Illinois Plumbing Code Practice Exam 2025 – All-in-One Guide for Exam Success!

The correct answer indicates that a clean-out must be provided at or no more than 4 feet above the base of each vertical waste or soil stack. This requirement is established to ensure that plumbing systems can be effectively cleaned and maintained. Clean-outs are essential access points that allow for the removal of blockages and buildup in the piping system, facilitating proper drainage and reducing the risk of sewage backflow or leaks.

Having a clean-out at this specified height helps ensure that it is easily accessible for maintenance personnel while still being functional in terms of the plumbing design. The maximum height requirement is important in maintaining optimal operational efficiency and safety within the plumbing system.

The other options suggest various heights (2, 6, and 8 feet) that do not align with the established codes, either offering insufficient access or potentially complicating maintenance procedures. The 4-foot height strikes the right balance between accessibility and practicality in the context of plumbing maintenance.