Monolithic foundation slab: thickness for a house made of aerated concrete, minimum value

Aerated concrete as a building material has the lowest degree of elasticity compared to other concrete, so it is extremely important to organize a reliable power structure so that such a house lasts as long as possible.
In private housing construction, a monolithic slab is used as a foundation for aerated concrete buildings.

We will talk about the advantages and disadvantages of a slab foundation for a house made of aerated concrete, the thickness of the slab and its depth, and self-construction of the foundation in the article.

Kinds

There are several types of monolithic base.

Finally, monolithic foundations also include monolithic foundations for road signs, designated FM 1. They are round bases made of reinforced concrete.

Depending on the type of burial, slab foundations come in two types.

Shallow. It sinks into the ground no more than 50 cm. In this case, a thick sand “cushion” is required to level out the heaving of the soil. Shallow foundation is used mainly on non-heaving soils for small buildings with walls made of wood or light building blocks.

Typically used in the construction of massive objects on a slab or structures above two floors.

What does the indicator depend on?

The slab in this case is a monolithic reinforced base under the entire area of the structure.

The power structure consists of fundamentally significant layers:

compacted cushion made of non-metallic materials;
heat insulator and waterproofing;
footings, as well as the concrete slab itself with an embedded reinforcement frame.

The thickness of the monolith determines the strength and reliability of the base and depends on a number of parameters, including:

characteristics of the soil under the supporting base area;
laying depths of the power structure;
design loads, which are determined by the design features of the structure, operating conditions, and climatic conditions in the region.

Professional designers take into account all of the above factors, which requires a thorough understanding of the technology and experience in laying slab structures.

Private developers, in order to save on the services of specialists, use a simplified methodology, which is based on taking into account three parameters:

reinforcement thickness;
gap between reinforcing chords;
thickness of concrete above and below the reinforcement cage.

As a rule, if you add up the three indicated parameters, you get a slab thickness value ranging from 0.2 to 0.3 m. The final indicator is adjusted taking into account the characteristics of the soil, the uniformity of rock occurrence and the complexity of the design of the future building.

In addition to the indirect assessment given by practicing builders, according to established standards, it is necessary to check the selected slab thickness in relation to the parameter - the optimal specific pressure of the structure on the ground (more details in the table).

Optimal value of distributed load (kgf/cm²) depending on soil type
plastic clays, sandy loams	0,50
dense sands, loams	0,35
medium density sands, hard clay	0,25

Features of a slab foundation for a house

Professionals are confident that a slab foundation is suitable for aerated concrete and brick houses. It consists of powerful reinforced concrete structures. This base boasts the following features:

The slab base is not familiar with the problem of pressure from the soil. Therefore, soil heaving due to frost will not in any way affect the strength and integrity of the structure.
If you correctly calculate the thickness of the slab foundation, then the finished foundation will be able to evenly distribute all the pressure that comes from the side of the building. Thanks to this, the owner of the house will not be afraid that over time the building will deform and become unsuitable for use.

Working with this type of foundation for a building made of aerated concrete is easy and quick. The most difficult step that must be completed is creating a suitable pit. It must be dug, covered with crushed stone, compacted, and then a thin layer of concrete base must be formed. And also do not forget about the waterproofing film, which should be located between two layers of the base for the house. With its help, you need to protect not only the base, but also the base of the building from moisture. When all work on the pit comes to an end, you can begin laying the slabs. For this, the builder will need special equipment, since he will not be able to lay heavy reinforced concrete structures manually. To calculate the foundation, you need to determine its length and width. These are the main parameters. It is also necessary to find out the thickness of the slab foundation. Its size should be between 20–30 centimeters. A foundation thickness of 15 centimeters is only suitable for the construction of light-weight buildings on non-heaving soil. Choosing this support for a building makes sense only when the owner of the site is faced with the task of building a house on heaving soil. And also if he is ready to spend an impressive amount of money on construction.

Useful tips

Before you begin to calculate the amount of materials and the foundation itself, you need to study all the features of the soil. Heaving soil can rise and fall several centimeters throughout the year. If this is not taken into account, then over time the foundation will begin to burst under loads, and cracks will spread throughout the house.

The reinforcement is connected to each other with wire, which makes it movable and because of this, the hardened concrete, under the influence of soil deformations, will also be movable, which will preserve its structure and guarantee the absence of cracks.

What foundation is best to build for an aerated concrete house?

Before installing a foundation for a house made of aerated concrete, the following factors are taken into account:

aerated concrete has low strength and is used for the construction of low buildings of 1-3 floors. This is taken into account when choosing a foundation, since then there is no need to spend money on a massive monolithic foundation;

Foundation for a house made of aerated concrete

take into account the geology of the site, groundwater level and freezing depth; take into account the need for space under the cellar.

Monolithic slab foundation

The monolithic slab is universal; it is suitable for any type of soil with even terrain. It is considered the most expensive, since a large amount of materials will be required to fill it, but it provides reliability and strength to the base.

A monolithic foundation is installed along the entire perimeter of the building:

suitable for any type of soil;
will qualitatively withstand aerated concrete walls of a 1-2 storey building;
is not afraid of soil and groundwater deformations.

Such a foundation is resistant to temperature changes and does not need to be deepened to the level of freezing of the ground.

Monolithic slab foundation

Monolithic strip frame

A strip foundation for a house has the shape of a strip and is poured around the perimeter of the house and under all load-bearing walls of the building. If the aerated concrete house does not have a basement, then choose a shallow strip foundation. If you need a basement and build a foundation on clay and heaving soil, you will need a buried type of foundation.

Lightweight aerated concrete is suitable for a strip foundation for a house, but before installing it, a high-quality soil analysis is required

Before pouring it is important:

install strong and reliable formwork for the foundation;
pour a cushion of sand and crushed stone and compact it securely;
carry out reinforcement with periodic profile reinforcement.

Monolithic columnar foundation

When installing a columnar foundation, you can save on materials in comparison with previous types of foundations. This foundation is suitable for light buildings and is installed on soils with low groundwater levels. This type of foundation is often chosen if the house design does not include a basement.

Construction of a columnar monolithic foundation

Columnar foundation is suitable:

non-heaving and clay soils;
soils that are too plastic require additional strengthening of the foundation;
on slopes they are reinforced with additional supports.

Pile foundation

On soil with a high groundwater level and if the soil in the area is floating, it is advisable to install a pile foundation under aerated concrete. Then the piles will transfer the load from the building to the deep, solid soil. Bored piles are very popular due to the possibility of not using special equipment.

The pile foundation for aerated concrete is connected with a reinforced concrete grillage on which the walls of aerated concrete blocks will be installed. The advantages of a pile foundation include:

high installation speed;
has high-quality load-bearing capabilities;
used on uneven areas with significant soil freezing depth.

