Floating foundation - building step by step

The foundation is designed for uniformload distribution created by the weight of the building and transferring it to the ground. When its construction should be borne in mind that it must go on naturally compacted soil slightly below the freezing depth.

Depending on the soil type, and size of buildingsa number of other factors are divided into floating foundations, strip, pile and bar. In this article we consider in detail the technology of building a floating foundation.


  • Floating foundation - what is it
  • Layout area under the floating type base
  • Preparation of the excavation
  • Preparatory layers
  • formwork
  • The device of the floating foundation - reinforcement
  • Concreting of the floating foundation
  • Major errors in the construction of

Floating foundation - what is it

On the heaving soils, characterized by an increasedinstability, as well as in high wetlands, it is best to use a floating foundation. A very common misconception that this type of property is characterized by a "float". In fact, the foundation will swim with the house only if the work will be done properly. On the condition of the house, which is located on such a basis ground motion does not affect, as there is no misalignment of one corner of the house relative to the other. And it is called floating because, moving along with the house, protects it from destruction in any soil loss.

Another term that has a foundation- Floating slab. It is the presence of a monolithic reinforced concrete slab is a characteristic feature of the floating base. Therefore, it is very resistant to loads of varying severity that arise during freezing or thawing of the soil, as well as soil loss. In addition, such a foundation is a reliable protection from the harmful effects of groundwater.

The structure of the floating foundation

The structure of the floating foundation

The main drawback of floating foundationsIt considered its high cost. To create a rigid structure requires a large amount of concrete, and special equipment. That is why the monolithic slab often filled by small structures, even though it provides a greater degree of reliability. Raise a floating foundation with his own hands is very difficult because of the complexity of the work, so it is best to invite a team of specialists, or even to enlist the support of relatives.

Layout area under the floating type base

The device of the floating foundation should start by marking areas designated for this purpose.

We need:

  • cord or fishing line;
  • level;
  • roulette;
  • angled triangle (can be made independently of thin strips, and the legs are to be equal 30 and 40 cm).

Note: according to state standards building should be at least three meters from the nearby area and not less than five meters from the front of borders own site.

Is planned on the site of one building corners and trying to drive to this place a peg.

Tip: best seen pegs, painted with red paint.

On peg put on a triangle and, continuing one of its sides, measure the length of the house, and on the other side - the width of the house. The endpoints trying to drive the pegs are the same - the second and third.

Layout area under the floating foundation with his own hands

marking precision - a guarantee of correct geometrical parameters of a house under construction

Now we define the axial line and hammeredfourth peg. Correctness of installation check with the help of a triangle, and by comparing the diagonals. If HOAR stakes scored correctly, the diagonal will have a difference of not more than 2 cm. In case of discrepancy between the size of the diagonals is necessary to achieve this condition by moving the corners. After that, the pins connect in pairs or fishing line cord and get a well-defined boundary of the future of the foundation.

Preparation of the excavation

Please remove all the vegetation layer with a planned area of ​​the house. Thus it is necessary to add 1 meter along the perimeter, it will need under the blind area.

Blind area - a strip of asphalt or concrete, which protects the foundation laid by the effects of water (rain and floods) and imparts an attractive appearance of the finished structure. Located at an obtuse angle to the structure.

All removed layer can be transferred to a place where you plan to split the lawn or planting trees. After that, you can start digging the foundation pit.

Preparation of the excavation under the floating foundation

Pit can dig so, but it is better to hire an excavator

Most often used excavator for digging. Pit digging under design elevation, and sometimes takes several bucket below it. When there is insufficient experience of the superintendent Perekop just poured sand machine and carefully zaravnivayut. This is the most common mistake in the construction of the foundation.

Note: the building, put on such a ground, be sure to burst at the site of Perekop and in very rare cases it is possible to save.

When the soil sample should take into account the factorloosening. Rocks increase its volume twice topsoil and sand - three times, and rubble - four. Some of the excavated land mass should be left at the site, it may be useful in subsequent studies and garden landscape broken down, and the rest will need to bring special transport.

Tip: The pit should be dug with a slight slope walls. The best option is a gradient of 1: 0.25. This will prevent fraying of the pit edges.

Preparatory layers

Before pouring the foundation necessary to floatto hold a series of preparatory work. To start at the bottom of a well-aligned base (using level) should be pour a layer of gravel about ten centimeters tall. Laying should be carried out in several stages, carefully ramming each layer using a special device (you can use the log with a handle). After that is filled with a layer of sand, gravel and riving precluding its subsequent "festivities." In addition, high frost resistance of sand will help prevent squeezing of the finished basement. The sandy layer is recommended to seal using a vibrating tool. To achieve the best effect, you can sand lightly with water.

