How to Measure Toilet Rough-In: Standard Dimensions Explained

The installation of toilets is one of the more problematic areas in bathroom renovations, especially when it comes to the control of the drain distance (pit distance). So, what is the standard pit distance for toilets? Let’s take a look.

What is the standard pit distance for toilets？

Generally, the pit distance is between 30 to 40 centimeters. It cannot be too large or too small. A pit distance that is too large requires an extension of the drain pipe, which not only increases costs but also makes it more likely to experience blockage issues in the future. Conversely, if the pit distance is too small, it may result in installation issues. Additionally, because 2 centimeters must be reserved for wall tiles during installation, the pit distance should be controlled between 32 to 42 centimeters.

What should be noted in toilet installation？

1、Conduct thorough checks on the pipelines

Before installation, it is crucial to perform a comprehensive check of the relevant pipelines to avoid problems that could hinder installation or lead to blockages in subsequent use. Check whether there are any mud, sand, waste paper, or other debris in the drain pipe; neglecting these issues can lead to blockages. It's also important to check that the installation floor is level, as an uneven surface can lead to leaks or unpleasant odors.

2、Pay attention to the length of the drain pipe

When installing the toilet, the drain outlet needs to fit into the drain pipe, so the distance must be appropriate. The drain pipe should be 2 to 5 millimeters above the floor level. Typically, it is made slightly higher to prevent dirt from falling in, and can be carefully cut down after the floor construction is completed.

3、Consider the toilet's S-bend

The S-bend of the toilet is crucial for normal drainage. The surface glaze must be smooth and free of defects or rough textures; otherwise, it can accumulate dirt and lead to blockages. When purchasing, observe the inner wall of the S-bend for any pinholes, missing glaze, deformities, etc.

4、Be aware of the toilet flushing method

Toilets can be classified into two flushing methods: siphon and washdown. The siphon type is more common and can quickly remove waste. The washdown type, on the other hand, features a larger pipe diameter, making it easier to flush down larger waste.

In summary：by now you should have a better understanding of the standard pit distance for toilets. If you would like to learn more related knowledge, feel free to follow us at Hawkrown.