# Sewage Pipe Grade



## gtdail (May 31, 2006)

Not a plumber myself but I helped a friend get water hooked up on a mobile home he bought could anyone tell me at what grade/slope the plumbing needs to be hooked up at to drain to the septic tank? Thanks for your help.


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## Glasshousebltr (Feb 9, 2004)

Between 1/4 to 1/2 inch a foot.....1/4 being preferred.

Bob


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## Teetorbilt (Feb 12, 2004)

What Bob said. If you can get away with a higher pitch, go for it. 1/4" in 12 is minimum, more pitch = less problems.


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## Tom R (Jun 1, 2004)

I don't know about 'more pitch = less problems' . . . 

Too much pitch leaves the solids behind, - - 1/4" is the ideal pitch.


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## Double-A (Jul 3, 2006)

Grade on 4" and smaller is generally 1/4" per foot. Best bet is to check with your AHJ (local inspector).

Although it may not kill anyone if this is not done properly, I would suggest having a licensed plumber do this work. Bellies, backfall, lack of cleanouts or misplaced cleanouts can all lead to serious and costly problems down the road. A plugged sewer is no ones idea of a fun filled weekend.


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## Glasshousebltr (Feb 9, 2004)

Double-A said:


> A plugged sewer is no ones idea of a fun filled weekend.


A plugged sewer can create a lot of crap.:thumbsup:

Bob


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## Teetorbilt (Feb 12, 2004)

Tom, over 90% of what flows through the pipe is water. Think about it. Peeing, showering, washing dishes, laundry, all water. 

The worst problem has always been grease. It will stick to the walls of a pipe and restrict the flow. I have seen clumps the size of basketballs in wetwells, they can shut down a pumping stations pump.


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## Joasis (Mar 28, 2006)

Has anyone read anything about septic systems designed to take only black water into the tank and field, and then what do they do with the grey water? The point being a perfect system will never cause problems, but grey water is what kills the bacteria in the system.


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