From the article you will learn how to install a septic tank of concrete rings with your own hands. After all, life in a house cannot be considered comfortable without a high-quality sewage system. If you live in an apartment building, then you do not suffer from this issue, because there is an excellent central system into which you can dump a large amount of waste. But when building a country house, there are no such privileges, as a rule. Therefore, the water discharge system must be considered independently.
You can make a simple system - dig one hole, overlay it with brick or even tires, it will last several years. But it will be much better if you install a septic tank - a design that allows for quality wastewater treatment. And at the exit you can get water that you will use for irrigation. And it should be noted that when using concrete rings you will be able to build a high-quality and reliable septic tank. We will talk about how to make a septic tank from concrete rings on our own in our material.
Design features of septic tanks
It is recommended to install septic tanks from reinforced concrete products on soil that drains well and is not prone to heaving during cold weather. The basis of a septic tank is concrete rings placed on each other. Nothing complicated, but some design features should be considered. Even if there are protrusions for fixing and high-quality fasteners, heaving of the soil can easily move the rings.
As a result, the tightness of the structure is violated, repairs will be required. It is also worth mentioning that the price of a turnkey concrete septic tank made of concrete rings is high - it can reach 50-60 thousand rubles. Therefore, it is unforgivable if such a system collapses very quickly.
And there is no guarantee that after the repair there will not be a second shift. For this reason, it is best to install septic tanks of this type on sandy and sandy soil types. In the case when the groundwater is low, and the soil removes water well, you can take the pipe from the septic tank to the drainage column. This device is ideal for our system. If the groundwater is high, then the treated effluents must be discharged to the drainage field. But it is worth noting that with their arrangement, a large free area is necessary.
The principle of operation of the septic tank
The septic tank consists of two chambers that are located at a distance from each other. They are connected by one pipe (overflow). In these sealed containers, wastewater is treated. The third column is a drainage well or filtration field. At the bottom of the well there is a hole through which purified water flows into the soil. The device of a septic tank made of concrete rings allows you to maximize the cleaning of drains from various kinds of contaminants.
Now we will consider what processes proceed in the system. First, the effluents enter the first tank, which is tight and almost no air enters it. It is in the absence of air that the decomposition of waste occurs. All organic constituents are processed by bacteria and microorganisms. Thanks to bacteria, the organic components decompose into almost pure water and insoluble sediment (it always accumulates at the bottom, since it is heavier than water).
Now water with a minimum content of pollutants enters the second chamber through a pipe. There, too, the cleaning procedure begins, but everything happens with the participation of oxygen. For this reason, the second chamber is necessarily equipped with a ventilation pipe. Organic matter also settles at the bottom in the form of sediment. Almost pure water enters the drainage column. But it is not drinking, but can be used for technical needs.
Determination of the volume of a septic tank
One chamber should have a volume that is equal to three times daily water consumption by residents of the house. Moreover, when calculating, it is assumed that one person spends about 250 liters of water per day (this is 0.25 cubic meters). If a family of 4 people, then per day it will consume exactly 1 cubic meter. m, and in three days - 3 cubic meters. m. Therefore, the volume of each chamber should be at least 3 cubic meters. m. Please note that in the calculation you do not need to take into account the dimensions of the filter column - this is a completely different design, it is not cumulative. Carefully study the device of a septic tank made of concrete rings and decide which parts of the system are responsible for what.
It is worth noting that in Europe the standards are slightly different: oddly enough, but the “thrifty” residents of the capitalist world spend more water. Although they bathe and wash, they are much less likely than the average family in Russia and the CIS countries. But back to our construction. Most of the effluents are in two tanks longer if the tank volume is large. This means that cleaning will be much better.
Nevertheless, it is recommended that when designing make tanks about half the maximum daily discharge. This will be especially useful if the house has a bathroom, washing machine and dishwasher, etc. Based on the size, you need to choose concrete rings.
A bit about concrete rings
Now let's see what sizes concrete rings can be. Their diameter is 80-200 cm, but more can be found - about 250 cm. The height of one ring is from 0.5 to 1 m. When calculating, you need to consider that in fact the column must have a volume with a margin. After all, the drains will never fill the tanks completely; they will only rise to the level of the overflow pipe. It is from this level that you need to start the countdown.
Count the number of columns
It is necessary to pay attention to the fact that three storage cameras can be used. Except, of course, columns for filtration. Sometimes it happens that such a device is more practical if it is necessary to install more than 6 rings in each column. If you do this, then to install 6 rings you will need to dig a very deep foundation pit. It is much more profitable and more convenient to make an additional column. And in each you need to install 4 rings of concrete. And do not forget that the price of concrete rings for a septic tank is quite high - at least 1000 rubles (depending on size).
But you can make another option. For example, you need a small volume septic tank. This often happens in summer cottages, which are rarely visited and a small number of people live in them. In this case, it is possible to make one column, and to divide the rings from the inside using a sealed partition. Inside this partition, you need to make an overflow hole at the right level.
General rules for the manufacture of storage tanks
The most common linear designs of septic tanks. Columns are installed strictly on one line. Storage tanks are located next to each other, and the filtering well is at a distance from them so that the drains do not fill the soil very much and do not freeze. This is done in order to exclude the appearance of heaving.
It is recommended to purchase rings that have locks. They are installed much easier, less likely to shift during heaving. In addition, they have a high degree of sealing. It is imperative that the rings be treated with waterproofing material before mounting. And for this, mastic based on bitumen or deep penetration impregnation, based on cement, is used. If this is not done, then it is possible that sewage will leak out of the tank, and groundwater may enter.
Basic rules for the installation of septic tanks
And now we will consider what are the rules for the installation of concrete rings of the sewage system.
