Strip foundations are often used in low-rise construction - they are easy to make, and they are universal, suitable for all types of buildings and almost all soils. Let's look at the strip foundation for a house from all sides: what it should be like according to construction science and standards, and how this theory is embodied by the hands of FORUMHOUSE users.
Design features Shallow strip foundation MZLF Fully buried strip foundation Tape: calculation algorithm How to build a strip foundation with your own hands Example: MZLF 11*14 m Example: foundation made of FBS 10x10 To help the strip builder
How to calculate the cubic capacity of the foundation for a house.
How to calculate the cubic capacity of the foundation? – the algebra and geometry of the school course will help here. Basically, the volume of the concrete mixture is calculated based on the cubic capacity of the internal capacity of the formwork, which is determined at the design stage either from the drawings, or even more precisely from the data taken from the finished structure.
How to calculate the volume of foundation mortar.
The simplest solution is to use a special calculator program into which you enter the expected length, width, height and thickness of the foundation walls. The result is the exact volume of the required solution and recommendations are given for its preparation from sand, cement and crushed stone.
How to calculate the volume of foundation formwork calculator.
The foundation is the basis of the entire supporting structure. The technical and operational qualities of the structure depend on the correctness of the calculations made and its laying. Therefore, the stage of calculating construction costs and drawing up appropriate estimates is very important.
Properly calculated cubic capacity is an opportunity to avoid unnecessary cash costs for building materials and not to disrupt the technology of the pouring process.
Concrete is measured by its volume, not its mass, due to the difference in weight values for 1 cubic meter of mixture of different brands. In the presence of complex foundation geometry, the calculation process is facilitated by breaking the structure into its simpler components.
How to calculate the volume of the foundation.
To calculate the cubic capacity for different types of foundations, different methods are used.
What to pay attention to when laying a foundation
In some cases, the cost of installing a foundation reaches a third of the cost of the entire construction, so the desire of some developers to save money results in dire consequences. There are also errors due to the inexperience and carelessness of performers. Let us briefly list what should not be allowed when laying the foundation:
1. Inconsistency of the foundation structure with the type of soil at the building site. Strip foundations, in particular, are installed on stable, dry soils. On waterlogged soils, pile or slab structures are preferred. If there is no design solution, specialists should recommend the type of foundation.
Wall cracks due to foundation settlement
2. Incorrect arrangement of the sole under the strip foundation. Often the sole is arranged carelessly, because unscrupulous builders do not consider it necessary to carefully carry out work, the results of which are difficult to control. As a result, the distribution of the load on the sole turns out to be uneven, the foundation “creeps” - cracks appear in it, and then in the constructed building.
3. Incorrect installation of formwork and, as a result, insufficient outer layer of concrete to guarantee the closure of the reinforcement cage, corrosion of the reinforcement. Unreliable fastening of the formwork.
4. Lack of calculation of the concrete cube. This calculation needs to be done when pouring yourself. Since the components of concrete have different properties, a cube of concrete should be calculated in order to accurately determine the volume of materials for constructing the foundation.
5. Inaccurate adherence to the geometry of the structure. Uneven corners in rooms are not the biggest nuisance, which can be a consequence of irregularities in shape. The consequence of such an error may be, for example, a lack of slab length for the floor installation.
6. The lack of reinforcement or “savings” on diameters and quantities threatens that the foundation will not withstand the load.
7. Incorrect bandaging (or lack thereof) of foundation blocks when constructing prefabricated types of foundations.
The importance of soil composition.
For high-quality arrangement of the base, it is necessary to determine the type of soil under the structure being built. Sandy soils can sag, so the foundation is laid to a depth of 4-8 dm.
Clay-type soils can freeze, so the trench for foundation construction is dug to its entire depth. The depth of pouring the base also depends on the level of freezing of the substrate, which is influenced by the geographical location.
Calculate how many cubes of concrete are needed for the foundation.
If the depth of the foundation arrangement depends on the soil composition and the location of groundwater, and the length will depend on the size of the structure, then the width will depend on the thickness of the walls being built - from 20 to 40 cm. Therefore, calculating the base cube is not difficult, it is only important to determine its type.
Laying depth
The depth indicator is directly dependent on the following factors:
- ground water level;
- depth of soil freezing (data by region is presented below);
- condition of soils, their heaving, subsidence, etc.;
- height of the building being constructed;
- design features (for example, the planned basement will significantly deepen the foundation );
- the presence of underground communications, buildings and structures in the immediate vicinity.
Monolithic slab.
This is a monolith, which is a rectangular parallelepiped, the faces of which are calculated using an already constructed formwork structure or according to drawings. The slab is located under the entire area of the building.
Its pressure on the ground is minimal while withstanding significant load-bearing loads. The volume of this structure is calculated by multiplying the area of the base base and the height of the formwork structure.
How to calculate the volume of the foundation in m3.
The area of the sole is calculated by multiplying the width and length of the grillage.
For example, to calculate the cube of a base with grillage parameters of 10×12 m and a slab height of 0.4 m, you need to multiply all the values and get 48 cubic meters as a result. m (10×12x0.4=48 m3). For accuracy, the cubic capacity of the reinforcement layer is calculated from this result.
Ground Load Calculation
The next step in the calculations is to determine the load on the ground. To understand whether the soil can support the building, it is necessary to calculate the weight of the foundation of the house .
To do this, we calculate the volume of the base using mathematical formulas and multiply it by the density of concrete (average densities of different types of concrete can be found in the table below).
Then we will carry out simple calculations using the formula:
(VF+VD)/Ppf, where VF is the weight of the foundation, VD is the weight of the house, Ppf is the area of the base.
Thus, we have determined
how many kilograms of load should be carried by 1 cm2 of soil .
Now it is important to correlate the required soil load with the permissible values indicated in the table.
If the load obtained during the calculations is greater than the calculated resistance of a given soil type, it is necessary to increase the supporting area of the house, namely:
- The tape can be made expanded towards the base ( the cross section looks like a trapezoid ).
- Increase the width of the parallelepiped foundation.
- For a columnar base, you can increase the diameter of the pillars or their number .
