Before you build a building, it is important to determine what foundation is best for the house. Its performance depends on the service life of the future structure and the quality of operation. Choosing the initial level – a very complex procedure, because here you need to take into account the peculiarities of the structure. In this article, let’s consider the main criteria for choosing the optimal design, which will help you during the construction work.
Variants of foundations according to soil properties
When choosing a foundation, it is necessary to start from the type of soil and the project itself. To determine the type of land, a geological survey is carried out at the site of the planned site. In the construction industry, the following types of soil are distinguished:
- rocky; semi-rocky;
Each of the varieties has its own properties, which should be taken into account in the design. It is worth noting that when deepening, the species may change, so it is necessary to consider the thickness of the layers. For example, sandy ones are characterized by low stability and small size of components. Here you need a large reserve of strength when erecting. The clay type consists of even finer particles. For stable soil, a strip foundation is suitable, which does not need to deepen much. In this case, often do not use monolithic structures, but prefabricated from individual blocks.
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Movable soils require solid slabs to be installed throughout the structure. They are reliably reinforced and provide a high margin of safety. If you have groundwater close to the site, the best options are post and pile. The same requirements are for plots with uneven terrain and rock formations. It is worth noting that the pile and post options are unacceptable to use in places where the ground is prone to move horizontally. This will lead to displacement and destruction of the structure. Often in individual construction to save money, people try to determine the type of soil on their own without conducting surveys. In most cases, this is quite possible. Usually the following method is used:
- we take some soil from the site;
- add a small amount of water and roll the resulting substance;
- and then try to roll it into a ring;
- If this succeeds, most of the soil consists of clay;
- when disintegrated, most of the mixture is sand.
Another method is also used. The soil is placed in a container with water, its turbidity can be caused by a large content of small particles, characteristic of clay and loamy species.
What is the best foundation for a house on clay soil
Typically, clay varieties are characterized by large swelling, especially in the off-season, when the moisture level is quite high. In this case, the foundation is subjected to deformation, which over time leads to the destruction of the structure. To avoid this, you need to carefully plan the construction of the house and make a quality drainage system. In our country there are many areas with high clay content in the soil. This makes construction much more difficult, but a properly chosen initial level will allow you to build a durable and comfortable house in any place. The main types of good foundation in such a case are:
- strip foundation with a large recess;
- reinforced plate on a sandy cushion;
- screwed pile.
Types of foundations
Proper analysis of the composition of the soil allows you to make the best choice of construction foundation. The most common varieties are:
- strip – represents a concrete frame in the form of a ribbon, passing under all supporting structures;
- plate – is in the form of a monolithic reinforced slab laid on the ground;
- post – most often used for wooden buildings and is deepened into the ground columns, which may be collapsible system;
- pile – uses different types of piles, which provide a solid system.
During the operation of any building, the soil is subjected to high loads. The most durable in this regard is the strip variety of foundation, which is a reinforced concrete strip that takes on all the loads. On stable soils, there is no need to deepen it. If your plot is unstable or too wet, experts advise building on a plate version. Before choosing the right foundation for the house, you should consider the following factors:
- The foundation should provide sufficient strength for your structure with the possibility of expansion;
- at the same time, it should minimize heat transfer from the room to the ground and vice versa;
- its service life should be higher than that of walls and other structures because it is not always possible to repair it
- It is necessary to provide the possibility of creating cellars, garages and various outbuildings;
For private construction is important economics, but at the same time inadmissible loss of quality. Each of the considered types of bases has its own advantages and disadvantages. It is impossible to call any model the best, because they are all used for different situations. Let’s consider in more detail the most commonly used types.
It is distinguished by its versatility. It can be used both for frame structures and capital stone structures. The only limitation is the possibility of its erection on dense rocks without strong swelling. In this case, the site should be sufficiently flat terrain. The main advantages of this type are:
- high strength, able to withstand brick buildings;
- great opportunities for the use of interior spaces.
Among the disadvantages are the low level of thermal resistance and resistance to moisture. Therefore, it is not recommended to install it in areas with high humidity. This base is installed along the perimeter of the entire house. It is also necessary under the internal bearing walls. Its erection is accompanied by a lot of ground works and most often requires the installation of a formwork. At the same time, this type of foundation is considered one of the easiest to construct. With such a basement, you can easily equip quality and spacious basements. In this case, the concrete strips themselves serve as walls in the lower rooms. However, during construction, it is necessary to take into account the level of groundwater.
The service life of the ribbon type depends on the material from which they are built. So, brick structures last 40-50 years, concrete 60-80 years. If they are made of monolithic concrete, they can successfully perform their functions for several centuries. It is worth noting that longevity also depends on the quality of raw materials, soil conditions and other factors. Such foundations can be monolithic, precast and combined. The first type is made directly on the site, by pouring concrete. To increase the strength, they are reinforced. Prefabricated is collected from individual reinforced concrete blocks, which are then fastened to each other using concrete and reinforcement. Depending on the material used, such foundations are divided into:
- Butte – is laid of large stones of natural origin;
- Brick – is the usual masonry of moisture-resistant bricks;
- Concrete – poured in a pre-prepared form.
