Hello,
I am hoping that I can get some advice regarding the rough in main drain I need to trench in before the concrete guy's show up.

I have a small mountain of plumbing books from the library, but none of them deal with my issue.

Here it is... and you are probably going to laugh at my lack of knowledge... I am about to put in a 4' frost wall with a slab. I need to place the main waste pipe , but I can't find any info about where it should go and how it should exit the building.
Do I make a 90 degree downward turn and exit under the 4' frost wall footer or do I run it through the concrete wall simply following the 1/4" rule?
Once outside in my frozen wasteland of an environment I need to run the pipe 70' to a holding tank. (the tank will be in a heated above ground structure) If the pipe does not have to go under the footer, is it possible to simply run the pipe at such a shallow depth in a cold climate?

(You have no idea how much I wish I could simply run this grey water to my water starved willows and forgo the holding tank.)

Any advice?

Hi Morpho...

You said, "Once outside in my frozen wasteland of an environment I need to run the pipe 70' to a holding tank. (the tank will be in a heated above ground structure)"...

But the tank will be in the ground...right? Otherwise, please explain how this works...

In terms of establishing where to start your main drain you really need to establish where the inlet to holding tank will be. From there you will need to pitch up at 1/4" per foot. If the pipe ends up below the footing... great! If not, you will need to build a "knock out" (a 6" pipe is good here) in the frost wall so the pipe can penetrate the frost wall AFTER the wall is poured and stripped.

Let me know more... OK?

Mark

Hello Mark,
Thanks for popping in on this.


Well, the house is on a small rise (About 5-6' above where the greenhouse is to be located. I want to run the pipe the 70' so it empties out into a tank in the greenhouse.
If I put the tank in the ground I have a whole bunch of very expensive rules to follow. Type of tank, depth tank is to be dug, who can install it etc, etc,
If I run it into a tank above ground there are no rules. I can have it run into a rubbermaid garbage can if I want to. Strange huh? (Not to worry, I have a very nice 1200 gallon norwesco hippo tank I can use for the purpose) But the thousands of dollars spent to put the tank into the ground would build me a very nice greenhouse space for the tank and to grow plants in. The actual volume of water I use is low. Really low. We are water misers. I made a composting toilet so there is no water used for that duty and I have been measuring our water usage and it has yet to exceed 20 gallons per day between the two of us. And more often than not it is more like 10 gallons. And remember this is strictly going to be grey water leaving the cottage.

So running it through the wall is not unheard of then?
I take it I place a section of 6" pipe in the wall and pour the foundation around it then?

Thanks for your thoughts.

You could place the 6" pipe into the form before pouring the concrete or you could build a box and join it to the form... ;) If you install the pipe you'll need to be present when pouring the concrete to assure that the pipe doesn't move.

I'm still concerned here though as you seem to be suggesting that the pipe you're running will need to be exposed to the elements (freezing cold and heat from sun)at some point before it enters the building at a height that will allow it to fill a tank as you need.

Let me know more...

I think I have it covered.. literally and figuratively. The greenhouse is excavated into the slope by three feet and the tank can be set into the ground another foot or two, so that should bring the pipe out of the ground and into the top of the tank... I hope. Hmmmm?

Trust me I will be present and up to my knees in concrete if need be. Same goes for every other thing involved in this build. Good point though!