Foundation one-story house, of course, differs from the foundation of a multi-story building. After all, one floor “presses” on the supporting structure with less force than a multi-story colossus. And the dimensions of a “one-story” foundation will be much more modest than those of a high-rise building.
However, this does not mean that the foundation is under one-story house You can build whatever suits your needs. But this is a full-fledged supporting structure and the construction of a foundation, even a “one-story” house, must be organized according to all the rules. And in this article we will introduce our readers to these recommendations.
Foundation for a one-story building - types of structures
A one-story house can be built on a strip, column, pile or monolithic foundation. The choice of a specific option depends on the specific operating conditions of the building.
For example, practically the key characteristic that determines the outcome of the process of choosing the type of foundation is the composition of the soil on the site. After all, whatever foundation you choose for a one-story house, it will stand on the ground. Moreover, each variety (type) of soil has its own foundation design. So, for non-heaving, loose soils, a strip or columnar version of the foundation is suitable; in swampy areas it will be necessary to equip or monolithic slab, or pile foundation.
In addition, the choice of foundation design option is influenced not only by the type of soil, but also by the topography of the site. After all, from an economic point of view, on relatively flat areas (with a slope of no more than five degrees) it is possible to equip both a slab and a strip base. Areas with a slightly greater slope force the use of a columnar structure. And steep slopes will only accept pile foundation.
And, of course, the type of foundation construction is influenced by the type building material, used in the construction of the house itself. After all, the foundation for a one-story brick house will be slightly different than the foundation for a wooden structure. Moreover, if we consider this criterion, then the relationship between the type of foundation and the type of building material can be expressed in the following chain:
wood is laid on a columnar base, stone, brick and foam block - on a strip base, and all these building materials can be laid on pile-type bases.
Dimensions of the foundation for a low-rise building
The dimensions of the base are determined by the dimensions of the facade. After all, the perimeter of the walls must fit into the perimeter of the foundation. Therefore, the dimensions of the base will be slightly larger (or equal) to the length and width of the building itself.
But the depth of the foundation (its height) is determined by completely different criteria.
This parameter is influenced by the following factors:
- Level groundwater– the closer it is to the surface, the lower the height of the base. For example, for swampy areas, a monolithic slab that is practically not buried in the soil is chosen.
- The depth of soil freezing - the height of the foundation for a one-story house built on heaving soils should be 300-500 millimeters greater than this parameter. Otherwise, a relatively light, one-story structure will shift (play) under the influence of soil heaving deformation.
- Structural features of the foundation - if the building design includes a basement or basement floor, then the height of the foundation will be equal to the height of the underground part of the house, increased by 30-50 centimeters (slab thickness).
The thickness of the foundation for a one-story house, as a rule, is equal to the thickness of the wall, increased by 10-15 centimeters.
As a result, this parameter depends only on the heat resistance of the main building material. For example, the thickness of the foundation under wooden house cannot exceed 40 centimeters, because a 25-centimeter crown protects the interior of the home even from severe frosts.
For a house made of foam blocks, the thickness of the foundation can be 60 or even 75 centimeters. Indeed, to ensure sufficient heat resistance, the walls of a building made of foam blocks should be no thinner than 60 centimeters. Natural heat resistance in brick house possible only with a wall thickness of 80-100 centimeters. That is, the thickness of the foundation for such a brick house cannot be less than 100-120 centimeters.
However, the thickness of the foundation can be changed due to a layer of insulation mounted on top of the base and facade. After all, a 50 mm layer mineral wool is able to reduce the thickness of a foam block wall by as much as 15-20 centimeters. And heat-resistant hollow brick masonry allows you to build a wall only 50 centimeters thick, which reduces the thickness of the foundation by almost half.
Construction technology
The technology for building a foundation for a one-story house, in most cases, is selected based on the design features of the foundation and the type of building material used.
For example, columnar foundations
are erected manually by pouring pillars into permanent or removable formwork. It is not wise to use ready-made (purchased) mortar during the construction process. After all, the filling volumes are minimal. Well, building pillars from brick is simply stupid: after all, the sand-cement mixture allows you to reduce the cost estimate and speed up the construction itself.
