I am trying to install a double sink vanity in our master bath remodel. However, when I exposed the pipes to plan my plumbing I ran into a dilemma. How do I tie double sink plumbing into my current plumbing. The issue I have is trying to properly vent and drain the system. In the second photo...
Blue = Existing Vent,
Black = Existing 3" Drain
Red = New plumbing
Need to add 2nd story lav sink. Can I do a wet vent from the new lav sink to the exiting lav sink on first floor? If so, do I need to, or should I remove the "dashed" line i have in image?