The foundation is a very important and expensive element of a building. The durability and strength of a house or outbuilding depends on how correctly it is built (poured), and given that, depending on the specific conditions, the cost of a strip foundation can range from 30 to 70 percent of the construction cost, it is very important to correctly calculate how much concrete will be needed for its construction.
In this case, the following factors influence the design of the strip foundation:
- Relief of the land plot for construction of the structure;
- Soil type;
- Soil freezing depth. Affects the amount of foundation heaving;
- Height of standing groundwater. It also affects the amount of foundation heaving (linear movement in winter).
The calculations use the usual mathematical and geometric formulas that are taught as part of the high school curriculum.
How to calculate how much concrete is needed for a strip foundation
Strip foundations are widely used by private developers in the construction of low-rise residential buildings, bathhouses, garages, sheds, temporary buildings and other similar buildings. The popularity of strip foundations lies in the simplicity of the design and the possibility of independent calculation and construction.
To calculate the amount of concrete needed to pour the foundation, you will need to calculate the volume of the foundation in cubic meters. In this regard, two options are possible. The first option is that the length, width and height of the structure are the same along the entire perimeter of the “ribbon”. The second option is that the height and width of the foundation are variable.
You can calculate how many cubes of concrete are needed for the foundation according to the first option as follows.
For example, by measuring the length of the foundation “ribbon” (perimeter), width and height, you received the following initial data:
- Foundation perimeter (L): 40 meters. Important! The perimeter is measured not along the external or internal border, but strictly along the center of the foundation trench;
- Height(H) 1.5 meters;
- Width(S) 0.7 meters.
We substitute the initial data into the formula for the volume of the parallelepiped V=LxHxS: V=40x1.5x0.7=42 m3. To pour a strip foundation you will need 42 cubic meters of concrete.
An example of calculating concrete for a strip foundation
Let's say your foundation with a total length of 40 meters consists of two parts that differ in width: 10 meters of tape 0.7 meters wide and 30 meters of tape 0.5 meters wide. In this case, we use the same formula for the volume of a parallelepiped, only we make two calculations: for a “piece” of 10 meters (V1) and a “piece” of 30 meters (v2). Then we sum up the resulting volumes and get the volume of concrete to be poured (V)
- V1=10x1.5x0.7=10.5 m3;
- V2=30x1.5x0.5=22.5 m3;
- V=10.5+22.5=33 cubic meters of concrete.
How much cement will be needed?
To mix concrete for pouring a strip foundation, you need to know how many components are required: cement, sand, crushed stone and water. In general, M200 grade concrete is used for the construction of strip foundations. According to GOST, concrete M200 is mixed in the following proportions of components:
- Cement – 1 part:
- Sand – 2.8 parts;
- Crushed stone – 4.4 parts;
- Water – 20% of the total volume.
Assuming that: 1 m3 of concrete weighs about 1,500 kg, 1 m3 of Portland cement weighs approximately 1,300 kg, 1 m3 of crushed stone 1,450 kg, 1 m3 of sand weighs 1,700 kg, to prepare 1 cubic meter of M200 grade concrete you will need: 255 kg of cement, 1,127 kg of crushed stone, 714 kg of sand and approximately 190 liters of water.
In order to avoid overuse of materials and downtime due to shortages during the construction stage, it is important to calculate the cubic capacity of the foundation in advance. Having understood the general principle of the technique, it will not be difficult to perform this work with any base configuration.
General provisions
For calculations, it is enough to use formulas from a school mathematics course and some techniques that simplify calculations in order to quickly obtain the necessary data. Calculations can be carried out using the calculated data available in the design documentation for the future structure or using the finished formwork. The second method is more accurate.
When using reinforced concrete, some part of the volume will be occupied by metal structures. The calculation can be carried out in a similar way, the error will be insignificant.
To simplify calculations, foundations of complex geometry are divided into simpler constituent figures, and their volume is represented as the sum of the volumes of these simple figures.
With complex foundation geometry, you can apply the geometric trapezoidal rule: measure the width of the base at the bottom and at the surface. The arithmetic mean between them is used in further calculations.
