The foundation calculator will help you independently calculate the required volume of concrete for pouring the foundation, and will also calculate the amount of formwork and reinforcement. It is worth noting that the “Foundation height” parameter includes both the depth of the underground part and the height of the above-ground part.
If your interior partitions are not represented by a load-bearing type structure, then a lighter foundation layer is used under them, which has its own geometric parameters, and you need to calculate the foundation for the partitions separately in a calculator, and then summarize the data obtained.
Foundation calculation
Before you start building a house, the first thing you should do is familiarize yourself with the composition of the soil, since both the choice of foundation type and the costs associated with the construction process depend on the quality of the soil.
The next step is to calculate the foundation, namely to calculate the permanent load from the house itself, and the temporary load from wind and snow cover, in order to determine whether the soil will withstand the load from the house and the foundation.
Then you can start calculating the volume of concrete for the foundation. To do this, the length of the structure should be, and this includes both the perimeter from the outside and the length of absolutely all partitions between rooms, multiplied by its height and width, but provided that the foundation strip has the same cross-section along its entire length.
Concrete volume V=L*A*B , Where
L - Foundation length
A - Foundation height
B - Foundation width
If you are planning to prepare concrete yourself, then you should know that concrete is most often prepared from cement grades M 500 and M 400 using sand and crushed stone. When calculating the proportions of concrete, many factors should be taken into account, such as fractions of crushed stone and sand, their density, and the required qualities of concrete. The table “Concrete proportions” shows average data.
When calculating reinforcement for foundation reinforcement, it is worth knowing that longitudinal bars bear the load, and therefore ribbed reinforcement is used for them, mainly 10-12 mm, and vertical and transverse bars are made of smooth and thin reinforcement, since they do not carry loads.
To quickly calculate the volume of concrete for pouring the foundation, as well as all the necessary building materials, you can use our foundation calculator located above.
Calculating the foundation for a house is the most important stage of construction, which would be better entrusted to professional design engineers.
However if the construction is planned no higher than two floors and you are confident in your abilities, then you can take on the calculation yourself.
The main thing is to take everything into account.
Main functions
The foundation is the main supporting structure of the house.
His main tasks:
- Support the weight of the entire building.
- Evenly distribute the load on the ground.
- Prevent flooding with melt and groundwater.
Types of foundation for a house
Before calculating the foundation of the house, you need to decide what type of foundation will you use for your building?.
According to the type of construction they are divided into:
- tape;
- slab;
- columnar;
- pile
A monolithic reinforced concrete slab is called slab, laid in deep and leveled soil. The rare use of this type of base, despite the possibility of using it on unfavorable soil, due to high cost.
Columnar- This is a structure of pillars connected by beams. Although this is the cheapest option, it is recommended to use it for soils not subject to temperature changes. Besides, he can only support a small wooden house.
Foundation on piles can be used on soft soils or during the construction of a multi-storey building. However, the need to use a lot of equipment significantly increases the cost of the entire building.
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.
Base load calculation
When starting to calculate the foundation for a house, first calculate the load it will hold.
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.
Don't 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.
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.
For this calculate the volume of the base, using mathematical formulas, and multiplying 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 1 cm2 of soil bear?.
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 ( 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! 
Calculation of the amount of concrete, wire and reinforcement
Having decided on the size of the foundation, you need to calculate how much reinforcement, wire and concrete will we need?.
With the last one everything is simple. The volume of concrete is equal to the volume of the foundation, which we already found when we calculated the load on the ground.
But what metal to use for reinforcement has not yet been decided. Here it all depends on the type of foundation.
Reinforcement in strip base
For this type of foundation, only two reinforcement belts and reinforcement up to 12 mm thick are used. Horizontal longitudinal reinforcement bars are subject to greater loads than vertical or transverse ones.
Therefore, ribbed reinforcement is placed horizontally, and smooth reinforcement is placed vertically.