Strip foundations They do not accept such simple solutions. After all, a strip-type base can not only be poured into permanent or removable formwork, but also laid out from bricks or blocks. In this case, the latest version of the foundation construction technology is set up manually - laying a foundation from a block or brick. Pouring the strip version into the formwork involves maximum automation of the process and the use of ready-made concrete. After all, a monolithic tape should be filled in one pass.
Today, do-it-yourself construction of a variety of non-residential buildings, as well as houses and country cottages, has become widespread.
Building a house has some difficulties due to many parameters that must be taken into account before planning the foundation; how long the house will last depends on them.
Laying the foundation is the most important part of construction, and its depth determines the strength of the entire further structure.
What determines the choice of depth?
For any building, the depth cannot be simply determined by eye; many calculations are needed here, and first of all you need to pay attention to:
- groundwater flow level;
- climatic features of the area in which the house will be located;
- soil freezing depth;
- total building load and construction materials;
- selected foundation type.
The first thing you need to know when calculating the depth of the foundation is that it must be laid below the freezing level of the ground so that the foundation does not deteriorate due to repeated freezing and thawing.
It should also be located above the level of groundwater flow, which is strong destructive force for the foundation.
An example of a finished structure for a one-story house without a basement is presented below.
Types and varieties of soils
When calculating the depth, you need to immediately find out which soil will be under the foundation of your house. They are:
- heaving, that is, clay, loam, sandy loam;
- non-heaving: sand, rocks;
- slightly heaving soils - various mixtures.
The most optimal soil for construction is non-heaving soil, as it is durable and can withstand any load. You can see an example of such soil below.
You can find out such data by contacting specialists and taking a soil sample from the site.
![](https://i1.wp.com/fundamentt.com/wp-content/uploads/2014/08/2.%D0%9D%D0%B5%D0%BF%D1%83%D1%87%D0%B8%D0%BD%D0%B8%D1%81%D1%82%D1%8B%D0%B9-%D0%B3%D1%80%D1%83%D0%BD%D1%82.jpg)
In accordance with the data obtained, the first calculations can be made, following which the optimal depth for non-heaving soils will be 0.5-1 meter.
For clayey soils - 1.2-1.5 meters, for mixed soils - from 0.5 to 1.25 meters, depending on how mobile the soil is and what percentage of the heaving mixture it contains.
Determination of groundwater level
In determining the second parameter, you can also turn to specialists or try to find out this yourself using special wells called shufrs.
They are dug out at the site of future construction, their minimum depth is 2-2.5 meters.
Using such a well, you can determine the depth of soil freezing and the presence or absence of groundwater. An example of such a well is shown in the photo below.
![](https://i1.wp.com/fundamentt.com/wp-content/uploads/2014/08/3.%D0%A8%D1%83%D1%84%D1%80-%D0%B4%D0%BB%D1%8F-%D0%BE%D0%BF%D1%80%D0%B5%D0%B4%D0%B5%D0%BB%D0%B5%D0%BD%D0%B8%D1%8F-%D1%82%D0%B8%D0%BF%D0%B0-%D0%B3%D1%80%D1%83%D0%BD%D1%82%D0%B0.jpg)
The terrain of the site for construction is also important, because it is easier to lay a foundation on a flat surface.
If the site is on a slope, then it will either need to be leveled as much as possible, or when laying the foundation, take the lowest point as the basis for measuring the depth.
After determining the soil and the absence of obvious presence of groundwater, you can think about the type of future foundation.
It also depends on the type of soil whether lateral reinforcement of the walls is necessary so that the foundation does not tilt over time.
Selecting the type of foundation according to the soil
The foundation itself directly depends on what depth is needed for your construction and on the type of soil being determined.
If it is not heaving, then you can plan a regular strip or columnar foundation, but if the ground is heaving or slightly heaving, then you will have to make a monolithic slab or pile foundation.
Let's consider the main types of foundations for a one-story house, taking into account the depth of foundation:
- Strip foundation, which can be either shallow (for light weight wooden one-story buildings) or buried. This type is the easiest for independent device and the cheapest. If great depth is not required and the weight of the structure itself is small, then you can choose it.
- Pillars and piles can strengthen a strip or conventional foundation, while for a house that is lighter in weight, it is better to use pillars. If the materials for construction are brick or stone, then it is better to drive in piles that can withstand heavy loads, distributing the entire load-bearing weight over perimeter and deeply strengthened in the ground.
