The stable operation of the sewer system of a private house in the cold season depends on how to insulate its constituent elements. Next, let's talk in more detail how to equip a cesspool so that it does not freeze in winter. Particular attention should be paid to the upper part of the well. Waste water does not freeze even in the most severe frosts due to the activity of bacteria that cause fermentation. The upper part of the cesspool is less populated by these bacteria, therefore, those elements of the septic tank that are located in the freezing zone of the soil, and also protrude above the ground, need insulation.
You can insulate the drain pit using the following materials:
- foam plates, thickness not exceeding 100 mm;
- a layer of expanded clay with a thickness of not more than 300 mm;
- mineral wool with waterproofing.
Cesspools with overflow mechanism
Next to the cesspool, another septic tank is dug, deeper. Its walls are reinforced with reinforced concrete rings, and the bottom is left earthen. Through the holes in the upper rings, the pits are connected with overflow pipes. The pipes should be laid at a distance of at least 500 mm from the surface of the soil, that is, below the zone of its freezing. If the region has very harsh winters, then this figure can be increased to 800 mm.
A septic tank from two wells is the optimal solution to the issue of sewage insulation.
What are the cesspools
All cesspools in a private household can be classified according to two criteria:
- By type of construction (absorbing and storage);
- By the materials used (concrete rings, bricks, rubber tires, plastic containers).
Absorption wells usually do not have a sealed bottom, and sometimes walls: liquids through a drainage layer of gravel and sand in a filtered form naturally go into the soil mass, freeing up the cesspool space.
Storage tanks are sealed structures that take in all sewage waste and are cleaned only with a sewer machine. In some cases, sealed containers are preferable to absorbing wells, or generally the only possible option.
Two main types of cesspools
The use of concrete rings, concreting the pit with formwork, and brickwork can be used for both constructive types of pit latrines, while the use of car or tractor tires is more suitable for an absorption well, and special plastic containers for a sealed storage pit.
When choosing the type and materials for construction, it should be borne in mind that the best cesspool is the one that is optimal for your site, taking into account its layout, the location of water sources, the depth of groundwater and the quality of the soil itself.
Insulation of the drain pit with polystyrene
One of the most widespread technologies in the field of thermal insulation of various objects is polystyrene insulation. This method is also suitable for a cesspool. It is especially convenient that today polystyrene can be purchased not only in the form of flat plates, but also in the form of "shells" - half rings. In addition, you can always choose the required thickness and diameter.
Warming begins with the fact that the cesspool is surrounded by a trench with a depth of at least 1.5 meters. Then, pre-prepared polystyrene half rings are installed in this trench. The insulation is attached to the walls of the well using the thorn-groove mechanism, after which the trench is buried. The pit cover must also be carefully insulated.
A significant advantage of this method of warming is that if you need to clean or repair the drain pit, it will not be difficult to dismantle the polystyrene "shell", and return it to its place upon completion of all work.
Location and type of cesspool on the site
The current sanitary norms and rules establish legal requirements for the location and design type of a cesspool in a personal (summer cottage) plot. In their main points, these norms are simple and consist of several rules:
- the distance from the cesspool (hereinafter - VYa) to the nearest well is at least 20 m, to the central water conduit - 10 m;
- it is impossible to locate the VY closer than 4-6 m to a residential building on the site itself and to houses (capital structures) on neighboring sites;
- to the fence, limiting the territory of home ownership, the VYa must be at least 1 meter and must be in the territory immediately adjacent to the residential building;
- the depth of the VP depends on the characteristics of the soils in the area and the depth of the groundwater, however, it should not be more than 3 meters.
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If flood events are often observed in your area, it is impossible to leave filtration holes in the walls of the cesspool, and it is also advisable to raise the inspection hatch cover to a height sufficient to avoid flooding the hole.
Effective operation of absorbing (filtering) cesspools is possible only in conditions of loose soils with filtering properties. Clay, sandy loam, loam, as well as rocky and semi-rocky rocks cannot be attributed to such soils - you will have to equip a sealed storage pit.
An important and practical advice is to separate the drains and arrange two cesspools on the site at once. One, sealed - for the toilet, it will not fill up so intensively and the frequency of calling the sewer truck is noticeably reduced. The other, absorbing - for the shower, washing machine and kitchen sink: insoluble inclusions in the so-called. There is very little “gray water”, so almost everything is absorbed into the soil.
When choosing a place for a cesspool, do not forget to provide for the possibility of a large-sized sewer truck entrance.
