Usually the process of any construction involves work on the foundation. They include the digging of a trench or pit, the installation of formwork, as well as the construction of a frame of reinforcement. At the next stage, the structure is poured with concrete, and then the foundation is backfilled. When the foundation is erected around the perimeter of the building, voids are formed, which are called sinuses by the builders. They should be bombarded with different materials, which are chosen by the owners of the house or developers. The construction phase only seems easy, in fact, in the process of these works it is necessary to take into account many nuances.
Backfill time
Despite the fact that future home owners want to speed up the process, there is no need to rush with backfill. It is necessary to wait for the foundation to harden, and also to finish work with the basement of the building. The design of the base must solidify completely, as this is dictated by the loads exerted on the material.
The base is much easier to equip if the foundation is not yet covered. The flooded base after work must be left at least 10 days in sunny weather. However, experts recommend extending this period to 20 days. In some cases, during construction, backfilling is carried out too quickly, because some believe that the lateral load does not have a special effect. But such pressure is very strong.
Material selection
When the backfilling of the foundation is carried out, specialists choose materials, they can be:
If it was customary to use the soil, then the one that was taken out when digging the pit is taken. All of these options have their advantages and disadvantages. For example, if you use sand to fill your sinuses, then you will need to mix it with gravel, the resulting composition passes water well. Using this material allows you to negate the effects of frost heaving forces. However, water permeability has its drawbacks, which are expressed in the fact that all water from nearby soil will drain into the backfill. As a result, an excessive load on the waterproofing is formed, and the bearing capacity decreases in the soil.
This problem can be solved only partially - using the blind area. It is a waterproof strip that is installed around the perimeter of the foundation and protects it from moisture. The blind area can be done independently, for this waterproofing and the underlying layer are used. Ensuring perfect tightness is unlikely. Water flowing down the blind area must be diverted, therefore, it is also necessary to arrange drainage.
Use of clay and soil
Backfilling of the foundation can be carried out using clay. This is a heaving material that will absorb water. You can use the technology, which involves the use of soil. He is taken from a dug pit.
This approach eliminates the cost of removal, in addition, you will have the opportunity to store soil near the construction site. Formed residues, such as the topsoil, can be used effectively if you are keen on landscaping.
Technology features
Backfilling of the foundation should be carried out according to the technology, because only in this way it will be possible to avoid trouble during the operation of the building. The process should begin by checking the soil at the work site. In order for the filling to turn out to be of high quality, you need to make sure that no forgotten tools, concrete, pieces of wood and other foreign materials are left at the place of work.
It is important to check the soil moisture. This parameter is determined by the method of laboratory research. To carry out backfilling, do not use too dry soil, it should not be mud-like. Depending on what kind of soil is on the site, its moisture content can range from 12 to 15%. This is true for heaving soils. As for heavy soils, their moisture content should be equal to 20%.
If the humidity requirements are not met, work is carried out on wetting or drying. In the second case, the soil is dried in the sun, while if necessary, moisten the soil must be exposed to cement milk, which you can make yourself. To do this, a certain amount of cement should be dissolved in water. As soon as the liquid turns white, the milk is ready for use. If backfilling of the foundation sinuses involves moisture, it is necessary to determine the type of soil. If it is connected, then you can bring it into compliance in the pit. In all other cases, work is carried out on the material to be poured.
Filling the bottom of the pit
The technology of backfilling the foundation consists of several stages. The first step is to place the material used on the bottom of the pit. It can be sand or earth. The thickness of the layers can vary from 0.3 to 0.5 m. The layers, if necessary, are sprayed with cement milk and well compacted. Fertile soil is not allowed to be used during such manipulations, because it contains a lot of organic matter. Over time, it will begin to decompose, which will cause shrinkage.
Base filling
When you decide how to backfill the foundation, you need to familiarize yourself with the technology. At the stage of filling the cap, the material is placed inside the sinuses. This is true if you are not planning a basement device. When the structure does not have a cellar, it is necessary to follow this algorithm. The technique will depend on the size of the pit. If it is large enough, then you need to use a special technique, namely:
- bulldozer;
- excavator;
- glider.
Backfilling can be carried out manually, for this it is necessary to enlist the help of one or two people. Work is carried out immediately along the entire length of the foundation, otherwise the lateral pressure in some areas will become too strong. This phenomenon leads to the fact that the foundation is deformed over time.
Soil compaction
Backfilling the box foundation necessarily involves compaction of the soil. It is necessary to carry out such work with the help of additional equipment, because if you use a hand tool, then the tamper will be too time-consuming. When it is planned to use special equipment in the work, the layers must have a certain thickness. When using sand, this parameter should not exceed 70 cm. Whereas in the case of clay, the thickness is 50 cm. Loams and sandy loams are laid in layers up to 60 cm.
If you still plan to carry out the work manually, then the above parameter should be 30 cm or less. The final value will depend on the type of soil. It is necessary to start work from the area that is closer to the building. In the process, you will advance to the edge of the slopes. After tamping, a blind area is installed on the ground, which is necessary to protect the foundation and soil from excessive moisture. If you decide that you do not need a blind area, then you should be prepared for the fact that meltwater and precipitation will wash out the soil. This will be followed by deformation and destruction of the base, so the blind area is necessary even in cases where the structure has a drain.
Backfill
Backfill inside the foundation also involves the selection of technology and material. They will depend on several factors, among them it should be highlighted:
- type of operation of the building;
- floor / floor structure;
- basement height;
- ground water level.
As for the first factor, if the building is used for permanent residence, and the heating is year-round there, then the soil will not freeze under the sole, so filling can even be done with clay, which can swell during freezing. It is important to consider the construction of the floor as well as the floor. If the project provides for overlapping, arranged along the beams, then backfilling is best done with clay. Backfilling of the foundation with sand from the inside is carried out with floating floors arranged on the ground. Sand will be needed to level the base, and it fits in a 10-cm layer.
Foundation construction
If you want to backfill the foundation, then you will need to familiarize yourself with the technology for the construction of the foundation under the house with your own hands. It is necessary to begin with determining the state of the soil and the depth of groundwater. To do this, go deeper by 1 m and evaluate the composition of the soil by the presence of water in the pit. If it is, then the depth of the foundation should be 0.5 m more. If there is no water, then the depth of the base may not exceed 0.5 m.
When building the foundation under the house with your own hands, you must mark the territory and remove the fertile soil layer. To do this, dig trenches around the perimeter of the future home, and the bottom is leveled with sand. The next step is to fill. For this, formwork is installed from plywood or boards. Pouring can be done with concrete. The density of the solution is directly proportional to the strength of the future design. The width of the foundation should be 20 cm greater than the thickness of the future wall.
Methodology
Before you begin, you need to study the step-by-step instructions. In this case, you can lay the foundation with your own hands without any problems. At the next stage, after solidification of the solution, it is possible to waterproof the structure. To do this, roofing material is laid in two layers on the surface, and the underground part can be smeared with hot bitumen until the moment of filling. As soon as the waterproofing layer is laid, you can start laying blocks or bricks, and ventilation holes are arranged on the opposite walls, which will eliminate the dampness of the space under the floor.
Conclusion
If you decide to build the foundation with your own hands, a step-by-step instruction of the process will become in this case the best assistant. Having become acquainted with it, you will be able to understand that before the backfill of the side walls of the base of the house, a lot of work is necessary. Among them, marking, digging a pit, installing formwork and pouring mortar should be highlighted.
In works where concrete is used, rush is useless. Therefore, after the pit is filled, it should be left until the solution solidifies. Once this happens, you can continue to work. This can be not only backfill, but also preliminary waterproofing of the surface.