Subtlety calculation of the foundation plate

Modern houses are elevated on different foundations. The choice directly depends on the loads, the relief of the selected area, the structure and composition of the soil itself and, of course, climatic conditions. This article reveals complete information about the slab foundation, intelligibly answers the question of how to make a complete calculation, which will help build the right foundation.


The tiled type of foundation consists of the base of the construction, which is flat or with ribbed ribs, reinforced concrete slabs. The design of this foundation is several types: team or monolithic.

The prefabricated foundation is called laid out ready-made plates made at the factory. Plates laid construction equipment on pre-prepared, i.e. aligned and compacted, base. Aerodrome plates (PAG) or road plates (PD, PD) can be used here. Such technology has a big drawback. It is connected with the missing integrity, and, as a result, with the corresponding impossibility of resistance, even the smallest movement of the soil. It is for this reason that the collection type of the slab foundation is mainly used only on surfaces from rock soil or on non-empty large-grade soils for the construction of small wood buildings in areas where the minimum drainage depth.

But the monolithic slab foundation is one whole rigid reinforced concrete construction, which is being built under the area of ​​the structure.

By geometrical form, this type of foundation is several species.

  • Simple. When the bottom side of the foundation tile is flat and smooth.
  • Reinforced. When the bottom side has rigidity ribs that are located in the calculated procedure calculated by special calculations.
  • Ushp. So called the warmed type of Swedish plates, which relate to the variety of foundation plates of the reinforced species. During construction, a unique technology is used: the concrete mixture is poured into a separately developed factory type of non-removable formwork, which allows for further forming on an elastic basis, or rather, in its lower part and on the surface the grid of the burned and small rigidity. Also, the UCP has a heating system.

This article tells about the simplest monolithic slab foundation.

Advantages and cons, selection criteria

First dignity – practically perfect versatility. Sometimes in the network you can meet articles in which it is said that the foundation tile can be built everywhere.

Even if construction work is carried out on a swampy terrain, nothing terrible with tiles will not happen: in the period of strong cold, it will rise, and in the hot period, on the contrary, it will fall, so to speak, swim.

It turns out a kind of “concrete ship”, which has a superstructure from the whole house.

And yet, the following remark will be fair: the only foundation that allows you to produce a fairly reliable construction on landing and rapidly suitable soils, including a wetland type of soil, – pile foundation. This type of foundation is used when piles are enough of its own length for fastening in the lowest bearing ground layers.

Frosty type of transition, including drawdown, during the thawing either sidewalks due to moisturizing the soil surface (for example, during the lifting of groundwater), occur under the surface of the entire tile equally cannot. In any case, only one of the sides will shift more. Simple example, it can be a spring outdation of the soil surface. The exhausting process will proceed much faster and with greater intensity on the south side of the house, rather than in Northern. Meanwhile, the tile will be exposed to huge loads, which, by the way, it does not always withstand. All this will affect the structure: the house just can touch. Will not be so scary if this building is wooden. And if it was erected from bricks or blocks, cracks on the walls may appear.

The slab foundation allows you to build at home even on the most complex soils, which include the mid-circuit type of soil, which has the smallest carrier ability, rather than, for example, belt ground. But it is not necessary to overestimate this feature.

Does the slab foundation use during the construction of large buildings? Some argue that on the monolithic plate you can only build the easiest and with it not enough durable buildings. This statement is not quite correct, since when choosing a favorable conditions and a true designed foundation with competent construction work, a slab foundation is able to withstand even the metropolitan Central Committee. By the way, the building is just built on the stove.

Too high price. This opinion for some reason is distributed. Almost everyone is confident that the slab type of foundation is very expensive, more expensive than the existing types of foundations. Also, for some reason, the majority believes that the cost will be about half of the existing costs for all subsequent construction work.

In this case, no one has ever done any comparative analysis. For some reason, many do not take into account that during the construction of the house, for example, the floors do not have to. Of course, it is said here about the rough floor surface.

The complexity of the work itself. Often this statement is heard: “For the construction of a baseline basement, you will need the experience of qualified workers”. And yet, if you estimate, it becomes clear that such “masters” strongly overestimate the rates for their work. In fact, only ignorance technology usually leads to errors, and it is possible to ventive with any other foundation.

So with what difficulties can be encountered while working with a slab foundation? When aligning the site? No, everything is also no more difficult here, rather than when moving a runt of a broken belt foundation. Maybe difficulty with waterproofing or with insulation? Here, rather, it is better to perform these operations on an even horizontal surface, rather than on vertical planes.

Maybe it’s in a viscix of the reinforcement frame? Again, you need to compare and understand what is easier, for example, you can take the reinforcement, unfolded on the site level, or climb the ribbon foundation with its arms with its formwork. Maybe the case in the fill of the concrete mix? In this embodiment, it does not depend on the selected foundation, but rather, from the characteristics of a separate section, on whether the mixer can drive up to the construction site or have to interfere with the concrete manually.

