Adding a second vanity sink

[Reach4]

Minimum distance between what and what? Are you talking 1st floor or second floor?

The horizontal purple lines must be at least 6 inches above the flood level of the lavatories below them.

 

[wwhitney]

Not sure I follow the question, but a horizontal vent, or a joint between two vents, needs to be at least 6" above the flood rims of any fixtures served. Just 6" is enough.

Cheers, Wayne