- Required materials for drainage
- We draw up a project of the future drainage system
- Breakdown and excavation
- Installation of intermediate collectors
- Laying geotextiles and drainage pipes
- Filler filling drainage trenches
- Water drainage from the drainage system
Groundwater can wash out the soil under the foundation of a country house, which can lead to a strong settlement of the building. Also, high groundwater levels can seriously hinder the cultivation of many fruit trees. How to drain a site with your own hands, you will learn from this article.
Required materials for drainage
The following materials will be required for the drainage device:
- Coarse quarry sand.
- Crushed stone of fraction 20-40 mm.
- Washed gravel, fraction 5–20 mm.
- Gravel fraction 40-60 mm.
- Geotextile fabric.
- Perforated drainage pipes.
- Plastic drainage wells with a shaft diameter of 300-400 mm.
We draw up a project of the future drainage system
By type, drainage systems are divided into open and closed. Open drainage implies the presence of sewage trenches on the surface of the soil, which, due to a slight slope, will drain excess ground or rainwater. Most often, this technology is used in the agricultural sector in fields or plots with a large area. We are talking about a country house with a plot of 6 acres. Therefore, for us, the best option would be a closed drainage system..
When drafting a drainage system, the following points must be taken into account:
- Soil type.
- The upper level of groundwater flow during a non-rainy period.
- Total land area.
- Foundation cushion level.
Drainage system project option: 1 – drainage well; 2 – main drain; 3 – collecting drains; 4 – trench around the house; 5 – drainage well
The classical arrangement of drains is considered to be their arrangement parallel to each other, observing the distance calculated based on the type of soil. At the same time, plastic drainage collectors are installed at the corners of the most extreme drains, to which intermediate drains are supplied. That is, an underground cascade drainage system is obtained.
Drainage pipes are laid 30-50 cm below the freezing level. If the base of the foundation is below this mark, then the laying of drains must be carried out on the lip below 50 cm of the foundation.
Distance between parallel drains is calculated based on the table data:
Drain depth, m Distance between drains, m light soils medium soils heavy clay soils 1.8 18-22 15-18 7-11 1.5 15.5-18 12-15 6.5-9 1,2 12-15 10-12 4.5-7 0.9 9-11 7-9 4-5.5 0.6 6.5-7.5 5-6.5 3-4 0.45 4.5-5.5 4-5 2-3
The pipes are laid with a slope of 2 cm per 1 meter of the trench. The slope is made towards the well, the water from which will be drained from the site.
Breakdown and excavation
Stakeout is the process of transferring the location of drains and collectors from the paper plan to the surface of the site. The future location of the main elements of the drainage system on the ground surface is indicated by hammered wooden pegs with a twine stretched over them.
After completing the breakdown, they begin earthworks, that is, the creation of trenches. The profile of the drainage trench in most cases is made in the form of an inverted trapezoid. The width of the trench at the very bottom should be 40 cm, and at the top point near the very surface of the soil 60–70 cm. When performing earthworks and digging trenches, about 50% of the selected soil is removed from the site irrevocably. The remaining soil is placed along the created backfill trenches..
Installation of intermediate collectors
After excavation and creation of all drainage trenches, the bottom is leveled to obtain the required slope and carefully rammed. Further, at the locations of the drainage collectors, additional sampling of soil is made, deepening by about 30–40 cm. The soil under the future collectors is rammed and a sand cushion 10–15 cm thick is poured. sand pillow. After completing all work, the collectors must be cut at ground level and closed with a special hatch.
Laying geotextiles and drainage pipes
A cushion of coarse sand about 10 cm high is poured into the bottom of the trenches and carefully rammed. Next, a layer of crushed stone with a fraction of 20–40 mm and a height of 15 cm is poured onto the sand cushion. Having leveled the crushed stone along the length of the trench, they begin to lay geotextiles. The canvas is cut and positioned so that it completely covers the bottom of the trench covered with rubble and both walls of the trench to the very surface of the soil.
Schematic diagram of the drainage trench: 1 – soil; 2 – coarse sand; 3 – crushed stone of fraction 20-40 mm; 4 – geotextile; 5 – gravel of fraction 5-20 mm; 6 – drainage pipe; 7 – gravel of fraction 40-60 mm; 8 – gravel of fraction 20-40 mm; 9 – crushed stone of fraction 5-20 mm; 10 – backfilling
After laying the geotextile, a layer of washed gravel (fraction 5–20 mm) with a thickness of 15–20 cm is poured onto the bottom of the trench. The gravel is leveled along the entire length and perforated PVC drainage pipes with a diameter of 110 mm are laid on its base. At this stage, when the height and position of the drainage pipes are already known, holes are made in plastic vertical collectors using a crown for connecting drainage pipes to them. As a rule, the connection of drainage pipes with vertical collectors is carried out with special couplings that have O-rings in their design. Drainage pipes are connected to each other with a conventional or tee PVC coupling.
Filler filling drainage trenches
After laying the drainage pipes and bringing them to the collectors, thereby creating a cascade system, a layer of 10-15 cm of coarse gravel of 40-60 mm fraction is poured along the edges and on top of the pipes. Drainage pipes can be lined with a larger stone, for example, river stone or small quarry. Since this layer of filler will serve to pass ground water and protect drainage pipes from deformation.
On top of the coarse gravel, a cushion of gravel of 20–40 mm fraction, 20 cm high is poured, and after that the edges of the geotextile fabric are overlapped with gravel. On top of the geotextile, a small layer of crushed stone, 5–10 cm, fraction 5–20 mm is poured. After that, the drainage trenches are filled with soil selected during earthworks. Taking into account that the soil will settle, the backfill is performed above ground level.
Water drainage from the drainage system
The drainage system performed in the described way will accumulate water in the lowest intermediate collector. The drainage from it can be gravity, through a pipe located at a slope in the ground, through which water will be discharged from the collector to the nearest sewer, or forcibly installed in the collector with a submersible water pump, for example, “Stream”. When draining water by a pump, it is necessary to provide a “frog” switch in its connection diagram.
Cost of materials used
Material Unit measurements average cost Quarry sand 1 cubic meter m 450-800 rubles. Crushed stone 20-40 1 cubic meter m 1200 rbl. Gravel 40-60 1 cubic meter m 1200 rbl. Geotextile 1 sq. m 15-30 rubles. Drainage pipe 110 mm 1 m running 50-60 rubles. Drainage well 315×2000 1 PC. 2700-3000 rubles.