Alabama Journeyman Plumbing Pre-Test Practice 2026 - Free Plumbing Practice Questions and Study Guide

The recommended size for a residential water service pipe typically falls within the range of 3/4 inch to 1 inch in diameter. Choosing a 3/4 inch pipe is common and often considered adequate for most residential applications, providing a good balance between water flow and pressure. This size can sufficiently meet the demands of household fixtures such as sinks, showers, and appliances while maintaining appropriate water pressure.

Using a pipe that is too small may lead to lower water pressure and insufficient flow, especially when multiple fixtures are in use at the same time. Conversely, while a larger pipe size, like 1 inch or 2 inches, could technically accommodate more flow, it may not be necessary for standard residential usage and could lead to increased costs for materials and installation without providing significant benefits for the typical household.

In summary, a 3/4 inch water service pipe is generally recommended because it effectively meets residential water demands while ensuring efficient flow and pressure.