What is the minimum size of the water supply inlet for a shower stall?

The minimum size of the water supply inlet for a shower stall is typically established to ensure that the shower can deliver an adequate flow of water for a comfortable and efficient experience. A water supply inlet of 1/2 inch is considered sufficient for most residential shower installations. This size allows for an optimal balance between water pressure and flow rate, ensuring that the showerhead provides a steady and enjoyable stream of water.

Using a larger inlet, such as 3/4 inch or 1 inch, is generally unnecessary for residential applications and may lead to excess water flow rates that are not typically required for shower use. Conversely, a smaller inlet, like 1/4 inch, may not provide enough water pressure or volume, resulting in poor shower performance. Thus, the 1/2 inch inlet size strikes a practical balance for efficient plumbing without compromising user experience.