Slab foundation
Using calculators
Instead of “manual” calculations, many people use special calculator programs. After entering the basic parameters of the future foundation, the program produces detailed results, including not only the cubic capacity of concrete, but also the recommended parameters of the foundation, as well as other necessary data. This method is optimal in the absence of preliminary engineering calculations.
Calculation of slab foundation
The calculations will be somewhat more complicated if there are stiffeners. Such amplifiers can have a rectangular or trapezoidal cross-section and are also calculated according to the parallelepiped rule (LxWxH), and in the second case the above-mentioned trapezoidal rule is applied.
Calculation example
If, based on the results of measuring the installed formwork, the length, width and height of the base are determined to be 10, 5 and 0.15 m, respectively, then the volume (or cubic capacity) of the foundation will be 10x5x0.15 = 7.5 cubic meters. m.
Let us assume that such a slab has four stiffeners - two longitudinal and two transverse, respectively, with volumes of 0.12 and 0.15 cubic meters. m. In this case, the volume of stiffeners is added to the volume of the foundation parallelepiped. The final result will look like the sum of 7.5 + 2x0.12 + 2x0.15 = 8.04 cubic meters. m.
Depending on the configuration of the base, the stiffeners can be the same or different (longitudinal and transverse) in size.
Slab foundation with stiffeners.
Calculation of strip foundation
The area of a strip foundation can be calculated as the difference between the areas of rectangles (or more complex shapes) calculated along the outer and inner contours. To make it clearer: the strip foundation plan consists of two figures identical in shape, but differing in size, one inside the other. The difference between the areas will become the required area of the base. To calculate the cubic capacity of concrete, it remains to multiply the resulting area of the tape by its height.
When calculating a strip foundation, it is important to remember that to the calculated cubic capacity of the main strip it is necessary to add the volume of concrete for the foundations of internal load-bearing structures, if any are provided for in the project.
Calculation example
Tape width – 0.4 m,
The sides of the outer rectangle formed by the strip foundation are 6 and 7 m.
The total length of the tape is 2x6+2x7= 26 m.
Sectional area 0.4x0.8=0.32 sq. m.
The cubic capacity of the strip base is 26x0.32 = 8.32 cubic meters. m.
Strip foundation
Pile foundation calculation
A pile foundation is a complex of cylindrical supports, the volume of each of which is calculated as the product of the area of the base-circle (PI multiplied by the square of the radius) and the height. PI=3.14. Having calculated the volume of one support, the total cubic capacity of concrete is calculated by multiplying the resulting volume by the design number of piles.
Calculation example
If the diameter of each support is 20 cm, then its radius in meters is 0.1.
Sectional area S=0.0628 sq. m.
If the height of the pillar is 2 m, the volume of each support will be 2x0.0628 = 0.1256 cubic meters. m.
It remains to multiply the volume of one support by the number of piles.
Pile foundation.
Calculation of a bored foundation with a monolithic grillage
This type of foundation can be considered the most complex from a geometric point of view. However, when the structure is broken down into simpler figures, the calculation becomes as simple as the techniques used in other cases. The grillage slab is a parallelepiped and a complex of cylindrical columns. Examples of calculations of cylinders and parallelepipeds are described above.
Rice. 5. Bored foundation with a monolithic grillage.
Bored foundation with a monolithic grillage.
Calculation of material requirements
After calculating the cubic capacity, another important task is set - to calculate the consumption of concrete. Theoretically, the need for the materials that make up the mortar may differ. The calculation is influenced by the grade of concrete and the nuances of the object (type of soil, load on the base from walls, roof, etc.). That is why many people prefer to use calculator programs, which, as a rule, produce complete calculations. In practice, universal concrete is suitable for almost any private housing construction project (residential, commercial, fence, etc.), the preparation of which requires the following materials:
By multiplying these numbers by the total cubic capacity of the foundation, we obtain the required amount of materials for construction.
In order to avoid overuse of materials and downtime due to shortages during the construction stage, it is important to calculate the cubic capacity of the foundation in advance. Having understood the general principle of the technique, it will not be difficult to perform this work with any base configuration.