Pile foundation technology

Monolithic design

If the choice is a monolithic slab, pouring the foundation for a house made of aerated concrete includes the following steps:

Preparatory work. The construction site is cleared and leveled, a foundation pit is dug. For a shallow foundation for a house made of aerated concrete, 50-70 cm of soil is removed.
Installation of formwork. It is erected along the entire perimeter of the pit using wood boards and plywood sheets.
Backfilling with sand and crushed stone cushion. It reaches 25-35 cm and each of the materials is compacted as much as possible.
Reinforcement. Before reinforcement, the cushion is waterproofed using rolls of roofing material. The reinforcement is knitted with special wire and placed on stands so that it is inside the concrete base.
Pouring concrete solution.

A profitable alternative is piles and pillars

Many experts consider these types of foundations for an aerated concrete house to be the most suitable. Their distinctive advantages are:

budget;
piles are easy and quick to install;
long service life of the base.

Foundations made of pillars or piles will require less money and power costs from the owner of the house. Such foundations are easier to install, and a pile foundation is suitable for problematic soils. Screw piles can be installed at any time of the year. They do not require drilling or waterproofing.

Concrete foundation pillars

Concreting the floor

There are rules for concreting that must be followed unquestioningly in order not to subject the structure to destruction in the future:

Laying concrete into the floor must be done in one go. If concreting remains idle for a long period of time, the laid concrete may set and the new one will not be able to mix with it. As a result, you will get a boundary along which a crack can go.
When concreting in a cool period (0...+5 °C), use special anti-frost additives. Read more about winter concreting in this article.
Be sure to use vibrators - deep or surface. Without vibration, concrete has 40-50% of its design strength. You will find more information about concreting in our article.
The floor formwork is dismantled no earlier than 28 days after laying the concrete.

Vitaly Dolbinov, rmnt.ru

A floor slab is a horizontal building structure that separates floors from each other. This structure is load-bearing, it distributes loads and provides rigidity to the building. A monolithic floor slab is a structure made at the building construction site by pouring reinforcement with concrete mixture.

You cannot change the design of a house without the consent of the architect, because these slabs are designed specifically for a specific building, since the location of the reinforcement and the method of support must be determined for them.

Steel is much stronger than concrete, which is why the reinforcing mesh is located at the bottom of the slab. This mesh should not be close to the formwork; the distance between the reinforcement and the formwork should be more than 3 cm. Reinforcement is used with a cross-section of 8-12 mm. The concrete must be at least 10 cm thick. The slab must be concreted in one go. The formwork is made in the form of the bottom and walls of the future slab. For durability, strength and reliability of the floor, concrete grade M200 and higher is used. To do this, it is better to buy ready-mixed concrete at the factory.

This type of floors has advantages over ready-made reinforced concrete slabs:

monolithic slabs are used in cases where it is difficult to organize the work of a crane on a construction site, and also if the building has non-standard dimensions and architectural forms;
due to the strong connection of the slab elements, high structural rigidity is ensured;
saving money on electricity, loading and unloading operations, welding work to eliminate joints, lower costs for materials;
all necessary materials are freely available;
the lower surface of the slab is smooth and even, making plastering work easier;
the absence of joints increases the sound insulation of the building;
the material does not burn and is not subject to rotting;
This method of constructing a building allows you to make external structures (balconies), the base of which is a single slab with an interfloor ceiling. This increases the strength and reliability of the balcony.

The main disadvantage of this type of flooring is the increased complexity of work in the cold season. The required strength is achieved after 28 days. Due to high humidity and low temperature, concrete will take longer to harden, which increases construction time. The execution of a monolithic floor requires high-class specialists, since the slabs must be reinforced with additional supports.

Another disadvantage is that formwork must be made before pouring concrete into the reinforcement. This usually takes a lot of time and wood material. This shortcoming can now be avoided. On the building materials market, ready-made elements of panel formwork (plywood boards) are sold or rented.

Calculation examples

For foam concrete, the thickness of the slab is minimal. Strength is achieved by reinforcement

Since aerated concrete, even with its finishing, is light in weight, such a one-story house requires a supporting system of the minimum permissible thickness. To achieve the required strength, you should use 16 mm reinforcement and M300 concrete.

The calculations are based on the following data:

The maximum distance between rows of horizontal bars is 100 mm.
The concrete layer between the reinforcement and the edges of the slab is 50 mm (× 2 = 100).
Reserve 5 cm.

In total, it turns out that for a one-story mansion made of aerated blocks, a load-bearing slab 250 mm thick will be required. All that remains is to draw up a drawing and carry out calculations based on it. On average, pouring 1 m² of slab requires 0.25 m³ of concrete and 25 linear meters of reinforcement.

What does the cost consist of?

The slab has only one drawback - the high cost, which entails a huge amount of class B22.5 concrete required for pouring. Its volume is calculated by multiplying the area by the height of the foundation of a 2-story building made of aerated concrete (on average it is 300 mm) and by a safety factor of 1.1. In addition to this, concrete preparation with a thickness of 100 mm is also carried out - from cheaper lean concrete B7.5.

As an option, instead of a footing, a profile membrane is laid, which also costs a lot of money. Concrete also requires reinforcement and floating waterproofing, which is laid between the preparatory and main concrete layers. On heaving soils, a layer of rigid polystyrene foam is also placed under the slab, which prevents the foundation from coming into contact with frozen soil.

If you add up all the layers, the price of such a foundation is twice or even three times higher than the total cost of the concrete used. So, it will definitely not be possible to reduce the cost of the zero cycle.

How to calculate the foundation

A slab monolith is not an option that is easy to fill yourself. And the concrete must be factory-made, with specified characteristics that exactly correspond to the specific brand. The structure needs to be designed correctly. In addition to the foundation itself, these are also the inputs of utility lines, since after pouring it will no longer be possible to make them.

Preliminary calculations of the slab are aimed at correctly determining its thickness, which can withstand the weight of the building. In this case, the bearing capacity of the soil is taken into account, which can be taken from the standard tables, which provide average data. Accurate figures can only be obtained as a result of hydrogeological surveys, which are necessarily carried out during individual design.

For example, construction will be carried out on loam, the bearing capacity of which is 3.5 kg/cm². In the problem, the area of the house is 9*10 m (9000 cm²) and it weighs 200 tons. We calculate the required load on the ground 9000 * 3.5 = 315 tons. We subtract the weight of the house from them, we get 115 tons - the weight of the foundation slab. Let’s say that minus the weight of the reinforcement, 85 tons of concrete with a specific gravity of 2.8 t/m² remain. Dividing these values, we get 30.36 m³ of concrete. We divide 90 m² (the area of the house) by 30.36, and we get 29.6 cm - the thickness of the slab.

