundations is possible in the construction of buildings on the slopes of hills, clay-sandy soils and swampy soils.

When building a lung wooden house or at home of frame-panel construction, you can save money on the foundation without sacrificing quality. For such a house, the use of a shallow foundation would be optimal. To do this, you need to remove the top layer of soil 50 cm thick, then lay the rubble and tamp it. Then a drainage pipe is installed around the entire perimeter. A road membrane-film is covered on top of the crushed stone layer. A layer of compacted wet sand and insulation are placed on top of it. Next, waterproofing is performed and reinforcement is strengthened. At the end, concrete is poured, which forms a solid monolith.

Back to the table of contents

Choosing the type of foundation

Here we will try to answer the question: what type of foundation to choose?

For the correct choice of the type of foundation, you need to understand that the soil and foundation are unified system... It is necessary to have an idea of ​​the mechanism of interaction of five elements: foundation, house, soil, groundwater and air temperature.

The main planning issues for building a house are:

• what will be the load from the house, which is transmitted through the foundation, and will the soil withstand it;
• what effect groundwater will have on the ground in the warm and cold seasons.

First of all, the properties of the underlying soil are important. The durability of the foundation and the house built on it depends on the sufficiency of the bearing capacity of the soil, its ability to retain water and the presence of resistance to deformation with changes in temperature and moisture saturation.

Consider the main reasons for soil movement that affect its bearing capacity.

Settlement of the soil can occur under the influence of its own weight and external load. Unlike subsidence, there is no change in the structure of the soil during settlement. Air and water are squeezed out of the soil. Settlement can be immediate or long-term.

For example, clay settles over several years due to the fine, scaly structure that retains water. Long-term sedimentation is characteristic of porous organic soils. Under the load of gravelly, coarse sandy and rocky soils, the sediment ends by the end of construction. Soil subsidence with a change in structure can occur both under a load from and its own weight, and when the soil saturation with water changes. For example, the crystal structure of chalky soils can weaken in the event of saturation with water or changes in the chemical composition of groundwater. As a result, the chalky soil will subside.

The movement of soil in the form of rises and precipitation usually occurs when the volume of soil changes:

• when their humidity changes as a result of swelling and shrinkage;
• when water freezes and ice thaws in the ground as a result of frost heaving and thawing of the ground.

Horizontal displacements occur with erosion of slopes, subsidence, large vertical displacements of soils. The deformation of the earth's surface in the form of subsidence is associated with the formation of natural or man-made underground cavities, a decrease in the level of groundwater. This is typical for clay and organic soils.

Deformations of soils in the form of subsidence, settlements, displacements in the horizontal plane occur from the application of an external load. For example, from the movement of heavy equipment, loads at construction works, loads from the house itself.

Deformations of the second type in the form of horizontal and vertical displacements of the soil (subsidence under its own weight, subsidence, expansion with moisture saturation, frost heaving) are not associated with external load.

Uneven soil deformations are dangerous for the foundation. They can be caused by the heterogeneity of soils, the presence of lenses and large inclusions, the unevenness of their compaction during construction work, the unevenness of soil moisture, the wedging of soil layers at an angle.

To predict the safety of the foundation and structure and prevent deformations that can lead to the destruction of a house, the concept of the bearing capacity of the soil is used - the resistance of the foundation.

It is necessary to compare the bearing capacity of soils with the load from the building, wind, snow, operational loads, taking into account the safety factor.

The bearing capacity of soils increases significantly when the foundation is buried into the ground to a depth of more than 2 m due to the appearance of additional resistance to the load from the building by perpendicular forces from the lateral soil pressure. These forces are not taken into account at a depth of less than 2 m. When the foundation is deeply laid, the soil acquires the properties of a liquid: a buoyant force acts on a body (foundation) immersed in a liquid.