i am relaying out my entire second floor bath room ,my new toilet runs aprox 9 feet 3 inch pipe from the 3 inch vent pipe, shower is 11 feet from vent using 2 inch pipe , bath tub is 4 feet inch n half and sink is 4 feetinch half , will i need to run a new vent out from any of these new areas or can i use the existing 3 inch vent ?