Important! As the size of the base increases, the structure of the house will become heavier. Therefore, be sure to re-calculate the load on the ground!
Strip foundation.
This is a similar rectangular parallelepiped, hollow from the inside, with the possible placement of supporting elements for interior wall panels inside it.
How to calculate the volume of the foundation of a house.
For low-rise construction, strip foundations are popular due to their high load-bearing capacity, small dimensions and simple installation. How to calculate the cubic capacity of the foundation in this case?
To do this, the difference is calculated, where the volume of the parallelepiped from the outer formwork walls acts as the minuend, and the volume of the parallelepiped from the inner walls acts as the subtracted one.
Next, the volume of internal tapes intended to support interior partitions is added to the total. The transverse and internal ones represent 1 parallelepiped, and the longitudinal ones go beyond 2 parallelepipeds.
Calculate the volume of concrete for pouring the strip foundation.
For example, with a base volume of 10×12 m with a tape base width of 0.4 m and a depth of 2 m, with an additional 1st inner tape, 0.5 m in thickness:
- The external parallelepiped will be 10x12x2=240 m3;
- Internal – (10-0.4-0.4)x(12-0.4-0.4)x2=206.08 m3;
- The volume of the strip base under the supporting structures is 240–206.08 = 33.92 m3;
- Internal tape base (10-0.4-0.4)x0.5x2=9.2 m3;
- The required filling cube is 33.92+9.2=43.12 m3.
For an example of foundation calculations, watch the video:
Carrying out cubic capacity calculations depending on the type of foundation
From the school algebra course, the volume of any body can be calculated by finding the product of its height, length and width. However, calculating the cubic capacity of common types of house foundations predetermines taking into account their individual characteristics.
Calculating the volume of a monolith
This type of base has the shape of a rectangular parallelepiped, the edges of which can be found by comparing with a sketch at the planning stage or by actually measuring the erected formwork.
When measuring the height of the formwork, it is worth considering that the required level of concrete is marked on it, and it is erected with a margin of 10-15 cm.
Watch the video in which an expert explains how to correctly calculate a monolithic slab.
The volume of the presented base is calculated by the general formula: H x A x B, where H is height, A is length, B is width. For clarity, it is worth giving an example. So, with a foundation depth of 0.8 m, a length of 10 m and a width of 10 m, the cubic capacity of the required concrete is 0.8 x 10 x 10 = 80 m3.
Belt volume calculation
Calculating the cubic capacity of the strip foundation of a house also comes down to calculating the volume of a rectangular parallelepiped minus the internal hollow areas. Despite its apparent complexity, this indicator is easy to calculate in practice.
To make the calculation, it is necessary to calculate the volumes of the external and internal parallelepiped from the drawn drawing, find their difference, and then add the cubic capacity of the internal strip elements to the result obtained.
We recommend watching a video about calculating a monolithic base tape.
So, with foundation dimensions of 12 x 15 m and a tape width of 0.5 m, deepened into the soil by 1.5 m, with an internal additional tape 0.6 m wide, the cubic capacity of the base is calculated as follows:
- We set the cubic capacity of the external parallelepiped: 12 x 15 x 1.5 = 270 m3.
- We determine a similar indicator for the internal figure: (12 - 0.5 - 0.5) x (15 - 0.5 - 0.5) x 1.5 = 231 m3.
- We find the difference between the obtained values: 270 – 231 = 39 m3.
- We calculate the cubic capacity of the inner tape: (12 - 0.5 - 0.5) x 0.6 x 1.5 = 9.9 m3.
- The final volume of pouring the strip foundation: 39 + 9.9 = 48.8 m3.
Calculating the volume of a columnar foundation
The volume of columnar type bases is calculated as the sum of the volumes of two geometric bodies - parallelepipeds of the column and its base, multiplied by the total number of supporting elements.
In digital terms, to calculate a columnar foundation for a structure 8x8 m with a total number of pillars with 2 m pitch in 16 copies (4 corner and 12 auxiliary), the soles of which have dimensions of 0.6 x 0.6 x 0.3 m, and the body pillar supports 0.4 x 0.4 x 1, calculated according to the following principle:
- The final volume of the sole: 16 x 0.6 x 0.6 x 0.3 = 1.73 m3.
- The final cubic capacity of the pillar supports: 16 x 0.4 x 0.4 x 1 = 2.56 m3.
- The final volume of concrete required: 1.73 + 2.56 = 4.29 m3.
Watch the video on how to correctly calculate a columnar foundation with your own hands.
Calculation of the volume of a bored foundation with a solid grillage part
The total cubic capacity of the presented type of house foundation is established as the sum of the volumes of bored pillar supports (cylinders) and a monolithic slab of the grillage part (classical parallelepiped). Just as when calculating the cubic capacity of the bases presented above, to calculate the total volume of concrete you will need to divide the figure into its component elements, determine the volume of each of them and sum the resulting values.
In this case, it must be remembered that the volume of a column or any cylindrical building element is calculated as the product of the base area and the height. In this case, the area of the sole is determined by the formula:
where π is a mathematical constant (3.1415...), D is the diameter of the circle (sole).
For clarity, let us give an example: the total volume of the base on 20 supports with a diameter of 0.5 m and a depth in the soil of 2 m, supporting a grillage part with dimensions of 10 x 15 x 0.5 m, is established according to the following principle:
Cubic capacity of pillars: 20 x (3.14 x 0.5 x 0.5 / 4) = 7.85 m3.
- Cubic capacity of the grillage part: 10 x 15 x 0.5 = 75 m3.
- Total volume: 7.85 + 75 = 82.85 m3.
Base on stilts.
Pile foundation is an oriented group of supports that are buried in the ground. A simple and economical basis. When erecting it using the drilling method, concrete is poured into pre-drilled round holes.
In this case, the cubic capacity is the sum of two geometric figures. The first figure is the sole, in the form of a wide and low parallelepiped. The second figure is a pillar, in the form of a tall and narrow parallelepiped.
Calculation of the pile foundation.
This value is multiplied by the number of pillar supports in the base, which are located along the perimeter every 2 m.
