The construction of any building is impossible without the construction of a foundation. This is the basis of any construction that provides reliability and durability. There is a fairly wide variety of types of foundation. Modern construction ensures the introduction of new technologies, which is aimed primarily at cost-effectiveness. This property is achieved through the use of materials that retain heat. Such an innovation at the stage of laying the building is the USP-foundation (USP - insulated Swedish plate).
Foundation Features
The insulated Swedish stove, as the basis for the arrangement of the foundation, was first introduced by German developers, despite its name. The UWB foundation is used in Russia for a relatively short time, but is already very successful. The Swedish stove is a monolithic structure, which plays the role of not only the foundation, but also the overlapping of the first floor with a finished heating system. Such a foundation has good bearing capacity, it can be laid on almost all types of soil - weak, freezing, chemically aggressive, etc. The difference from other types is that the insulation layer is provided not only on the lower base, but also along the perimeter of the structure on the side walls.
Benefits of the Swedish foundation
This may include:
- quick terms of construction;
- possibility of application on various soils;
- increased thermal insulation of the base of the building, ensuring the constancy of the temperature regime inside the building;
- savings on heating by reducing heat loss;
- after laying the foundation leveling work of the surface is not required;
- improved waterproofing, which prevents the penetration of moisture and the formation of mold;
- hiding all communication systems, by laying them under a foundation slab.
Design
In order to start laying work, it is necessary to carefully design the UWB foundation. Calculation needs to be made, starting from the project of the building itself. The need to account for design data ensures the correct location of all necessary communications. When designing the foundation, you can only rely on the primary sources provided by Swedish manufacturers, because there are no Russian analogues of the calculation yet. Many construction firms have developed instructions that describe only the sequence and correctness of work to form the foundation.
Foundation technology
The use of high-quality heat-insulating material can reduce the thickness of the entire stacked structure, which can significantly reduce the time of laying. On average, the construction of the foundation structure, depending on the area, takes about 7-10 days. If we compare the terms with the filling of a conventional strip foundation, then here the process takes a fairly long period: from 30 to 45 days. Do-it-yourself USP foundation is not particularly difficult if you adhere to the rules provided by the project. The sequence of all work can be divided into several stages.
Preparatory operations
- A foundation pit is being prepared for the foundation; for this, a soil layer with a depth of 10 to 50 cm is removed by the size of the future foundation.
- If the soil on which the USP base will be mounted is very moist, first you need to drain and drain the groundwater. The drainage layer is a pillow made of crushed stone and coarse sand.
- After arranging drainage, geotextiles are laid at the bottom of the pit, and sand of a certain fraction is poured on top of it, which is provided for by the technology and compacted.
- USP-foundation, laying communications. This operation is quite responsible. It is necessary to provide for all inputs - sewer, electrical, plumbing, etc., which must be laid with particular accuracy, ensuring the correct connection of communication systems in the house.
- The formwork is being installed. Then, on top of the laid sand, gravel is poured and compacted. This layer should be about 100 mm.
Laying the thermal insulation layer
For these works, an insulation type of extruded polystyrene foam is used. When choosing a heat-insulating material, it is worth paying attention to such parameters:
- as the strength of pressing at a 2% rate of maximum deformation, because it will bear the load of the whole house. The pressing strength should not be less than 0.2 MPa;
- thermal conductivity of the material from 0.030 to 0.034 W / (m · K);
- the presence of L-shaped edges that will simplify installation, and exclude cold bridges.
During the installation of the installation, lateral insulation plates are installed with a thickness of at least 100 mm. Then the insulation is laid over the entire plane. The minimum thickness of the material should be at least 200 mm, that is, if the polystyrene has a thickness of 100 mm, it is necessary to lay the insulation in 2 layers.
Structural reinforcement
This process has its own characteristics and provides for two successive stages:
- For the grillage, a special longitudinal spatial construction is made with a step of transverse dressings of 300 mm. The diameter of the fittings used should be 12 mm. It is only necessary to twist the bundle of fittings, which will be installed on the USP foundation, the technology does not allow the use of welding. Welded fittings may affect the strength of the future foundation monolith. This reinforced structure is assembled outside the foundation, and then transferred to it and installed.
- The foundation surface is reinforced. It is necessary to carry out these works with fittings with a diameter of 10 mm. The rods are stacked longitudinally with a pitch of 150 mm, after which the transverse rows are superimposed at the same distance and the reinforcement is connected to each other. The overlap of the joined rods cannot be less than 25 mm.
Installation and connection of the "warm floors" system
The only type of foundation that is combined with the heating system is the USP base. The underfloor heating system requires professional design, which will maximize the use of the heat given off. With proper calculation, there will be no need to use additional sources of space heating. The system is laid on top of an installed reinforced structure. You can use these types of pipes:
- metal-plastic;
- polyethylene;
- copper.
One should pay attention to the choice of pipe products, because for such a system it is acceptable to use only high-quality pipes that are designed to work at high temperatures. Otherwise, any jump in temperature will disable the system, and then you can forget about the "warm floors" of your house. Molecularly cross-linked polyethylene can be considered the best option for such structures; it has very high strength. Using this type of pipe, you get a reliable USP-foundation, the problem of long-term operation of the "warm floor" system in your house will be solved.
The main condition for high-quality insulation is rationally laid out pipe contours:
- the distance between the laid pipes should be not less than 10 cm, but also not more than 25 cm;
- the length of one circuit should not exceed 90 m;
- fastening to fittings can be performed with nylon clamps;
- layout by room - in the center of the room there should be more pipes, and less near the walls.
Concreting process
Before starting
concrete pouring , the heating system must be checked for leaks at a test pressure that exceeds the working pressure three times. During concreting, pipes must be filled with liquid to prevent their deformation. Only high-quality concrete can be used for pouring; its distribution over the surface is carried out using shovels. Spreading of concrete should be provided in all inaccessible places for reinforcement. The pouring time of the concrete mixture should not exceed 1 hour. It is undesirable to concrete the UWB foundation with your own hands at low temperatures, for such work a high qualification of the fillers is necessary, because such a temperature regime involves special technologies. To get finished floors for finishing, you must carefully smooth and polish the surface of the concrete layer. After work on pouring concrete, it is necessary to ensure the correct maturing regime, which in the future will provide a quality foundation. We examined the main stages of the foundation laying process. Arranging such a foundation for your home, in addition to all the charms, has disadvantages.
USP-foundation. Cons of using an insulated Swedish stove
- Laying this type of foundation requires considerable costs, because only high-quality materials should be used in the process.
- Under the projected building, it is impossible to provide for the construction of basements, since this is prohibited by the construction of the base of the insulated Swedish stove.
- Such a base of the house, such as an insulated Swedish stove, is not suitable for structures of large mass. This foundation finds its application for the construction of single-story cottages or not too large two-story houses.
Of course, each person has his own opinion on this. If you are interested in the impressions that the UWB foundation makes on the owners, feedback from people who built this foundation for their homes, you can always study at any building forum. There is no unequivocal opinion, but most positive reviews give an advantage in favor of the use of such technology.