- A monolithic slab can be used in the case of heaving soils and in identifying groundwater.
This design is the most reliable and will withstand any impact and weight, but it will also be expensive and will be difficult to install yourself.
An example of such a plate is shown below.
![](https://i2.wp.com/fundamentt.com/wp-content/uploads/2014/08/4.%D0%9C%D0%BE%D0%BD%D0%BE%D0%BB%D0%B8%D1%82%D0%BD%D0%B0%D1%8F-%D0%BF%D0%BB%D0%B8%D1%82%D0%B0-%D0%BE%D1%81%D0%BD%D0%BE%D0%B2%D0%B0.jpg)
Calculation of foundation depth
When you have finally decided on the type of soil and foundation, you can make a final calculation, which will determine the depth of the foundation for a one-story house.
Some try to make the foundation “with a reserve”, that is, to deepen it more than the required level for reliability.
But this will only be an extra financial cost and time-consuming work, and if all calculations are made correctly, then no reserve is required.
Any foundation is laid based on the level of freezing of the ground and is laid 10% lower, that is, if the freezing depth is 1 meter, then it should be laid to a depth of 1.1 meters, this will be enough.
If the climatic conditions in the region of construction are moderate and the soils are loose, then it is most appropriate to lay a shallow strip foundation, which is easy to do with your own hands and will be durable.
It can be either monolithic with a self-filled solution, or prefabricated with ready-made blocks.
By average standards, such a foundation is laid to a depth of 45 cm to 1 meter. Such a foundation looks like the one shown below.
![](https://i0.wp.com/fundamentt.com/wp-content/uploads/2014/08/5.%D0%93%D0%BE%D1%82%D0%BE%D0%B2%D1%8B%D0%B9-%D0%BB%D0%B5%D0%BD%D1%82%D0%BE%D1%87%D0%BD%D1%8B%D0%B9-%D1%84%D1%83%D0%BD%D0%B4%D0%B0%D0%BC%D0%B5%D0%BD%D1%82.jpg)
In more severe winter conditions or when the soil mass is heterogeneous, it is better to make a deeper and reliable foundation, the depth of which can be from 1 meter to 2 meters.
For a one-story house made of ordinary brick, a recessed strip foundation with pillars that will strengthen the entire supporting structure would be quite acceptable.
If the area is swampy or very clayey, then you will have to lay a monolithic slab with piles, even if the structure of the house itself is light.
This will entail considerable financial costs, but you don’t have to worry about the reliability of the design. This foundation can reach a depth of up to 2.5 meters.
Choosing materials for the home taking into account depth
Most economical option These days there are wooden one-story country houses, in which you can make an attic.
When choosing such materials, the house will be quite light and the chance of destruction of the foundation will be minimal, so you can choose a shallow depth and lay the foundation yourself in case of any difficulties.
This building looks like the photo below.
![](https://i0.wp.com/fundamentt.com/wp-content/uploads/2014/08/6.%D0%94%D0%B5%D1%80%D0%B5%D0%B2%D1%8F%D0%BD%D0%BD%D1%8B%D0%B9-%D0%BE%D0%B4%D0%BD%D0%BE%D1%8D%D1%82%D0%B0%D0%B6%D0%BD%D1%8B%D0%B9-%D0%B4%D0%BE%D0%BC.jpg)
One-story houses made of foam blocks are also easy to build and do not require a large laying depth, but they must be wider, since the wall in such houses should be about 60 cm for heat resistance.
Brick or masonry requires that the laid foundation can withstand a large load, so it is advisable to choose both a large laying depth and reinforcement with piles.
This foundation looks like the image below.
![](https://i2.wp.com/fundamentt.com/wp-content/uploads/2014/08/7.%D0%A1%D0%B2%D0%B0%D0%B9%D0%BD%D1%8B%D0%B9-%D1%84%D1%83%D0%BD%D0%B4%D0%B0%D0%BC%D0%B5%D0%BD%D1%82.jpg)
Considering all these factors, we can say that the depth of the foundation for a one-story house can be very different, but all the above factors should be taken into account for the reliability of the structure.
The main reference point remains the depth of soil freezing, which underlies all calculations of deepening.
