I am redoing my Master Bath. I removed the tub and shower and going to replace it with a two head shower, I was going to use the tub drain but it is only uses 1 ½ “. If I use the shower drain that is 2” I need to move it 8’. (See Attachment)
My question is having a vent that is 10’ from the drain will it cause problems with the p trap?
Should I add the second 1 ½” pipe (See Red dotted Line) just to make sure I do not have any problems?
Thank you for your help