Length of ribbed reinforcement It’s easy to calculate if you multiply the total length of the base by the number of rows of rods. If the foundation is narrow (40 cm), two longitudinal rods for each belt are sufficient. Otherwise, the amount of reinforcement in the belt will have to be increased.
Transverse rods are installed every 0.5 m, retreating 5-10 cm from the edge of the foundation. We determine the number of connections by dividing the entire length of the foundation by 0.5 (the step between intersections) and adding 1.
To find smooth reinforcement length required for one intersection, we use the formula:
(ShF - 2*ot)*2 + (VF - 2*ot)*P, where ShF and VF are the width and height of the foundation, from is the offset from the edge of the foundation, P is the number of rows of reinforcement in the belt.
After this, we multiply the two resulting values, getting the amount of smooth reinforcement required for the foundation.
Costs of binding wire for foundation– this is the product of wire consumption for one bundle (30 cm), the number of bundles at one intersection (equal to the number of rows of reinforcement multiplied by 4) and the number of connections.
Reinforcement in slab foundation
For slab base ribbed reinforcement is used 10 mm thick or more, laying it in a grid, in increments of 20 cm.
That is, for two reinforcement belts you will need:
2*(ShF*(DF/0.2+1) + DF*(SF/0.2+1)) m reinforcement, where ShF is the width, DF is the length of the foundation.
To connect two planes of the frame, you need each connect the intersection of the upper grid with the corresponding intersection of the lower one.
Taking into account the thickness of the slab and the distance of the frame from the surface of the slab, we determine the amount of reinforcement required to connect the belts using the formula:
((DF/0.2+1)*(SF/0.2+1))*(TP-2*from), where TP is the thickness of the slab, from is the distance from the surface.
It is enough to add the two resulting numbers to know how much reinforcement is needed for a slab foundation.
The length of the knitting wire is calculated based on the formula:
General estimate
To summarize, so that the entire theory presented above becomes a little clearer, we present example of calculating the foundation for a one-story house.
The building measures 6x10 m, with an internal six-meter wall. At the same time, the height of the first floor is 3 m, and the height of the attic is 2 m.
As you can see, calculating foundations is not such a complex science that one should refuse to build on their own, and this example of calculating a foundation is given here as the main evidence.
They can be used for different houses on different types of soil; you can do the calculations yourself. This does not require knowledge of higher mathematics or strength of materials. There is a method in which everything is simple, but cumbersome: you have to collect a lot of data. This calculation of the strip foundation is called “based on the bearing capacity of the soil.” But first you will need to collect the loads from the house: calculate how much mass will fall on each square meter (centimeter) of the base. Then, choosing the width of the foundation base, select its optimal width.
Calculation method
We know for sure that the foundation is built first. But it is designed last. Its task is to transfer the load from the house. And we will know it only after we have decided on the type of all building materials and their volumes. So before you start calculating the foundation you need to:
- draw a plan of the entire building with all the walls;
- decide whether a basement is needed or not, and how deep it should be if needed;
- know the height of the base and the material from which it will be made;
- determine the type and thickness of materials used for insulation, wind protection, waterproofing, finishing both inside and outside.
For all materials used during construction, you need to find their specific gravity. It is advisable to make a table: it will be easier to work. Only after this can you begin to calculate.
Strip foundations are most often made monolithic or. Brick or rubble concrete belts are made much less often today: they are less reliable, but at the same time, their construction requires a larger amount of material, although its cost may be less.
Conventionally, the calculation of a strip foundation can be divided into several stages:
- Determination of the load on the foundation.
- Select ribbon options.
- Adjustments depending on conditions.
Now about all the stages in more detail.
Collection of foundation loads
At this stage, the mass of all building materials that are used for construction is summed up:
As already said, by this moment a building plan with more or less accurate dimensions should already be ready. Calculating the mass of building materials used is simple: find the area on which it will be located, multiply by the specific gravity, and get the mass.