Video calculations of the foundation depth of a one-story house
In the next video, experts will tell you what rules must be followed when calculating the depth of the foundation, which will help you correctly determine all the parameters, and you will be able to independently build your house, which will last for a very long time.
13.08.2014
Although the depth of the device strip foundation is not the only indicator of reliability and durability; it plays a huge role in the integrity of the entire house during its operation. A reinforced concrete strip of any size and brand of concrete can burst over time if it is not placed correctly in the ground, without taking into account its characteristics.
In order not to get confused in all types of foundations and soils, let's try to understand everything in order. First, we will analyze the types of monolithic strips, and then specifically for each type of strip foundation we will determine the depth of installation.
Factors influencing the depth of strip foundations
It’s probably worth starting with the fact that the strip foundations themselves are divided into three main types:
- Non-buried
- Shallow
- Recessed
Each of these types is laid to a certain depth, which depends on several main factors:
- Soil freezing depth
- Soil type
- Groundwater level
It is worth noting that depth of strip foundation- this is the distance from the surface of the soil to the base of the foundation, and not the depth to which the trench is dug. In addition to the foundation, there may be a cushion in the trench.
Now let's figure out how these factors affect each type of strip foundation separately.
Non-buried strip foundation
A non-buried strip foundation is used extremely rarely in the construction of private houses, because it is a very weak support for the future structure. As a rule, it is all located on top of the ground, and inside there is only a sand or sand-gravel cushion.
I won’t write much about the non-buried strip foundation, especially since a whole article was already devoted to it earlier. And in general, such a foundation does not have the very concept of depth.
Calculation of the depth of laying shallow strip foundations
This is the most capricious foundation in terms of depth. Firstly, it is not as reliable as a buried one, and secondly, in order for such a strip foundation to withstand the load of the structure, and also to restrain all heaving forces transmitted from the ground, its calculation must be approached with special responsibility.
I have already described in detail how to fill it in one of the previous articles. Therefore, we will not go into details.
Such a strip foundation is laid at a depth that is significantly higher than the depth of soil freezing, which is why it is called shallow. Unlike a buried one, it can be significantly affected by soil heaving forces.
Also, an important difference between shallow foundations is that it must be made monolithic not only below the ground level, but also immediately, after placing the formwork, pour the above-ground part of the foundation - the base. This will greatly strengthen the entire strip foundation.
The depth of a shallow foundation directly depends on all three factors described above. In order not to get confused, let's look at the table.
Table No. 1: Depth of laying a strip shallow foundation (minimum), depending on the type and depth of soil freezing
Soil freezing depth, m | Laying depth
foundation, m |
|
The soil is slightly heaving | The soil is not heaving,
hard rocks |
|
more than 2.5 | - | 1,5 |
1,5 - 2,5 | 3.0 or more | 1,0 |
1,0 - 1,5 | 2,0 - 3,0 | 0,8 |
less than 1.0 | less than 2.0 | 0,5 |
Note:In order to find out what the depth of soil freezing in your region, look below at table No. 2, which gives values for some cities, taking into account the type of soil. Click on the table to enlarge. |
Table No. 2: Soil freezing depth in some regions
Note: In addition to the fact that the depth of laying a strip foundation is influenced by the depth of freezing and the type of soil, you should also not ignore another very important factor - the groundwater level, which we will discuss further.
Dependence of the depth of the strip foundation on the groundwater level (GWL)
There are two options for the location of groundwater - when it is located below the depth of soil freezing, and when it is located above.
The groundwater level is below the soil freezing depth
This can be considered a good indicator, and in this case, groundwater in most types of soil does not have a particular effect on the depth of installation of a monolithic reinforced concrete strip.
The only limitation, in this case, is that in soils such as loams, clays and the like, the tape must be laid at least half the freezing depth of such soil. In other, “good” soils, this factor does not affect the laying of the foundation.
In other words, if the freezing depth in your region is, say, 1.5 meters, then the tape shallow foundation it is necessary to arrange at least 0.75 meters.
The groundwater level is above the soil freezing depth
If the groundwater is located high, then the depth of digging the trench for strip foundation does not depend on their level only on rocky soils, coarse-grained sand, gravel and the like.
On any other types of soil, with high groundwater level, the monolithic tape will have to be buried below the freezing depth by 10-20 cm (Table No. 2). In this case, it will become a buried foundation.