Step-by-step instructions - do-it-yourself foundation

The thickness and height of the tape of the base under consideration, as well as the depth of its placement, are selected based on soil analysis, climatic conditions of the area and the number of storeys of the building being built. Without knowledge in this area, it is better to entrust this design stage to a professional. There are many nuances and requirements of GOSTs that must be observed.

But it is quite possible to create a support for your house using a ready-made project yourself. But in order to avoid mistakes, it is best to make the strip foundation yourself with the step-by-step instructions given below. It describes all the intricacies of building such a structure for a typical one-story cottage.

Stages of work

The first stage is marking and excavation work. Regardless of the depth of the foundation, the sole must rest on solid layers of soil. It can be clay, sandy loam, rocky layers or loam. They are usually hidden under turf and layers of ordinary soil. All this will have to be torn down and removed before starting to build the foundation of the house.

To mark the area you will need pegs, tape measure and twine. If the soil is dense, then the walls of the dug trench will make excellent formwork. It will only be necessary to build it up from above. If the soil is loose and constantly crumbling, then the trench will have to be dug somewhat wider so that formwork boards can be placed inside the hole.

The second stage is preparing the pillow. The bottom of the dug trench is leveled with sand and fine gravel. This sand and gravel layer should be thoroughly compacted, pouring water as it is poured. It should be between 10–30 cm in height. This cushion serves to redistribute and reduce point loads on the strip foundation from below during seasonal heaving of the soil.

The third stage is placing the formwork. Here you will need bars with a cross section of 30 to 40 mm and boards with a thickness of 15–20 mm or laminated chipboard. The formwork created for the concrete foundation of a house will subsequently be required to withstand a considerable mass of concrete poured into it. It should be made strong and reliable. If, after filling with the concrete mixture, it collapses, then everything will have to start again.

If the groundwater at a construction site is high, then reinforced concrete will require waterproofing. From above, at the level of the base of the house, it is usually done as a coating. And to protect that part of the base that remains in the ground, roofing material should be laid in the trench on the sides and on the bottom. It will reliably protect concrete from excess moisture in the soil at the stage of its hardening and after.

The fourth stage is laying the reinforcement. For reinforcement, steel rods with a cross-section of 14–16 mm and thin dressing wire are usually used. The reinforcement can also be fastened using electric welding. But in this case, you need experience working with a welding machine and yourself. Plus, when performing welding, you must be prepared for the occurrence of metal corrosion in the future.

Inside the trench, a frame of reinforcement with cells of 25–30 cm should eventually be formed. Moreover, it is laid so that the steel is covered on all sides by the poured concrete. Otherwise, the metal will inevitably begin to rust, and the house will definitely not last long.

The fifth stage is pouring concrete or laying out FBS. If it is decided to equip the foundation for a house being built using block technology, then this greatly speeds up the process of its construction. Here you don’t have to make formwork and wait almost a month for the concrete to set. However, support on foundation blocks will cost more than a monolithic counterpart. Plus, they will have to dig a larger trench in width. To distribute the loads for the bottom row, FBS masonry is made with an expanding base. If a monolithic option is chosen for the support structure, concrete should be poured immediately over the entire surface. No breaks in length and no layers in height. A monolith is just a monolith. The house must stand on a reliable foundation.

When preparing the concrete mixture yourself, you need to mix cement, sand and crushed stone in proportions 1: 3: 3

But it is better to initially order a ready-made solution with a grade of M300 or higher.

When pouring concrete, it is extremely important to ensure that no voids form inside it. There are special vibrating machines to perform compaction.

However, you can also use a piece of reinforcement to pierce the poured mass and release air from it.

The sixth stage is waterproofing and blind area. It is allowed to begin waterproofing work 3-4 days after pouring concrete. It takes about three weeks for it to fully set. But you can already begin treating the strip foundation for the house with mastic, even if it has not yet completely hardened.

Also, along the entire perimeter of the building, you will need to make a blind area to drain rainwater away from its walls.

USP at a price of 3,000 rubles per m2 - reality or magic

I don’t know how, but here is a real person, Alexander Dobrynin, who could do this. I quote:

In 2022, I built a USHP for myself. Followed all the rules described in the Dorocell cards. Area with terrace 146 m2 All materials and delivery cost 430 thousand, that is, 3 thousand rubles/m2 for materials.

Here's the full calculation:

The tractor dug a pit, buried water pipes, then leveled the sand and pulled away the selected soil for 11,000
Then three workers leveled the pit and dug a trench for drainage for 8,000
Purchased 200 m2 of geotextile 150 for drainage and 200 m2 of geotextile 300 for the slab for 13,800
70 meters of drainage pipe 7000
5m3 of crushed stone for filling a drainage pipe - 7500
Drainage wells, covers, various gaskets and transitions for 12725
Drainage pump and hose - 2000
The first layer of ASG - 45 tons - 19500
Filling the rest of the cushion with sand 90 tons - 42000
Buying a tamper - 25,000, after filling I sold it for 20,000. Total I write 5,000
Sewer pipes and fittings – 6780
Eps TechnoNIKOL CARBON ECO SP 12 packs - 32820
PSBs-25 GOST 21 cubic meters or 105 sheets for 44940
Adhesive foam Tytan 5 cans and gun for 2172
Flat slate 8mm - 10 sheets for 4400
Reinforcement 12 - 400 kg, 6 - 600kg, 8 - 100kg for 42560
Knitting wire 20kg – 2037
Hooks 2 pcs – 326
MP water supply pipes - 7880
Mushrooms for fastening L-blocks 10-180 - 500pcs - 2340
Chairs with supports – 750pcs for 3930
Heated floor pipes 4 coils of 200m each - 17824
Various ties 2000pcs approximately 1500
Insulation for pipes - 1000
Manifold for 8 outlets with flow meters, with Eurocones and delivery of TC from MSK - 15100
Rack profile Knauf 50-50 - 19 pieces - 4250
Concrete pump - 13200
Concrete B25 M350 P4 - 19m3 - 89300

The total is 420,884. I’ll add all sorts of little things, screws, lace, delivery, maybe I forgot something. Let it be 430,000 rubles. The total area of the house with a terrace is 146.6 m2, the price is 2,933 RUR/m2. If you don’t count the terrace, then the area is 124 m2, the price is 3,468 RUR/m2

Features of using slab bases

Foundations made of reinforced slabs are usually installed on soft soils. They can consist of 1 or several monolithic elements fastened to each other. Fastening is done using a concrete screed. are built if:

there is a high occurrence of groundwater;
the soil at the construction site is heaving, has a high level of subsidence or mobility;
construction of small one-story buildings is underway.