For example, for a building 6×6 m with the number of pillar supports 20 (4 in the corners and 16 intermediate), the base of which is 0.5×0.5×0.2 m, and the pillar supports 0.3×0.3×0, 8 m, the base volume will be 20 × 0.5 × 0.5 × 0.2 = 1 m3. For pillar supports this value is 20×0.3×0.3×0.8=1.44 m3. Accordingly, the cubic capacity of the fill is 1+1.44=2.44 m3.
For an example of calculating a pile-tape foundation, look at the video:
Calculation of materials for wall construction
The price of construction is largely determined by the cost of the materials used, and that is why it is so important to know in advance how much of something will be used to construct the walls. As a rule, walls are not cast entirely from concrete, but a monolithic frame is made in the form of columns in the corners and horizontal crossbars
Wall blocks, bricks or other masonry materials are placed in the cavity of the frame
As a rule, walls are not cast entirely from concrete, but a monolithic frame is made in the form of columns at the corners and horizontal crossbars. Wall blocks, bricks or other masonry materials are placed in the cavity of the frame.
In order to calculate the volume of the frame, you need to draw a diagram of the structure as a whole and break it down into individual columns and crossbars. Now we have to calculate the volume for each individual element, which will be much easier. To do this, calculate the cross-sectional area of the columns and crossbars and multiply them by the height.
Bored base with a monolithic grillage.
The volume of the base in this case is the sum of the cubic capacity of the supporting elements and the grillage slab. A complex structure is divided into numerous simple figures, for which the volume is calculated separately.
The volume of the supporting elements is the product of the area of its base and the height from the base to the lower edge of the monolithic grillage. And the area of the round base is ¼ of the product of twice the diameter and the number π (3.14).
How to calculate the volume of the foundation in m3 calculator.
Example for 20 supports with a cross section of 0.4 m, recessed by 2.5 m and a grillage element 10x12x0.3 m:
The volume of supports is made as 20x(¼x 3.14x0.4x0.4)x2.5=6.28 m3;
The cubic capacity of the grillage element is 10×12x0.3=36 m3; In total there will be 36+6.28=42.28 m3.
Construction of the base is a complex and multi-stage process. The full process of calculating consumable building materials involves many nuances that an experienced engineer can do.
How to calculate the volume of a house foundation in m3.
Here are simplified foundation calculation models to help the homeowner who must adequately spend his money on the construction processes.
The role of the foundation in construction
The stability and strength of any house depends on the reliability of the foundation. Its role in the construction of any building is great. The cost of installing the foundation can reach 20% of the entire construction budget. Moreover, any mistakes made at the initial stage cannot be corrected. If an incorrectly made roof or walls can still be somehow redone, then the foundation of a building is almost impossible to correct. Therefore, when designing a house, you need to pay special attention to the laying of the foundation, its type and materials.
Construction of the foundation is one of the most important and critical stages of building a structure.
How is the cubic capacity of the foundation calculated?
Calculate the cubic capacity of the house foundation.
Calculation of foundation cubic capacity (table).
Almost any existing foundation requires a competent calculation of the amount of concrete, reinforcement, wood for formwork, and other materials required for its construction.
But, without a competent calculation of the cubic capacity of the future foundation, it is practically impossible to predict the costs of constructing a foundation, especially since there are a large number of different types of foundations.
Accordingly, you have to remember the school mathematics course, look up formulas for the volume of structures, and only then sum everything up, multiply and divide.
But in any case, it is impossible to do without a detailed calculation of the cubic capacity of the future foundation, because it is this value that already leads to the calculation of the amount of cement, sand, reinforcement and other materials.
Measure seven times - cut once!
We recommend checking everything several times before proceeding with the actual construction of the foundation. Not only the future of the structure, but also its reliability and operational safety depends on this. Economic factors also play a significant role, including the cost of building materials. In one of the following articles you will learn how to calculate the volume of a concrete mixture and be able to estimate the total cost of the foundation. I would like to believe that the information provided was useful to you!
Monolithic slab base.
How to calculate the volume of a house foundation in m3 calculator.
Determining the volume of materials on a slab base.
A monolithic base is a large rectangular slab immersed to a specific depth in the soil.
This means that calculating the volume of the slab will take a minimum of time, because using ready-made drawings of load-bearing walls you can calculate the length, width and thickness of the structure.
For example: the length of the foundation is 12 meters, width 7 meters, thickness 0.6 meters. As a result, the volume of the slab will be as follows: 12*7*0.6=50.4 m3.
But this volume does not entirely correspond to reality, because any monolithic slab has a reinforcing mesh. You can also calculate the total volume of all the rods and trim and subtract it from the total volume of the foundation.
But in private construction no one makes such detailed calculations, because the total volume of reinforcement is rarely more than 1 cubic meter.
Base load calculation
When starting to calculate the foundation for a house, first calculate the load that it will support .
To do this, calculate the surface area of all walls, floors and roofs, multiply the area of each structure by its specific gravity, which can be taken from the table below.
Do not forget also that furniture, household appliances, things and, of course, people will later be added to the weight of the house . All this also needs to be taken into account when calculating the load on the base, so it’s better to consider it with a margin.
Strip foundation made of blocks or stone.
Calculate the volume of the foundation pit.
Ready trench for strip foundation
The calculation of a strip structure resembles a monolithic one, only there are a number of features. To begin with, there is always less concrete mortar used here, because the strip base has load-bearing side and intermediate edges, and the inner surface is empty. So, what quantities are needed to accurately calculate the strip structure:
- The length of all load-bearing walls and intermediate load-bearing partitions;
- The width of the foundation pit, taking into account the thickness of the walls and the allowance for formwork;
- Foundation depth;
- Type of base: monolithic concrete or prefabricated with blocks, natural or artificial rubble stone.
In the simplest calculation, you can simply calculate the total volume of the finished parallelepiped according to the principle of a monolithic structure and subtract the volume of voids from it.
