On problematic soils, especially prone to shifts, this type of foundation, such as floating , is often used as a support for buildings. It is a monolithic slab located immediately under the entire area of the house. In the event that a shift occurs, the foundation will advance along with the ground and the entire building. As a result, the walls will remain intact.
Floating foundation is also called "slab." In the construction, several types of such bases are used for the building: deep, medium deep and shallow. In private housing construction with independent construction of houses, only the last type of slab foundation is used. This is due primarily to the fact that its construction is a rather laborious and costly process in terms of money. Experts for the same reason advise private traders to apply such a foundation only for small buildings. So, how do you build such a foundation yourself?
First of all, you need to prepare the site. All garbage is removed from it, bushes are uprooted, etc. Then make markings around the entire perimeter of the future building. It is important to ensure that all angles are straight. After this work is completed, they begin to dig a foundation pit actually under a floating foundation.
The depth of laying depends on the characteristics of the soil on the site. Usually, the level of
groundwater and the depth of freezing of the soil are taken into account. Formwork is installed around the perimeter of the pit.
Further, in order to arrange a floating foundation, a layer of sand mixed with gravel is poured onto the bottom of the pit, which will serve as a kind of reinforcing pillow and at the same time drainage. The layer thickness depends primarily on the severity of the future walls of the building. 5 cm concrete is poured on top of the sand and waterproofing is mounted. To do this, lay the bottom of the pit with roofing material in two layers in different directions, smearing the seams with bitumen.
A floating foundation, the construction technology of which does not differ in particular complexity, must be reinforced. For this, wooden bars of the same thickness are installed in several places on the waterproofing layer. They will serve as a support for the reinforcing mesh.
The latter is made from 10-16 mm rods. Thickness also depends on the severity of the house. The mesh size of the reinforcing mesh is 20 * 20 cm. It is best if it is not welded, but connected by a wire. The bars are again installed on it, and on them is the second of the same design. Thus, the future foundation will be reliably reinforced. All that needs to be done next is to pour concrete over this entire structure. The foundation must be carefully aligned at the top. Concrete will finally mature one month after pouring. After that, you can mount the waterproofing and walls.
Like any other design, a floating foundation has some of its drawbacks. First of all, this, as mentioned above, is its rather high cost. After all, concrete, metal, gravel and sand take up much more on it than, say, on the same tape or column. In addition, the complexity and huge amount of work do not allow to erect a similar design without the use of technology. It is unlikely that you will be able to dig a pit even under a small building, using only a shovel, not to mention pouring it with concrete.
Therefore, it is first of all necessary to determine the appropriateness of using such a foundation as a floating foundation under the house. The disadvantages of such a support can make a more successful and correct choice, for example, tape or pile construction.