What is a Closet Flange?

A closet flange is a device used to seal a toilet to the floor. A closet flange is typically made of a plastic hub and a steel mounting ring. Other materials sometimes used to create a closet flange are brass, copper and stainless steel. The closet flange commonly fits around the drain pipe and is mounted to the floor with screws or nails through the steel mounting ring. A wax ring is used to seal the fit between the toilet and the closet flange, and the toilet is bolted to the steel ring and not to the bathroom floor.

In what is commonly the highest-volume drain system in a household, the closet flange maintains a leak-free pathway with no actual contact between the toilet and the drain pipe except a soft and pliable ring of wax. Derived from the term water closet, the closet flange is the engineering marvel that made in-home toilets a reality. Often, this flange will last a lifetime without leakage or incident; however, it sometimes becomes necessary to replace the flange, the toilet or the entire system in the case of a bathroom remodel.

In the typical configuration, the steel or plastic drain pipe is positioned underneath the bathroom floor and the toilet fixture. The closet flange is placed over the drain pipe and glued into place with the same glue used to complete the rest of the plastic plumbing. To prevent the pipe from developing a crack or a leak caused from movement, the steel mounting ring is affixed to the bathroom floor with screws or nails. This steel ring also serves as the mounting bracket for the toilet as bolts placed through the ring protrude upward and through mounting holes cast into the base of the toilet bowl. This ensures that the toilet will not move separately from the drain pipe and the flange.

In cases where a new floor is being applied directly over an existing floor or ceramic-type tiles are being placed on the floor, the flange may become too low to provide an adequate base for the toilet. In this situation, a flange extension can be used to raise the height of the flange to the level of the new floor. By following the installation directions, the new flange can be installed without incident and the toilet will function as intended. It is also possible to purchase a closet flange in different heights and offsets to accommodate a remodel and repositioning of the toilet.