Thus, a typical calculation of a strip structure with overall dimensions of 10x12 meters, a strip width of 0.4 meters and a depth of 2 meters, as well as one longitudinal strip for an interior partition with a thickness of 0.5 meters, can be calculated in the following way:
- Solid parallelepiped taking into account voids: 10 x 12 x 2 = 240 m 3.
- Empty sections inside the structure: (10-0.4-0.4)*(12-0.4-0.4)*2 = 206.08 m3.
- The difference in volumes that will go to all external and internal walls is: 240-206.08 = 33.92 m3. You immediately need to round this value to a larger whole number, because there is also the thickness of the space for the formwork.
- Interior tape (10-0.4-0.4)*0.5*2 = 9.2 m3.
- Total. The total cubic capacity of the strip foundation with the given parameters is 33.92 + 9.2 = 43.12 m 3 (44.0 m 3).
Features of choice
If heaving soil is on the surface, then it can be partially replaced with sand.
Other types of soils, sandy, clay, peat, loam, to one degree or another, have the property of heaving. Therefore, when carrying out work on laying the foundation, regardless of whether it is with or without a basement, we pay attention to the following factors:
- At what depth does the heaving type of soil lie? If it is located on the surface and throughout the entire depth of the test wells, then you can replace some part, for example, with sand and begin laying the strip base. Or immediately equip a pile foundation.
- Study the level of groundwater. The higher they go, the fewer types of foundations are suitable for laying. If the water passes at a depth of one meter, then it is better to choose a slab foundation. Arranging a basement is out of the question. If it’s lower, then you can opt for a shallow strip foundation.
- Soil freezing level. If the heaving soil lies to the depth of soil freezing, it should be replaced. Otherwise, a buried strip base or foundation using piles is installed. In some cases, you can choose a shallow slab foundation.
When making calculations, it is necessary to take into account all three factors simultaneously.
Columnar foundation.
Calculate the volume of concrete for the foundation calculator.
Working formulas for calculating the volume of foundations, in particular columnar ones
Columnar bases are considered one of the simplest and most convenient to calculate, because they are the sum of two geometric figures - parallelepipeds of the column and the base.
The resulting volume is multiplied by the number of pillars installed under the grillage at intervals of 2 meters.
If we take a more practical calculation, then for a structure measuring 6*6 meters you need to use 20 pillars with base dimensions of 0.5*0.5*0.2 meters and a columnar part of 0.3*0.3*0.8 meters.
As a result of simple calculations, the following parameters of the columnar structure can be obtained:
- Base: 20×0.5×0.5×0.2 = 1 m3.
- Columns: 20*0.3*0.3*0.8 =1.44 m3.
- Total volume of the columnar foundation: 1 + 1.44 = 2.44 m 3.
Calculation of the foundation for a private home
Let's figure out how to calculate the cubic capacity of a foundation - a concrete structure with a minimum thickness. The formula used is:
V = A×B×C, where the final value is volume, and the rest are length, width and height. Thus, obtaining the cubic capacity of this type of foundation is simple and quick, you just need to know the initial data.
This foundation structure is considered the most durable and stable, because there are no joints on it that somewhat violate the integrity.
For example, a building has an area of 10 × 10 meters and the structure will use 20 supports with a square cross-section. The location of the pillars will be as follows:
- 4 in the corners,
- 16 on the remaining area around the perimeter of the facility.
The concrete pillar has a cross-section of 300 × 300 mm and a height of 2 meters, the base has a cross-section of 500 × 500 mm and a thickness of 20 centimeters. The cubic capacity of the base of the concrete pillars is 20 × 0.5 × 0.5 × 0.2 = 1. And the volume of the supports: 20 × 0.3 × 0.3 × 2 = 3.6. And if you add up the calculation results, it turns out that 4.6 cubic meters of foundation are required for this construction project. For round posts the formula is used:
V = π × r2 × h, where the height of the support and its diameter are involved. When the volume of one pillar with a circular cross-section is determined, you need to multiply by the number of supports.
Pile-grillage and screw foundation.
How to calculate the volume of cement for the foundation.
Scheme of a piled concrete foundation.
The total cubic capacity of such foundations is the summation of the volumes of the pillars and slabs of the grillage.
In other words, this is a combined version of calculating a strip foundation and a columnar one.
Only here the cubic capacity of the pillar cylinder is taken into account in the calculation.
Attention, if factory bored piles or screw metal structures are used, then only the tape part of the grillage is calculated, and the parameters of the pillars are not used.
They can only be used when calculating the required amount of excavation work.
Formula for calculations
The required amount of concrete must correspond to the formwork parameters. Therefore, in order to calculate the cubic capacity of concrete for driving the foundation, it is necessary to know the geometric dimensions of the form. Armed with a tape measure, we measure the already set form and rely on the necessary parameters:
- width;
- height;
- length.
As many years of construction practice show, relying on ready-made formwork in calculations, you can get more accurate calculations than being guided by dry numbers of working drawings. In addition, by taking repeated measurements, you can identify errors in the installation of the foundation mold and eliminate them in a timely manner.
In the case of simple figures, the calculation formula is as follows:
When performing calculations, the values should be brought into a unified calculation system - cm, m. For concrete, the parameter most often used is m 3, less often liters. When converting units of measurement between values, the following proportion is used: 1 m 3 of concrete = 1000 liters. In this case, the density of the composition does not affect the quantitative indicators. The mixture, compacted, for example, by vibration, in its cubic capacity corresponds to the displacement, like concreting materials made using conventional technologies.
In the case of constructing a foundation of a complex configuration, the object is conditionally divided into simple figures - parallelepipeds or other simple elements (circles, cylinders, etc.). Calculations are made for each element separately, and the resulting values are summed up.
Types of concrete structures.
How to calculate the volume of concrete for a foundation.
The foundation is the basis of any structure. Based on this, it is necessary to ensure that it is sufficiently reliable and durable.
From the very beginning you need to decide on the type of foundation. It depends:
- on the massiveness and area of the building;
- building materials from which it will be built;
- type of soil on the site;
- climatic conditions;
- soil freezing level;
- availability of groundwater.
Only after this can you calculate the volume of the foundation yourself. At the moment, there are three most common types of concrete foundations: strip (monolithic). slab, as well as from concrete pillars.
