How a cesspool is built in a private house: materials, nuances, calculations

Autonomous sewerage - this is a forced step in the absence of a central highway. But if you have a private house outside the city, the likelihood of being able to connect to a centralized channel is negligible. So it makes sense to find out how a cesspool is built in a private house and choose the most suitable material for your case. That's exactly what we'll talk about today.

Types of cesspools

classify cesspools It is possible according to three criteria: according to the material of the walls, according to the design of the tank and according to the principle of operation of the pit itself.

If considered by materials, cesspools are:

• plastic - specialized containers with a volume of 1 cubic meter;
• metal - containers and containers that were previously used for other purposes are usually used;
• concrete - for such a design, monolithic concrete or concrete rings, which are produced in the factory, can be used;
• rubber - for this purpose, used car tires from trucks are used, they are bolted together for structural strength;
• brick - the easiest option for self-production of a large-volume pit.

PHOTO: rebathroom.ru

Another principle of gradation of cesspools is by the nature of the design. There are only two options - open and closed. Open pits are extremely rarely made, only in the case of a significant distance from residential buildings and a very small volume of drains. Finally, cesspools can vary in how they work. Here the division occurs into single-chamber (the simplest options) and multi-chamber (with complex principles of wastewater treatment).

Separately in this row are septic tanks - structures that are complex in their design with pumping wastewater, additional treatment and their disposal. The output is technical water, which can be use for watering and other technical needs.

What you need to know before building a cesspool

Ignoring some of the rules for building cesspools can lead to rather unfortunate consequences: you can invest funds, but as a result, get a structure, the volume of which will be sorely lacking, so you have to constantly spend for cleaning. In addition, without taking into account some of the nuances, there is a risk of getting a completely idle object.

How to calculate the optimal volume of a cesspool

The volume of a septic tank directly depends on the characteristics of water consumption in your house and the number of residents. If you visit the cottage on weekends and do not invite guests, a small hole will last for a long time.

Based on average indicators, one adult consumes 0.5 m³ of water per day. For children, as usual, half the norm is calculated. If you have, for example, a family of three, then the calculation will be 0.5 + 0.5 + 0.25 = 1.25 m³. It makes sense to round this figure up to 1.5 m³. This is an indicator of the collection of effluents per day. Now think about how often you can clean the hole. The volume of the sewer truck is usually up to 12 m³, it makes sense to correlate your calculations with this. The maximum depth of a high-quality cesspool is up to 3.5 meters. It makes no sense to make it deeper - the hose of the sewage machine may not reach deeper.

Requirements for the location of the cesspool

There are SanPin standards that require you to retreat 20 meters from a residential building, and not only your own, but also from your neighbor's. From non-residential buildings, the distance must be measured at 15 meters. If a basement or ground floor goes outside the house, the countdown is made from its wall.

If there is a well in the yard or adjacent body of water a septic tank from the toilet is installed from them at a distance of at least 30 meters. from the road or fence should be at least 2 meters, from the garden - 5 meters.

PHOTO: septik27.ru

The nuances of laying a sewer pipeline from the house to the pit

Sewer pipeline in private households, they usually do not lay deep into the ground, but this is precisely what is fraught with a number of operational difficulties. If the pipes are too high, the water in the sewer can simply freeze, and in this situation the entire sewage system will stop working. Moreover, pipes with frozen water can break, and then you will also have the hassle of re-laying the system.

So you need to look for the optimal depth at which the water will not freeze and the normal functioning of the entire system will be ensured. If the distance from the house to the collector is up to 10 meters, a depth of 35 cm is sufficient. If the distance is greater, the pipe must be laid deeper and must be additionally insulated.

The further north the land is located, the deeper the pipes will need to be laid, and this will affect the size of the septic tank, because you understand that the pit will be filled exactly before the pipe enters it, and after contents of the septic tank might just go backwards.

PHOTO: sidingvin.ru

In terms of choosing materials for pipes, it makes sense to focus on plastic ones. They have smooth walls, which is good for transporting waste. In addition, plastic copes well with aggressive chemical environments and has a very long service life. The only disadvantage of these pipes is the threat of mechanical deformation under excessive pressure. When laying such highways, it is necessary to think over their additional protection from this weak side.

Related article:

How to organize an autonomous sewage system on the site: arrangement and operation of cesspools, septic tanks and treatment stations, advantages and disadvantages, comparison of three systems.

Brick drain pit: arrangement nuances

The most difficult part of the work in arranging a cesspool is, of course, digging a pit. Manually digging a hole 2-2.5 meters deep is quite realistic, but long and hard. The technology of manual work is the simplest: the soil is loosened with a bayonet shovel, and then raised to the surface with a bucket. To facilitate the task at the last stage, when the depth already significantly complicates the lifting of the soil, use the system of the most primitive lifting mechanism.

It is much faster and easier to involve equipment for digging a pit, in which case the walls may not turn out as smooth as when working by hand, but this can be compensated for when laying bricks or pouring concrete.

The pit for the pit is dug in such a way that the walls converge slightly to the bottom, and the bottom itself has a slight slope to the side.

PHOTO: septik27.ru

Foundation laying

If you have conceived a sealed container, then the bottom of the pit needs to be concreted. And here, instead of manually pouring, you can find a simple way out - lay a concrete slab of a suitable shape on the bottom.

