What is the minimum size for a residential drainage pipe?

The minimum size for a residential drainage pipe is 1 1/2 inches. This size is specified in plumbing codes to ensure adequate flow capacity and prevent clogs in drainage systems. A 1 1/2-inch pipe can effectively handle the typical waste water flow from fixtures such as sinks and showers, which is crucial for maintaining proper drainage and sanitation within a residential setting.

Choosing a pipe size smaller than 1 1/2 inches would risk reduced drainage efficiency and increase the likelihood of blockages. In contrast, larger pipe sizes, while capable of transporting waste efficiently, may not be necessary for smaller residential systems and could result in higher material costs and installation complexity. Thus, 1 1/2 inches strikes a balance between effective drainage and practical application in residential plumbing systems.