The construction of any building begins with developing a project, determining the need for materials, and calculating the estimated cost. Before starting work, it is important to choose the right type and design of the foundation, which will ensure the stability and durability of the structure. Knowing the parameters of the designed foundation, the calculator will allow you to quickly calculate the amount of concrete, as well as determine the need for steel reinforcement and other necessary materials. For calculations, you can use an online concrete foundation calculator or do the calculations yourself.
How to calculate the foundation for a house
How to correctly determine the consumption of materials for the foundation - getting ready to perform calculations
Before starting construction activities, it is important to correctly determine the need for building materials. This will allow you to plan the amount of costs and rationally use available financial resources. Since the construction of houses is preceded by the construction of the foundation, it is necessary at the initial stage to calculate the volume of concrete mixture required for pouring the foundation. In order to perform foundation calculations, a calculator is required.
You can perform calculations in different ways:
- using a ready-made program. A foundation calculator posted on professional websites will help speed up calculations;
- performing the calculation manually. It is easy, using a regular calculator, to calculate the amount of concrete for the foundation with a high degree of accuracy.
When performing calculations, it is necessary to take into account that the amount of concrete solution is measured in cubic meters, and not in liters or tons. Taking this into account, in the process of calculations we will obtain the volume of the concrete composition, and not the weight. Before starting calculations, you should decide on the type and design of the foundation.
To do this, you need to perform a number of activities:
- carry out geodetic surveys. They help determine the level of groundwater, soil characteristics and freezing depth;
- determine the loads acting on the base. The calculator posted on the website will help you correctly and quickly calculate the foundation for a house.
Calculation of the foundation using the example of a 6x4 meter bathhouse Having calculated the amount of concrete for the foundation, the calculator will take into account the following data:
- type of foundation being constructed. The professional program allows you to calculate the strip base, slab base and columnar structure;
- foundation design and dimensions. The configuration and dimensions depend on the characteristics of the building, the operating loads and soil characteristics;
- the brand of concrete mortar used for pouring. It is selected depending on the level of mechanical loads;
- soil freezing level. It is determined taking into account the territorial location of the construction site.
The correctness of the calculation of the solution, as well as the consumption of materials, depends on the completeness of the entered data.
What initial data are included in the calculator for calculating the foundation for a house?
Wanting to determine the total cost and calculate the need for materials, it is important to understand how to calculate the foundation for a house.
The calculator with which the calculation is performed processes a large amount of information for each type of basis:
- for a strip-type foundation base, it is necessary to take into account the dimensions of the strip, as well as its configuration;
- for a columnar base, information is processed on the number of supporting elements, their length, cross-sectional dimensions and immersion depth;
- for a structure in the form of a monolithic slab, it is necessary to take into account the thickness of the base, the area of the structure being built, as well as the design features of the frame.
Configuration and calculation results of a solid foundation After the calculation of materials for the foundation is completed, the calculator will be able to provide the following information:
- volume of required concrete solution;
- footage of rods (m) and total weight of reinforcement (kg);
- range of reinforcement for the frame;
- the magnitude of the load on the ground;
- the need for wood for the manufacture of formwork.
Based on the results of online calculations, you can also obtain information about the dimensions of the spatial reinforcement frame.
Calculation of a strip foundation for a house - calculator
To determine the volume of concrete composition and calculate the need for materials, it is important to consider the following points:
- the length of the base, which must correspond to the perimeter of the building;
- the width of the tape, which should exceed the thickness of the walls by 10–15 cm;
- level of penetration into the soil corresponding to the characteristics of the soil.
Calculation of strip foundation By multiplying the indicated values, we obtain the volume of the foundation tape corresponding to the cubic capacity of concrete. Knowing the mass of a cubic meter of reinforced concrete, equal to 2.4–2.5 tons, it is not difficult to obtain the weight of the base. To do this, you need to multiply the total cubic capacity by the weight of one cubic meter of base. When performing calculations manually, there is a small error of 6–8%. It is important to accurately calculate the solution for the foundation. The calculator, which can be used online, provides this opportunity.
