International Residential Code (IRC) Plumbing Practice Test 2026 - Free IRC Practice Questions and Study Guide

When replacing the entire sanitary drainage system of an existing building, it is essential to confirm that the piping is sloping correctly, not broken, and not obstructed. This is crucial because proper slope in drainage pipes ensures that wastewater flows efficiently towards the sewer or septic system without standing water, which can lead to clogs and backflow issues.

Moreover, ensuring the pipes are not broken is vital for maintaining system integrity; any broken pipes can lead to leaks, contamination, and costly repairs. Additionally, unobstructed pipes are necessary to facilitate the smooth passage of waste and prevent blockages that may cause sewage backups or system failures.

In the context of the other options, verifying that pipes are newly installed and connected correctly is certainly important, but it does not encompass the broader requirements of checking for slope, breaks, or obstructions, which are fundamental to ensuring the system functions as intended. Similarly, while maintaining clean and disinfected pipes is beneficial, it does not address the structural aspects of the drainage system critical for performance.