If the element being calculated is rectangular, find its area by multiplying the length of the sides. If you count in meters, you get m2. Multiplying by the thickness of the material in the same units (in meters) you get the volume in cubic meters - m3. It will be more convenient to work this way: most of the specific gravity of building materials is given in kilograms per cubic meter (kg/m3). By multiplying the found volume with the specific gravity of the material, you get the mass of the material for this plane.
Example of wall mass calculation
To make it clearer, let's give an example. Let's calculate how much a wall made of profiled pine beams 150*150 mm will weigh, with cladding made of linden lining 14 mm thick, lathing made of pine beams 50*20 mm. The wall is 4 m long and 2.8 m high.
The specific weight of the purchased pine timber (can be different) is 570 kg/m 3 , lining 530 kg/m 3 , timber 510 kg/m 3 .
Wall area: 4 m * 2.8 m = 11.2 m 2.
The volume of the timber in the wall will be 11.2 m2 * 0.15 m (thickness of the timber) = 1.68 m3.
Multiplying the volume by the specific weight of the timber, we get the mass of the wall: 1.68 m 3 * 570 kg/m 3 = 957.6 kg.
Now we find the volume of the lining on the wall: 11.2 m2 * 0.014 m (thickness of the lining) = 0.16 m3.
We find out how much the lining weighs by multiplying its specific weight by volume: 0.16 m 3 * 530 kg/m 3 = 84.6 kg.
The amount of sheathing is calculated differently: we determine how many planks are nailed. We will nail the sheathing lengthwise in increments of 60 cm. We will get 5 planks 4 m long. There will be a total of 20 linear meters. Now we find the volume: 20 m.p. * 0.05 m * 0.02 m = 0.02 m 3.
Now we find the mass of the sheathing: 0.02 m 3 * 510 kg/m 3 = 10.2 kg.
Now find the mass of all materials for the wall: 957.6 kg + 84.6 kg + 10.2 kg = 1052.4 kg.
We calculated that the mass of a wall with an area of 11.2 m2 will be 1052.4 kg. It turns out that one square weighs 1052.4 kg / 11.2 m2 = 93.96 kg/m2. Now, having calculated the area of all walls with such decoration, we can find their total mass. Let their total area be 42 m2. Then they will weigh 42 m2 * 93.96 kg/m2 = 3946.32 kg.
Using this method, find the mass of all the listed elements. If they have complex geometry, break them down into simple shapes and determine the area that way. There shouldn't be any problems with the rest.
In addition to building materials, the entire environment in the house will put pressure on the foundation: furniture, equipment, people, etc. It takes a very long time to calculate all this, so when planning it is assumed that per square meter of area the payload is 180 kg/m2. To find out the total payload of the house, multiply its area (of all floors) by this figure.
In most regions, snow loads on the foundation must also be taken into account. Snow loads are determined by region (see photo), their values are given in the table.
Snow loads in Russia (to enlarge the picture size, right-click on it)
But since the roofs are different, different amounts of snow accumulate on them. Therefore, depending on the angle of the slope, the following coefficients are applied:
- the angle of inclination is less than or equal to 25° - the coefficient is 1 (snow load is taken from the table without changes);
- the angle of inclination is greater than or equal to 60° - the coefficient is 0 - the snow load is not taken into account.
In all other cases (roof inclination angle from 25° to 60°), values are selected from 0 to 1 (a graph is drawn and the coefficient is determined from it).
Snow loads in Ukraine (to enlarge the picture size, right-click on it)
Example: let the snow load in the region be 180 kg/m2, the total roof area is 65 m2, the roof slope angle factor is 0.82 (tilt angle is about 30°). We find the snow load: 65 m2 * 180 kg/m2 * 0.82 = 9594 kg.
This load will need to be added to the weight of the house and its payload.
Calculation of strip foundation: determining the width of the sole
When calculating a strip foundation, it will be necessary to determine two of its parameters:
- + base height = height;
- tape width;
The third - length - is known. This is the sum of the lengths of all the walls under which the foundation will be laid.