Note! During computational work, all necessary parameters should be carefully measured. Even a small inaccuracy can have a very sad effect on the outcome of your efforts.
Slab
A slab foundation is a continuous monolithic foundation under a building site. For its construction, concrete of a grade not lower than M100 is used. Calculating the volume of this monolith is quite simple - just multiply the length, width and height of the slab.
Pouring a solution of cement and sand with the addition of large fractions for a monolithic slab is carried out to a height of at least 100 mm. Thus, for a slab with a thickness of 100 mm, the following volumes of concrete are obtained:
- for a house 10x8 – 8 m3;
- for a 9x9 house – 8.1 m3;
- for a house 18x8 - 14.4 m3.
This calculation is suitable for completely flat slabs, but to give the base higher strength characteristics, additional stiffeners are often installed in the form of trapezoidal longitudinal beams. Therefore, the correct calculation of a slab foundation must also include the volume of pouring stiffeners.
How to count cubes of concrete for a foundation? Online calculators will help you perform these calculations for free, you can refer to special tables, or it’s not difficult to calculate the required volume of concrete yourself.
To the already obtained volume of the slab, it is necessary to add the volume of the stiffeners, for which the formula for the area of a trapezoid is used. The volume of a slab foundation with stiffeners is found as follows:
- Calculate the volume of your slab: V=h*b*l .
- Find the area of the trapezoid: S=h1*(a+c)/2 , where h1 is the height of the edge of the trapezoid, and and c are the lengths of the bases of the trapezoid.
- Find the volume of the stiffener and multiply by the number of ribs: V1=S*l*n , where n is the number of stiffeners.
- The resulting volumes are added up and the total volume of required concrete is obtained: Vtot = V + V1 .
Typically, reinforcement is located at the bottom of the base in increments of 3000 mm. They can be made as exclusively longitudinal reinforcements, or with intersections, forming squares. Typically, the ratio of the wide part of the trapezoid of the stiffener is 1.5:1. To calculate a slab foundation, volume adjustments are also provided with an error factor of 2%.
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Special programs for calculations.
Calculate the volume of concrete for the foundation calculator.
The photo shows a program for calculating the foundation.
Most construction sites provide a special service - a calculator for calculating the cubic capacity of the foundation. This program greatly facilitates the design of the building base. It will help you calculate the required amount of concrete solution, as well as reinforcement and formwork for arranging the structure.
Depending on the difficulty level of the program, you will be able to find out the following.
- Base area. This is necessary to determine the required amount of waterproofing for the finished foundation.
- Volume of concrete solution. as well as a sand and gravel cushion for the structure.
- The total amount of reinforcement for the frame. its weight based on diameter and length.
- The area of the required formwork. as well as the amount of timber in pieces and cubic meters.
- The cost of all building materials for the future foundation of the house.
- Advanced programs also provide a drawing of the proposed design.
If you use such a calculator, you will not worry about how to calculate the cubic capacity of the foundation. Such services are very simple and intuitive.
The need for accurate calculations
The photo shows large-scale concreting in industrial construction
Why is it so important to correctly know the volume of the required solution, because if there is not enough material, more can be made? In fact, maximum strength and durability of monolithic structures is ensured only if the solution is supplied to the formwork for concrete products without long downtimes. You can avoid downtime that can lead to delamination of concrete by knowing the exact amount of mixture that will be required for certain construction work
You can avoid downtime that can lead to delamination of concrete by knowing the exact amount of mixture that will be required for certain construction work.
Current calculation formulas
In the photo - an installation for preparing mortars in limited quantities
At the moment, there are many ways to carry out calculations, for example, you can use a concrete volume calculator. But an online calculator may not be available at the most crucial moment, and therefore we will consider those formulas that can be implemented in practice at any time and under any circumstances.
It is no secret that there are several types of foundations laid to varying depths before the start of the main construction work. Depending on the configuration of these structures, their size and, as a result, the volume of solution that is required varies.
Formula for columnar bases
In the photo - formwork for a columnar (pile) foundation
So, how to calculate the volume of concrete? To do this, you need to measure the height of the structure, find out the area and multiply these indicators. But the approach to calculations in accordance with the formula V=S*H is relevant only for simple structures, while a different approach will be required to calculate the volume in relation to complex structures.
The calculation method for columnar foundations with round piles is as follows:
- We calculate the area of the base of each pillar, we do this using the formula S = 3.14*r², where r is the radius of each individual pile;
- Next, we multiply the area parameters by the estimated height of the pile and get the volume;
- Then we multiply the resulting volume by the number of piles that will be used according to the project.
Calculations for slab-type foundations
In the photo - slab base formwork
Now let's look at how to calculate the volume in m3 of concrete for a slab foundation.
The instructions in this case are simple, since such a base is a solid structure.
- First, we divide the planned perimeter of the foundation into rectangles. This must be done if the shape of the base is complex. If the configuration is simple and is a rectangle or square, we find out the area by multiplying the length by the width.
- Next, we determine the depth of the bookmark and multiply this number by the resulting area.
Calculation of the volume of material for a strip foundation
In the photo - strip base formwork
A strip concrete foundation is by far the most popular type of foundation, as it is characterized by sufficient strength and durability. In addition, by choosing this type of base, you can save mortar, since it will not be poured along the entire perimeter of the object, but only under load-bearing walls and partitions.
Calculating the volume of concrete in this case is not complicated and is performed as follows:
- We measure the expected width and total length of the tape. We multiply the resulting parameters and obtain the area of the base.
- Then we determine how deep the foundation will be, and multiply this number by the area and get the nominal volume of mortar that is necessary for pouring into the formwork.
How do you make your own calculations?
Calculate the volume of the strip foundation.
For calculations, you need to know the dimensions of the foundation.
If for some reason you cannot use the described online service, you will have to carry out all the calculations on your own.
The cubic capacity of the slab base.
This foundation is the simplest option for calculations. To produce them, it will be enough to multiply the length of the slab by its width and thickness.
- For example, these parameters are 10, 10 and 0.4 meters.
