08 - DWV System Components - Fittings, Cleanouts, and Flow Direction

Send us Fan MailMaster the complex world of DWV system components in this technical episode covering pipe slope, direction changes, fittings, and cleanouts. Understanding how drainage systems manage flow is essential for identifying improper installations and potential problems.We begin with the physics of drainage: why slope matters, how much slope is required, and why too much slope can be problematic for pipes carrying solids. You'll learn the three types of flow direction changes—horizontal to vertical, vertical to horizontal, and horizontal to horizontal—and why each presents different challenges.Fittings receive comprehensive coverage, starting with bends (elbows). We explain the difference between long sweep and short sweep quarter bends, why vent quarter bends cannot be used in drainage applications, and the common mistake of using improper fittings when installing deeper sinks.Sanitary tees are examined in detail, including proper orientation, acceptable uses, and the most common installation errors found during bathroom remodeling. You'll learn why sanitary tees cannot change flow from vertical to horizontal or horizontal to horizontal.Quarter bends with inlets, wyes, and tee-wyes receive thorough coverage, including when each fitting type is appropriate and how to identify improper applications. We explain why some fittings can be used for any direction change while others have restrictions.Cleanout requirements are covered extensively, including proper locations, spacing, sizing, and clearance requirements. You'll learn where the building sewer cleanout should be located, when additional cleanouts are required, and how to use good judgment when evaluating older installations with different standards.Saddle fittings and drilled pipe connections receive attention as prohibited practices, helping you identify amateur plumbing work. The episode concludes with backwater valve requirements and building trap discussions.Intro This episode is brought to you by GetSync.pro This episode is hosted by Charlie Bellefontaine of Chicagoland Home InspectorsFor complete training with visual materials, practice exams, and certification support, visit nhiexamprep.com© 2025 National Home Inspector Exam Prep Podcast. All rights reserved.