Planning to add plumbing to garage

[Mike E]

Hello,
I have a 2 story garage not connected to the house.
I want to add bathroom to the 2nd story.
Garage is about 60 feet from house and I do not think I can get the slope needed to just connect to sewage line in the house crawl space (city sewer not septic tank). So I believe I need a pump.
Initial questions:
Can the pump be on the bottom floor of the garage or does it have to go below ground?
Can the line from 2nd floor drop straight into the tank for the pump?
Does the line from the pump to the house have to go through the concrete slab out to the house or can it go through the wall to the outside then down? I am in NC, not too cold.
Should this be a grinding pump?

 

[frodo]

You need to do some home work first before you go the extra expense of a pump and pit

where is the sewer tap?
see drawing.

garage floor is ''0'' elevation
using a transit, shoot the garage floor
swing around to the sewer in the yard. what is the invert [bottom] of the sewer pipe?
what is the distance from garage?

My recommendation is to rent a back hoe, dig up the sewer then shoot it with the transit
run the new sewer from the garage to the sewer in the yard in front of your house
you will save literally thousands of greenbacks

 

[Mike E]

No direct route to sewer tap. Garage lines up to the right and behind the house. Per your drawing, in front of garage is the concrete driveway. A more direct route...to me anyway...is to the back of the house from the front left corner of garage. Then thru the foundation to the crawl space to tie in with house sewer line in crawl space. With your drawing, we are digging up the concrete driveway. There is no path to not do that.

 

[Diehard]

Not positive but I think the minimum bury depth would be 12".

You don't need a grinder pump. What you need is a sewage pump(designed to handle up to 2’’ diameter solids).

Sounds like you may be able to tie into the house for sure with a pump.

In the absence of a transit, I have used a garden hose filled with water to get level readings.(Water seeks its own level.) It may be awkward but it's accurate.

EDIT: A sump in the slab would give you the advantage of adding fixtures down low, like floor drains. On the other hand, a lot easier.
Remember you need a piped vent for a sanitary sump. No AAV(Air Admittance Valve) allowed!

 

[Mike E]

OK. I know I cannot get the slope and 12 inch bury depth for the run.
The only thing I plan to have on the ground floor is a big wash sink. So I may need to plan for the pump tank to be set into the floor slap so everything can drain into it correctly. So the easy way is probably out...
If that is the case, how do I configure the drain from the pump/tank? Everything I have seen so far show the exit line coming off the top of the tank cover going up....as from a basement. I would need it to go horizontal out through the foundation....at least 12 inches down....am I correct?
Venting is not a problem. The way the upstairs is constructed allows for an easy straight shot for the vent pipe.

 

[frodo]

There is NO MINIMUM bury depth of 12''
Your plumbing is on the 2nd floor,You can exit the building above grade


Take a look a this as a possibility
https://www.plumbingsupply.com/when-and-where-to-use-a-macerating-toilet.html
That range is dictated by the power of the pump, and varies between models - usually it's somewhere between 10-15 feet of vertical lift and 100-150 feet of horizontal run. Many units have additional inlets to hook up a sink (kitchen sinks are not recommended), shower, or tub. Macerating toilets are safe to use with septic systems.

Never mind..You just added a drain on the bottom floor

 

[frodo]

I prefer 2 pits, one for waste a small pit for the ck valve/union/valve
It is cleaner looking
the waste line and vent can both be in a wall
so all you actually see is 2 pit covers


opps....

 

[Mike E]

Interesting. I am assuming the check valve is to keep things from going the wrong way. Why the check valve pit?
I was looking around and found Liberty side discharge sewage pumps. All pre-built ready to go. Is that something worth looking into or is that a bad direction?

 

[frodo]

your IPC NC plumbing code