I am in the process of adding a second, 3 piece bathroom in my house. I am planning on running the drain through floor, parallel to the joists. I have enough room for proper slope. Here is my layout. Does this look suitable?
assuming the branch on the 3x2 wye enters above the centerline of the 3", the only problem i see is the lav drain. the wet vent needs to be plumbed into the vent line, not the drain line. basically tie it into the vent for the toilet or tub above the drain for the fixture