What is the maximum horizontal spacing allowed for PVC drainage pipe?

The maximum horizontal spacing allowed for PVC drainage pipe is determined by the need to maintain structural support and prevent sagging or displacement over time. When installed correctly, the spacing ensures that the pipe has adequate support to handle the weight of the soil above and any additional stress from external factors.

In this context, a spacing of 4 feet is appropriate because it complies with industry standards, which typically specify that supports should be installed every few feet to ensure the long-term integrity of the piping system. Spacing greater than this, such as 5 feet or beyond, may lead to insufficient support, potentially causing the pipe to sag or become misaligned, which can obstruct flow and lead to blockages.

Smaller spacings, like those at 2 feet or 3 feet, would provide excessive support, which is generally unnecessary and could increase installation costs without offering additional benefits. Therefore, 4 feet provides an optimal balance between support and practicality.