Common Sizes of Toilet Drain Pipes: A Comprehensive Guide

Our daily lives are inseparable from toilets, but many people do not have a deep understanding of them. It is essential to know the specifications to ensure smooth drainage. So, what is the size of the toilet drainage pipe?

What is the size of the toilet drainage pipe？

There are many types of drainage pipes available for toilets, with common sizes being 300, 350, 400, and 450 millimeters. According to relevant standards, the length from the center point of the drainage pipe to the wall is generally about 300 millimeters. This is considered a relatively standard size, and slight deviations from this measurement are normal, typically falling between 300 and 400 millimeters.

If the diameter of the drainage pipe is 110 millimeters, the distance from the wall is usually either 300 or 400 millimeters, and 350 millimeters is also acceptable as long as it allows for proper installation later on.

Why can't the toilet be installed？

1、Many people find that their toilet does not match the specifications of the sewage pipe; this is often due to choosing the wrong drainage pipe. According to domestic standards, the distance of the drainage pipe from the wall should be approximately 300 millimeters. Even if there is a deviation, it should not be excessive.

2、When considering the pre-embedded pipes, the thickness of the brick wall must be taken into account. The specifications for the toilet outlet are 35 or 40 millimeters, and it is crucial to understand whether the drainage is from the bottom or the back. If it is the former, the distance from the wall to the center of the pipe is about 36 millimeters; for the latter, it connects directly to the wall and links to the sewage outlet.

3、The drainage pipes installed must also be within the specified range; otherwise, installation may fail. Additionally, if installation is not executed properly, it may lead to blockages, affecting daily use.

In summary：the above information provides insights into toilet drainage pipes. From the discussion, it is clear that there are various sizes of drainage pipes to choose from. How to proceed depends on your home’s actual situation and needs. This will help ensure smooth drainage, reduce the likelihood of future blockages, and save materials and costs. I hope this information is helpful to everyone.