Usually, the process of any construction involves work on the foundation. They provide for 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 the builders call the sinuses. They should be filled 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 this work, many nuances must be taken into account.
Backfill time
Despite the fact that the future owners of the house want to speed up the process, there is no need to hurry with backfilling. It is necessary to wait for the foundation to harden, and also to finish work with the basement of the building. The structure of the base must be completely cured, as this is dictated by the loads exerted on the material.
The basement is much easier to equip if the foundation has not yet been covered. floodedthe base after work must be left for 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 side load does not have much effect. But such pressure is very strong.
Selection of materials
When the foundation is backfilled, specialists choose materials, they can be:
- clay;
- sand;
- ground.
If it was customary to use the soil, then the one that was taken out when digging the pit is taken. All of the above options have their advantages and disadvantages. For example, if you use sand to fill the sinuses, then it will need to be mixed with gravel, the resulting composition passes water well. The use of this material makes it possible to negate the effect of frost heaving forces. However, water permeability has its drawbacks, which are expressed in the fact that all water from the nearby soil will drain into the backfill. As a result, an excessive load on the waterproofing is formed, and the bearing capacity of the soil decreases.
This problem can be solved only partially - with the help of a 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 made independently, for this, waterproofing and an underlying layer are used. A perfect seal is unlikely. flowing downthe blind area needs to be diverted, so you will also have to arrange drainage.
Using clay and soil
Backfilling the foundation can be done with clay. This is a heaving material that will absorb water. You can use the technology that involves the use of soil. It is taken from a dug pit.
This approach allows you to eliminate the cost of removal, in addition, you will have the opportunity to store the soil near the construction site. Leftovers such as topsoil can be put to good use if you're into landscaping.
Technology Features
Backfilling of the foundation should be carried out according to the technology, because this is the only way 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 backfill to be of high quality, you need to make sure that there are no forgotten tools, concrete, pieces of wood and other foreign materials left at the work site.
It is important to check soil moisture. This parameter is determined by the method of laboratory research. For backfilling, do not use too dry soil, it should not be mud-like. Depending on what kind of soil is on the site, its humidity can range from 12 to 15%. This is true for heaving soils. As for the heavysoil, then their moisture content should be equal to 20%.
If the humidity requirements are not met, wetting or drying work is carried out. In the second case, the soil is dried in the sun, while if necessary, moistening the soil must be exposed to cement laitance, 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 the backfilling of the sinuses of the foundation provides for moisture, then it is necessary to determine the type of soil. If it is coherent, then you can bring it into line in the pit. In all other cases, work is carried out on the material being filled.
Filling the bottom of the pit
The technology of backfilling the foundation consists of several stages. At the first, it is necessary to place the material used at 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. If necessary, the layers are sprayed with cement milk and well compacted. It is not allowed to use fertile soil during such manipulations, because it contains a lot of organic matter. Over time, it will begin to decompose, causing shrinkage.
Filling the plinth
When you decide how to backfill the foundation, you need to familiarize yourself with the technology. At the stage of filling the base, the material is placed inside the sinuses. This is true if you are not planning a devicebasement. When the design 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 done manually with 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 causes the foundation to deform over time.
Soil compaction
Backfilling a box foundation necessarily involves soil compaction. It is necessary to carry out such work with the help of additional equipment, because if you use a hand tool, then ramming will turn out to be too laborious. 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 move towards the edge of the slopes. After tamping, a blind area is installed on the ground, which is necessary for protectionfoundation 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 melt water and precipitation will wash away 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.
Internal backfill
Backfilling inside the foundation also provides for the choice of technology and material. They will depend on several factors, among them should be highlighted:
- building operation type;
- floor/floor construction;
- basement height;
- groundwater level.
As for the first factor, if the building is used for permanent residence, and the heating is year-round, then the soil will not freeze under the sole, so filling can be done even with clay, which can swell during freezing. It is also important to consider the design of the floor, as well as the floor. If the project provides for a ceiling arranged along the beams, then backfilling is best done with clay. The 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 is laid in a 10-cm layer.
Building the foundation
If you want to backfill the foundation, then you will need to familiarize yourself with the technology for building the foundation for the house with your own hands. It is necessary to start with determining the condition of the soil and the depth of groundwater. To do this, you should go deeper by 1 m and evaluate the composition of the soil according tothe 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 foundation may not exceed 0.5 m.
When building a foundation for a house with your own hands, you must mark the territory and remove the fertile soil layer. To do this, trenches are dug around the perimeter of the future house, and the bottom is leveled with sand. The next step is to fill. For this, formwork made of plywood or boards is installed. Pouring can be done with concrete. The density of the solution is directly proportional to the strength of the future structure. The width of the foundation should be 20 cm more than the thickness of the future wall.
Work methodology
Before starting work, 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 the solution has solidified, it is possible to waterproof the structure. To do this, roofing material is laid on the surface in two layers, and the underground part can be smeared with hot bitumen until backfilling. Once the waterproofing layer has been laid, blocks or bricks can begin to be laid, and ventilation holes are arranged on opposite walls, which will eliminate the dampness of the space under the floor.
Conclusion
If you decide to build a foundation with your own hands, the step-by-step instructions for the process will be the best assistant in this case. After reviewing it, you can understand that until the side walls of the base of the house are backfilled, a lot of work needs to be done. Among them, it should be notedmarking, digging a pit, installing formwork and pouring mortar.
In works where concrete is used, there is no need to rush. Therefore, after the pit is filled, it should be left until the mortar solidifies. Once this happens, you can continue working. This can be not only backfilling, but also preliminary waterproofing of the surface.
