Why do you need a sewerage scheme? Primary information for the design of the drainage system. The main elements of internal and external sewerage and the rules for their placement.
Water supply and sewerage design is the development of a layout of pipelines and plumbing fixtures for installation work. A well-planned complex creates a comfortable environment in the house and does not require repairs throughout the entire period of operation. How to draw up a sewer project correctly, we will talk in our article.
Features of designing a home sewer system
In the photo, the project of the sewerage at home
During the construction of a private house, it is necessary to solve issues related to the drainage of wastewater from plumbing fixtures in the house to a septic tank or a central sewerage system. Therefore, before purchasing and installing equipment, you should develop a system design.
It is needed for several reasons:
- Sewerage, like other engineering systems, is installed taking into account building codes. The plan must indicate all the parameters that allow the correct construction of the structure: dimensions, tolerance, slopes, etc.
- Without a diagram, it is easy to get confused when laying routes and placing plumbing equipment. As a result, time, effort and money are wasted. The consequences of haphazard assembly will be blockages, an unpleasant odor in the house and other troubles. Therefore, when designing a sewage system, SNiP should become your reference book.
Before starting the development of a sewer project, find out the following:
- Sewerage type - local or centralized. To connect to the centralized, you will need permission from the local authorities for the tie-in. The autonomous complex has a septic tank into which waste is discharged.
- Information about the depth of soil freezing in your area, groundwater level, soil type. They will help determine the volume of earthworks and the need for insulation of the outer part of the highway.
- Information about the amount of precipitation, allowing to resolve the issue of the need for rainfall.
- The maximum volume of drains, which depends on the number of people living in the house and the types of household appliances. It affects the size of the septic tank.
- The list of plumbing fixtures in the house and the wishes of the owners for their installation.
Sewerage scheme development
For a country house, two projects are being developed - for internal and external drainage. The diagram of the interior shows the location of the pipes in the house, through which dirty water is removed from the plumbing fixtures. In the diagram of the outer part, you can see how the drains enter the septic tank.
Internal sewerage design
The internal sewerage system of a house is an extensive network of pipelines from plumbing fixtures and various mechanisms to a common highway that directs drains to the place of disposal or temporary storage. It is distinguished by its complex structure and great labor intensity during installation.
Designing an internal sewage system, start with the placement of plumbing fixtures: sinks, washbasins, taps, toilets, washing machines, etc.
It is also necessary to show the distance from them to the riser, the diameter of the supply pipes, the method of fixing the plumbing and the option of connecting to the main. The number of pipes will be reduced if they are installed close to each other. In multi-storey buildings, it is recommended to place the equipment one above the other, which will allow the use of only one riser.
Photos of pipes and fittings for domestic sewage
For wiring and connecting individual parts, the following products are used:
- Pipes - polypropylene, polyvinyl chloride and cast iron. Metal products have been used for many years, but today they are being successfully replaced with plastic ones. They are distinguished by a long service life and high performance characteristics. Gray plastic pipes are installed in the house.
- Knee - are used to turn the highway at an angle other than 90 degrees. Use two 45 degree products if necessary. Smooth angle changes will reduce the likelihood of system clogging. Elbows connect pipes with extensions and rubber seals.
- Elbows and tees - connect the cuts with the same diameter.
- Couplings - are used for joining products of various diameters.
- Clamps - to fix the line in the design position.
When designing water supply and sewerage systems, find out the instantaneous flow of each plumbing device, by which you can determine the diameter of the supply pipe. Inside the house, the products are used, which are shown in the table:
| Purpose of the pipe | Diameter, mm |
| Connection to sink and bidet | 30-40 |
| Bathroom connection | 40 |
| Bends from the riser | 65-75 |
| Riser and toilet bends | 100 |
| Connection to other plumbing fixtures | 50 |
| Supply pipe longer than 3 m | over 75 |
| Pipe to the septic tank | more than 100 |
Horizontal sections should be sloped in accordance with the sewerage design standards. They depend on the diameter of the product:
- Diameter over 15 cm - 0.8-1 cm / m;
- Diameter 8, 5-11 cm - 2 cm / m;
- Diameter 4-5 cm - 3 cm / m.
