Illinois Plumbing Code Practice

What is the minimum diameter required for the outlet of a bathtub waste outlet?

1. 1 inch

2. 1.25 inches

3. 1.5 inches

4. 1.75 inches

The correct answer is: 1.5 inches

The minimum diameter required for the outlet of a bathtub waste outlet is specified as 1.5 inches in the Illinois Plumbing Code. This requirement is in place to ensure adequate drainage and to prevent potential clogs in the plumbing system. A bathtub typically holds a significant volume of water, and ensuring a proper outlet size helps facilitate the quick and efficient removal of water to avoid overflow and water damage. Furthermore, using a larger diameter outlet can help accommodate larger debris that may enter the waste system, promoting overall system efficiency and reliability. The standard size of 1.5 inches strikes a balance between sufficient flow capacity and manageable installation requirements within plumbing systems. Other sizes, such as those mentioned in the other choices, do not meet the standards required for a bathtub's waste outlet in Illinois.