If you live in a private house, then to lay the sewage system, if you have not done so already, you will have to do it yourself. You can, of course, trust the specialists, but the work will cost more. It is impossible to achieve without this proper level of comfort. However, there are many nuances in the work, one of them is expressed in the depth of the sewage. Efficiency and durability of the system largely depend on this.
Depth of laying communications
As the main component of the cleaning system, you should choose a septic tank. It is located in a pit near the house. The distance should not be less than 5 m. As for the depth, the septic tank is usually located 1.5 m from the surface of the earth. The foundation pit can be strengthened with concrete, which eliminates the destruction of the septic tank, which can be caused by soil pressure. Other factors, such as groundwater, sometimes contribute to this.
The presence of knees and turns
The depth of the sewage can be determined, guided by the level of location of the structure. When laying communications over the entire segment from the house to the septic tank, it is not recommended to make knees and turns. This approach is considered ideal. The pipeline should be made straight. Pipes are buried a line above the mid-point of freezing of the soil. It should also be taken into account that on sites and roads that will be cleared of snow in winter, the depth must be increased so that the pipes do not freeze and do not collapse.
The minimum laying depth is 80 cm. This value is relevant for regions with a warm climate. Harsh winter provides for a deeper pipeline.
Self-determination of depth
Before determining the depth of the sewage, you should take into account some points. Firstly, the products must have a sufficient diameter. Secondly, they should be laid with a certain slope, which is 0.03 m per linear meter. Thirdly, it is important to take into account the location of the septic tank and the point where the sewer pipe will leave the house.
The angle of inclination is determined in accordance with sanitary norms and rules. In this case, it will be possible to reduce the risk of blockages, as well as achieve spontaneous movement of wastewater. There can be any number of turning points and pipe connections in the house, but they must be avoided on the street.
The need for wells
Adhering to the aforementioned sewage depth is recommended for several reasons. If the pipes are located on the freezing line of the soil, the liquid may cool, which will contribute to congestion, and the sewage system will not be able to operate before the onset of heat. You can avoid blockages if there are minimal connections.
When it is not possible to manage without turns, a well must be made at the junction, and free access to it. If there are problems with the sewage system, the pipes can be easily cleaned and checked for quality of connections. When laying communications should take into account the freezing line of the soil. In each region, the level is different. If your region has a harsh winter, the trenches for laying the pipeline must be made even deeper.
Thermal insulation
In order to extend the life of the sewer, pipes should be insulated. For this, it is best to use polyurethane foam. A stainless pipe will be wrapped with this material, and a plastic sheath should be applied on top. This will prevent freezing. Most often, this problem occurs at the joints, as well as bends, so the pipeline should be made straight. High-risk areas must be well insulated.
To heat the pipe, you can mount an electric cable. The pipeline should be laid at a sufficient depth, despite the insulation. The degree of thermal insulation will depend on the climatic features of the region. The sewerage depth in the northern regions can reach 2.5 m, while in the southern regions there is no point in digging pipes to such a depth. It will be enough 1 m.
What materials to use
In an area where the climate is harsh, fiberglass or mineral wool should be used for insulation. These materials are used for pipes laid and above the soil. In this case, it is necessary to think about waterproofing.
What is important to consider when choosing a depth
When choosing the depth of the sewer pipe, several factors must be taken into account. This should include not only the freezing line of the soil and the strength characteristics of the pipes, but also the depth of the location of the entry point of the pipe into the septic tank or collector. A rather important factor is the dynamic load, which during the operation of the sewage system is transported to the pipeline.
Depth and laying pattern are determined taking into account practical and economic benefits. It is especially important to consider the climate factor more seriously. Many believe that the laying depth should be greater than the freezing line of the soil, which is true for pipeline installation works. However, determining this value is not easy.
It can help determine the depth of the sewage and SNiP. To do this, refer to the documentation of SNiP 2.01.01.82. In this document there is a map of zones indicating the freezing lines of the soil. Guided by the map, you can determine that the value for the Moscow region is 1.4 m, and for areas nearby Sochi this parameter is 0.8 m. But these calculations are valid only for large objects. If a residential building is under construction, then the level of depth of laying is determined differently.
