What is the trap size of a tub with an overhead shower?

The correct choice reflects the standard practice within the Massachusetts Plumbing Code, which specifies that the trap size for a bathtub with a shower overhead should be 1 1/2 inches in diameter. This size is considered sufficient for managing the wastewater and preventing potential clogs while also allowing for proper drainage.

Bathtubs with showers demand a larger trap than a standard sink trap because they typically handle more water volume, especially during use. The 1 1/2 inch trap provides an adequate flow rate for the combination of bathwater and shower usage, ensuring that the drainage system operates efficiently and effectively.

Understanding the nuances of trap sizes is essential for maintaining proper plumbing functions in both residential and commercial settings. Adhering to the code ensures that installations are not only compliant but also minimize the risk of plumbing issues related to inadequate drainage.