Let us accept that the depth of the foundation for our conditions is below the soil freezing level, the height of the base is 20 cm. The soil freezes in our region by 1.4 m. According to recommendations, the foundation should be 15 cm below the freezing level. We get the total height: 1.4 m + 0.2 m + 0.15 m = 1.75 m.
Select the width of the foundation depending on the material and the distance between the walls (to enlarge the size of the picture, right-click on it)
Foundation load calculation
Now you need to find the force with which the house will press on the foundation. To do this, divide the total mass of the house (mass of all elements + payload + snow) by the area of the foundation.
We find the area of the strip foundation by multiplying its length by the width selected in the previous paragraph. Then we divide the total load from the house by the area of the foundation in square centimeters. We get the specific load for each square centimeter of the strip foundation.
Example. Let the load from the house be 408,000 kg, the area of the strip foundation (length 4400 cm, width 30 cm) - 132000 cm 2. Dividing these values, we get: 3.09 kg of pressure per centimeter.
Now it is necessary to find out whether the soils under the base of the foundation will withstand this value. Any soil can withstand some pressure. These values are calculated and entered into the table. We find the type of soil under the base of the foundation (determined by geological research) and look at its specific bearing capacity.
Bearing capacity of soils - compare the found load from the house with the standard load for your soil
If the bearing capacity of the soil is greater than the load from the house, everything has been chosen correctly. If not, adjustments need to be made.
Adjusting parameters
If the load transmitted through the strip foundation is large for these soils, there are two options: use lighter materials during construction or increase the width of the strip.
Changing a material is very labor-intensive: often a change in one material entails a chain of changes in the parameters of a number of others. As a result, the mass calculation has to be redone. Because more often increase the thickness of the tape in the foundation. This increases and decreases the specific load. But a strip foundation that is too wide (wider than 60 cm), especially if it is deep, is not economically profitable: there is a lot of material consumption and labor costs. In this case, it is necessary to compare the cost of several types of foundation.
After changing the width of the tape, do not forget to recalculate its mass and adjust the mass of the structure accordingly.
How to calculate the cubic capacity of the foundation
It is better to take into account the mass of the foundation by calculating its volume: this figure will be useful to you when pouring the foundation: you will know how much concrete to order or how many materials you will need to purchase.
All initial data are already known: height, width and length of the tape. You multiply them and you get the cubic capacity of the foundation.
For example, let’s calculate the volume of the foundation for the previously calculated strip: length 44 m, width 30 cm (0.3 m), height 1.75 m. Multiply: 44 m * 0.3 m * 1.75 m = 23.1 m 3 . In fact, the consumption will most likely be a little more: about 25 cubic meters. Use this figure as a guide when ordering concrete.
The developer is always concerned about how wide the foundation of a strip structure should be. The greater the width of the foundation, the more labor and materials must be invested in its construction. Any excess in the consumption of building materials increases the cost of building a facility. To prevent this from happening, you need to accurately calculate the width and height of the strip foundation. Calculation of the foundation of the building determines the depth of the building, the height of the walls and the width of the foundation. It is also necessary to determine the amount of reinforcement and its diameter.
Why choose strip foundation
Compared to other foundation designs, strip support allows the load from the building to the ground to be transferred most evenly, therefore, if the results of a study of the strength of the soil foundation allow it, a strip foundation is chosen.
You need to make a strip foundation along the entire perimeter of the house and under the internal load-bearing walls. If heavy technological equipment (boiler) is installed inside the house, then a foundation strip is also placed under it.
Types of strip foundation
Among foundations of different designs, the developer often chooses a strip foundation for his home. The strip base of the structure is mainly of two types:
- strip foundation made of precast reinforced concrete;
- monolithic reinforced concrete strip.
Precast concrete
When installing reinforced concrete blocks in the design position, there is no need to arrange formwork. The block manufacturing technology includes vibration and steaming of concrete, which guarantees their strength.