During the construction of housing, the sewage system is usually gravity. It is important to observe a slope for proper functioning, which can turn into a real problem, this is especially true if the pipeline has an impressive length. When determining the laying depth, you should consider which treatment plant you plan to use at the end of the pipeline.
Specialist advice
With increasing depth of the bookmark, dig a deeper pit under the septic tank. It is not worth digging the treatment plant too much. The point here is not only that digging a hole will be difficult. The septic tank should be installed in order to bury only the main storage of drains, while the lid should be visible above the surface of the earth. If you dig a septic tank deeper than the recommended norm, you will have to increase the height of the neck, which is not always possible. Too deep pit under the septic tank makes it difficult to clean.
When determining the minimum depth of the sewage, it should also be taken into account that the pipeline can leak, and laying too deep will make it difficult to repair, especially in winter. In most cases, the depth is selected without taking into account the freezing line of the soil. There are reasons for laying pipes at a shallower depth.
The first of them is expressed in the fact that drains can have not only room temperature, but also high temperature. The frost formed on the inner walls will be washed off with warm water. Another factor: if they do not use domestic sewage, the pipes will remain empty, therefore, there is simply nothing to freeze in them. The third factor is that heat will enter the sewer from the treatment plant or septic tank, which is formed during the treatment and decomposition of effluents. This indicates that there is no need to make the laying depth greater than the freezing line. For the middle strip, pipes from the house are removed at a depth of 0.7 m, then you need to dig a ditch and lay communications, adhering to the necessary slope.
Storming Depth
You can also determine the minimum depth of the sewage according to SNiP. For this, it is necessary to be guided by SNiP 2.04.03-85. According to some points of this document, the laying depth of a stormwater pipe must be determined taking into account the cross-section. If it does not exceed 500 mm, then the system is laid at least 30 cm in the level of soil freezing. If the first value is more than 500 mm, then the second increases to 50 cm. However, these items are advisory in nature. Their application rests with the conscience of builders and installers.
According to SNiP, the depth of the sewage in a private house must be determined based on the experience of operating such systems in a particular region. Typically, the minimum rainfall depth is 70 cm from the surface. The best option would be laying pipes below the freezing level. When digging a trench, you should know this figure by adding to it the thickness of the sand cushion. In some regions closer to the north, the depth may be 1.5 m or 2 m. To this should be added soil, which can be rocky.
It is important to take into account the slope requirements. If the rules are not followed, the water will not leave, and the effectiveness of stormwater will decrease. In this case, if the terrain is uneven, the depth of the trenches can reach large values. Many people wonder whether the depth of the external sewage can be less to lay pipes closer to the surface. But it should be remembered that there is a difference between stormwater and domestic sewage, which consists in the temperature of the effluents.
There are no warm drains in storm sewers, and water is not always there. In winter, the pipes are completely empty, to this should also be added the minus temperature. With the onset of spring, warm water will fall into the cold "dungeon", which will contribute to the formation of icing and congestion.
If the depth of the storm sewage is no longer possible, communications should be insulated. If the pipes have thermal insulation protection, they should not be deepened into the ground too much.
Depth of pressure pipes
Answers to the question posed above can be found in SNiP 2.04.03-85. The smallest depth can be determined based on the operational experience of networks in a particular area. If there is no necessary data, then the minimum depth of the bookmark can be determined taking into account the diameter. If it does not exceed 0.5 m, then it is necessary to deepen the system by 0.3 m.
The depth of the pressure sewer is determined taking into account practical experience. In rocky and water-saturated soils, a pressure sewer must be laid at a depth of 4 m. If work is carried out in dry soils, then the depth must be increased to 7 meters.
Finally
Depth of laying is an important factor when installing a sewage system. If you do not comply with the norms, you may encounter freezing of communications, which will disable them. This often causes congestion.