How to calculate materials for a columnar foundation
When building a columnar foundation, it is necessary to correctly calculate the foundation for the house.
The online calculator processes the following data::
- number of support columns;
- diameter and height of piles;
- dimensions of the expanded part of the support located in the ground;
- grillage dimensions;
- grillage structure configuration;
- brand of concrete mixture used.
Using available information about the design features and dimensions of the pile foundation, calculations can be made manually. To do this, you need to determine the volume of one support and multiply the resulting value by the total number of piles. The volume of the grillage is calculated similarly to the tape base. By adding the volume of the supports with the volume of the grillage, we obtain the total volume of the pile structure. Now calculating the amount of concrete is not difficult.
Concrete calculator for a foundation in the form of a monolithic slab
Calculation of materials for slab foundations When planning to concrete a monolithic slab, developers are faced with the problem of how to calculate the amount of concrete for the foundation.
The calculator allows you to quickly determine the consumption of concrete mixture after entering the following parameters into the appropriate columns of the program:
- length of the slab base;
- width of the foundation slab;
- height of the reinforced concrete base.
By performing calculations manually, you can neglect the volume occupied by the reinforcement cage. You just need to multiply the dimensions of the structure and get its volume, which approximately corresponds to the need for concrete composition. To obtain accurate values, it is necessary to use software methods.
Calculation of materials for the foundation (calculator) - determine the need for cement
When preparing concrete mortar, various grades of cement are used as a binder. The strength, reliability and service life of building structures depend on the characteristics and quantity of Portland cement introduced into the concrete mixture. When calculating the material for the foundation, the calculator, which is a special program, processes a set of initial data and provides information about the need for cement for the foundation.
Material calculator for a monolithic foundation slab Using reference data, you can independently determine the amount of cement for preparing concrete mortar. It is important to consider the proportion according to which sand, cement and crushed stone are mixed. This ratio is 3:1:5. The concrete solution is formed from 9 parts, one of which is Portland cement.
Based on this ratio, the number of different grades of cement per cubic meter of concrete is determined.:
- M100 is used in quantities of 160–200 kg;
- M150 requires 200–220 kg;
- M200 is added at 240–280 kg;
- M250 is introduced at 300–330 kg.
As the grade of Portland cement increases, its quantity per cubic meter of concrete composition increases and is:
- M300 – 320–380 kg;
- M400 – 400–420 kg;
- M500 – 510–530 kg.
This information allows you to independently determine the need for cement with a high degree of accuracy. There is also a special online program that will quickly perform calculations after entering the required volume of the finished concrete mixture, the grade of concrete and the type of cement used.
Calculation of the foundation for a house - cost calculator
How to calculate the foundation of a house yourself Having decided on the methodology for calculating the amount of concrete solution and the Portland cement used for its production, you can begin to determine the overall level of costs for constructing the foundation.
Total costs include the costs of purchasing the following materials:
- medium-sized river or quarry sand;
- Portland cement of the required grade;
- medium-fraction crushed stone.
It is also necessary to take into account the cost of purchase:
- steel reinforcement intended for the manufacture of the frame;
- boards, plywood panels or metal for assembling formwork;
- tying wire used to join steel rods;
- hardware used to assemble the formwork structure.
An important element of the calculation is the transportation costs associated with the delivery of the necessary materials to the construction site.
Conclusion
Calculating cost items during the construction of the foundation allows you to accurately determine the total cost. You can use ready-made software products or perform calculations on your own. It is important to master a technique that ensures the right result. Timely budget planning will allow you to distribute funds evenly and ensure their rational use.
In cases where the solution is not mixed independently, but is ordered ready-made, the question very often arises of how to calculate how many cubes of concrete are needed. After all, any mistake can lead to a significant overconsumption of the composition or its shortage, both of which are extremely undesirable. But it is also important to know the proportions even when making concrete yourself - you can calculate how many components will be needed for the project.
Main features of calculation work
If you have to do all the work yourself, then you will have to master such an activity that is unloved by many as counting the necessary materials and components for them.