At the same time, slab foundations not only greatly facilitate the construction process, but also give buildings high strength and durability. At the same time, there are such disadvantages of foundations of this type as high cost, labor intensity, and the need to purchase a large amount of materials. Taking into account the above, the calculation looks like a necessary and justified measure, due to which it will be possible to avoid unnecessary expenditure of financial resources.

How to calculate the thickness for a foundation slab

The final thickness of a monolithic foundation is calculated based on the fundamental parameters:

Values: depth of freezing;
Soil characteristics;
Proximity of underwater arteries.

Basically, the final thickness is calculated by adding 60 cm to the freezing value. In case of instability of the soil cover, a continuous slab is made, but other indicators are taken as a basis.

The values of laying reinforcement pins, mesh indentation and protective layer. For example, the gap for laying the grid is 7 cm, the indent is 5 cm, the size of the pins is 1.2 cm. We calculate the final thickness: 7 + 5x2 + 1.x4 = 218, rounded to 220 mm.

https://youtube.com/watch?v=jqbEw9Ew8YQ

What foundation is best to build for an aerated concrete house?

Before installing a foundation for a house made of aerated concrete, the following factors are taken into account:

Foundation for a house made of aerated concrete

take into account the geology of the site, groundwater level and freezing depth; take into account the need for space under the cellar.

Monolithic slab foundation

A monolithic foundation is installed along the entire perimeter of the building:

suitable for any type of soil;
will qualitatively withstand aerated concrete walls of a 1-2 storey building;
is not afraid of soil and groundwater deformations.

Such a foundation is resistant to temperature changes and does not need to be deepened to the level of freezing of the ground.

Monolithic slab foundation

Monolithic strip frame

Lightweight aerated concrete is suitable for a strip foundation for a house, but before installing it, a high-quality soil analysis is required

Before pouring it is important:

install strong and reliable formwork for the foundation;
pour a cushion of sand and crushed stone and compact it securely;
carry out reinforcement with periodic profile reinforcement.

Monolithic columnar foundation

Construction of a columnar monolithic foundation

Columnar foundation is suitable:

non-heaving and clay soils;
soils that are too plastic require additional strengthening of the foundation;
on slopes they are reinforced with additional supports.

Pile foundation

The pile foundation for aerated concrete is connected with a reinforced concrete grillage on which the walls of aerated concrete blocks will be installed. The advantages of a pile foundation include:

high installation speed;
has high-quality load-bearing capabilities;
used on uneven areas with significant soil freezing depth.

Pile foundation technology

Monolithic design

If the choice is a monolithic slab, pouring the foundation for a house made of aerated concrete includes the following steps:

Preparatory work. The construction site is cleared and leveled, a foundation pit is dug. For a shallow foundation for a house made of aerated concrete, 50-70 cm of soil is removed.
Installation of formwork. It is erected along the entire perimeter of the pit using wood boards and plywood sheets.
Backfilling with sand and crushed stone cushion. It reaches 25-35 cm and each of the materials is compacted as much as possible.
Reinforcement. Before reinforcement, the cushion is waterproofed using rolls of roofing material. The reinforcement is knitted with special wire and placed on stands so that it is inside the concrete base.
Pouring concrete solution.

A profitable alternative is piles and pillars

Many experts consider these types of foundations for an aerated concrete house to be the most suitable. Their distinctive advantages are:

budget;
piles are easy and quick to install;
long service life of the base.

Concrete foundation pillars

Requirements for the foundation slab

In order for the entire structure to be strong and reliable, the slab foundation must meet the following requirements:

Have a high permissible load limit.
Despite the light weight of aerated concrete, the weight of people, furniture, snow layer, roofing, etc. is taken into account when designing. During operation, the owner may decide to increase the load on the foundation by adding an additional floor or attic, which also needs to be taken into account before starting construction.
Be able to withstand the bending forces associated with the reaction of the soil when it freezes. For this purpose, special attention is paid to calculating the optimal slab thickness and the quality of reinforcement of the concrete screed.

Designing according to current standards and using high-quality materials will allow the foundation to have all the necessary performance characteristics.

Necessity of calculation

Foam concrete cracks if the base slab is thin and bends

When planning the construction of a house from aerated blocks, you should take into account the features of this material. It is characterized by low specific gravity, high thermal insulation qualities and smooth edges, which contributes to smooth and neat masonry. However, the blocks are very fragile. If the reinforced concrete slab bends, the foam concrete wall will crack. In addition, you need to remember that the material is hygroscopic and needs external finishing.

The above factors determine the requirements for the foundation for a foam concrete house:

Sufficient strength to withstand vertical pressure from house structures.
Resistance to bending and twisting loads that come from unstable soil.
Low thermal conductivity, if construction of a basement level is not planned. Use of drainage, heat and waterproofing.
Long service life. Houses made of foam concrete are designed to last 60-75 years, the support system must correspond to it.
Stability in space. To do this, the slab is slightly recessed, and for additional stability it is equipped with stiffeners.
Sufficient area. On particularly unstable soils, it is advisable to extend the edges of the slab 100-120 cm beyond the external walls. This helps reduce pressure on the soil and eliminate the risk of subsidence. In addition, the protruding part of the foundation will act as a blind area. This strip of concrete gives the building a finished look, protects it from dirt and water, and can be used as a pedestrian path and parking for small wheeled vehicles.

When designing a slab-type support structure, you should not rely on minimum strength standards. A margin of 5 cm should be provided, which may be required when building up the building with additional levels in the future.

Pile

Recently, the use of . It is similar in design to a columnar structure, but instead of pillars, piles or supports are used. Unlike pillars, piles are narrower, longer and are divided into the following types:

screw;
bored;
driving.

— iron pipes with blades at the bottom for easy entry into the ground. The shallow installation method allows you to screw them in with your own hands; for greater depth you will need to use a special device. The inside of the piles is filled with concrete.

Wells are prepared for bored piles. A reinforcement cage is inserted inside the pipes and concreted. In practice, screw and bored piles are more often used. The tops of the installed piles are combined with a supporting structure, which allows masonry to be carried out. It is unstable to ground movement, so this type can only be used on dense soils.

Pillow is a guarantor of reliability

Compacted sand cushion for a slab foundation
The strength of a slab base is also closely related to a well-equipped cushion. The two layers of which it consists, that is, gravel and sand, work differently.

The top layer is gravel. Due to its characteristics, the material allows moisture to pass through, preventing it from collecting directly under the slab. Thus, water enters the lower layer - sand. Its tasks are to divert water to the underlying layers and evenly distribute pressure, compensating for heaving forces.