In fact, build the foundation plates – physically difficult task. Due to a fairly large construction area, this work can be called a tedious, but it does not say that the help of qualified builders will need. Therefore, with the case, ordinary “hand” men will be able to cope with. In addition, if we properly follow the technology of construction and a snip of a columnar, slab and other foundation – everything will be able to.


Each zero cycle will require a calculation, which is primarily in determining the thickness of the slab itself. This choice cannot be done approximately, since such a non-professional solution to the issue will lead to a weak base that can crack in frost. Too massive base of deep downstream does not make not spend unreasonable money.

To independently build houses, you can use the calculation below. And let these calculations are not equal to the engineering, which are carried out in design organizations, whether these calculations will help in implementing the quality of the foundation.

Explore the sad

It is necessary to explore the soil located on the selected building.

For further calculations, it will be necessary to select a certain thickness for the foundation plate with an appropriate mass. This will help get the best specific pressure on the existing type of soil. With exceeding loads, the structure usually begins to “drown”, with minimal – light frosty dust of the soil surface rolls the foundation. All this will cause the corresponding not too pleasant consequences.

The optimal specific pressure for the soil surface, on which construction is usually started:

  • Small sand either dusty type of high density sand – 0.35 kg / cm³;
  • Small sand with an average density – 0.25 kg / cm³;
  • Sacks in solid and plastic form – 0.5 kg / cm³;
  • Plastic and solid loams – 0.35 kg / cm³;
  • Plastic grade clay – 0.25 kg / cm³;
  • Clay solid – 0.5 kg / cm³.

Total weight / weight of the house

Based on the developed project of the future building, you can determine which house will be a total weight / weight.

Approximate value of the specific mass of each structural element:

  • Brick wall with a 120 mm thick, that is, in the Pollipich, – up to 250 kg / m²;
  • Wall from aerated concrete or 300mm foam concrete blocks of the D600 – 180 kg / m² brand;
  • Wall of logs (diameter 240 mm) – 135 kg / m²;
  • 150 mm timber wall – 120 kg / m²;
  • 150 mm frame wall (insulation required) – 50 kg / m²;
  • An attic of wooden beams with mandatory insulation, the density of reaching 200 kg / m³, – 150 kg / m²;
  • Concrete hollow plate – 350 kg / m²;
  • Inter-storey or base of wooden beams, insulated, density reaches 200 kg / m³ – 100 kg / m²;

  • Monolithic overlap from reinforced concrete – 500 kg / m²;
  • Operational load for overlapping inter-storey and basement – 210 kg / m²;
  • With the roof made of steel sheet, professional flooring or metal tile, – 30 kg / m²;
  • Operational load for the church overlap – 105 kg / m²;
  • With a two-layer roof from the frontieroid – 40 kg / m²;
  • With the roof of ceramic tiles – 80 kg / m²;
  • with slate – 50 kg / m²;
  • Snow type load applied to the middle lane of the Russian territory – 100 kg / m²;
  • Snow type load for the northern regions – 190 kg / m²;
  • Snow load type for southern part – 50 kg / m².

Expecting Plate Square

The area of ​​the entire plate need to count on, relying on the engineering project. The weight of the structure should be divided into the area to obtain an indicator of the specific load acting on the ground surface. By the way, the result obtained does not take into account the foundation mass. Further to compare the resulting digit with an optimal focused load, then you can count the difference, that is, to find out how much does not reach the optimal value of the specific pressure. The resulting difference must be multiplied by the Plate itself to obtain as a result of the required mass of the foundation.

Further resulting result of the mass of the foundation plate is divided into a density of reinforced concrete 2500 kg / m³. In this way will receive the required volume of the foundation plate. This volume should be divided into the value of the area of ​​this slab to get its thickness.

The resulting thickness must be rounded to the nearest largest or, on the contrary, the smallest value that is multiple of 5 centimeters. According to the already rounded values, it is necessary to reconnect the weight of the foundation, folding the number with a mass of the building to determine the calculated specific pressure acting on the ground surface. Next, you should compare the result with the optimal. It is important to remember that this difference cannot exceed ± 25%.

Specific type of total weight of the construction affects the concrete below. Stripping from this, you need to determine the optimal brand of concrete, which will be used for infusion, with the condition that the strength of the concrete coating will be preserved on compression, that is, to calculate to join. Mostly the choice is between M300, M200 and M250 brands.

In fact, such calculations are considered simple. Here you will need only knowledge acquired in school in the lessons of mathematics.

How to build and calculate the monolithic foundation, see the following video.

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