Vent Sizing For Bathroom

[Toddy]

Is there a limit to how many fixtures you can vent on one line, currently have toilet, bathroom sink, tub and laundy tub want to add shower, sink and toilet. Vent is 1.5 until enters attic than goes to 1.25 than 3 inch out thru roof. House is a backsplit new bath will be under original bath upstairs total run of vent including elbows less than 30 feet.

[DUNBAR PLUMBER]

Of course, that is what dictates minimum and maximum sizing of DWV lines.


Need to let us know what state you reside in so we can find out what code your state refers to.


My state of Kentucky, NPC is the governing body.



Knowing it went from 1.5" to 3" VTR, sounds like NPC regs.


I believe 1.5" carries 10 DFU's, 2" is 24.

Don't have my codebook in front of me to clarify those numbers.