I am adding a bathroom to my basement. I am using a Liberty Ascent system with maceration pump. A vent is required from the pump that will operate the toilet, sink and shower. I can run the vent up through the two floors into the attic and tie into the vent pipe near the roof exit. Does that sound ok? Also do I need a back flow device on the 1" discharge pipe? If so any suggestions? Thank you.......Dan