After determining the basic requirements for the arrangement of foundations, you can move on to more specific examples of laying foundations for various types of structures.

Structure by layers

This is what the most complete structure of a monolithic slab as the foundation of a house looks like. Source pinterest.ru

The standard full-profile “pie” looks like this:

leveled and compacted “mainland” soil;
separating geomembrane (desirable, but not required);
a cushion made of sand (or two layers - sand and crushed stone)
footing;
waterproofing;
sheet insulation;
base plate.

In Europe and here, a modification of the foundation called the “Swedish slab” has recently become increasingly popular. The peculiarity is that the warm water floor is not laid in the screed, but in the slab itself.

Swedish foundation slab for a private house with heated floorsSource pinterest.com

Types of calculations used in the design of slab foundations.

When designing a foundation slab for a house made of aerated concrete, you must do the following:

determining the thickness of the base is an important value

It will be given special attention in this article; find the mass of the future house, taking into account constant and variable loads - this will be needed in the future for strength calculations; calculating the perimeter of the foundation is necessary to calculate the amount of insulation; determine the surface area, including the lateral one; calculate the required amount of concrete and its mass. The first value is found by multiplying the area of the base by the thickness

Second, the resulting volume is multiplied by the density of the mixture; calculate the mass of the base; find the pressure of the slab on the ground - otherwise this is called the calculation of bearing capacity; calculate the total length of the reinforcement.

Preparation process

Sketch of stage-by-stage work on the foundation slab
When constructing a frame house, the slab should not be too powerful, 30 centimeters is enough. If a house is built from brick, the dimensions of the floor thickness can reach 50-80 cm. A standard cushion of 200 mm thickness is poured under a small house made of aerated concrete and lightweight foam blocks.

Let us consider step by step the work for a heavy structure for a brick house.

The site is leveled and is wider in size than the future building by 1.2-1.5 meters. We cook more widely because of ease of use, as well as to ensure the full floating effect. We remove the top layer of soil to a depth of 40-50 cm, and in this process you can use either small equipment or dig a pit manually. This foundation pad does not require deep excavation.

The sand is compacted to a very dense cushion. The vibratory rammer can be used electric or gasoline (in the absence of an electrical network). For the frame version, tamping passages can be reduced up to 8 times over the entire plane of the intended ceiling.

Stage two is the arrangement of wooden removable formwork for the floor slab. It is made from flat boards 120 mm wide, and is mounted around the entire pre-marked area; its height must correspond to the height of the entire future floor slab. We must not forget about communications; it is better to arrange their laying and insulation in advance.

Stage three - preparation of the reinforced frame. Here the thickness of the overlap is taken into account. In this case, it is recommended to manufacture a spatial frame. Reinforcement with a diameter of 12 mm is suitable. With this installation, the cell is made 300x300mm, tied together with wire. During installation, distances are used so that the ceiling reinforcement does not lie on the sand, but has a gap. A gap of 40 mm will be sufficient.

Stage five - pouring floor slabs under a brick house. In fact, it is no different from pouring a house made of aerated concrete, a frame structure or a house made of foam blocks, except for the obligatory compaction with a vibrating lath or deep concrete vibrator. A house made of foam blocks does not weigh as much as a brick one; compaction is not necessary there.

It is strictly prohibited to lay a structure without a well-compacted sand cushion; it compensates for soil movements during heaving. The use of road slabs is justified in the construction of country houses and dachas, where it is not possible to carry out the construction process all year round. And also during the construction of small frame-type country houses, or from light foam blocks or aerated concrete.

The soil under a slab foundation may freeze if the load-bearing soil is highly mobile or measures have not been taken to insulate concrete abutments and blind areas. The foundation must have good support.

Despite the ease of construction, installation work using road slabs requires skills and preparation; these are still heavy concrete structures. The construction of any facility in which reinforced concrete slabs will be used requires the use of heavy equipment. It is advisable to cast the foundation (slab) yourself, saving the budget allocated for construction.

What data will be required for the calculation?

In addition to the climatological indicators of the region, the hydrogeological structure of the soil and the determination of the material of the foundation walls, to develop the project it is necessary to determine the total weight of the building, the bearing capacity of the soil and the length of the walls.

Determination of building load

The weight load on the strip foundation is determined by a simple formula:

M+P+S+V, where:

M – dead weight of the building, including the weight of all building structures and elements, including the foundation;
P – payload or weight of everything that will be inside the building and create pressure on the floors;
C – maximum possible mass of snow cover in winter and at the beginning of melting;
B – wind pressure on walls and roof.

The resulting calculated result should be multiplied by a factor of 1.2-1.25, providing a 20-25% safety margin for the strip foundation structure.

Bearing capacity or soil resistance

This indicator is given in the regulatory literature and is determined by GOST 25100-95 “Classification of soils”. For the most common soil types it is (in kg/cm2):

loam – 1.5-2.8;
dry dense clay – 1.6-3.0;
fine-grained sand – 2.2-3.4;
medium-grained – 2.5-3.6;
sandy loam – 2.6-3.6;
coarse sand – 3.6-4.6;
gravel, crushed stone, pebbles – 5.1-6.5.

The indicator of resistance to weight loads is also affected by soil moisture, fluidity and porosity, which must be taken into account when preparing calculation data.

Factors influencing foundation depth

Regardless of what type of base you use, the bottom mark of the base of the structure is determined by a set of rules, taking into account the following factors

Regardless of what type of base you use (shallow or shallow, strip or slab, FBS or monolithic), the lower mark of the base of the structure is determined by SP, taking into account the following factors:

Type of soils, their features and characteristics. Complete information about the composition of the soil at the construction site can be obtained after geological surveys. You won’t be able to do these things yourself; you’ll have to turn to specialists. Also, the calculation of the depth of the foundation is influenced by the level at which groundwater flows. You will also receive this data after conducting hydrogeological studies of the area. According to the joint venture, average temperatures in the region should also be taken into account

This is especially important if a shallow or shallow foundation will be used, because the structures may be affected by heaving forces in winter. Availability of a heated basement. Average depth of rock freezing in the region.

Soil type, ground level and heaving forces

If you are making a shallow or buried foundation for a house with your own hands, then you should follow some recommendations

If you are making a shallow or recessed foundation for a house with your own hands from aerated concrete, brick, wall blocks and other materials, then you should adhere to the following recommendations from the joint venture:

When building on rock and coarse rocks, as well as on gravelly, coarse and medium-fraction sand, the distance from the top of the earth to groundwater does not matter in the winter season. In this case, any type of foundation can be used, regardless of what depth of soil freezing the calculation shows. According to the joint venture, shallow foundations and non-buried foundations can be used on such soils.
When constructing foundations from FBS and reinforced concrete on rock made of fine and silty sand, as well as hard sandy loam, the choice of foundation type:

does not depend on the calculated freezing depth if the groundwater is at least 2 m below the calculated freezing mark;
the foundation should be no higher than the freezing point according to calculations, if the groundwater level is no more than 2 m above the freezing mark. Under these conditions, sandy loam can have any consistency.

