What is the recommended size of concealed pipe within a wall going to a fixture?

The recommended size of concealed pipe within a wall leading to a fixture is typically 1/2". This size is commonly used in residential and commercial plumbing for distributing water to fixtures such as sinks, toilets, and other outlets.

Using 1/2" pipe ensures that there is adequate water pressure and flow to the fixture while minimizing the amount of space needed within the wall. This size strikes a balance between effective water delivery and the structural concerns within the wall cavity, allowing for easier installation and less risk of complications during plumbing repairs or renovations.

Larger pipe sizes, such as 3/4" or 1", while they can carry more water, are generally unnecessary for individual fixtures and could lead to issues related to water temperature regulation and increased material costs. Smaller sizes, such as 1/4", would not be sufficient to meet the flow requirements of typical fixtures, resulting in inadequate performance. Thus, 1/2" is widely accepted as the standard size for concealed pipes in these applications.