What is the minimum diameter for bathtub outlets and overflows, according to plumbing code?

The minimum diameter for bathtub outlets and overflows, as stipulated in plumbing codes, is indeed 1.5 inches. This specification is based on ensuring adequate drainage capacity to prevent overflow and maintain proper flow rates during tub usage.

A diameter of 1.5 inches allows for efficient drainage, which is critical in preventing water from backing up during use and minimizes the risk of any potential water damage. This size is a standard that helps to promote uniformity in plumbing systems and ensures that bathtubs can drain quickly enough to avoid standing water, ultimately contributing to sanitation and hygiene in residential settings.

When examining other options, it becomes clear that smaller diameters such as 1 inch may not provide sufficient drainage capacity, while larger diameters could lead to unnecessary excess in material costs and installation complexity without practical benefits. Adhering to the 1.5-inch standard helps maintain an efficient and effective plumbing system compatible with typical bathtub designs.