Minimal slope on sewer lines Home › Forums › Archives › Old Bulletin Board Archives › Minimal slope on sewer lines This topic has 2 replies, 2 voices, and was last updated 24 years, 11 months ago by Jack. Viewing 2 reply threads Author Posts 22 Oct 1999 at 1:18 am #284837 pedro What is the minimal slope for a waste line? 22 Oct 1999 at 1:06 pm #308383 JackParticipant It depends on if youre talking about the line itself, or the service line from the house ? On an 8 line, minimum slope is 0.40%. On the service line, 1.0% minimum. If you need slope on a different line size, let me know. 22 Oct 1999 at 1:06 pm #308393 JackParticipant 3 and smaller, 1/4 per foot. 4 1/8, and 6 1/16: What is the minimal slope for a waste line? Author Posts Viewing 2 reply threads The forum ‘Old Bulletin Board Archives’ is closed to new topics and replies.