When constructing a strip foundation from precast reinforced concrete on soft soils, the blocks are supported on concrete pads (wide slabs). Pillows increase the support area of the base of the house, thereby reducing pressure on the soil.
Foundation blocks of monolithic reinforced concrete are marked with letters - FBS. The main dimensions of the FBS are shown in the table:
In addition, the industry produces FBP blocks. The blocks are a lightweight version of FBS of similar height and width with square voids. The length of the FBP is 238 cm. The blocks are used to support internal load-bearing fences and basement walls.
Disadvantages and advantages of a block foundation
Precast concrete foundation calculations cannot be economically accurate. The reason for this is the standardization of the sizes of reinforced concrete blocks. For example, if the calculation determined the thickness of the strip foundation to be 550 mm and the height of the wall to be 500 mm, then the size of the blocks used will be 600 mm and 580 mm, respectively.
Along with this, the block base has a number of advantages over monolithic tape:
- significant reduction in the volume of wet processes;
- no costs for formwork work, reinforcement, preparation and pouring of concrete solution;
- all-season installation work;
- The construction of the foundation of the house is carried out in a short time and does not depend on the hardening time of the concrete.
Monolithic reinforced concrete strip
The calculation of the monolithic tape should ensure the construction of a strong and reliable foundation of the building.
If the depth of the strip depends on the groundwater level, the bearing capacity of the soil foundation, and the thickness of soil freezing, then the width of the strip foundation is determined based on the total load from the structure and the thickness of the external walls.
The strip foundation must be made of such a width that the total area of the base of the building corresponds to the resistance of the soil foundation.
Calculation of the area of the base of a strip foundation
The calculation of the base area of the building must be such that, under the influence of the total load, the house does not push through the ground and is not pushed upward by frozen swollen soil. In the regulatory documentation you can find a formula for calculating the base area of a house.
S>kF/k(c)R, where
S – area of the foundation base;
k – reliability coefficient equal to 1.2, that is, an area reserve of 20% is provided;
k(c) – soil composition coefficient (plastic clay – 1, sand – 1.4, etc.);
R – calculated soil resistance (taken from the SNiP table).
All elements of the formula are for reference only, except for the total load F. The total load is calculated using reference tables of regulatory documentation. For this purpose, indicators of the average specific gravity of roof, wall and ceiling structures are used.
Data such as snow load are also taken into account. In central Russia this is 100 kg/m2, in the north of the country – 190 kg/m2, in the south – 50 kg/m2.
The total amount takes into account the weight of the foundation itself and the payload (technical equipment, filling the premises with furniture, etc.).
Video “Independent calculation of the supporting area of the foundation”:
An example of independent calculation of the width of a strip foundation
Initial data:
- size of the house in plan – 10 m x 10 m. Building area – 100 m 2;
- inside the house there is a load-bearing wall in the middle;
- the walls are brick, 1 brick thick - 250 mm and 2.7 m high. The specific gravity of the brickwork is 1600 kg/m 3;
- slate roofing – 40 kg/m2;
- flooring made of reinforced concrete slabs - 500 kg/m2;
- soil freezing depth – 700 mm;
- groundwater level – 2.2 m;
- soil base – dry loam of medium density with a design resistance of 2 kg/cm2;
All values of standard loads are taken based on reference data. The amount of snow load is determined from the corresponding section of SNiP for the southern regions of Russia.
Determination of the total load from the house on a strip monolithic foundation
Based on the available initial data, the total load on the foundation is calculated. The dimensions of the monolithic tape are also determined. It is necessary for developers to make calculations in the following order:
Roof
The roof is made of slate and has a gable roof. Taking into account the slope of the roof and its overhangs, a coefficient of 1.1 is used. The load from the roof will be: 100 m 2 x 1.1 x 40 kg/m 2 = 4000 kg.
