How do I fugure out a pvc pipe fall for sewer drain

1/4" per foot or 1" in four foot.

Hi Chester...

For 3" pipe or smaller you want 1/4" pitch per foot of pipe. For 4" pipe or larger you want 1/8" pitch per foot.

To make this work so you are consistent in pitching 3" drain pipes, for example, you want take a 2 foot level and tape a 1/2" nut (or block of wood) on one end of the level (gives 1/4" pitch per foot). Set the level on the pipe so that the lifted end is toward the low end of the pipe and set the pipe so that the level reads perfectly level. This should guarantee a pretty consistent pitch to your pipe.

If you use a 4 foot level and want 1/4" pitch per foot you would use a 1" block of wood. If you want an 1/8" pitch per foot and you are using a 4 foot level you would tape a 1/2" block of wood, etc...

Hope that all made sense... ;)

MARK

Back when I was out doing rough ins I used a torpedo level and Just cracked the bubble on 4" mains and a 1/4 bubble for the smaller stuff. Just another option, (although probably not as accurate as M arks) Good luck, Tom

One of our Inspectors actually owns a torpedo level that works like Mark describes with his drawing. It has adjustable plate on on end for 1/16", 1/8", and 1/4" slopes. Kinda nifty tool to have ...

Some levels designed with plumber in mind have small red marks on bubble glass, past the middle point. Each mark indicates either 1/8" or 1/4" slope. When side of the bubble hits that mark - you are at that particular slope...