These inclination angles allow the drains to move independently under the influence of gravity.
Place the toilet bowl as close to the riser as possible, but no further than 1 m. Do not connect other devices to the pipe between it and the toilet bowl. Place drains from other appliances above the toilet connection. The dimensions of pipes and adapters should not be smaller than the hole in this plumbing fixture.
Install clamps for fastening the line with a certain pitch, depending on the diameter of the product. It is generally accepted that the distance between them should be equal to 10 pipe diameters. When installing a track with a diameter of 10 cm, the clamps are placed every 1 m.
Connection diagram of the toilet bowl with the sewer system
Show the location of the riser on the diagram. This is a vertical pipe to which drains are supplied from horizontal sections. Most often it is placed in the toilet. Pipes are connected to the riser using oblique tees and crosses. Direct products are not used in this case. The horizontal section of the sewer pipe in the house should not exceed 10 m (the optimal size is 3 m). If the line is very long, lay a second riser. It is buried in the basement, and then joined to a horizontal pipe that connects the internal and external sewers. Then the water moves to the storage tank. A large house may need 2-3 risers.
When designing sewerage networks, do not forget about the revision to clean the system, they should be on vertical and horizontal branches in an accessible place. If the structure is hidden in the grooves, make openings 40x40 cm. Otherwise, you will have to break the wall to remove the blockage. Openings for cleaning the mains should be located in the riser on the upper and lower floors.
Internal sewerage installation scheme
The part of the basement through which the outlet pipe is stretched must be separated by a wall. For its wiring through the foundation, a steel pipe is embedded into the wall, the diameter of which is 2-3 cm larger than the diameter of the sewer pipe. The gap is filled with insulation.
Note! In one-story houses, a riser is usually not made. The drains move horizontally through pipes and corners.
The internal sewerage system must be ventilated, for which the risers will be connected to the atmosphere with special pipes. They are brought out through the roof and protrude at least 0.5 m above it. A weather vane cannot be placed on the ventilation system, but an umbrella is allowed. The hood should be located more than 4 m from windows and balconies. It must not be connected to the ventilation pipes of the house. If you do not adhere to these conditions, the unpleasant smell will spread throughout the house. Products that do not go to the roof are closed with aeration valves. If errors are found in the sewage project, the installation of the system will have to be repeated.
Outdoor sewerage design
In the photo, pipes and fittings for external sewerage
The typical outdoor design is a straight line to the storage tank at the lowest part of the site. It is allowed to change the direction of the route, but at the place of the turn it is necessary to build a viewing well.
When designing an external sewerage system, problems often arise with the local system, because it must have a drive. There are several types of such septic tanks, which are chosen depending on various factors: the level of groundwater, the number of residents, funds on the user's account, etc.
In the photo, the types of septic tanks for sewage
Consider a brief description of each design:
- Cesspool … Small tank without bottom. It is used in houses where 1-2 people live. Usually waste from the toilet is drained there.
- Sealed storage … A container for collecting sewage, which must be periodically cleaned. Show the dimensions of the pit and its arrangement on the diagram. You can purchase a ready-made tank (for example, a eurocube) and install it in the pit. Often the walls are finished with bricks or concrete formwork. Also note the road on which the suction truck will drive up to the tank for cleaning.
- Septic tank … Multi-section storage with cleaning properties. After it, the liquid is removed to the ground. A filtering field should be built next to the septic tank or a well for additional treatment of wastewater should be located. On the diagram, be sure to show its dimensions, as well as the composition of the working layer. If the soil does not allow the construction of a soil filter, a third storage tank will be needed to store the effluent. It must be installed in a place where a sewer truck can easily drive up.
- Biological treatment station … A device for high-quality water purification from impurities. After that, the water can be used for irrigation.
External sewerage scheme
When designing a sewerage system, be sure to consider the following:
- The number of people living in the house, on which the size of the septic tank depends. The dimensions of the device are determined based on the value of 200 liters of water per person per day. This volume must be increased by 3 times and a margin must be added if the house has a washing machine, dishwasher, bath.
- The depth of the groundwater table. It is forbidden to build a cesspool or septic tank with a drain if the groundwater is closer than 1 m from the surface.