- Therefore, the volume of concrete required: 10 × 10 × 0.4 = 40 cubic meters.
- Note! However, often, in order to increase the strength of the foundation, its slab is equipped with stiffeners. If the foundation design is exactly like this, to calculate the amount of material needed, you need to separately calculate the volume of the ribs and slab, then add up the results.
We already know the figure regarding the slab. Let's calculate the cubic capacity of the reinforcing elements.
- Let our foundation have four of them. Suppose the length of the edge is 10 m, height 0.25 m, width 0.3 m. This means the volume of one element is: 10 × 0.25 × 0.3 = 0.75 cubic meters.
- Total value for all ribs: 0.75×4= 3 cubic meters.
- Now we just have to add the numbers to get the amount of mortar needed for the foundation: 40+3=43 cubic meters.
Calculate the volume of the foundation calculator.
Computer calculation program.
Initially, it is necessary to determine the cross-section of such a foundation. When it is equal, everything is simple. It is necessary to multiply the perimeter of this structure by its width and thickness. Below are calculation instructions.
Let's take as an example the same structure with sides of 10x10 meters. Let the width of the base be 0.4 m and the thickness 0.7 m.
- Its perimeter is: 10×4=40 meters.
- We multiply the values and get 40 × 0.4 × 0.7 = 11.2 cubic meters. But this is only the volume of the base for the external walls.
Note! The cross-section of the foundation strip for external walls and partitions, as a rule, is not the same. The walls are much lighter and thinner, so there is no need to build sections of the base for them that have the same width as for the outer walls.
- Let the house have two partitions, one 10 m long, and one perpendicular to it - 5 m. Their width will be 0.3 m, the thickness will be the same - 0.7 m.
- Cubic capacity of the first section: 10×0.3×0.7= 2.1.
- Parameters of the second wall: 5×0.3×0.7=1.05.
- We add up all the values and get the final volume of concrete required for the strip base: 11.2 + 2.1 + 1.05 = 14.35 cubic meters.
Construction of houses
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Before starting the construction of any building, it is necessary to correctly calculate the foundation. You can make the calculation with the help of specialists or yourself, and save a little. Having made the correct calculation of the foundation, your house will stand securely on the ground. Let's consider the main points, such as calculation of the load, the volume of the foundation pit and recommendations that should be taken into account to create the correct design for the foundation of a house.
Table of contents:
- Foundation types
- Strip foundation
- Columnar foundation
- Tile foundation
- Pile foundation
- Calculating the weight of a house structure
- Calculate the foundation area and weight
- Calculate the amount of concrete needed for the foundation
- Strip foundation
- Columnar foundation
- Tile foundation
- Calculation of the required amount of reinforcement and wire
- Strip foundation. Quantity of reinforcement and binding wire
- Columnar foundation. Quantity of reinforcement and binding wire
- Tile foundation. Quantity of reinforcement and binding wire
- How much will it cost to reinforce the foundation of a private house?
- How much will the foundation of a house cost?
Foundation types
The foundation must be strong and reliable. There are several types of foundation, each of which is suitable for different types of structures and soil.
Strip foundation
This type of foundation is a strip buried in the ground that takes the entire load of the house structure. The base of the tape itself is the foundation slabs. Suitable for private houses of various sizes with more than two floors. Also, the inner area of the foundation can be used as a basement. The house itself can be built from bricks, blocks, reinforced concrete. This type of foundation is very often used due to its simplicity, durability and ability to support heavy structures.
Columnar foundation
It is a structure of pillars immersed to a certain depth and connected by beams. It is used for small 1-2 storey houses built from light materials, for example, timber or log house. This type of foundation is applicable on soil that is not subject to temperature changes. In addition, such a foundation is much cheaper than a strip foundation.
Tile foundation
This is a monolithic reinforced concrete slab laid in deep soil. The soil is leveled using concrete, sand or gravel. By using this foundation, the load of the structure will be evenly distributed over the entire surface of the foundation. Suitable for use on unfavorable soils; also used for heavy structures with two or more floors. The only drawback is the very high cost compared to other types of foundation.
Pile foundation
This is a structure consisting of a group of piles connected to each other by a reinforced concrete slab or beam. This foundation is used for weak soil that cannot withstand heavy loads; they are also used for large multi-story buildings. Installing such a foundation requires a large amount of equipment. The cost of such a foundation for a house will be very high.
Calculating the weight of a house structure
In order to calculate the foundation for a house, it is necessary to calculate the load that it will experience. The average weight of the main house structures is presented in this table.
Using the data presented in these tables, you can calculate the approximate weight of the structure.
Let's use this data as an example:
You are going to build a house that is 1 story high, 5 x 8, plus an interior wall, and the height from floor to ceiling will be 3 meters. Let's substitute the data and calculate the length of the walls: 5+8=13 meters, then add the length of the inner wall: 13+5=18 meters. As a result, we get the length of all the walls, after which we calculate the area by multiplying the length by the height: S=18*3=54 m.
Next, we calculate the area of the basement floor by multiplying the length and width of the house: S=5*8=40 m. The attic floor will have the same area.
In order to calculate the roof area, you need to multiply the length of the sheet by the width, for example, a sheet of roofing will have a length of 6 meters and a width of 2 meters, which means the area of one sheet will be 12 m, and in total we will need 4 sheets on each side . The total is 8 sheets of roofing covering with an area of 12. The total area of the roofing covering will be 8*12=96 m.
To calculate the area of the front part of the roof, you need to refer to the formula for finding the area of a triangle: S=1/2*a*h, where A is the width, H is the height from the corner to the opposite point. For example, the height of the roof will be 3 meters and the width 5, which means the area of the front part of the roof is 15 m on each side.
Having received all this data from the table, you can calculate the approximate load on the foundation. It is best to take the maximum weight so that the calculation can be made with a margin.
Calculate the foundation area and weight
An important factor is the soil itself, since it may not withstand high loads. To do this, you need to calculate the total weight of the building, including the foundation.
Let's look at the process of calculating the approximate weight of the foundation using an example.