Recessed strip foundation
A recessed strip foundation is considered the most reliable of all strips. It is laid 10-20 cm below the freezing depth of the soil. Another condition for its construction is that the soil under its base must be more or less hard.
In the case of swampy soils, peat bogs and the like, the strip foundation is laid at a depth that is below these layers. In some cases, it is enough to dig a trench to hard soil, and then build a sand or sand-gravel bed to a level that is just below the freezing depth of the soil in your region.
When the soil on a construction site is very bad for laying a strip foundation, or its installation requires enormous costs, you can try to calculate another type of foundation, for example, slab. Perhaps it will be both cheaper and more reliable.
How to reduce the depth of a strip foundation
After all the calculations have been made regarding the depth of the strip foundation, it often happens that, taking into account the soil and the region, it needs to be laid very deep. This raises the question of how to reduce costs and reduce depth.
There are several ways to reduce the depth of strip foundations, all of them are based on reducing the importance of the main factors affecting the foundation.
Reducing the depth of soil freezing
We, of course, will not be able to change the climate in the region, but we will be able to change the depth of freezing, specifically under the base of the foundation, by insulating the foundation itself and the soil adjacent to it from the outside.
This way we can reduce the depth of the foundation, as well as reduce the cost of it.
Drainage of groundwater from strip foundation
Another effective way to reduce the depth of a strip foundation is to drain water from it.
This is done using a good device drainage system, which will remove a significant part of the water from the foundation and will not allow it to have a detrimental effect on it.
Sand or sand-gravel cushion under the foundation
In the case where the heaving layers of soil lie deep enough in the area, strip foundation will also have to be laid to greater depth. It can be reduced by replacing the heaving soil with a sand or sand-gravel cushion.
In other words, it is necessary to dig a deep trench down to hard ground rocks, and then place a massive sand and gravel cushion there, which will distribute the load from the foundation and the house onto the ground evenly and will not allow heaving forces to have a detrimental effect on the foundation.
It is advisable to make a pillow not only under the base of the foundation, but also next to it, as shown in the diagram.
It is worth noting that the most reliable method of reducing the depth of a strip foundation is a combined method, i.e. and the installation of a pillow, and insulation, as well as a drainage device, if necessary.
All more people Every day they think about building their own private house, while most of them try in every possible way to protect themselves from the bustle of the city, and choose suburban areas. Of course, not everyone can afford global construction, and therefore more and more people are building one-story buildings, but in order for them to be truly beautiful and durable, you should be very careful when choosing a foundation. Moreover, quite often over time, such houses begin to seem small to their owners, and therefore they expand them or build them up. And here it is the foundation of the house that plays the most important role, since the reliability of your home will depend on its quality in the future.
Which foundation is suitable for a one-story house is, of course, not an easy question, especially considering the variety of them that currently exists.
How to choose the right foundation for your future home?
First of all, what kind of foundation you need directly depends on what material you plan to build the building from.
Main criteria for choosing a base:
- Groundwater flow level. It is their depth that determines which foundation you should use, since if you approach this issue incorrectly, your structure may soon be damaged.
- The condition of the soil itself, as well as its immediate appearance. There are several main types:
- heaving is nothing more than clay, sandy loam and loam;
- non-heaving or slightly uplifted - these mainly include rocks and sands.
- The special characteristics of the future home also play an important role when choosing a suitable foundation. These include: construction of a basement or underground garage.
- The weight of the future house is also not the least important, and it is directly influenced by what material you plan to build the house from.
Well, the last criterion will be your financial capacity, and I would immediately like to note that it is not recommended by architectural experts to save on the foundation, since the durability and reliability of your building depends on it.
In most cases, for the construction one-story houses Such types of foundation foundations are used as strip columnar-pile and slab foundations. In addition, these types of foundations are used for extensions.
Strip foundations
These foundations are divided into two main types:
- Shallow or MZF - a depth of no more than 60 cm is usually used for it, and therefore it is also called floating. It is this kind of base that is highly susceptible to heaving phenomena from the soil itself, which is located under its sole, and therefore it is used only for light structures.
