- Placement of a cesspool on the site
- Determining the size of the structure
- Counting the required materials for construction
- Preparatory work
- Pit bottom concreting
- The next stage is the walls
- Final works
Many plots intended for construction or garden plots are located away from sewers. The owners of such plots have a reasonable question – how to get rid of domestic wastewater?
There are several types of structures that allow you to do this. A cesspool also belongs to such structures. A cesspool is a well, at least two meters deep, with a concrete bottom and stone walls. The most successful shape for such a structure is considered to be a round shape, since the loads from soil pressure on the walls of the well are distributed tangentially. However, laying out a round well is quite difficult, especially for an untrained bricklayer. Therefore, rectangular or square shape is mainly used..
Wastewater entering the well undergoes a chemical reaction due to anaerobic bacteria. At the same time, the volume decreases with the release of gas, the wastewater in the upper part is noticeably clarified, and sludge forms in the lower part of the sump.
Placement of a cesspool on the site
When planning the placement of a cesspool on a site, it is necessary to take into account the requirements of SNiP 30-02-97, which regulate the placement of a latrine from a residential building at least twelve meters, the distance from the treatment plant to the fence is at least one meter.
Determining the size of the structure
In order to determine the size of the future structure, you need to know how many people will permanently reside in the house. Roughly, a family of three to four people fills a volume of about twelve cubic meters per month.
For example, a cesspool with a size of 3×2 meters and a depth of 3 meters will be calculated, while its volume will be 18 cubic meters.
Counting the required materials for construction
The bottom of the pit must be concreted, and the walls can be laid out of cinder block or brick, or cast from concrete. You will also need to concrete the ceiling above the cesspool and lay out a small brick hatch in order to be able to clean it with sewage machines.
When calculating the volume of materials for concreting, it must be borne in mind that crushed stone is needed as much as cubic meters of concrete. The proportion for making concrete for such work is as follows – 6 parts of crushed stone, 4 parts of sand, 1 part of cement, water as needed.
When calculating the amount of materials for the walls of the cesspool, you need to take into account the thickness of the bottom, as well as the fact that the overlap needs to be done 30-40 centimeters below the soil level, so that later it is covered with earth in order to avoid freezing of wastewater. Based on this, we subtract from the total height of 300 cm the bottom thickness equal to 10 cm, the overlap thickness equal to 15 cm and 40 cm of the upper soil layer. We divide the obtained height of 235 cm by the thickness of the brick or cinder block, taking into account the thickness of the seam. Thus, we get the number of required rows.
Materials, required for the construction of a cesspool from a cinder block:
- Cinder block – 240-250 pcs;
- Cement – 250 kg
- Crushed stone – 1.2 m3;
- Sand – 0.8 m3;
- Water – 1 m3;
- Rebar with a diameter of 12 mm – 35 m;
- Brick – 48 pcs;
- Knitting wire.
Instruments, which will be required for construction:
- Pegs for marking;
- Concrete mixer;
- Building level;
A safety fence should be erected around the construction site to prevent anyone from accidentally falling into the pit. To do this, you can use a red-and-white striped signal tape stretched over posts at least half a meter high.
After all the materials have been prepared and placed near the site, you can start marking the structure on the ground. The planned site needs to be cleared of weeds, old trees must be uprooted. Then you need to outline the size of the cesspool with pegs. Measure the sides of the rectangle again so that they correspond to the given dimensions and diagonals, so that the corners are straight.
After marking, you can start digging. The top fertile soil layer, about half a meter, should be stored near the pit, but so that it does not interfere with further construction. This land can be used for backfilling.
You need to dig until the required depth is reached.
Pit bottom concreting
The bottom must be carefully compacted with a rammer, after which concrete can be poured. Concrete for such a structure can be made in the following proportion – 6 parts of crushed stone, 4 parts of sand, 1 part of cement. Water is added until the concrete is so thick that each pebble is completely submerged in the solution..
Ready concrete is poured to the bottom of the pit and leveled. After the bottom is concreted, it must be left for seven days for the concrete to gain 80% of the grade strength. If the weather is hot in summer, then the concrete surface should be moistened with water as it dries.
The next stage is the walls
After the concrete has hardened, you can lay out the walls of the sump. Rows of bricks or cinder blocks are laid out with bandaging, in the upper third of the pit, several cinder blocks are placed on their side, through these holes filtered water will go into the soil.
When all the rows of the cinder block are laid out, the soil is dug up another 20 cm on each side around the perimeter of the pit. This is done so that the slab lies not only on the pit walls, but also on the ground, which will give it additional support. Sheets of corrugated board can be used as a permanent formwork for pouring the slab. They will give additional rigidity to the plate and are easy to use. Below, from the side of the pit, the corrugated board is fixed with boards and posts. Also, the formwork is done around the perimeter of the hatch..?
After the installation of the formwork, the reinforcement is laid in perpendicular directions with a distance between them of 100-150 mm. At the intersection, the pieces of reinforcement are tied to each other with a knitting wire. Now you can fill the floor. The concrete is prepared in the same proportion as for the floor. When pouring concrete, it must be bayonetted so that it better fills the mesh from the reinforcement. After the concrete covers the entire floor area, the reinforcement mesh must be slightly raised so that the reinforcement is completely in the concrete.
? Then the concrete is poured to the required floor thickness. After pouring, we leave the concrete to gain brand strength, one hundred percent of which it will reach in 28 days. Recommendations for the summer period are the same as for concreting the bottom..
After the concrete hardens, you can remove the formwork supports and lay out the walls of the hatch from bricks. Then the walls from the outside must be plastered and smeared with bitumen so that atmospheric moisture does not get into the cesspool. It remains only to fill the earth back and level it.