What is the required drainage piping slope for pipes under 2 1/2 inches in diameter?

The required drainage piping slope for pipes under 2 1/2 inches in diameter is 1/4 inch per foot. This slope is specified to ensure proper drainage of wastewater, preventing issues such as clogs or backup. The rationale behind this specific slope is that it effectively encourages the flow of liquid through the pipe while allowing solids to settle appropriately.

When pipes are laid at the proper slope, gravity can assist in moving water and waste down the line, which is crucial for maintaining a functional drainage system. If the slope were to be less than 1/4 inch per foot, there is a risk that wastewater may not flow efficiently, leading to potential drainage problems. Conversely, a slope that is too steep can create velocity issues, leading to erosion or the scouring of solids from the pipe, which could also impair drainage efficiency. Thus, the 1/4 inch per foot standard balances effective drainage while minimizing the potential for problems associated with both insufficient or excessive slope.