I am adding a bath in my gameroom and need some help with the sewer line/ vent setup. This room had a toilet at its current location with a 1 1/2 in vent come up the wall on the right side of toilet. I would like to add the tub and the 2 sinks. I have the slab busted and the 4 in line exposed it is about 15 to 18 inches from the back 8ft wall. Can somebody help me with how I need to run the vents? Thanks for any help. Michael