Brick walls
To determine the load from the walls, knowing their thickness, you need to calculate their length. The length of the walls along the perimeter will be: (10 x 4) – (0.25 x 4) = 39 m. The deduction of the double thickness of the brickwork is made because the axes of the house plan are drawn in the middle of the thickness of the walls. The length of the internal load-bearing wall will be 10 - 0.25 = 9.75 m. The total length of the load-bearing walls will be equal to 48.75 running meters.
The volume of brickwork will be: 48.75 x 0.25 x 2.7 = 32.9 m3. The total load from the brick walls is: 32.9 x 1600 = 52,670 kg.
Flooring made of reinforced concrete slabs
The one-story house has ceilings on two levels. This is the ceiling of the basement and the ceiling in the house. The floor area is: 100 x 2 = 200 m 2. Accordingly, the load from the floor slabs will be equal to: 200 m 2 x 500 kg/m 2 = 100,000 kg.
To calculate the snow load, take the total roof area of the house - 100 x 1.1 = 110 m2. The snow load will be: 110 m 2 x 50 kg/m 2 = 5,500 kg.
The rate of this load is calculated based on the average weight of technical equipment, internal communications, room decoration, furniture and other things. The specific weight of the payload ranges from 18 to 22 kg/m2.
The payload is calculated on the basis of an average of 20 kg/m2. The weight will be: 100 m 2 x 20 kg/m 2 = 2000 kg.
In total, the total load on the foundation will be equal to: 4,000 + 52,670 + 100,000 +2,000 = 159,000 kg.
Calculation of the width of a monolithic tape
According to the above formula, the minimum area of the foundation base is determined:
(1.2 x 159,000 kg): 2 kg/cm 2 = 95,400 cm 2. That is, the minimum allowable area of the base of the house will be 10 m2.
The total supporting area of brick walls is determined by the product of the plan length of the load-bearing walls and their thickness: 48.75 m x 0.25 m = 12.18 m 2.
According to generally accepted practice, the minimum width of the strip foundation is 100 mm greater than the thickness of the walls.
The result shows that the calculated support area is less than the minimum support area of the walls. Therefore, the width of the strip foundation should be equal to 250 mm + 100 mm = 350 mm.
Requirement for materials for the construction of a monolithic tape
Taking into account the thickness of soil freezing (0.7 m) and the depth of the groundwater level (2.2 m), the monolithic tape is made shallowly buried - 1 m.
To fill the formwork, concrete M 300 is used. The volume of need for concrete solution is equal to: 0.35 m x 1 m x 48.75 m = 17 m 3. . Taking into account unforeseen losses, the need for concrete will be 17.3 m 3.
The reinforcement frame consists of 4 longitudinal reinforcing bars of a periodic profile with a diameter of 12 mm. Since the transverse rods of the frame are made from the same rods, the total need for reinforcement will be: 50 m x 4 = 200 m.
From all of the above, we can conclude that it is quite possible for people who are more or less knowledgeable in the construction business to calculate the width, height and length of the strip foundation for their home.
A strip foundation for a house made of foam blocks, gas silicate or brick is one of the most common options. It works great on stable soils and allows you to organize a full-fledged basement in the basement. But for the construction to be truly durable, everything must be done with high quality.
When ordering turnkey construction, you can simply rely on the calculations of the company’s managers, without going into too much detail. But it’s still worth roughly estimating the amount you’ll spend on building materials and services. To do this, you will need at least a schematic drawing of the future monolith with all the dimensions marked, as well as an online calculator for more accurate calculations.
Initial data
If you have a strip foundation in your house design, to calculate it you will need to not only determine the length and width of the monolith, but also the height, dividing it into an underground and above-ground part (basement). This will allow you to find out the depth of the trench and include prices for excavation work in the estimate. The diagram should also show all the lintels on which the internal walls of the house will rest. If the project has a heavy stove or brick fireplace, you will also need to pour a concrete bed under them.
Correctly drawn base geometry also makes it possible to determine the costs of auxiliary materials:
- The area of support and contact with the ground in the underground part corresponds to the dimensions of the waterproofing.
