Sewer Line Slope Per Foot

[Hinesley]

What's the biggest sewer line slope per foot that is safe? I'm wondering if I should put an elbow in the plumbing to limit the fall.

 

[Qapla]

According to plumbing code, drain pipe has to be sloped a minimum of 1/4-inch per foot and a maximum of three inches per foot. A slope of less than 1/4-inch per foot will cause constant drain clogs and a slope of more than three inches will allow the water to drain without the solids.

If you are need a drop greater than this, it is best to use 2 - 45º elbows to create the drop to a lower level instead of 2 - 90º elbows so that the solids do not create a problem when dropping vertically.

 

[naykid]

We try for a 1/4" per foot. Poop needs to float or it will get stuck.

 

[kneedeep]

1/4" min
1/2" max
Per foot.
Just installed line to new tank. 50' @ 18" total fall with cleanout 25' apart.