- Reinforced concrete or monolithic strip - such a foundation is more often called GPG, which stands for the depth of soil freezing, and the foundation itself is laid below this level. This type of foundation is used for complex and heavy buildings made of materials such as brick or aerated concrete. It is worth noting that such a base is considered one of the most reliable and durable. If you decide to use this type of foundation, then you need to be very careful in choosing specialists for its construction, and you will also need specialized equipment.
Column and pile foundation
These are quite common types today, but the first ones appeared much earlier, and therefore are used more often.
It is also important that columnar foundations of simple structures are only suitable for very light structures such as, for example, sandwich panels. If you are planning to build a higher quality house, then you should pay attention to bored or screw piles.
Their big advantage is that you can easily build such a foundation yourself.
Monolithic foundations
This is pouring the foundation for the entire territory of the future building, and it can be carried out both in a pre-prepared foundation pit and without it. In terms of quality, this type of base is practically no different from a strip base; its only drawback is its high cost, and therefore not everyone can afford such a pleasure.
Regardless of what type of foundation you choose for your one-story home, before you begin, carefully examine the existing soil and measure the depth of the groundwater. Always remember that the quality of your structure and its durability will depend on these parameters in the future. And if you are not confident in your abilities, it is advisable to turn to professionals.
Video
Errors when laying the foundation can lead to serious problems with the future building. If you want to avoid them, watch this video.
The depth of the foundation for a one-story house is one of the important criteria that determines the strength and operational characteristics of the object. Its value is determined based on engineering surveys, technical parameters of the building being constructed and climate characteristics in a particular region. The designer faces a difficult task - to create a design drawing that reflects the optimal ratio of the cost of the object to the cost of building materials in combination with its reliability and durability. Therefore, the calculation must be carried out by experienced specialists.
Why is it important to consider the foundation depth?
![](https://i0.wp.com/fundamentaya.ru/wp-content/uploads/43-10.jpg)
The construction of one-story buildings by many non-specialists is carried out without calculating the foundation depth and height using generalized tabular values taken from SP 22.13330.2011.
Many people use them to construct a frame building, believing that since it has minimal weight, many influencing factors can be neglected.
For most cases, this is quite reasonable, and the selected parameters are quite sufficient to ensure the required level of strength and reliability. However, quite often many factors are not taken into account, which in a particular situation can play a negative role. An example would be the laying of a buried strip or slab foundation in soil with minimal bearing capacity (sandy loam or alumina), where the total mass of the structure is critical.
As a result, approximately 25-40% of financial resources from the total cost of the object will be spent on construction, which will not be justified.
Exceeding or reducing the safety factor relative to its optimal value can have significant disadvantages that will reduce the service life of a one-story house, especially a brick one. Therefore, it is important to correctly calculate the backfill depth based on SP 22.13330.2011.
Factors influencing the choice of foundation height
The height of any type of foundation for a one-story house is determined taking into account the following criteria:
- Features of the relief of the built-up area. If there is a slope, it will be necessary to deepen the foundation due to the effects of shear forces and increased upward or downward wind loads. There may also be areas with seismic activity that require measures to be taken to calculate a safe burial depth to increase the stability of the object. To understand what design and what parameters the foundation will have, a full calculation should be carried out based on geodetic data.
- Purpose, level of importance, as well as design features of the building.
- Groundwater level according to hydrogeological survey data.
- The presence of nearby buildings and types of foundations used. Houses based on blocks or bricks create significant loads on the ground. This makes it impossible to build objects on deep foundations due to their possible destruction due to a decrease in the load-bearing characteristics of the soil. That is, you should select a suitable foundation device.
- Soil composition and depth of dense layers.
- Soil freezing depths.
- Engineering geological survey data: mechanical, physical and chemical properties soil, the presence of strata, various voids and other features of the site.
Many foundation projects involve not only an underground part, but also an above-ground part. Therefore, the total height of the base structure is the sum of these two values. Moreover, their sizes are determined on the basis of different calculations. To determine what the height of the foundation should be above ground level, you need to assess the possible flooding conditions of the site, take into account wind loads, ensure high-quality thermal insulation of the base, and total weight object.
Height of the above-ground part of the pile foundation frame house made of timber or blocks can in some cases be up to several meters. This is due to the relatively light weight of the structure, compared to brick or block buildings.
Thanks to this, it is possible to construct one-story buildings on water, in seismically active zones and on soft soils with minimal financial costs. In order to understand exactly what length it should be, it is necessary to carry out the appropriate calculations.
