The foundation is the part of the building that takes on the entire load of the structure and transfers it to the ground. From the strength of the foundation depends on the stability, strength and durability of the whole house, so it is very important to choose the right type.
One of the types of foundation is columnar. Its arrangement is advisable when deep laying is required and other types of foundations, such as strip or slab, are too expensive an option. As a rule, columnar foundations are arranged for light, one or two-story structures made of wood or brick.
To build a foundation with your own hands is a columnar or some other, though not simple, but quite feasible, you should only study the construction technology well.
The construction of the pillar foundation consists in the construction of separate, unconnected pillars, under the main components of the structure - at the corners, around the perimeter of the building, the intersection of the walls, under the walls and other points of great concentration of loads. As a rule, building a foundation with their own hands is columnar, the distance between the elements is 1.2–3 m. On the erected pillars, strapping beams are laid, on which, in fact, the laying of walls begins.
Building a foundation with your own hands, a columnar can be used for this the following materials: concrete, concrete, but-flagstone, natural stone or brick. The dimensions of the pillars depend on the material of the foundation, the dimensions of the structure and the material from which it will be built.
Starting to build a pillar foundation with your own hands, you should know the exact dimensions of the building and its internal layout, that is, the location of the bearing walls and partitions. First of all, you need to make markings on the site, for this, the length of the walls is measured with a tape measure, pegs are hammered in the center of the supposed posts, without fail, checking the diagonals in order to avoid skewing and ensure all angles are 90 °.
Further, building a pillar foundation with your own hands, you need to properly work with a drill to dig a small pit under each pillar. Its depth depends on the depth of soil freezing in this region. For example, if this value is 1 m, then the depth of the pit should be 1.2 m, the width of its sides depends on the cross section of the column. In each dug hole, you need to clean the walls, put them on the sides with a waterproofing layer, for this you can use a regular roofing material, and pour a small sand pillow on the bottom, which is recommended to be well tamped. In the center of the future column, several rods of reinforcement are installed, which should protrude above the surface of the earth to the estimated height of the element.
The next step is pouring the prepared excavation with concrete to the ground level, then, around each column, formwork should be arranged. It can be wooden or metal, collapsible or monolithic. Concrete should be taken with a high grade, and when preparing the concrete mix yourself, you need to make sure that the cement has a brand of at least 400. If you wish, you can build a foundation with your own columns from burnt bricks on cement mortar, with obligatory dressing of joints.
The main thing, in the construction of this type of foundation, you must adhere to the iron rule: the height of all columns must be horizontally aligned, for this you can use the water level and regulate not only the neighboring columns, but also the diagonal ones.
You can use an asbestos-cement pipe as a permanent formwork . In this case, it is installed at the bottom of the recess, carefully calibrated vertically and filled with concrete to the entire height of the column, ramming it well.
Finished columns should be left for complete hardening of concrete for at least a month, covering from precipitation.
Before starting construction, a columnar foundation should be calculated. It’s unlikely that this can be done independently, since this procedure is quite painstaking and requires some special knowledge, but in general it consists of the following steps: determining the nature of the soil and using special tables to find the maximum permissible load, then calculate the weight of all the structures of the house and determine the places of maximum load points. Then, the largest weight value is divided by the permissible load and, as a result, the area of the foundation support is obtained. Usually, for reinsurance, add another 40% of the value to it. But this is a simplified scheme, since when calculating the column foundation, the concrete grade, the amount of reinforcement and some other necessary parameters are also taken into account. In any case, you should not deal with the foundation calculations yourself, because it is the most critical part of the structure and an error in its calculations can cost too much.