What name is used to refer to the pipe in the floor that the toilet sits on?
The pipe in the floor is called the “drain and waste” or DWV. A “flange” sits atop the DWV and has holes for the “t-bolts” of the toilet to attach and secure positioning. A “supply line” runs from the wall or floor near the toilet and connects to the toilet tank, providing water to the toilet. The “wax ring” sits atop the flange and creates a seal between the flange and the bottom of the toilet.
