The rough-in of a toilet is the vertical distance between the center point of the waste pipe reserved in the floor and the finished tile surface. Typically, it’s either 305mm or 400mm. Here are the installation ranges:
1. For a 305mm rough-in, the range is 290-390mm.
2. For a 400mm rough-in, the range is greater than 390mm. Note: If the installation range is less than 290mm, installation will fail.