On sandy loams of plastic and fluid consistency at any groundwater level, a shallow foundation and a non-buried foundation should not be higher than the freezing point of the rock according to calculations.
On hard loams and clays, a shallow slab or strip foundation can be used, provided that the groundwater level is at least 2 m below the freezing point.
On soft-plastic loams and clays, provided that the groundwater level approaches the freezing mark no closer than 2 m, you can use any type of shallow foundation (the classification of shallow foundations is given above) for houses made of aerated concrete, logs and timber. However, in this case, according to the joint venture, for houses made of aerated concrete and other lightweight materials and blocks, measures must be taken to protect the foundation from saturation with surface water.
If a slab or strip foundation made of FBS or monolith is erected with your own hands on fluid and fluid-plastic loams and clays at any groundwater level, according to the calculation, the laying depth should not be higher than the freezing point.
In conditions where a slab or strip foundation made of reinforced concrete or FBS is built on loams and clays with a groundwater level no more than 2 m above the freezing point, the mark for laying the base of the foundation structures is calculated to be no higher than the freezing mark.

Stages of construction of a monolithic foundation step by step

Work begins with an analysis of the condition of the soil and calculation of the thickness of the base itself and the cushion underneath, after which the required amount of building materials is determined. When constructing a monolithic slab, it is recommended to adhere to the following procedure:

1. Site marking and excavation work.

2. Laying geotextile fabric along the bottom and perimeter of the walls of the excavated pit.

3. Placement of drainage outlet. An optional stage, selected when the groundwater level is high. In this case, shallow trenches are dug along the bottom of the pit, covered with the same geotextile, on top of which plastic pipes with holes are laid. After which they are covered with crushed stone and covered with another layer of mesh. The recommended pipe layout is across the future monolithic slab.

4. Organization of the cushion, crushed stone is poured and compacted first (on particularly difficult soils - impregnated with bitumen), after which this operation is repeated with sand, to facilitate the compaction process it is slightly moistened. At this stage, vibration technology is used; achieving the required density without equipment is not easy.

An important nuance: only large fractions of sand are used; if the thickness of the cushion exceeds 10 cm, it is compacted in layers.

5. Laying communications according to a pre-drawn diagram (if necessary). This stage is carried out simultaneously with the previous one; water or sewer pipes are placed on top of a layer of crushed stone

Drilling a monolithic foundation slab after hardening is considered a gross violation of technology; it is important to think through every detail

6. Leveling the bottom of the pit with thin concrete. Another optional, but recommended stage, selected if there is a risk of flooding or soil displacement. The thickness of the poured layer is within 10 cm.

7. Installation of formwork structures, checking markings and level deviations.

8. Flooring of rolled waterproofing with a mandatory release of about 1 m at the edges. Experienced builders use at least two layers, all joints are processed with a soldering iron.

9. Insulation of the future monolithic slab (recommended) - laying extruded polystyrene foam along the bottom and sides of the pit, taking into account the holes for communications. Their thickness is taken into account in advance, before the installation of the formwork begins.

10. Reinforcement - tying iron rods with a minimum cross-section of 12 mm using plastic clamps or wire at intervals of 20 to 30 cm. The mesh is placed in two layers, the bottom one is tied from thicker and stronger reinforcement

At this stage, it is important not to damage the insulation (if any) or waterproofing, so special plastic supports are placed under the rods

11. Pouring concrete. This stage is carried out in one day; if the volume of the foundation is large, it makes sense to order a ready-made solution. It is allowed to independently prepare concrete with a strength grade of at least M300, but the permissible break in the process does not exceed 12 hours. Concrete is poured, leveled and compacted exclusively in layers along the entire perimeter of the monolithic slab. Filling in individual areas leads to the formation of cracks, this factor is another argument in favor of the factory solution. The poured concrete is compacted with deep vibrators, or, in extreme cases, manually, after which its surface is smoothed, leveled with slats and covered with plastic film.

12. Curing of a monolithic foundation - at least 4 weeks, with mandatory surface care (spraying with water) during the first 7-10 days.

13. Removal of formwork, waterproofing of the side walls of the slab, namely, lifting and fastening previously deposited rolled building materials to the walls.

This technology for building a foundation requires significant investment and labor; it is important to understand that all of them will be useless if you choose the wrong slab thickness or depth. Stages such as analysis of soil conditions, calculation of foundation parameters and direct concreting should definitely be entrusted to specialists

This step-by-step instruction is suitable for the construction of a flat monolithic reinforced concrete slab; if it is necessary to lay stiffeners, the process becomes more complicated: special trenches are prepared along the load-bearing walls in increments of at least 3 m. But their exact dimensions and spacing are determined by complex engineering calculations; in private construction, this option is rarely used .

Monolithic slab for a house made of aerated concrete - construction technology

The procedure for constructing a monolithic slab is as follows:

Prepare the site.
Make markings.
Dig a pit.
Form a pillow.
Install the formwork.
Lay waterproofing.
Install insulation.
Assemble the reinforcement grid.
Perform concreting.

When performing each stage of work, you should be guided by the requirements of a previously developed project.

Advantages and disadvantages of a “floating” slab

Schematic representation of a floating slab base

A generally recognized advantage of such a foundation is the possibility of its construction for a two-story building made of brick or blocks. At the same time, the slabs can be installed on different types of soil, including loose and subsidence. However, good strength indicators directly depend on compliance with the norms for laying the “pie” of the base.

But, despite the significant advantages, a floating slab costs the developer much more than, say, a strip base or the use of TISE technology. Most often, a slab base is chosen due to its reliability and the absence of the need to cover the underground areas of the house.

"Pillow" under the base

Do not forget that in addition to such a parameter as the thickness of the strip foundation, it is necessary to calculate the thickness and cushion under it. In this case, everything also depends on the type of soil. If sandy soil, as is known, is not subject to change, then you can be sure of the reliability of the foundation, but on heaving soil everything is much more complicated.

Clay soils, or areas in which groundwater is located close to the surface, are subject to severe heaving in frosts, which also affects the foundation of the building. Also, such soils undergo changes not only in winter, but also in autumn and even in summer. For example, during heavy rains they swell, but during drought they settle, because of this the difference in soil marks can be 10-15 cm.