In the case of manual pouring, a sand and gravel cushion is first laid on the bottom with a layer of 15–20 cm. The bottom is reinforced with a metal wall and the screed is poured over it. Next, you need to wait until the base gains strength before starting brickwork. It will take about 28 days for a full set of strength, but after a week you can start work without waiting for the end of this period.

If the pit is not planned to be completely sealed and its bottom will be a filter backfill, the screed is still made, but it is made around the perimeter along the width of the brickwork, constructing wooden formwork for filling. This design works without pumping for a very long time.

PHOTO: ac-bastion.ru

Brickwork

It is possible to perform brickwork in a cesspool even with a complete lack of experience. Here, perfect seams and a flawless look are not so important. For a garbage pit, any type of brick, it is permissible to use the remnants and minor battle left after the main brickwork. If there is a choice, it is better to use a solid brick. With long-term operation of the cesspool in an aggressive chemical environment, everything is destroyed, and brick is no exception.

It is recommended to add lime or clay to the masonry mortar. The proportions are as follows: for 3 parts of sifted sand, take 1 part cement brand not lower than M400, ½ part of slaked lime or clay and 0.8 parts of water. Masonry is checked building level, although the aesthetic part is not so important here. The walls must be level so that there is no collapse.

When arranging a permeable pit, the brick is laid in such a way that there is a small gap between it in the vertical seams. To check the direction of the masonry, a plumb line and a building level are used.

PHOTO: pro-dachnikov.com

Often, drain pits are made round - this shape is convenient for cleaning. The principles of brickwork in this case are exactly the same as in rectangular or square pits. Before laying the brick, it is necessary to lower it into water for a while, this will significantly improve adhesion. It is desirable to reinforce each 5th row with reinforcing mesh, metal or synthetic fiber. Do not forget that a sewer pipe must be brought into the pit at a certain level. All voids at the pipe entry point are filled with mortar.

Waterproofing and covering the pit

If the pit must be airtight, the brickwork is additionally covered waterproofing layer. Liquid mastics that are resistant to aggressive chemicals are suitable for this purpose. Mastics are applied on a dry base, preferably not in one, but in 2-3 layers.

The top cover of the pit can be made from a finished slab with a hole for the hatch cover. Such plates are sold, and there are practically no problems with their installation. Making a floor slab by hand is much more difficult and troublesome.

In principle, it is possible to cover the pit with wooden flooring, but evaporation and constant humidity quickly affect the wood, and after 2-4 years this design will have to be changed. It is much more reliable to make concrete pouring on the formwork. The dimensions of the fill should be larger than the dimensions of the pit by at least 30 cm around the perimeter.

PHOTO: mkuralsteel-vld.ru

If a car will not pass through this place, it is quite reasonable to get by with a lightweight metal-plastic construction. It is possible that for cleaning work, sooner or later someone will have to descend from the pit, so the lid must be of such a size that a person can squeeze into it. Usually sewer manholes are made like that.

The last nuance in the construction of a cesspool is the arrangement of ventilation. The decomposition of organic waste leads to the formation of an explosive gas - methane. Therefore, in cesspools, a ventilation hole is mandatory and a pipe is installed with a height above the level of a person’s head and a protective cover.

The overlap of the pit is covered with a layer of liquid or rolled waterproofing, and soil is already poured on top of it, on which lawn grass can be planted.

Related article:

The article tells how to make do-it-yourself septic tank without pumping 10 years for home and garden. Description of construction requirements is supplemented with reviews of effective technologies and finished models with characteristics and prices. This information will help to implement the project quickly, at a reasonable cost.

Features of the arrangement of a concrete cesspool

When constructing a concrete pit, the pit is dug in the same way. The difference lies only in the material of the walls. To fill the walls with concrete, a “sliding” formwork is made of boards and timber. Polyethylene is stuffed onto the inside of the formwork on the boards so that they can be easily moved as the mortar is poured and becomes solid.

To leave drainage holes in a monolithic fill, cut pipes are used. They are placed in the formwork perpendicular to the walls of the pit. For concreting the pit, 4 parts of sand and 6 parts of screenings are taken for 1 part of cement of grade not lower than M400. The solution is kneaded to the consistency of thick sour cream and poured in stages in increments of 20 cm. Each layer of the fill is left to solidify for 3 days, and only after that the formwork is rearranged and a new one is poured. When pouring, each layer is compacted so that there are no voids and bubbles.

At the end of the pouring, the formwork is removed and also kept for at least 72 hours before the installation of the floor slab with a sewer hatch. The surface of concrete walls must also be waterproofed with liquid mastic, but only after complete drying. A concrete drain well can also be made from ready-made rings. All work takes several hours, but special equipment will be required to install heavy elements.

PHOTO: podmasterij.ru

Installation of finished cesspool tanks

Plastic cesspool tanks are durable and airtight structures, but at a cost, such a pleasure, of course, is much more expensive than the options that you can build with your own hands. But - no problems with installation and work. All these efforts are usually undertaken by product suppliers. Special equipment prepares a pit of the appropriate size for the tank, the crane loads the septic tank - and you have an almost ready sewer in just a day. How it happens - see the video:

What material for cesspools do you consider the most practical? Share your opinion in the comments!