Effective insulation of the sewer: we save not only the pit, but also the pipes from frost
How to insulate not only the drain pit, but also the communications suitable for it, that is, to approach the solution of the problem of thermal insulation of the sewer system in a comprehensive manner? Of course, the ideal solution to the problem of freezing of sewer pipes is to lay them below the freezing level of the soil. If this is not possible, the pipeline should be carefully insulated. Some difficulties always arise with the pipes at the entrance to the room and with those sections of the sewage system that pass through unheated rooms. In these cases, it is advisable to use heating with a 10 W electric cable. The cable is wrapped around the sewer pipe at a certain frequency. When connected to the mains, the wire heats up, heats the pipe, and therefore the liquid in it. Thus, the possibility of freezing the pipe is simply excluded.
It is recommended to use a generator as a backup power source.
disadvantages
The only drawback of this method of insulation is a significant increase in electricity consumption. On the other hand, severe frosts last 1-2 months, and heating up already frozen pipes will cost you much more. In addition, only the most problematic sections of the sewer pipes can be wrapped with an electric wire. Difficulties with protecting pipes insulated in this way from freezing can arise even when there are power outages. In this case, an autonomous generator will save the situation.
Thus, the insulation of the sewer system of a private house should be approached comprehensively.Insulating a cesspool means solving only one of a number of tasks. By taking measures to insulate the sewer pipes, you can be absolutely sure of the stable operation of the entire system even in the most severe frosts.
How to preserve a septic tank for the winter
If the septic tank is installed in winter, but no one plans to use it yet, the system needs to be mothballed. It is important not to leave the structure without water for a long time.
A number of recommendations on how to preserve a septic tank for the winter so that it does not freeze and break will help you do everything right and avoid mistakes:
- Disconnect and dismantle electrical equipment: pump, grinder, etc.
- Fill the septic tank with at least 70% water. If there is less water, the structure may float, if more, it may crack from the expansion of frozen water.
- Place a container of sand in each chamber. Plastic bottles on a string will do. Fill them with sand, but so that the bottle retains its buoyancy. Such a simple trick will reduce the load on the case.
- Close the cover tightly and replace the thermal insulation.
If the above cannot protect the water inside the septic tank from freezing, it can prevent equipment failure or deformation of the case.
If your treatment plant is frozen, don't panic.
Since all elements of the system are in order, you only need to melt the ice and continue to use the autonomous sewage system
Hot water or brine can help melt frozen pipes. Thus, you can easily and inexpensively bring the septic tank to life in winter and continue to use it.
For more information about the preservation of the septic tank for the winter, the rules for maintaining the treatment plant in the cold season, see the articles:
- How to preserve a septic tank for the winter: step by step instructions
- Septic tank maintenance rules in winter: cleaning measures and preventive work
Arrangement of a cesspool
So, finally, let's start considering such issues as the construction of a cesspool and the process of its independent construction. We will give as an example several of the most practical design options for household needs, which you can easily implement with your own hands.
Cesspool made of concrete rings
When deciding how to make a cesspool in a private household, which will effectively last more than one decade, many owners choose reliable concrete rings as a material. This is a justified choice, since such a technology is time-tested, understandable and accessible, and concrete as a material is very durable, resistant to the effects of an aggressive environment and soil pressure. Moreover, as already mentioned, with the help of concrete rings, you can build a cesspool of both types.
First you have to dig a pit - manually or with a tractor. The pit diameter should be approximately twice the size of the rings used. The bottom should be well tamped and as even as possible, observing the horizontal level. The rings themselves are laid with the help of a truck crane - they are too heavy, one cannot do without mechanized assistance.
Usually, wall concrete rings of standard sizes with an inner diameter of 1 m (wall thickness - 8 cm) and a height of 89 cm (KS10-9), 59 cm (KS10-6) or 29 cm (KS10-3) are used. By choosing the right dimensions, you can equip a cesspool of any required depth. For a larger volume, take rings with an inner diameter of 1.5 m (respectively KS15-9, KS15-6 and KS15-3).
To ensure the tightness of the pit, either a lower ring with a dead bottom is installed
either put the tower of their rings on a concrete support - the finished bottom plate PD-10 (PD-15) or fill the bottom of the pit with a 15-centimeter concrete screed, keeping an eye on its horizontal level. In the case of concrete pouring, add another week to the total construction time of the cesspool to harden the concrete.
In the case of an absorbing pit, instead of a concrete bottom, a thick (1 meter long) filtering layer of crushed stone with a sand filler (20 cm) is poured, on top of which a layer of sand (80 cm).
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From above, the structure of concrete rings is covered with a PP-10 (PP-15) floor slab with an opening for the hatch.
A neat hole for the sewer pipe is hollowed out in the wall of the upper ring. The depth of the pipe should be lower than the depth of the winter freezing of the soil in your area. Also, be guided by the minimum standard slope of 2-3 mm per 1 meter of pipe length.