- The location of the septic tank on the site must comply with SNiPu. Basic requirements: place it at a distance of at least 1 m from the border of the site, at least 5 m from the road, at least 20 m from the house, at least 30 m from the source of drinking water. Its location is also influenced by the composition of the soil. The more sand, the further from the building.
- Place the pipes in the trench with a slope of 2 mm / m. For turning, it is recommended to use two angles of 45 degrees instead of one at 90. This reduces hydraulic resistance and the risk of blockages.
- The drainage outside the house is collected from pipes with a diameter of at least 150 mm, red or dark orange. These dimensions are used in gravity systems. You can also use a corrugated product with a diameter of 200 mm.
- Provide inspection wells with revisions in places where the highway turns or increases the slope of the route. On horizontal sections, they are made at a distance of 10-15 m. The diameter of the viewing window is 70 cm.
To supply the sewage system to the storage device, you will need a trench, which must also be applied to the drawing. Ditch dimensions:
- Width - 20 cm recommended.
- The depth is below the level of soil freezing for the given area.
- Tilt angle - no more than 7 mm / m.
- The ditch bottom is covered with a mixture of sand and gravel.
When designing a sewage system located outside the house, keep in mind that plastic pipes are afraid of ultraviolet radiation. At a temperature of -10 ° C, the plastic becomes brittle, so they need to be insulated if they are located close to the surface.
Sewerage design price
You can develop a sewer system project with your own hands, but in this case there is no guarantee that the system will function correctly and will last for many years. Therefore, it is better to entrust the work to specialists of engineering systems.
It should be borne in mind that an external sewerage project with a connection to a centralized system can only be done by organizations licensed for this type of work.
Design work includes several stages. The price of the work is determined at the stage of preparing a feasibility study for the sewer system. At this stage, the user transfers his requirements to the contractor and forms the tasks that must be taken into account in the documentation.
Internal sewerage scheme at home
When determining the cost of designing a sewage system, the following factors are taken into account:
- Waste disposal method. There are two options for removing industrial water - through the central sewerage system or using septic tanks. In the first case, the cost of the project increases several times, since will have to coordinate the documentation with city services and pay for their services.
- The purpose of the building, its shape, area, number of storeys.
- For a private house, the terrain on which it is built, the composition of the soil, the distance from the central sewerage main (if any) are important.
- The complexity of the project and the wishes of the user, which affect the complexity and complexity of design work.
- The number of plumbing fixtures and mechanisms that use water, as well as their location in the house.
- Sewerage type. It can be gravity or pressure.
- Additional services. Often, organizations offer a service to support the installation of the sewage system, during which the compliance of the work performed with the design documentation is monitored. If necessary, the developed scheme can be corrected on the spot.
- Scope of work. The standard set of documents included in the sewerage project includes: an explanatory note, floor-by-floor sewerage wiring indicating the location of plumbing fixtures and other equipment, a plan for the location of elements of the sewer system outside the house, detailing the connection of the main nodes, a sewerage scheme in axonometry, decoding of symbols on the diagram (Hardware Specification). At the request of the customer, part of the documents can be omitted and the price of the sewerage project can be reduced.
Below is the estimated cost of these works. The price is for 1 m2 premises.
Sewerage design price in Russia (Moscow):
| Type of work | Price |
| Apartment internal sewerage project | From 100 rubles. for 1 m2 |
| Private house internal sewerage project | 90-140 rub. for 1 m2 |
| Outdoor sewerage project | From 16,000 thousand rubles. |
| Author's supervision of the sewerage installation | 3000 rub / day |
Sewerage design price in Ukraine (Kiev):
| Type of work | Price |
| Apartment internal sewerage project | From UAH 30 for 1 m2 |
| Private house internal sewerage project | 30-50 UAH for 1 m2 |
| Outdoor sewerage project | UAH 14-40 for 1 r.m. |
| Author's supervision over the installation of the sewerage | 700 UAH / day |
How to make a sewage project - watch the video:
As you can see from the article, designing a house sewage system is a rather laborious process that takes a lot of time. There are no special requirements for its design, you can make a sketch on paper or draw on a computer. The main thing is to display all the elements of the line, taking into account the requirements of SNiPs for the sewage system.
