max or min fall rates ?

[bcenter]

HI, Are there maximum or minimum rates of fall for horizontal drain piping,
such as 1'' of fall in 4' run ? :confused:

[hj]

That is the minimum according to most codes for pipe up to 3". Larger than that the codes usually have an optional smaller slope.

[Mike Swearingen]

1/4" per linear foot up to 3" and 1/8" if necessary for 4" and up.