I have a plumbing problem where the main line which is a 4" line from the house is not draining properly to the latteral 6" line located approximately 60' away. I am being told by the local plumber that the sewer line does not have enough fall from the house to the latteral line 60" away.

What is the required fall in a 4" sewer line for it to properly drain? Thanks!

Robert Haak

1/8" per foot for a 4 or larger line.