Interpretation #8415
Published May 24, 2020
Original Request
- Code Version
- 2017
- Code
- PLUMBING
- Code Description
- Chapter
- Chapter 9 Vents
- Section
- 915.2.3
- Topic
- Connections permitted in a Combination Waste And Vent System
Question
Can a combination waste and vent branch connect to a building drain or to a branch of the building drain that receives discharge from waste stacks as long as there are other branches somewhere on that same floor level that have vented fixtures and that also connects to the same building drain?
Answer Published 05/24/2020 at 8:30 AM
Yes. Section 915.2.3 only requires a dry vent when the combination waste and vent system is connected to a horizontal drain that is not otherwise vented. So, as long as there is at least one other vented fixture on the horizontal drain, an additional dry vent would not be required. Wet vent systems and circuit vent systems are "horizontal drains that are vented." The IPC Commentary contains several illustrated examples.
Commentary
None.