- The squaring of the side surface of the tape from the outside is necessary in order to find out the amount of insulation; adding to it the area of the internal walls, we get the formwork consumption.
Another important point is the brand of concrete. Here you already need to know the weight of the building and the operational loads that affect the strip foundation. After conversion to units of support area, you will receive the required value in kgf/cm2. Multiply this figure by a factor of 1.2 to have a 20% safety margin, and select the nearest M grade (rounded up).
Then you can use any online calculator to calculate the concrete foundation, but it will only give an approximate consumption. It remains to be determined how much turnkey construction services will cost. Here, a lot depends on the package offers of the contractors themselves, so it is better to first contact a suitable company to clarify all the nuances. Often the price list includes the following items:
- Transportation of the crew and/or accommodation on site during construction.
- Delivery of materials and equipment.
- Rental of special equipment.
- Using a generator and delivering water if there are no communications on the site yet.
The final cost of the work may also be affected by the season, soil characteristics and the depth of the aquifers - how much it will be in ruble equivalent, the foreman will tell you after assessing the site.
Calculation of materials for strip foundation
Here it all starts with the installation of a support layer - a sand and gravel cushion. You can determine the flow rate for it using simple calculations: multiply the area of the base by the height of the compacted backfill (as a rule, it is 20-30 cm). The preliminary estimate should also include underlying waterproofing, which will prevent the solution from seeping into the pillow.
Afterwards you can proceed to the calculation of the formwork. Paired panels made of plywood or knocked down boards should have a height no less than the future strip foundation. They are installed along the external and internal perimeter of the house in accordance with the diagram. You will also need to calculate the amount of reinforcement to strengthen the concrete. It is laid in a monolithic tape with two longitudinal rods in the upper and lower parts. That is, the length of the future casting must be multiplied by 4, plus allowance for overlaps. Transverse ligaments are added to the resulting figure, which transform individual steel rods into a spatial frame. Calculators do this based on the requirements of SNiP.
At the same time, you can calculate the concrete for the strip foundation. Knowing the geometric dimensions of the base, the total volume of the mixture is determined by simply multiplying the area by the height. It is better to immediately add a reserve of about 10% so that there are no problems when the solution compacts in the mold. The possible difference between the design data and the actual volume of already assembled formwork should also be taken into account.
Then everything depends on the place where the solution is prepared. It is easier and more expensive to order its delivery from the nearest RBU - in this case, the cost of special transport services must be added to the cost of the mixture itself. It is best to confirm the final batch volume after the formwork has been assembled and re-measured on site. A more labor-intensive process is making concrete by hand. In this case, you will have to spend money on purchasing cement, sand and crushed stone, and also pay extra to the crew.
Turnkey filling price
When contacting contractors who will be pouring a strip foundation, you should decide whether you will provide them with building materials yourself or entrust the purchase to a construction company. In the first case, you only pay for the work - on average it will cost 4000-4500 rubles/m3. In the second, the cost of the finished base will be about 11,000 rubles/m3.
The concept of turnkey construction varies from company to company; the list of basic services needs to be clarified. You can find out prices for them separately if you want to save money and you are ready to do some of the work yourself. The “average” price looks like this:
- Site breakdown – 2500 rubles
- Digging trenches - 500-1000 rubles/m3.
- Sand and gravel cushion with compaction – 500-1100 rub/m3.
- Insulation tape – 150 rub/m2.
- Waterproofing is 360 rubles/m2 for single-layer pasting and 650 for two-layer.
- Assembling formwork, frame and pouring concrete - from 3000 to 4500 rubles/m3.
Approximate prices according to Moscow Region for a turnkey foundation
In the foundation calculation calculator you need to enter all the dimensions of the foundation, indicating the design features and the depth of the tape. Also, for correct calculations, you will need to independently determine the grade of concrete. Then the service will calculate everything automatically: up to the number of boards for formwork and the diameter of the reinforcement.
Online calculation service