When installing the rings one on top of the other, make sure they are aligned, avoiding distortions and shifts. A great solution to the problem is rings with connecting locks or quarters at the ends. After installing the rings, seal all cracks, joints and the entrance of the sewer pipe with cement mortar.
Outside, the resulting well is sealed (optional) with bituminous mastic and additionally wrapped with roofing material. The upper part can be additionally insulated to the depth of freezing, for example, with a layer of mineral wool or foam.
After the completion of all "concrete" work, the space around the well is covered with construction waste and soil taken out during the excavation of the pit.
Use the lower clay soils, while the fertile soil of the upper layer is poured over the beds and flower beds.
Cesspool from car tires
A very cheap, and often generally free, way of arranging a durable cesspool in the country is to use used automobile or tractor rubber tires to strengthen the walls of the pit. This is perhaps the best "summer cottage" option, which does not even require helpers. The main thing is to pick up a sufficient number of identical (of the same type) tires.
The pit is usually dug with a shovel, deepening in a circle counterclockwise. The diameter of the pit turns out to be larger than the outer diameter of the tires by about a shovel bayonet on each side.
The depth is calculated from the maximum allowable 3 meters, and includes a filtering layer of crushed stone and sand. The edge of the upper tire should be a dozen centimeters below ground level, in which an appropriate deepening is made and an overlap made of solid boards treated with a protective composition, wrapped with a layer of roofing material, with a hole for a hatch through which the waste not absorbed into the earth will be pumped out will be carried out.
For better operation of the cesspool, the side surfaces of the tires must be cut off with a jigsaw, and the opening of the sewer pipe inlet must also be cut out with it.
The tires themselves should be fastened together: sometimes a bolted connection is recommended, but it is better to use plastic ties that are more durable in an aggressive environment.
The upper three tires must be sealed at the joint, the lower ones are optional, you can even make holes in them for water to enter the ground.
Brick cesspool
Another good and very popular option for arranging a reliable and durable cesspool is brickwork. The use of solid red baked clay bricks is said to guarantee 50 years of flawless tank service! Moreover, it is not at all necessary to buy a new brick, it is enough (or maybe even better) to purchase material from the dismantling of old buildings.
To create a storage tank, you will have to pour a concrete screed along the bottom of the pit and wait a week for the concrete to harden. For a filter pit for brickwork, a strip foundation is needed: a wooden formwork is built around the perimeter and poured with concrete, preferably with the laying of reinforcement, and they also wait a week.
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A pit can be dug in a round, square or rectangular shape, exactly the size for laying bricks close to the walls or larger, in order to then additionally seal the outer surface of the brick well (box). At the same time, a trench for the sewer pipe should also be dug, which is usually laid in advance, and then bricked and sealed with cement mortar.
Masonry does not need beauty and precision, but it should still be laid from the corners. If you are making an absorbing cesspool, the bottom third of the masonry can be laid loosely, with the spaces between the bricks as drainage holes.
You can cover the "brick" cesspool in different ways - you can buy a ready-made reinforced concrete slab with a hatch, or cast it yourself, by erecting a formwork and placing there reinforcement made of metal rods laid with a side of a 10 cm square and tied at the intersection with wire. All this is poured with concrete and waiting for its complete hardening (one and a half to two weeks).
Cesspool from a plastic tank
Not to say that it is cheap, but it is quite simple to use a special plastic (polypropylene) container as a storage cesspool, which are produced by the industry in a large assortment, of different shapes and volumes.
This is a reliable and durable option that will last for more than a decade, since polypropylene feels great in the ground and in contact with the aggressive environment of household drains.
However, when installing plastic cesspools, there are critical nuances, failure to comply with which is likely to lead to big problems. However, there is nothing to worry about.
First, the plastic barrel is light and can be pushed out of the earth.
Solution to the problem: a concrete screed 20 cm thick with reinforcement and metal lugs is poured onto the bottom of the pit, which is digging with a margin of 30-40 centimeters in area on each side of the barrel, to which the barrel is then “anchored” with metal chains or strong belts ... You can put a ready-made reinforced concrete slab, you can “anchor” the barrel with chains to concrete blocks separately laid in the pit.
Second: when filling-tamping the foundation pit, the barrel may crack. Solution: in parallel with the compaction of the soil around the barrel, pour water into it, the level of which is always slightly higher than the ground level. Then the water is pumped out using a conventional pump. Solution 2: erect brickwork around the barrel or use a so-called storage tank as a storage tank. Eurocube, which was initially “dressed” in a metal frame.
