What is the slope of the sewer pipe should be

When designing and installing a sewer system, it is necessary to know about the correct inclination of the sewer pipe. The system is gravity, drains move through the pipes under the influence of gravity. Failure to choose the inclination of the pipe can lead to incorrect sewage system operation. What slope of the sewer pipe should be and how to choose it correctly - you will learn about this by reading the article.

Not many Russians can afford pressure sewers in private construction. When drafting a free-flow sewage system, the main thing is to correctly calculate the angle at which the sewage pipes should be mounted. Errors are fraught with failures of the system, and even the impossibility of its use.

How does the sewage system

What is the slope of the sewer pipe should be work? The home sewage system

Pipe network that diverts sewage from sanitary devices to the treatment plant - forms a sewage system. Unlike measuring various angles in degrees, the slope of a sewer pipe is defined in cm per meter of pipe.

Water does not flow uphill, so the pipeline is mounted under a slope, and drains move by gravity through the pipes. It would seem that the conclusion suggests itself: the greater the bias, the better, but this is not the case. Sewage drains have various inclusions: garbage, grease, pieces of food. If all this settles in the pipe, then eventually the passage will be completely clogged and the water will not be able to go to the treatment plant. The system will work fine if you select the optimal speed of the flow of sewage through the sewer pipes, and it is controlled by the angle of the pipe. The speed of 1 m / s is optimal for the fluid in the free-flow sewer system. At this speed, the water will wash away all sewage in a septic tank. The sewage system will self-clean, and blockages can occur only in extraordinary cases. You will not need to constantly fight them.

What is the slope of the sewer pipe should be Insufficient slope

The slope of the pipe is made insufficient, what happens in this case? Water will not be able to flush all solids, they will precipitate and form a blockage in the sewer pipe.

The slope of the free-flow sewage system is made large, but then various problems can arise:

  • the water velocity will be great, it simply will not have time to wash off the solids and unclean;
  • large the inclination of the pipe can lead to breakdowns of the water valves during draining, and this will lead to the appearance of a specific smell of the sewage system into the room.

Calculation of slope

What is the slope of the sewer pipe should be Slope values ​​of sewage pipes

Slope of sewer The pipeline is determined in centimeters. To better understand the designation of the slope of the pipe, consider a simple example. The slope of the pipe is 0.04 cm. This means that the height of the slide is 4 cm per meter of sewer pipe. The pipeline length is 4 m, which means that its lower point is 16 cm below the upper one (4x4 = 16).

Determining the optimal slope of the pipeline in the room will help calculate the degree of filling of the pipe. Do not go into mathematical calculations. The filling capacity for smooth plastic pipes is 0.5, and for pipes with a rough uneven surface is 0.6.

These pipe filling indices allow fluid to move through sewer pipes at optimum speed.

Standards of slope values ​​

What is the slope of the sewer pipe should be Sewage pipe slope

The slope of the pipeline depends on the diameter pipes. There are pipe slope norms:

  • pipe section 50 mm, inclination angle 0.03;
  • pipe section 85-100 mm, inclination angle 0.02.

Standards of tap for sanitary devices

  • wash basin, the tap is made by pipes with a diameter of 40-50 mm with a tilt angle of 0, 025-0.035;
  • toilet bowl, pipe with a cross section of 100 mm is used for removal, inclination 0, 012-0.02.

What is the slope of the sewer pipe should be Proper installation of sewage pipes

When installing free-flow sewage, the choice of slope plays the last role pipes located outside the building. Typically, these pipes have a larger diameter than the pipes of the house sewer. When installing pipes with a cross section of 150 mm, observe the inclination angle of 0.008; in exceptional cases, 0.007. If you use a pipe of 200 mm cross section for external installation of sewage, their optimum inclination will be 0.007 and the minimum 0.005.

The maximum allowable angle of inclination of the external sewage pipes is 0, 15. This means that the sewage system cannot work effectively if the inclination of the external pipes exceeds 15 cm per meter of its length.

Choosing the right slope is a guarantee of efficient operation of the free-flow sewer system. In case of violation of the norms of calculation and installation, the high-quality operation of the system is impossible, it will constantly form blockages.

When installing the sewage yourself, strictly adhere to all rules and regulations, if you hired workers, make sure that they strictly follow them, then you will have a perfectly functioning sewer system in your house.


In conclusion, we offer, for informational purposes, to watch a video about the rules for laying sewers:


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