Of course, with an incorrectly constructed foundation, such significant changes in the soil will not go unnoticed and will most likely lead to the foundation not being able to withstand the load and bursting.

To prevent troubles, the strip foundation is not only laid at a depth below freezing of the soil, but also a sand cushion is placed under it.

Features of aerated concrete as a building material

Aerated concrete is building blocks made by mixing cement, quartz sand, water and chemical gas-forming agents
. Aerated concrete is building blocks made by mixing cement, quartz sand, water and chemical gas-forming substances. As a result of this chemical “neighborhood”, foaming of the components occurs, after which the blocks harden. They are cut into pieces of the required size and hardened in an autoclave. Thus, the aerated block material gains strength and wear-resistant characteristics.

It is a mistake to believe that a house made of aerated blocks may not withstand ground shifts. If you choose the right foundation, then the block building is not afraid of any relief changes. The fact is that gas (foam) blocks have the lowest elastic modulus among all types of concrete available in the construction industry. That is why the strength of the blocks is beyond doubt among both professionals and beginners.

A properly selected foundation will ensure high-quality operation of a reliable block structure. It should be selected based on the following parameters:

The composition of the soil on the site (sand, clay, loam, etc.);
Groundwater level at the construction site;
Relief features of the building site;
Soil freezing depth;
Total number of floors and weight of the finished building;
Desire to have a basement;
Design features of the finished house;
Temporary load on the house (meaning the weight of all the furnishings in the house, including plumbing equipment);
And, of course, the budget allocated for the construction of a house from blocks.

Choosing the type of foundation for the garage

Arrangement of a garage slab base

Garages are classified as lightweight non-residential premises, but it should be borne in mind that additional load will be placed on the floor from the weight of the machine. Therefore, it is necessary to decide on the choice of the most suitable base option. From the experience of constructing such buildings, the following must be taken into account:

Building design. Design features include the number of floors, dimensions, height of the walls and materials that will be used in their construction. This determines what the load on the base surface will be. This also includes the functionality of the future garage. Will it be used to repair the car, that is, will it have special performance characteristics?
Condition of the soil under the garage. Different types of soils also require different design solutions when building the garage itself and, in particular, when laying the foundation.
The level of water occurrence and the level of freezing, and therefore the impact of frost heaving forces.

In addition to the above, the possibility of using the garage for storing food and belongings is also taken into account. Accordingly, it must be equipped with electrical wiring and ventilation. Most of these structures have a basement and an inspection pit. Other features are possible in the form of additional insulation and sewage systems.

Summarizing all the above requirements for a garage foundation, a universal solution arises - a floating monolithic slab. This can be a buried monolithic reinforced concrete slab, or a monolith, on a layer of crushed stone and sand.

The disadvantage of the design is still the same - a significant volume of concrete pouring and significant costs for reinforcing the slab. However, regardless of the rise in cost of the structure, many give their preference to this type of foundation due to its undeniable advantages:

The construction of the slab is possible regardless of the complexity of the soil.
The floating structure prevents the movement of garage elements and prevents damage.
After carrying out the necessary measures for waterproofing and drainage, the structure will always be dry, regardless of the water level.
The slab will serve as a floor that can support the weight of the car. Accordingly, no base is required for arranging the floors. Immediately after laying the slab, you can screed and begin additional finishing.

There is an opportunity to install a heated floor, abandoning traditional radiators. This solution will save on heating the garage. Thanks to its integral design, the slab prevents rodents and insects from entering the room.

Drainage and waterproofing

The main reason for the soil getting wet and losing its load-bearing properties is not groundwater, which lies much deeper than the base of a shallow foundation, but in the perched water. This includes precipitation, seasonal snow melting, as well as water infiltration from nearby bodies of water if their “mirror” is at the same level as the slab. To a lesser extent, but the capillary rise of water in some types of soil also has an effect.

The nature of drainage measures depends on the characteristics of the region and site. If the house is located on a slope, then it is possible to install a cut-off drainage. On flat areas, it is possible to install a comprehensive storm drainage system, including drainage of water from platforms and paths outside the site. But in any case, below the level of the concrete foundation slab, along the perimeter of the blind area, drainage pipes are laid, which are led with a slight slope into a drainage well.

Laying a drainage pipeSource katlavan.ru

Waterproofing is complex. To briefly formulate the essence of the technology, it lies in the fact that the slab is literally wrapped in two layers of rolled insulation. The full list of works looks like this:

After carrying out the zero cycle and backfilling the sand and gravel cushion, two layers of rolled bitumen insulation sheets are laid on the leveled area.
All sheets are laid overlapping, and the top layer relative to the bottom is shifted by a width of half a sheet.
Along the entire perimeter, roll waterproofing should be laid with a margin sufficient to bend the edges towards the end of the slab.
After pouring and curing the concrete, the protruding edges of the waterproofing are glued with bitumen to the end of the base.
Carry out waterproofing work to protect the top and side surfaces of the foundation

Home weight calculator

Allows you to determine the amount of pressure on the foundation from the side of the building and choose the right type of foundation.

Calculations are performed in two stages. At the first stage, the total length of the walls is calculated; this requires a drawing of the plan for the future building.

At the second stage, an assessment of all loads on the base of the structure is carried out.

The calculations take into account a number of factors:

materials for building structural elements made of expanded clay concrete blocks;
roof features;
regional weather conditions;
layout and dimensions of the attic space;
height of the base.

The pressure on the foundation consists of the mass of external walls and internal partitions. The presence of the screed and the type of finish matter.

The best option is to distribute the loads evenly across all fragments of the foam concrete structure. It is recommended to include a reserve when making calculations.

Design advantages

When pouring a monolithic slab, you can immediately install a heated floor system

In addition to being economical, a big plus of this type of base is the large surface area of the slab. Due to this, the pressure on each square centimeter of soil is reduced, which prevents deformation processes and uneven settlement. Other advantages include:

Possibility of installation on different types of soils, including those characterized by increased mobility or high water rise. If you have to build a house on “inconvenient” soils, slabs are an excellent option. However, on a slope it is difficult to make a reliable foundation of this type; here it is better to choose piles.
Excellent insulation ability. If the foundation is made in accordance with the technology, good protection against heat loss is achieved. It also does not allow moisture to pass through.
Durability: A solid slab can last more than a century without signs of deterioration.
Rigid design thanks to a reinforced frame, large dimensions and a structure that does not include suture elements. This makes it suitable for buildings made of brick, aerated concrete and other materials that react negatively even to minimal movements.