Next waterproofing layer is laid. As it is used thick polyethylene film or any other material having similar properties. This will not only avoid further infiltration of moisture in the finished ground, but also the flow of the concrete, "milk" by pouring a solution. For thermal protection can be laid extruded polystyrene, but not necessarily.

Then poured a thin layer of a cheaper grade of concrete M-100 - footing.


Once the pit is ready,Getting to the device casing. In that case, if the foundation is submerged in the soil, can do without it, this role will be played by the pit wall. A significant drawback of this method is the inability to create a high-quality waterproofing the outside of the base of the wall.

Tip: formwork better not to save, and how to fix it carefully to avoid bursting the concrete layer.

Formwork for floating foundation

Pouring concrete into formwork for monolithic slabs

For shuttering boards require no more than the thickness25 mm and not less than 20 mm, of which panels are prepared. The width of each panel should be 50-100 mm larger than the height of the planned structure. Boards attached to the vertical walls of the well and sealed with roofing felt, paper or cardboard.

At the upper edge of the formwork is laidcontrol cord, and for the convenience of fixed only one of its sides, and the second with a load attached freely hanging on the other side and is removed at the time of filling solution.

The device of the floating foundation - reinforcement

Now we proceed to the installation of reinforcement. Reinforcement of the floating foundation - A very important and significant step. In this case it is necessary that in places walling metal rods sticking out of the basement. This achieves an inextricable link base and walls.

Linking fittings with a soft wire

Linking rods reinforcement of soft wire

Important: when connecting parts of a metal reinforcement between them in any case can not use the welding machine. When welding any metal changes all of their consumer properties. Attach reinforcement rods should be using soft binding wire.

When installing the valve care must be taken todistance between adjacent rods is not more than thirty centimeters (ideally 20-25 cm). All the reinforcing structure must become one inseparable whole, and at the same time to go to the ends of the blind area of ​​the proposed site. In the corners of the metal bars should be close in a semicircle, and make their ends in the side walls of the foundation. The result is a flexible one-piece construction.

Preparatory layers of rubble and rebar

Now you can pour a concrete layer

Concreting of the floating foundation

Now we proceed to the concreting of the base. Stacking layers of the solution is carried out not more than fifteen centimeters, carefully leveling and ramming each shtykovaniem. Concrete is poured at once, so it is best to book a car ready solution. If you decide to fill their own foundation, then for him to one part of cement is taken over a part of the water and sand.

Important: Fill the plate should be made no more than one hour. The only way to achieve the best result.

compacting concrete

Concrete ramming up wet shine

Trumbo concrete until the surface of the shiny wet layer.

Align the top layer of the foundation can be with wooden slats.

How to dry floating foundation

To correct a floating foundation is dry, it must be wet in the early days

On the first day of the foundation should be every 4-5 hoursmoisten with water or cover film, otherwise there can be cracks, especially in hot weather. On the second day of the foundation is wetted only 3 times, and the next is only in the morning and evening. After drying, the formwork can be removed, but the foundation will be fully prepared to just one month.

Ideally, proceed to the next stepconstruction work is recommended only for the next year, then there is a ready structure must defend winter and only after complete drying of the meltwater can begin the erection of walls. But if the timing really running out, it is necessary to wait at least a month. Otherwise, you can get disastrous results, such as misalignment, subsidence or destruction of the structure.

Major errors in the construction of

Sometimes there is a violation of the building structure inthe destruction of the fundamental layer due to mistakes made during its construction. Only if a responsible approach and compliance with all the recommendations you will be able to build a house, pleasing residents for decades.

Thus, the most common errors:

  1. Placing the foundation above the freezing depth. For what it may lead - you guessed it;
  2. Construction design on frozen soil. Frozen soil increases in size, swells and after thawing necessarily squander. Of course, if such a ground base falls, then it gives way;
  3. The lack of waterproofing. If we neglect the vertical insulation, the spring and autumn, when the soil saturated with moisture, the foundation body begins to actively pull the water into itself. In winter, this moisture freezes and breaks the base. In the absence of moisture horizontal waterproofing of the foundation and actively moved in the walls, which leads to the same outcome.

Choosing a floating foundation, you'll not regret it. This type of foundation is very rare in need of repair. Of course, this is very expensive, but at the same time, the most reliable way.

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