Iím adding new bathroom in my basement and Iím moving a lot of the existing plumbing around to make room. All of the plumbing for the new bathroom is not relevant to this post (for now). It will tie into the main pipe further downstream, and Iíll be putting a new vent through the roof to service all of the fixtures (toilet+sink+shower+tub).

Iíve had a plumber come by twice now, and we talked over all the details. And I have my building permits, so everything will be inspected at the proper stages.

However, there is one area we talked about and I either forgot some of the details, or we did not discuss it specifically. We focused more on the new stuff then then old. So please look at pic1 and pic2. They show the existing plumbing. Pic1 also has more details written on the drawing. The two vertical stacks take up a lot of room, especially because I would need to keep the clean outs accessible. To avoid this, Iíll be moving them to the left (where the concrete floor has been broken up.

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Pic3 is a hand drawing of how all of this will look. I will cut the cast iron stack near the ceiling, use fernco coupler to transition to ABS, use a 90 and run the 3Ē ABS along the wall, then a 90 to run the 3Ē ABS down to the floor.

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The 1.25Ē vent shown in pic1 is not enough to service a laundry sink and washer, so I will be venting the laundry tub and washer drain as shown in pic3, and Iíll tie that vent into the new 3Ē vent Iím adding. Iíll tie it in above the flood line of all the fixtures it services.

Before I continue, are there any other issues with pic3?
The San-T that I circled in redÖ Iím pretty sure this needs to be a wye (with a 45, or long sweep). Is that right? I think I want to use a 2x2x1.5 wye that comes off with a 45.
Is the 1.5Ē vent is large enough for the laundry tub and washer? From my understanding it is.
I know there is a maximum ďlength of trap arm to ventĒ, which I will satisfy. But is there a minimum distance a vent needs to be from the trap?
The 4x4x3 Tee-wye at the bottom, Iím using the 3Ē off the side because that 45 will go into the wall, so that all the plumbing above it will be in the wall, not out in the space.

My other Question is with the two pipes (1.5Ē drain and 1.25Ē vent) that come down from the kitchen. Right now they run directly into the floor. The 1.25Ē vent is no longer needed because the laundry is tied into the main stack, so Iíll tie the two together as shown at the top of pic4. And Iím already tying the laundry into the main stack. Is there any reason I canít do the same for the kitchen?
Pic4 shows three examples of how I could do this. Is there any reason I canít? I donít remember the plumber saying I could or could not. Is one of my examples better than the other?
I like option #1 the most. Option 3 will consume more head space.

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Thanks in advance!