You are going to build a brick house and have chosen a strip foundation for it. The foundation will be deepened into the ground below the freezing depth, approximately 1.5 meters and plus add 50 centimeters above ground level, in total the foundation will have a height of 2 meters. Next, we calculate the length of the entire tape, that is, the perimeter: P= (a+b)*2=(5+8)*2=26 m, then we add the length of the internal wall, it is 5 meters, as a result we get the total length of the foundation 31 m Then we calculate the volume, for this we need to multiply the width of the foundation by the length and height, let the width be 50 cm, which means 0.5 cm * 31 m * 2 m = 31 m2. Reinforced concrete has an area of 2400 kg/m3 (see table), having all this data you can find the weight of the foundation structure: 31m3*2400 kg/m=74 tons 400 kilograms. And its supporting area will be 3100*50=15500 cm2.
Then you should add the weight of the foundation to the weight of the house and divide by the supporting area, as a result you will get a load of kilograms per 1 cm2.
This table shows acceptable values for various soil types. If, according to your calculations, the permissible load exceeds these types of soils, you can change the dimensions of the foundation in order to increase the supporting area. For example, if you have chosen a strip foundation, then you can increase its supporting area by increasing the width. If you have a columnar foundation, you can increase the size of the column or their number. But remember, this will increase the total weight of the house, so be sure to re-calculate.
Calculate the amount of concrete needed for the foundation
Before starting construction, it is necessary to draw up a project for the foundation of a private house, according to which you can calculate the required number of building materials for the construction of the structure. In our case, we need to calculate the required amount of concrete to create a foundation. The data for calculating the amount of concrete is the type of foundation and some parameters. Let's look at the calculation system using an example.
Strip foundation
The volume of a strip foundation is much easier to calculate than others; for this we need data such as total length, height and width. The width depends on the area of the support, which we calculated at the beginning, but on average the width of such a foundation is 40 centimeters. The height is also taken from previous calculations; let’s take a value of 1.5 meters. The total length of the tape is calculated as the perimeter. For a house measuring 5 by 8 meters and having one wall 5 meters long, the perimeter will be 5+(8+5)*2=45 meters. With a tape width of 50 centimeters, the amount of concrete will be equal to 0.5 * 45 * 1.5 = 33.75 m3.
Columnar foundation
To calculate the required amount of concrete, you need to know the cross-sectional area and height of the pillar. Let's remember the formula for finding the cross section of a circle, S=3.14*R2, where R is the radius of the circle. This means that the cross-section of a column with a diameter of 15 centimeters will be 3.14 m2 * 0.075 m2 = 0.2355 m2. If such a pillar has a height of 1.5 meters, then its volume will be equal to 0.2355 * 1.5 = 0.353 m3. You can then easily calculate the total number of posts for your structure.
Tile foundation
A slab foundation is a monolithic structure poured under the entire area of the house. To perform the calculation, you need initial data, that is, area and thickness. Our house measures 5 by 8 and its area will be 40 m2. The recommended minimum thickness is 10-15 centimeters, based on this, to fill the foundation we will need 40 * 10 = 400 m3 of concrete.
Also, for greater structural strength, additional stiffening ribs are added over the entire surface area of the foundation. That is, square-shaped recesses are made at the lower level, which will provide additional support. To calculate the amount of concrete required for the stiffeners, you need to know their total length and area. For example, in a house measuring 5 by 8, ribs are poured every 2.5 meters, and two of them will be located at the edges. The number of ribs in width will be 3, and in length 4. The length of one stiffening rib in length will be 8 meters, and in width 5 meters, as a result, the total length will be (5*3)+(8*4)=47 meters.
The width and height of the stiffener is usually equal to the height of the main slab. Accordingly, with a height of the main slab of 10 centimeters, the depth and width of the stiffener will be 10 centimeters, it follows that the cross-section of a 10-centimeter rib will be 0.1 m * 0.1 = 0, 01 meters, then multiply the result 0.01 meters2 by the entire length of the rib 47 meters, we get a volume of 0.41 m3.
Calculation of the required amount of reinforcement and wire
To create a more reliable, durable and strong foundation, reinforcement is used. To calculate the required amount of reinforcement, the type of foundation, soil and load are taken into account. The larger the diameter of the reinforcement, the greater the permissible load for the foundation. When choosing, you need to take into account the type of soil and the weight of the structure. If the soil is dense enough, then under the influence of the weight of the house its deformation will be small, then too much stability will not be required from the foundation. Also, the amount of reinforcement depends on the weight of the house; the larger it is, the more load the foundation must withstand.
Strip foundation. Quantity of reinforcement and binding wire.
This type of foundation does not require too thick reinforcement (10-12 mm), since the strip foundation has a high load-bearing capacity. It uses only two reinforcement chords, regardless of height. The longitudinal reinforcement bars will experience the main load and are laid 5-10 centimeters from the concrete surface. Vertical and transverse bars will not experience loads, so smooth reinforcement is used for them.
For a house 5 by 8 plus one internal wall, the total length of the foundation will be 45 meters. To perform longitudinal reinforcement with 4 rods, the approximate consumption will be 45 m * 4 = 180 meters. The amount of reinforcement for connecting one level with a width of 50 cm and a height of 1.5 m and a pitch of 40 cm will be equal in length: (8 / 0.4) * 0.5 = 10 m, with 3 levels of connection 10 * 3=30, and two walls will need 60 meters in length. In width: (5 /0.4) * 0.5 = 6.25, with three levels 6.25 * 3 = 18.75, and in total for two walls in width you will need 37.5 m. The total consumption of smooth reinforcement for the entire area of the foundation will be 37, 5 m+60 m=97.5 meters. Plus the length of the foundation for the internal walls is added.
The amount of binding wire with a total foundation length of 45 m and a step of 40 cm for one connection will be equal to 30 cm, and the total amount (45 m / 0.4 m) * 3 (number of levels) = 338, multiplied by the wire size 338 *0.3=102 meters of binding wire.
Columnar foundation. Quantity of reinforcement and binding wire.
