What is the minimum thickness of a closet floor flange allowed?

The minimum thickness of a closet floor flange is critical for ensuring a secure and stable connection between the toilet and the sewer system. A thickness of 3/16 inch is specified as the minimum because it provides enough material to withstand the weight of the toilet and the forces exerted during use while still allowing for proper sealing and alignment with the mounting bolts.

Having a flange that is too thin could result in cracking under stress, leading to leaks or instability. The dimension ensures that the flange can maintain integrity during installation and throughout the life of the plumbing system. Thicker flanges, while potentially more durable, are not required by code for residential applications, making the minimum thickness of 3/16 inch sufficient for compliant installations.

In contrast, the other thickness choices exceed the necessary specification for standard closet flanges, making them unnecessary and potentially more costly without providing any significant advantage in typical residential plumbing scenarios.