Will my sink work? Fixture location question.

[Cable22]

I had to demo a bathroom laundry area due to a leak in my 70 year old house, now I am taking the opportunity to remodel. I am an intrepid diy’er, if I have a plan and I know the steps, I can do the work.

I have included a photo to show roughly the plan of where I’d like to put things. The pipe diameter of the stack I think is 2”. I understand that this restricts the maximum slope to 2", so at a minimum of 1/4” per foot slope the maximum length of the trap from the vent is 8’, but my sink will be about 10 to 12 feet away.

I would like to know if I can wye off the vent at a level 6” higher than the sink rim, come around 90 degrees and then down to the drain pipe under the sink, and attach the vent closer to the fixture. The waste drain would remain more than 8' away.

Will bringing the vent closer to the fixture rather than the fixture closer to the vent solve my problem? I will still have to drain into the stack coming out of the floor more than 8' away, but is the drain distance a problem if the fixture is already vented within a few feet of its trap?

Plumbing is new to me so I am not sure if my solution will work with the physics involved. Any advice is greatly appreciated.

 

[JG plumbing]

This is an Island vent it'll work.

Is the vent portion of this "stack" dedicated to venting? Or do other things drain into it from above?

 

[Cable22]

Nothing drains into it from above since there is a another drain behind where I stood to take the photo.

The upstairs kitchen sink and dishwasher drains into that one. I can hear the water come down it, but I have never heard anything come down this stack. This also corresponds visually with the layout upstairs.

Also behind me are the current toilet, vanity, and shower drains. I am leaving the toilet where is, and building a new shower and using the same shower drain as well. The only thing I am moving is the vanity/sink to make room for a larger shower.

At the other end of the house is the upstairs bathroom sink, toilet, and tub which drains into another drain that leaves the house through its own stack.

I spent sometime on the roof and found two vents. I believe the one I am going to use serves the fixtures in this bathroom and the upstairs kitchen sink and dishwasher, so no more than 7 fixtures total.

Thanks for your comment. Is there anything else I should know before I go about cutting into the pipe? Any tips or guidance, is there anything I should not do?