Without this, it is impossible to competently build a technological process, and we should not forget about the following factors:
- It doesn’t matter whether you buy ready-made concrete or prepare it yourself, the price of materials is quite high, and any mistakes can lead to significant costs. Of course, some reserve is necessary, but everything should be within reasonable limits.
- If you do not know how to calculate a cubic meter of concrete, it is better to first consult with specialists or find information on the Internet, especially since there are enough resources on construction topics, and there will be no problems. It is better to spend 10-15 minutes studying than to redo all the calculations.
Advice!
When ordering a ready-made composition for constructing a monolithic structure, many companies provide a free visit and calculation of the required amount of concrete.
This is the most acceptable option, since the supplier will be responsible for any inaccuracies and errors, not you.
- If all the steps are performed correctly, you will not only receive data on the required volume of a particular component, but you will also be able to accurately calculate how much the work will cost, which allows you to correctly distribute funds and prevent construction from stopping due to a lack of funds at the most inopportune moment .
- It is worth noting right away that most specialists and most developers agree that the ideal option for concrete work in the private sector is the M200 brand. It is based on this that it is worth figuring out how to calculate a cube of concrete and calculate how much material will be needed in total.
- You can also make your work much easier by using an online calculator - you don’t need to figure out how to calculate a cube of concrete, enter the required cubic capacity, and the program will give you the required volume of components. With this option, you will not have a question about how to calculate 1 cubic meter of concrete or any other value.
The following components are used in the work:
Calculation of the amount of solution depending on the type of foundation
While various programs can help with calculating components for a certain volume, you will have to determine the required quantity yourself. In this chapter we will look at how to count concrete cubes for different types of foundations.
Strip foundation
Without a doubt, this is the most common type of structure in private and low-rise buildings; with its help, work can be carried out very quickly and efficiently.
When carrying out calculations, you must be guided by the following recommendations:
- First of all, the thickness of the base is determined; as is known, this indicator can vary depending on the load that will affect a particular area. Therefore, you should write the measurement results of each part on a separate piece of paper; the lengths of elements of the same thickness are summed up.
- The next stage is determining the height of the structure. Since it is hardly possible to dig a trench of absolutely the same depth, and there may be a certain slope in the area, this indicator should be measured especially carefully and take into account that a certain error will be present in any case.
- Next, a calculation is made: the length indicator is multiplied by the thickness and height, all indicators are taken in meters. The result obtained will be the required volume in cubic meters. The values of sections with different thicknesses are summed up, the resulting value will reflect how much concrete is needed for the work.
Important!
Do not forget that concrete shrinks to some extent, so the finished result, taking into account possible errors, must be multiplied by 1.02.
Slab foundation
This option is a monolithic platform that is highly durable and reliable.
Instructions for calculating the material are as follows:
- The process is quite simple: you need to multiply the length by the width and multiply by the height. Indicators are taken in meters.
- If there are protrusions, then the volume of each of them is additionally calculated and added to the total figure.
- If ribs are provided at the bottom to increase strength, their volume is calculated separately.
Columnar foundation
This type of base is calculated as follows:
- The process depends on the cross-section of the columns; if it is square or rectangular, then the dimensions are multiplied (length by width), if it is round, then the area is calculated as follows: the radius is squared, and the result is multiplied by 3.14.
- Next, the area of the element is multiplied by its height, the resulting result will be the volume in cubic meters, it must be multiplied by the quantity.
- If the structure contains grillages, do not forget to calculate their volume.
Conclusion
In fact, the calculations are quite simple and will not cause difficulties. The main thing is to measure all parameters correctly. The video in this article will tell you some of the features of the process in more detail and detail.
This artificial stone is used in almost all types of work, be it the construction of a new structure or the reconstruction (repair) of an existing one. The solution is always poured into a specific form, in which it hardens. Calculating the required amount will prevent unnecessary waste, since there will simply be nowhere to put the excess, given that the time for “setting” the mass can be quite short. And a lack of material will only “slow down” the whole process. In addition, it is necessary to correctly determine the required amount of components used to prepare the mixture.
Let's consider this issue in relation to the most used type of base - strip monolith. The amount of concrete is calculated as follows.
