Illinois Plumbing Code Practice

The correct choice for the type of cleanout that should be provided at or near the base of each vertical waste or soil stack is the 2-way cleanout. This specific type of cleanout allows for access from both directions of flow, facilitating the maintenance and cleaning of the stack without the need for disassembly of the plumbing. In vertical waste and soil stacks, blockages can occur in either direction; therefore, employing a 2-way cleanout enhances accessibility for clearing any obstructions that might arise from either the upper or lower sections of the plumbing system. This ensures optimal functioning and maintenance efficiency. While the lateral cleanout is useful for horizontal runs of drainage piping, it doesn't specifically address the need for a cleanout at the base of vertical stacks. The roof cleanout serves a different purpose by allowing access for clearing blockages in vent stacks that extend to the roof, rather than addressing issues at the base. The main cleanout typically pertains to larger drainage systems and does not apply specifically to the individual stacks required by code. Hence, the 2-way cleanout is the most appropriate choice for this situation, aligning with best practices in plumbing code regulations.