Reply To: System Venting Size Required for 3 toilets? Home › Forums › Public Forums › General Plumbing › System Venting Size Required for 3 toilets? › Reply To: System Venting Size Required for 3 toilets? 23 Feb 2003 at 11:12 pm #294046 DEHParticipant How do I check our state of Ohio code? Yes there is 1 – 3″ thru the roof, and 1 lavatory for each toilet. I set is in the basement, with another set directly above that one, and the third app. 20 ft. away on the first floor.Thanks for your help!
