What's the difference between horizontal branch & building drain?

[Joe.B]

 

[AesclepianDream]

Well, if your proposed explanation says that (almost) none of the drains in my diagram are the building drain, and the letter of the code says they all are...

...But so far in this discussion I'm at the stage of the analysis of "do we agree on what the letter of the definition says?"

Well, let's see...
"BUILDING DRAIN. That part of the lowest piping of a drainage system that receives the discharge from soil, waste and other drainage pipes inside and that extends 30 inches (762 mm) in developed length of pipe beyond the exterior walls of the building and conveys the drainage to the building sewer." IPC 2021, Page 2-2 (27 of 273) (emphasis added)

Speaking in a strictly legal (letter of the code) manner, each 'and' in the definition of a building drain designates a mandated requirement for a drain section to be labeled a building drain. This means, depending on the sale of the drawing you shared, only the 30" segment of the drain extending past the north wall near the cleanout - or any piping like it - could possibly fit the description, assuming that this line also conveys the drainage to the building sewer. I'll have to double check to be sure, but it seems only this segment of pipe (building drain) and the pipe beyond it (building sewer) are required by the code to conform to the DFU/sizing allotments of IPC Table 915.2.2.

This should be self-evident, but my explanations were only explorations of the lines of reason behind the code - "to what ends are the terms differentiated?" - not proposed changes.

Humble regards, -AesclepianDreamer

 

[wwhitney]

Speaking in a strictly legal (letter of the code) manner, each 'and' in the definition of a building drain designates a mandated requirement for a drain section to be labeled a building drain. This means, depending on the sale of the drawing you shared, only the 30" segment of the drain extending past the north wall near the cleanout - or any piping like it - could possibly fit the description, assuming that this line also conveys the drainage to the building sewer.

The definition starts with "That part" which meets a bunch of requirements (foremost that it is part of the piping of a drainage system). So the requirements do not apply to each pipe separately or individually, but to a part of the piping system all together.

In other words to test if we have correctly identified the building drain, we should draw a circle (figuratively, I mean any loop) around part of the piping system (or possibly more than one circle, if there are multiple drainage pipes exiting the building.) The portion of the piping system within the circle(s) identifies "that part". Then we check whether all the requirements are satisfied by the circled part of the piping system. If so, we also need to check if we could expand the circles to include more of the piping system and still have the circled area satisfy all the requirements. If the circled part satisfies all the requirements, but no larger circled part would satisfy all the requirements, then we have determined the complete extent of the building drain.

Cheers, Wayne

 

[ICE]

The definition starts with "That part" which meets a bunch of requirements (foremost that it is part of the piping of a drainage system). So the requirements do not apply to each pipe separately or individually, but to a part of the piping system all together.

If the people that wrote codes had the same linguistic acumen as you and the big bird, a great deal of every code would be easier to understand. Jeff has superb mechanical skills.....(I didn't want to leave him out)

 

[jar546]

If the people that wrote codes had the same linguistic acumen as you and the big bird, a great deal of every code would be easier to understand. Jeff has superb mechanical skills.....(I didn't want to leave him out)

I like trains.

 

[ICE]

I like trains.

Trains are a safe way for you to get around.