Calculation of the foundation depth of a one-story house
![](https://i2.wp.com/fundamentaya.ru/wp-content/uploads/46-10.jpg)
The foundation for a one-story house must be laid at a depth that is below the freezing level of the soil. The drawing must take into account this criterion and is made taking it into account.
The normalized freezing depth is determined based on data obtained over the last 10 years for a specific region. The observation results are compared with GOST 25100, and then the line of transition of plastic frozen soil into solid soil is determined.
If there is no access to such data or they are lost, then for regions with a freezing depth of up to 2.5 m it is permissible to perform the calculation using the formula:
where Mt is a dimensionless coefficient, which is determined by the sum of all absolute temperature values below zero, according to SNiP 23-01. If information about temperatures in regulatory documents is missing, you must contact the hydrometeorological center to obtain them;
d0 is a value depending on the type of soil in the area. You can take it from SP 22.13330.2011.
If the freezing depth exceeds 2.5 m, then thermal calculations must be carried out in accordance with SP 25.13330. Calculation of seasonal soil freezing is carried out using the formula:
where kh is a dimensionless coefficient that takes into account the thermal regime for external and internal foundation structures based on information about the heating of the building. Determined according to Table 1 or taken equal to 1.1 for unheated premises (with the exception of the northern regions, where negative temperatures prevail throughout the year).
![](https://i0.wp.com/fundamentaya.ru/wp-content/uploads/Snimok-ekrana-2016-11-02-v-16.13.43.png)
The data in Table 1 is valid for those cases when the distance between the wall and the edge of the foundation is less than half a meter, and if it is exceeded, the coefficients should be increased by 0.1. If the temperature falls between table values, then take the value with the smaller value.
The depth of laying the external or internal foundation for heated rooms with cold basements or technical premises should be determined based on Table 2.
![](https://i2.wp.com/fundamentaya.ru/wp-content/uploads/Snimok-ekrana-2016-11-02-v-16.14.09.png)
Calculation of the foundation depth for a house made of blocks or bricks with a basement is carried out using the following formula:
where hs is the thickness of the soil above the base as viewed from the basement;
hcf – basement floor thickness;
γcf – value specific gravity basement floor designs.
Watch the video on how to make your own base scale.
What should be the height of the foundation above the ground?
The construction of most types of foundations for a frame or brick house requires the presence of an above-ground part. Its main purpose is to provide protection from precipitation and temperature fluctuations of the load-bearing part of the structure, which is located underground. How tall should it be? On the one hand, it is logical to increase the above-ground part in order to also protect the house itself, but on the other hand, doing this will be expensive from a financial point of view.
It is recommended to install a strip foundation made of blocks or bricks or slabs for a frame or stone house with an elevation from the ground surface of more than 30 cm. Such a device will visually clearly separate the building from the foundation and improve the integrity of the object when operating under the negative influence of the external environment.
For regions with flooded areas or increased precipitation upper part the foundation should be 10 cm higher than the maximum flood level.
This fact must be taken into account and the appropriate dimensions must be applied to the drawing of the house using reliable data for a specific region of development. To simplify the task, you can look finished projects houses that were built nearby. But it is still recommended to double-check the accuracy of the calculations.
When building a frame house, they usually try to save on the foundation and make it from timber. However, to provide additional protection against freezing and heaving of the soil, the height is made much higher than when laying a foundation made of blocks. The maximum permissible length is 30-40% of the total length of the piles, depending on the presence of compressive and tensile stresses in the soil, so that the foundation is not flooded with water.
If you plan to build a house from timber or brick on a foundation made of blocks or monolith, then the calculation must be carried out taking into account the factor of soil subsidence under heavy load. In such cases, it is necessary to provide a reserve of approximately 20-30% of the value taken taking into account the amount of precipitation. This will allow you to effectively deal with heaving and loose soils, as well as seasonal soil movements.
Conclusion
The calculation of the foundation of a frame, brick or block one-story house should be carried out taking into account many different factors that were described above. At the same time, it is important not to miss a single detail that can affect not only the strength characteristics of the object, but also increase the financial costs of construction. This article describes the main criteria that influence the choice of the height of the underground and above-ground parts of the foundation, and also provides formulas and tables for making calculations.