Since the pillar will not experience too much load, ribbed reinforcement with a diameter of a centimeter is suitable for its vertical reinforcement. The horizontal reinforcement will not experience any loads; it will only serve to connect the vertical ones, so smooth reinforcement with a thickness of 0.6 is suitable for it. The number of rods and their thickness in the frame depends on the diameter of the post, on average about 4.
For example, with a column height of 1.5 meters and a diameter of 15 cm, 4 rods with a frequency of 7.5 cm and a bundle in 3 places will be sufficient. The total amount of ribbed reinforcement with a thickness of 1 cm will be 1.5 m*4=6 m. The required amount of smooth reinforcement for one connection will be 7.5 cm*4=30 cm, and the total quantity will be 30 cm*3=90 cm. Let's say the foundation contains 20 pillars, which will require 20*6 m=120 meters of ribbed reinforcement and 90 cm*20=18 meters of smooth reinforcement.
Calculating the amount of tie wire is very simple. The number of connections, that is, 3 horizontal rods, is multiplied by the number of vertical ones and the number of wires for one connection: 3 * 4 * 30 cm = 3.6 meters, and the total number is 3.6 * 20 = 72 meters.
Tile foundation. Quantity of reinforcement and binding wire.
The amount of reinforcement depends on the soil and the weight of the house. If your structure stands on stable ground and is not very heavy, then thin reinforcement with a diameter of 1 centimeter is suitable for it. If, on the contrary, your structure is heavy and has poor soil, then thicker reinforcement from 14 mm will suit you. The reinforcement cage pitch is at least 20 centimeters, depending on the above parameters.
For example, the foundation of a private house is 8 meters long and 5 meters wide. With a step frequency of 30 centimeters, we will need 27 rods in length and 17 in width. Also, the minimum number of reinforcement belts is 2, so the required number of rods is (30+27)*2=114. This number is then multiplied by the length of one rod.
Afterwards, a connection is made - in the places of the upper reinforcement mesh with the lower one, at the intersection of the longitudinal and transverse rods. The total number of connections will be equal to 27 * 17 = 459. If the thickness of the slab is 20 centimeters and the distance of the frame from the surface is 5 centimeters, then for one connection you will need a reinforcement rod with a length of 20 cm-10 cm (5 + 5 below and above) = 10 cm, and with the total number of such connections, the result will be 459 * 0.1 m = 45.9 meters of reinforcement. As a result, all the values are added up and you get the length of all the reinforcement, after which, using the table below, you can calculate the approximate weight of the structure.
To calculate the amount of binding wire, you need to calculate the number of intersections of the horizontal rods. According to the calculation above, there will be 459 connections at the lower level and the same number at the upper level, for a total of 918 connections. To tie one such place you will need a wire bent in half, the total length for one connection will be 30 centimeters, which means 918 m * 0.3 m = 275.4 meters.
How much will it cost to reinforce the foundation of a private house?
Having received the required number of meters of reinforcement and wire, knowing the thickness, using the table above, you can calculate the approximate weight of the structure. Next, to calculate the cost, we find out the price for 1 kg of reinforcement and wire. Since prices in different regions can vary significantly, to calculate the cost, you can find it out at metal rolling shops in your city.
How much will the foundation of a house cost?
Having made all the necessary calculations and found out the number of required cubes of concrete and the price of the metal structure, you can calculate your costs and find out the total cost of the foundation of a private house. Prices for one cube of concrete are confirmed with sellers. Also, don't forget to take into account preparatory work such as excavation of the soil for the foundation, delivery of materials, labor and creation of formwork (consisting of boards that will need to be purchased).
Calculator for making calculations
In order to correctly and conveniently calculate the dimensions of the base area and cubic area, an online calculator is used. Its use eliminates the need to contact specialists and saves money. All calculations are performed in accordance with SNiP and GOSTB standards .
How to calculate the required values using a calculator:
- determine the linear dimensions that will be required for calculations - the length of the building, its width, the height of the foundation and the width of its section in meters;
- choose the type of foundation;
- enter data;
- make calculations.
Based on the results obtained by calculation on the calculator, we will obtain the following data:
- the total length of the base of the building - its perimeter;
- the area of the base supported by the ground is equal to the linear parameters of the required waterproofing;
- cubic base area or volume of material required to lay the foundation;
- average mass of concrete;
- load experienced by the support area.
When making calculations, you can also use drawings of the future structure - this way you can more clearly outline the details and appearance of the foundation for the correctness of calculations and the strength of the planned building.
Correct calculation of the cubic area of the foundation helps to find out how much material is needed to lay the foundation of a building, and knowledge of its supporting area allows us to take into account those parameters, the observance of which guarantees the stability of the house and the length of its service life.
How to determine the amount of reinforcement and wire
Installation of the foundation necessarily requires the presence of reinforcement in it. Concrete itself has high compressive strength. At the same time, it is weak when stretched. The soil under the foundation swells, which leads to cracking of the concrete and weakening of the foundation structure. That is why it is so important that it has a reinforcing belt, including longitudinal and transverse rods. The connection of vertical and horizontal rods occurs using a knitting wire. Approximately 40 cm of such wire is consumed per connection. Having calculated the amount of reinforcement for the foundation, the number of connections and wire consumption are calculated.
The amount of reinforcement depends on the type of foundation, soil, and the dimensions of the building itself. There are special construction requirements - SNiP 52-01-2003. With their help, the reinforcement class and cross-section are selected and its quantity is calculated.
You should read separately about how to calculate the reinforced belt for each type of foundation. Each type of foundation is characterized by its own characteristics and requirements.
The main cause of cracks and destruction of the walls of a house is uneven settlement of the foundation
Quantity of reinforcement for strip base
In a strip foundation, the most vulnerable to rupture is the longitudinal side of the base, so special attention is paid to the longitudinal reinforcement.
For strip foundations, three methods of longitudinal reinforcement are used:
- reinforcement with four rods;
- reinforcement with six rods;
- reinforcement with eight rods.
The number of rods depends on the heaving of the soil, the width and depth of the foundation strip. The minimum thickness of the longitudinal rod is 10-15 mm, and the transverse rod - from 6 mm. It is optimal to make the pitch of the reinforcement grid no more than 15 cm.