This is one of the most expensive types of foundation. It allows you to build reliable and durable structures. The foundation is a monolithic reinforced slab that is laid on a sand and gravel cushion. In order to obtain the necessary properties, a combination of technologies is often used and slab-and-tile and slab-and-pile are erected.
Sometimes several slabs are used instead of one slab to simplify construction. However, after laying them, you will still need a strong cement screed of the surface. The best foundation for a house of this type is a solid monolithic surface.
When deep buried, this variety can serve as a basement floor. To ensure the necessary strength, reinforcement is carried out over the entire area of the reinforced concrete product. This protects against the emergence of cracks, even with poor-quality soil. The main advantages of using the slab are:
- the possibility of operation under any loads;
- virtually no restrictions on the soil;
- good performance of thermal insulation;
- resistance to moisture.
The disadvantages are:
- the need for a perfectly flat surface;
- high cost;
- In case of shallow grounding there is no possibility of erecting underground premises.
To confirm the service life of the monolithic foundation, we can refer to history. Egyptian pyramids, installed on such a base, have been standing for several thousand years. It is the most durable material. However, it is not always possible to achieve such results when using slabs. Complex structures require complex load calculations. When used on problematic soils, the slightest flaws can affect the longevity of the product.
It is worth noting that slab varieties can compensate for significant horizontal and vertical fluctuations in the soil. That is why it is often used when the ground is bulk, friable and permanently frozen. It also protects the building from groundwater, but there should be a well-thought-out drainage system, waterproofing and thermal insulation.
In this variety, the main support element are piles. They evenly distribute the load from the building and are not afraid of uneven shrinkage, to which the strip foundation is very sensitive. This type is the only possible for use in some types of complex and mobile soils. In addition to providing stability to buildings, pile structures can strengthen the soil. There are several of these types, which are used depending on the requirements for the future construction.
Screw piles are suitable for low-rise structures on low-moving soils. Also, in order to use them, the groundwater must be deeper than 3 meters. They are a metal tube with a drill on the end. Therefore, when choosing them, you should pay attention to the quality of metal. It should be remembered that even corrosion-resistant metal products lose their properties over time, being in an aggressive environment. Among the obvious advantages is the ability to install such products without the use of special equipment.
Concrete piles are structures resistant to corrosive environments with high strength. They can withstand tremendous loads for a long time without changing their properties. Thanks to different types of concrete and reinforcement, it is possible to create reinforced concrete elements with different characteristics.
Bored products are considered the most reliable and can successfully withstand both vertical and horizontal loads. However, they are very expensive and their use in low-rise construction is not always economically justified. Working with such structures requires a lot of sophisticated equipment. You will also need a lot of high-quality concrete and reinforcement. The choice of the type of foundation for a house of the pile type is based on thorough surveying work. Its main advantages are:
- high resistance to various mechanical influences;
- resistance to aggressive substances;
- long service life;
- a large margin of safety, which is especially important for private housing, when the occupants are constantly expanding their buildings.
Among the disadvantages note:
- high complexity of installation;
- during installation, it is possible to damage the neighboring buildings;
- high cost.
However, despite all its disadvantages, this type is often used in both individual and apartment construction.
It consists of poles installed according to the calculations. It is suitable for small structures not exceeding 2 stories in height. The construction of such a foundation does not require ground works, and its cost is the lowest. However, this variety should not be used in the following cases:
- In areas with shifting soil in the horizontal plane or a high level of humidity;
- If you plan to build a large house with brick or reinforced concrete walls;
- In the case of a significant difference in elevation.
Pillar foundations are made of wood, brick, concrete and other materials. The service life of support structures depends on the choice of raw materials. Even for treated wood, the service life does not exceed 30 years. However reinforced concrete posts have a virtually unlimited lifespan.
To increase the longevity of products are treated with various compositions that protect against moisture, rodents and other factors. For wooden poles should be selected wood of strong species. Since ancient times, as materials for the erection of poles use rubble stone, which has a long service life. This variety is repairable and, if necessary, you can replace the damaged part with a minimum of labor. Depending on the depth of the columns, such a foundation is divided into:
- How to choose a foundation
As we see there are a huge number of varieties of foundations for the house. In order not to make a mistake when choosing, you need to:
- Determine all the parameters of the soil, the size of the layers and the level of groundwater;
- Learn all the nuances of the relief, and if possible, to level it as much as possible;
- Calculate the characteristics of the building.
The question of how to determine which foundation is necessary for the house, is the most difficult during the construction, so you should carefully perform all calculations, and better to entrust this task to professionals who have extensive experience in this area. It should be remembered that the life of your building and the comfort of its operation depends on this stage. Newcomers often make mistakes that lead to disastrous consequences. Therefore, if you are confident in your abilities and have done thorough research, you can make your own choice. For individual construction, the professional advice given in this article will help you to answer the question of how to choose a foundation for a house.