Pillow under the foundation - additional reliability at home

In order to build a reliable house, it is necessary to lay a solid foundation. Its main purpose is to transfer and redistribute the load from the weight of the whole house to the ground. A solid foundation prevents excessive building draft, thus protecting it from cracks, distortions and destruction.

There are several kinds of the basement . Specific type is selected depending on the design of the future building, as well as from the ground on which it will be erected.

For a house built on the basis of a frame, which consists of beams, columns, panels, overlappings, it is necessary to lay the foundation of columnar type. A feature of this type of foundation is that the entire load is overlaid on the substrate. There are situations when an additional monolithic slab is installed for this type of foundation . If the soil is not strong, then it is strengthened with a pile field.

When building cottages, as a rule, choose a tape type of foundation. In this case, it can be either monolithic or prefabricated. In some cases (for example, in weak soils), an additional monolithic cushion under the foundation is installed. The walls are made of blocks.

To date, the definition of the phrase "pillow under the foundation" has created confusion. It is believed that the pillow under the foundation is a sufficient compacted soil layer of gravel or sand, which is laid in the foundation of the foundation. But, for the pillow used and reinforced monolithic concrete.

A sand pillow under the foundation is laid about a hundred millimeters thick. This thickness is necessary in order to level the foundation pit. Concrete preparation for the foundation is necessary when the walls of the base of the building are too narrow.

The concrete type of pillow can also be made of slabs. Plates should be selected according to the width that is required to create a cushion. To understand what width is required, special calculations are necessary. The width of the cushion is also affected by the type of soil (more precisely, its bearing capacity) and the weight of the building.

In order to correctly calculate the width of the pillow, consider an example for which random values are taken. We assume that the weight of the building will be 10 tons per meter of length, and the bearing capacity of the soil is 2 kg per centimeter square. The formula for calculating the width of the cushion under the foundation will be: (100 kg / cm): (2 kg / cm2) = 50 cm. When choosing a monolithic cushion, the resulting width is rounded up. In this case, the figure obtained must be a multiple of one hundred. For example - 700 mm, 800 mm, etc.

The thickness or size of the cushion in the vertical should be at least 300 mm. Usually 300-400 mm is taken as a basis. This is due to the fact that when choosing a large parameter of the thickness of the pillow, excessive consumption of raw materials occurs.

After calculating the width and thickness of the cushion, it is necessary to prepare materials for reinforcement. The cushion under the foundation is reinforced with a special wire net, the diameter of which is more than 12 mm. The size of the cells should be on average 200 to 200 mm.

The concrete cushion under the foundation is installed in the following sequence:

1. First, a base is made of crushed stone or sand. The thickness of the base is 100 mm. The way of laying the foundation is tamping into the ground.
2. Next, the formwork is installed under the pillow of the foundation. After that, it is mandatory to waterproof the pillow with a "spill" hot bitumen. As a result, a waterproofing film is formed.
3. The next stage is reinforcement of the foundation with a special grid.
4. The pillow is poured with concrete and left until it is completely set and freezed (concrete picks up the "fortress" for about 21 days).

Only the observance of clear recommendations will create a reliable support for the future of the building.