The total volume is determined
As a rule, many buildings also have internal load-bearing walls (partitions), under which a foundation must also be installed. They are smaller in size, so all calculations are carried out separately - for the outer tape and its parts located inside the perimeter, although the methodology is the same.
It is necessary to measure parameters such as width and length, as well as the height of the monolith. The volume of the entire structure is equal to the product of these quantities. If the internal parts of the tape have different parameters, then for each of them the volume is calculated separately.
Naturally, to obtain the overall result, it is necessary to sum up all calculations.
Correction factor
When calculating the volume of concrete, it is necessary to take into account such a factor as its shrinkage. This refers to the inevitable evaporation of some of the water that was used in preparing the composition. In practice, after pouring the solution, it is often artificially compacted, using both vibrators and improvised means (bayonet shovel, metal rod). In this case, not only more intense evaporation of moisture occurs, but also air “bubbles” are removed, which in total can be quite large in volume.
As a rule, an average coefficient of 1.015 – 1.02 is used in calculations. Therefore, the total result is multiplied by it.
Design Features
Here it is necessary to focus on the construction design. Technological holes or large openings are often left in a concrete monolith (foundation, wall), which are necessary for “installing” various communications into the building. Sometimes there are quite a lot of them. Therefore, when calculating the amount of concrete, their total volume is subtracted from the final result.
If the solution is prepared directly on site, then knowing how much concrete is needed, you can determine the required quantity of its components, which should be delivered to the construction site. There are quite a few sites on the Internet that have special calculators for such calculations. But still, the principle must be understood, since the “machine” does not take into account all the features of a particular construction.
For example, when installing a slab foundation, so-called “stiffening ribs” are installed, which are located under the slab. They serve to increase its strength, and concrete mortar is also used for their equipment. Based on all of the above, one conclusion suggests itself.
Indeed, in practice, you will have to make calculations not only for the strip base, but also for other types and elements of any structure. For example, a columnar foundation can be represented in the form of 2 parallelepipeds: wide (the base) and narrow (the pillar itself). The same is true for calculating various beams, arches and floors, especially those with changing geometry.
Examples of concrete quantity calculations
Attention! The solution is sold only in “cubes”. All proportions for its independent preparation are also given per “m3”. Therefore, the results of all measurements must be recorded in meters.
Tape base
Let's calculate the amount of concrete for a house 6x8 m. Foundation - width 30 cm, length around the perimeter - 28 m (6x2 + 8x2). The depth is 60 cm, the above-ground part is 20 cm. The bases for 2 load-bearing internal walls are the same with a width of 20 cm, a total length of 12 m. The height of each part is 80 cm.
We determine the volume of the tape: 28 x 0.3 x 0.8 (0.2 + 0.6) m = 6.72 m3.
Volume of internal parts: 12 x 0.2 x 0.8 (m) = 1.92 m3.
The total volume of concrete required for the foundation for the entire building: 6.72 + 1.92 = 8.64 (m3).
It consists of individual pillars and beams that connect them. The latter are calculated using the above method.
The pillars have a cross-section, for example, 30 cm (0.3 m). The height of each is 1.5 m. Their total number is 20 pieces. They require concrete: 0.09 (0.3x0.3) x 1.5 m x 20 pcs. = 2.7 m3.
To this value is added the amount of mortar required for the grillage (beams). The result is the total “cubic capacity” of the material.
Useful tips
Quite often, an individual developer is faced with the question of how to calculate a cube of concrete. When determining this value, you need to focus on the type and brand of the final product. For example, heavy concrete is one thing, and foam or aerated concrete is another. The size of the component fractions and the presence of various additives in the mixture also play an important role. Only after determining all these components is the calculation made. But this is a topic for another article, since the issue of the proportion of ingredients, varying their percentages requires a more detailed consideration.
Material consumption can be reduced by installing formwork with a smooth inner surface. For example, for a removable option - plywood, steel sheets. For permanent formwork - polystyrene foam boards.
If a structure made of boards is used as such, then more water will escape through the cracks. This will change the amount of concrete shrinkage upward, therefore, its consumption will increase.