The procedure for creating a slab foundation

Let's consider the procedure for constructing a slab foundation made of reinforced concrete. This is a sequence of actions that requires compliance with sequence and technical requirements. Step-by-step instruction:

Preparing the site, removing all plants, foreign objects, buildings.
Marking, digging a pit according to the shape of the slab with a depth of about 70-90 cm. The shape must correspond to the configuration of the slab plus technological tolerance for installing the formwork (0.5 m on each side).
The bottom of the pit is leveled and a layer of crushed stone backfill is made to a thickness of 20 cm. It is compacted, after which a layer of sand 30 cm thick is filled in. Compacted using a vibrating lath (or vibrating foot), controlling the horizontal. The quality criterion is the condition of the surface - when walking in shoes there should be no traces left.
Laying a layer of geotextile in the shape of the slab with a margin for turning after the concrete has hardened. Waterproofing (film materials) is laid on top of it. The canvas is made up of strips laid overlapping (10-15 cm) and connected with a special adhesive tape.
Formwork is assembled around the perimeter of the slab. For it, edged boards with a thickness of 25-30 mm are used. As an option, plywood or metal panels are used.
Assemble the reinforcement frame. This is a two-layer spatial lattice made of corrugated reinforcement rod with a diameter of 12-14 mm. For knitting, soft annealed steel wire 1-1.2 mm is used.
The concrete slab is poured. The procedure must be performed without stopping, with parallel pinning of the layer to remove air bubbles.
The raw slab is covered with a polyethylene awning. Water daily to equalize humidity (the first 2 weeks - twice a day, then until the end of the aging period - once). Stripping can be done after 2 weeks, further work can begin after 28 days.
Laying a layer of thermal insulation on the surface of the slab (the best option is a layer of foundation foam). A heated floor system is installed on top of it and poured into a concrete screed. This will be the subfloor on which the flooring is laid.

The procedure for the construction of UFP - an insulated Finnish slab - is outlined. Other types of slab foundations require changes in technology in accordance with the characteristics and layer-by-layer composition of the slab.

What kind of reinforcement are the frames knitted with?

The type and size of the rods, the intensity of the reinforcement, must be determined by calculation. The layout of the reinforcement can be different, which, for example, in a slab affects the thickness of the concrete. On average, frames for the foundations of private houses are mounted from steel rods with a diameter of 10-16 mm, or composite rods 8-14 mm. The most commonly used steel reinforcement is A400 (for binding only) or A500C (can be welded). The lower class A240 is used in the form of smooth rods for the transverse connection of working reinforcement.

In slabs, strips and grillages, it is located horizontally and works in bending, thereby compensating for the insufficient susceptibility of the concrete itself to this load. The smallest diameter of the rods can only be in such a foundation, the length of one side of which does not exceed 3 m. These are more often outbuildings than houses - in other cases, the diameter of the working reinforcement starts from 12 mm.

In piles and pillars, the working rods are placed vertically, so they absorb mainly compressive loads. The default minimum diameter of working fittings here is also 12 mm, in quantities of at least 4 pieces. 8 mm cross bars are installed at 300 mm intervals from each other.

Solid foundation

If construction is not your main specialty, it is very difficult to make correct calculations and take into account all the nuances, so calculations should be performed long before the start of construction work.

Very often you can find the consequences of improperly laying the foundation for a house, which appear after the first winter and the most common reason is the owner of the house saving money on the construction of the foundation.

For example, a strip foundation erected to a depth of 60 cm with a soil freezing depth of 110 cm, with a two-story building made of timber, will lead to the fact that the foundation simply will not withstand the load and will crack.

Next, the owner will have to take measures to strengthen the foundation and additional reinforcing rings along the entire belt. Therefore, the most important stage in construction is geological surveys, which allow one to study the properties of the soil and determine the depth of freezing. A shallow foundation will also mean that the basement will constantly freeze, so that subsequently you will have to do additional insulation of the lower floor.

Having determined the properties of the soils located on your site, you can easily calculate what the thickness of the foundation should be in this area. And do not forget that when installing a strip-type foundation, it is necessary that the foundation is at least 30 cm above ground level.

And in no case do not save on money, even if you are very unlucky with the soil and preliminary calculations have shown that you will have to build a monolithic foundation. A solid foundation is, first of all, a high indicator of the safety of the entire house, and therefore it must meet all requirements. In addition, repairing the foundation, on the construction of which you tried to save money, may cost you the cost of the constructed foundation.

Ribbon part of the structure

It is not so difficult to build a strip foundation for a house made of aerated concrete with your own hands. You just need to purchase the basic material and tools, and also know how to calculate the thickness of the foundation and learn the rules for laying it. You need to start equipping a strip foundation for a one-story house by digging a pit.

It should be located along the perimeter of the building and under its internal load-bearing walls. It will be necessary to construct a monolithic slab of reinforced concrete, which will make the house stable. In order for the foundation for a 1- or 2-story aerated concrete house to properly cope with its main function, the builder should take care in advance to eliminate soil heaving. This problem can be solved by arranging a cushion in non-freezing layers of soil.

How much money will you need to spend on building a foundation for a two-story house?

To calculate the estimated price for the entire base, it is possible to take average statistical data from several construction services:

Diagram of shallow foundation parameters.

a fragment of a strip base 1 m long, 30 cm wide and 2 m deep costs approximately 6000-7000 rubles;
a fragment of a strip base 1 m long, 40 cm wide and 1 m deep costs approximately 3000-4000 rubles;
if there is a fragment of a shallow shallow foundation with a monolithic base 1 m long, a slab 20 cm deep and 80 m wide, a contour 50 cm high and 40 cm wide, you will need to spend approximately 5,000 rubles;
a fragment of a columnar base 1 m long, contour height 1 m and width 40 cm + 1 column 2 m deep and 15 cm radius will cost approximately 7000-8000 rubles;
1m? a fragment of an ordinary monolithic foundation 20 cm deep will cost approximately 8,000-10,000 rubles.

Prices are based on the provision of services by construction services under normal construction conditions.

The amount of money for laying the foundation of a private two-story house by such services may previously be increased if the construction site is inaccessible and excessively remote, if the groundwater is shallow, if the local terrain is of increased complexity, as well as when equipping a basement or raising the base.

Video description

All stages of work are clearly shown in the video:

In conclusion. Whatever they write about the possibility of constructing a monolithic slab foundation with your own hands, its construction technology requires, even for a small house, a significant amount of concreting with a continuous pouring cycle. And with a foundation thickness of 25 cm and a modest house size of 10x10 m, this is 25 m3 of concrete. And this does not take into account the concrete layer. Plus you need:

carry out a zero cycle;
make drainage;
bring, level and compact at least 30 m3 of sand and crushed stone for the cushion;
properly waterproof the slab;
install formwork;
connect two meshes of the reinforcing frame.

Only a team of professionals can carry out such a house foundation project with high quality. Source loghouse.msk.ru