- It is necessary that there is a distance of more than half a meter between the storage tanks. This gap, which is filled with earth, can serve as a buffer when the ground moves.
- At the bottom of the pit, it is imperative to pour and compact a layer of gravel. Its thickness should be about 20 cm. Ramming is done to achieve maximum density, it is best to use a vibrating plate. Please note that the bedding must have a horizontal and even surface. The plane must be checked using the building level, the length of which is about one and a half meters.
- Then it is necessary to install a concrete ring on the gravel. The septic tank from this material is obtained as tight as possible. Install it evenly so that the walls are vertical. Only in this case will you provide strength to the column.
- You can also fill in a monolithic concrete slab under a septic tank. The thickness should be about 30 cm, and preferably more. It must be 20 cm larger than the size of the rings. It is absolutely necessary to level the plate and make sure that its surface is horizontal. Concrete should dry for about a month. Only after that it is allowed to begin installation of the system. It is necessary to put a waterproofing layer on the concrete slab. After that, the first concrete ring is installed.
- On top of the first ring, the subsequent ones are installed. All joints must be carefully sealed. It is allowed to lay one layer of “Aquacement” type solution before starting the installation of the ring. This solution is able to provide high-quality waterproofing of all joints. But still, after mounting all the rings, it is necessary to lubricate the joints from both the inside and the outside.
It is not recommended to use toxic substances, since all bacteria that are responsible for the decomposition of organics will die. As a result, a septic tank built for a house made of concrete rings cannot work.
Ring assembly
In order for the fixation to be as strong as possible, the rings must be connected with metal brackets. They are mounted from the outside. Be sure to staple the concrete and cover it with a layer of waterproofing. The upper part of the structure must be insulated. For this, polystyrene foam or any suitable material is used. Of course, the wastewater is initially warm, but if the frost is severe, then it is likely that an ice crust will form on top. This will reduce the efficiency of wastewater treatment. The article provides a standard scheme of a septic tank made of concrete rings.
The sewer pipe is buried, as a rule, lower than the depth of freezing of the soil. If we are talking about the middle zone of Russia, then this is about one and a half meters. It is also necessary to make a slope so that the drains by gravity move to the tank. The slope must be about 2 degrees. This is quite enough so that the water inside the pipe does not stagnate.
Neck making
And now we will figure out how to make the neck and from what materials. Often use concrete covers with hatches. They can be purchased in the same place as concrete rings. They are simply mounted on the upper ring, fixed, and a metal or rubber standard cover is applied on top.
Monolithic reinforced concrete can also be used. This is an option in which the costs will be minimal. The cost of a septic tank made of concrete rings will be minimal, especially if you decide to do all the work yourself. But you have to spend time and apply the skills of the builder. If they are, of course. After all, you will have to assemble the formwork, knit the frame from the reinforcement, and also pour concrete. Moreover, the design will be ready at least in a month.
You can also lay out the neck of a brick. Then plaster on both sides, treated with waterproofing. This option is good in that you can set the dimensions and height of the hatch yourself. But still, you need to purchase a slab of concrete or fill it yourself.
Pipe layout
The overflow pipe, which is located between the containers of the septic tank, should be about 120 mm in diameter. Both plastic and asbestos materials are allowed. Entrance and exit must be carefully sealed. The inlet pipe going from the house and overflow pipes must be equipped with tees. With this you will direct all drains down, the crust will not develop. This is necessary so that the septic tank processes waste water better. Some tees have pipes that go down. The installation location of the overflow pipe depends on what level the inlet is at. On the opposite wall, the overflow should be 5 cm lower than the input level. But between the second tank and the sump or filtration well, overflow can be done at the same level as the inlet of the first pipe. It is allowed, of course, to lower it by 5 cm, but no more.
A little bit about the filtration well
In the manufacture of columns for filtration, it is necessary to dig a pit to the soil, which removes water well. Then, a layer of gravel should be poured to the bottom, its thickness should be about 25 cm. A layer of sand is poured on it, the thickness should be about 40 centimeters. After that, rings without a bottom are installed. You can install a perforated ring. Moreover, there is no need to make holes of 5 cm, since there are such products manufactured in factories. The cost of a turnkey concrete septic tank made of concrete rings is rather high - at least 20,000 rubles. The price includes work, and the acquisition of materials, and even the design of the project.
If you install perforated rings, it is recommended to remove soil around them and fill up with crushed stone. In this case, the water will be much better to leave. In general, the design of the filtration well, made of concrete rings, is similar to the scheme of storage tanks.
How to dig concrete rings
The most common and easy way is to dig one pit, which will be common to all tanks. Then, using a crane, all concrete rings are installed under the septic tank. After that, overflow pipes are laid, all the cracks and joints are sealed, covered with a layer of waterproofing. And only after warming it is possible to fill the soil and compact it. The method is ideal, but you just have to dig a very large pit.
To do all the work quickly, you can use the excavator. After all, you understand that it’s very long to do it manually, even if you hire a team of diggers. In addition, it will be more expensive than ordering special equipment. And you need to consider that with the help of technology you will make a foundation pit in just a few hours. And if you find a brigade, the process will last several days, or even a week.
There is another way, but it is more expensive, since it is quite difficult to excavate inside the rings and under the walls. But you can lower the ring under its own weight. But so you can bury the ring without a bottom. If you do this, you will have to fill the bottom separately. In this case, of course, the reliability of the design of the septic tank is reduced. Also, when using this option, there is no way to warm the structure. Still need to dig trenches to install overflow pipes. This method is problematic, but in extreme cases it can be applied.
Contact specialists if you are not sure that you can install a septic tank of concrete rings on your own. The cost of "turnkey" is from 20,000 to 60,000 rubles. But it all depends on the region.