The drainage system is an important component of any house. The function of the home drainage system is to transport wastewater and sewage to the sewage system. If you’ve ever wondered what drainage is, think of it as all the used water leaving your property through well laid network of pipes. There are different types of drainage pipes employed in the drainage system. GharPedia brings you a deep guide on different types of drains in your house drainage system.
A pipe is a circular, closed conduit through which the water may flow either under pressure or under gravity. When pipes do not run full, they run under gravity, such as in sewer lines. The latrines, bathrooms, sinks, wash basins etc are the important components of a house. The occupants of the house make use of the above-mentioned components and as a result of that, there is a creation of wastewater. The wastewater from latrines, bathrooms, sinks and wash basins is to be properly disposed into the municipal sewers through the underground drainage pipes. It is, therefore necessary to construct a system of conveyance of wastewater from bathrooms, latrines, kitchen and washbasins into the municipal sewer. The system is known as House Drainage System. The home drainage system comprises different types of sewer pipes. The home drainage pipes can be made of different materials, like cast iron, steel, plastic, cement, copper etc. Plastic drainage pipes and cement drainage pipes are popular types of underground drainage pipes.
Before we go in depth and know about the types of waste drainage pipes, let us first understand the characteristics of drainage pipes.
The Drainage Pipes Must Have the Following Characteristics
- Joints in the different types of drainage pipes should be durable, easy to install, and watertight to prevent leakage.
- The home drainage pipes should have the ability to resist impact loads encountered during installation, handling and transportation.
- The pipes should have a smooth non-corrosive interior surface for minimum resistance to flow.
- The walls and joints of the pipes must be impervious to prevent leakage of foul water polluting the groundwater.
- The interior of the pipes must be abrasion resistant to withstand the scouring action of the sewage carrying gritty materials.
Types of Drainage Pipes used in House Drainage System According to their Functions
The below-mentioned different drainage pipe types work together to work as an efficient house drainage system.
01. Soil Pipe:
A soil pipe is a pipe that conveys the discharge of urinals, water closets or fixtures having similar functions. It transports sewage or wastewater from a toilet or sink to a soil drain or sewer. Soil pipes run vertically from the underground drainage pipe to the top of a property, where they meet the roof gutter. The soil pipe, also known as a soil vent pipe, has a unique property that makes it ideal for transporting solid waste. It has a size that allows solid waste to pass through and is vented to reduce the risk of unpleasant odors. It is typically vented high at the top or near the top of a building.
02. Waste Pipe:
Any pipe that receives the discharge of any fixtures, except water closets or similar fixtures, and conveys the same to the soil pipe or house drains is a waste pipe or a waste drainage pipe. It is a type of drainage pipe designed to transport liquid waste, except for sewage. Waste pipes in homes, can be used for drain washers, sinks, dishwashers, and other plumbed fixtures. This is often a smaller diameter pipe that carries grey water from any appliance that uses water. Since the waste pipe is intended to carry only water, it is narrower than a soil pipe. Furthermore, it does not require the same venting system as a soil pipe. Moreover, since wastewater does not typically emit harmful gases, it does not need to be vented above ground level.
03. Vent Pipe:
It is a pipe which is installed for the purpose of ventilation. A vent pipe is open at the top and bottom, to facilitate the exit of foul gases. A vent pipe works in conjunction with your drainage pipes, but it does not carry water. It regulates the air in your plumbing system. The vent pipe, also known as a vent stack or plumbing air vent, regulates airflow to ensure waste and water flow through the different types of drains that drain out of your home. It also allows fresh air into the plumbing system, which aids in the smooth flow of water through the different types of drains. Clean drain pipes can only do their job if the vent pipe is operational. Each plumbing fixture in your home necessitates the use of air to move water through the drainage pipes.
04. Anti-Siphonage Pipe:
This pipe is provided in the house drainage system to preserve the water seal of traps. When one of the upper-floor toilets is flushed, a large amount of water gushes down the toilet line due to gravity. This rapidly moving water creates a low air pressure directly above it. The toilet’s water seal has normal air pressure on the toilet side and lower air pressure on the toilet pipe side.
Hence, the water seal in the toilet seat is sucked out into the pipe due to the difference in air pressure. As a result, the water seal is broken, and foul gases can enter the toilet room.
To keep the water seal, equal air pressure must be maintained on both the toilet room and soil/toilet pipe sides. Therefore, an additional pipe known as an anti-siphonage pipe is connected near the toilet seat outlet, with the other end open to the atmosphere. The anti-siphonage pipe allows atmospheric air to enter the low pressure zone and equalize the air pressure. This type of drainage pipe prevents the water seal from being sucked out of the flushed toilet seat, as well as all the toilet seats connected on lower floors.
05. Rainwater Pipe:
A rainwater pipe, also known as a downspout, is a type of pipe that connects to the side of a house to collect and disperse gutter water. Rainwater pipes shall be installed on the outside of the external walls of the building. Rainwater pipe shall not be discharged into or connected with soil pipe or ventilating pipe or waste drainage pipe. Rainwater is harvested, pushed to a nearby sewer, or allowed to seep into the ground after passing through a rainwater pipe. People who choose to harvest rainwater frequently use the collected water for a variety of purposes.
Speaking of the rainwater pipes, we have a detailed article on rain gutter:
A representation of all types of drainage pipes in house drainage system is shown below:
Minimum Diameter of Different types of Drainage Pipes
The following specifications indicate minimum diameter of house drainage pipes. They have been stated in Indian Standard code (reaffirmed 2001) IS: 5329-1983. Practice for Sanitary Pipe Work above Ground for Buildings:
| Type of Pipe | Minimum Diameter in mm |
| Soil pipe | 100 |
| Waste pipe (horizontal) | 30 to 50 |
| Waste pipe (vertical) | 75 |
| Vent pipe | 50 |
| Rain water pipe | 75 |
| Anti-siphonage pipe (connected to soil pipe) | 50 |
| Anti-siphonage pipe (connected to waste pipe) | 40 |
| Connecting waste pipe | 40 |
| Connecting soil pipe | 50 |
Conclusion
Summing up, the aforementioned drainage pipes work together to form an efficient house drainage system. Each drainage pipe has its different function and size. Here, we have discussed different types of drainage pipes used in house drainage system. Hope this article has broaden your knowledge on different types of sewer pipe and house drainage system. Before leaving, make sure to check our other articles: