TCM-221 MEP Print Reading Practice Exam 2025 - Free MEP Print Reading Practice Questions and Study Guide

The diameter of all cleanouts in the unexcavated area of the basement is standardized based on plumbing codes and practices. A 4-inch diameter cleanout is commonly used in residential and commercial plumbing systems. This size provides adequate access for maintenance and cleaning of drainage systems, ensuring that blockages can be effectively cleared without significant disruption. The 4-inch cleanout standard is also compatible with typical sewer and drain pipe sizes, facilitating a smooth integration into the plumbing system while meeting code requirements for wastewater flow management.

Using diameters smaller than 4 inches could impede access and limit the ability of maintenance personnel to properly service the plumbing, while larger sizes may be unnecessary and can complicate installation. Thus, the 4-inch cleanout is the ideal choice for efficiency and compliance in the unexcavated area of the basement.