Installing Toilet in woodshop 75 feet from house with no slope.

[Tom Beatty]

My woodshop needs a toilet and sink. The shop sits on a concrete slab 75 feet from the house that was built in 1850. The sewage outflow from the house is only 2 feet below grade and exits through the front wall of the basement to a sewer main in the street that has only about 3.5 feet of cover.

The only way I can make this work is with a sewer ejector.

My question is should I plan the ejector in the shop and depend on the long pressure line to reach the house outflow or do I run a gravity line outside to a pit with a manhole? Our winters are not severe so a 30" freeze line is adequate. The problem is a 75 foot gravity run is going to require too much drop and my water table is down only 15 feet.

Does anyone have experience with long runs on the pressure side for an ejector system? If that works i can have the sump in the shop. With that approach will odors be a problem if the toilet is used infrequently?

Should the pressure line be insulated?

Thanks in advance for any help.

 

[Reach4]

My question is should I plan the ejector in the shop and depend on the long pressure line to reach the house outflow or do I run a gravity line outside to a pit with a manhole? Our winters are not severe so a 30" freeze line is adequate

Check that number. I think that number is too low. You can usually get away with a gravity sewer above the frost line, because it clears out, but your line from the grinder pump is going to stay full. Re-check your frostline data.

Does anyone have experience with long runs on the pressure side for an ejector system? If that works i can have the sump in the shop. With that approach will odors be a problem if the toilet is used infrequently?

You will need a sealed pit with a 2 inch vent to the attic, and maybe expanding as it exits the roof.

Sealed indoors is fine. Indoors is easier construction than a pit in the yard.

In fact, there are some systems that can handle the toilet and a lavatory without going below ground, except for the pipe. That still needs a vent through the roof. https://www.saniflo.com/us/12-installing-a-toilet

 

[Sponsor]

 

[Jeff H Young]

If you ran 4 inch at 1 percent I'm rounding it off to 10 inches fall in 80 foot. ( my code wont allow 1 percent on 3 inch) 15 foot water table I don't know how that comes into play but I'm a warm weather guy.
You don't think the above works? due to freeze ? Id have to find out myself with local conditions

 

[wwhitney]

My woodshop needs a toilet and sink. The shop sits on a concrete slab 75 feet from the house that was built in 1850. The sewage outflow from the house is only 2 feet below grade

An important question is what is grade doing between the two buildings?

If grade is perfectly level between them, as Jeff pointed out you can run a sewer line at 1/8" per foot drop and still be 1' below grade at the woodshop. If grade at the woodshop is 1' higher, even better. But if it's 2' lower, then you have trouble, your sewer would be 1' above grade at the woodshop.

Cheers, Wayne

 

[Reach4]

if you ran 4 inch at 1 percent Im rounding it off to 10 inches fall in 80 foot. ( my code wont allow 1 percent on 3 inch) 15 foot water table I dont know how that comes into play but Im a warm weather guy.
You dont think the above works? due to feeze ? Id have to find out myself with local conditions

https://www.hammerpedia.com/frost-line-map/
https://www.hammerpedia.com/illinois-frost-line/

 

[Tom Beatty]

Check that number. I think that number is too low. You can usually get away with a gravity sewer above the frost line, because it clears out, but your line from the grinder pump is going to stay full. Re-check your frostline data.


You will need a sealed pit with a 2 inch vent to the attic, and maybe expanding as it exits the roof.

Sealed indoors is fine. Indoors is easier construction than a pit in the yard.

In fact, there are some systems that can handle the toilet and a lavatory without going below ground, except for the pipe. That still needs a vent through the roof. https://www.saniflo.com/us/12-installing-a-toilet

I checked the NOAA map for freeze line (east end of Long Island) and the max frost line is 12-18" so 30" is probably overkill. The main issue is the run. If I installed the unit in the shop by cutting a hole in the pad. I would have a 75 foot run on the pressure side of the pump to get to the house. I have only ever down gravity systems so I just want to be sure that a 75 foot run with worst case a 4 foot head on the termination end to transit the basement would be OK.

 

[Tom Beatty]

An important question is what is grade doing between the two buildings?

If grade is perfectly level between them, as Jeff pointed out you can run a sewer line at 1/8" per foot drop and still be 1' below grade at the woodshop. If grade at the woodshop is 1' higher, even better. But if it's 2' lower, then you have trouble, your sewer would be 1' above grade at the woodshop.

Cheers, Wayne

The wood shop is probably about one foot below the house, but the outflow in the house is 2 foot below grade.

 

[Reach4]

I checked the NOAA map for freeze line (east end of Long Island) and the max frost line is 12-18" so 30" is probably overkill.

Do you understand why I thought you were talking about the Rockford IL area?

 

[Tom Beatty]

I was thinking of specifying the Liberty P382LE51. it will pump uphill to a head of 10'. Is that right? Has anyone have experience with Liberty ejectors?

 

[Tom Beatty]

Do you understand why I thought you were talking about the Rockford IL area?

Yes. I should have been clearer.

 

[wwhitney]

Seems to me a gravity sewer would be preferable whenever possible, and that the sewer line doesn't need to be below the frost line. Your numbers make it seem possible but borderline that you could reach the wood shop (rising from the house sewer) while ending up below grade at the wood shop. Sharper numbers are required to be sure. If the house sewer is falling faster than 1/8" per foot between the house and the street, it may be advantageous to tie into that closer to the street.

Cheers, Wayne

 

[Tom Beatty]

Seems to me a gravity sewer would be preferable whenever possible, and that the sewer line doesn't need to be below the frost line. Your numbers make it seem possible but borderline that you could reach the wood shop (rising from the house sewer) while ending up below grade at the wood shop. Sharper numbers are required to be sure. If the house sewer is falling faster than 1/8" per foot between the house and the street, it may be advantageous to tie into that closer to the street.

Cheers, Wayne

The run to the street is 175 feet and the sewer main in the street is only 3.5feet down so there is no way to get 1/4" per foot on that run.

The run from the shop to the house is 75 feet, but the outflow to the street is only 2.5 feet down and my shop is slightly downhill from the house. So all in the pad that the shop sits on is about 12 inches higher that the sewage outflow to the street in the house basement at best.

It seems a gravity solution, even at 1/8" per foot and large diameter pipe is a problem. Over 75 feet, that is a 9 foot drop, isn't it?

 

[Tom Beatty]

The run to the street is 175 feet and the sewer main in the street is only 3.5feet down so there is no way to get 1/4" per foot on that run.

The run from the shop to the house is 75 feet, but the outflow to the street is only 2.5 feet down and my shop is slightly downhill from the house. So all in the pad that the shop sits on is about 12 inches higher that the sewage outflow to the street in the house basement at best.

It seems a gravity solution, even at 1/8" per foot and large diameter pipe is a problem. Over 75 feet, that is a 9 foot drop, isn't it?

No that is a 9 inch drop.

 

[Tom Beatty]

Check that number. I think that number is too low. You can usually get away with a gravity sewer above the frost line, because it clears out, but your line from the grinder pump is going to stay full. Re-check your frostline data.


You will need a sealed pit with a 2 inch vent to the attic, and maybe expanding as it exits the roof.

Sealed indoors is fine. Indoors is easier construction than a pit in the yard.

In fact, there are some systems that can handle the toilet and a lavatory without going below ground, except for the pipe. That still needs a vent through the roof. https://www.saniflo.com/us/12-installing-a-toilet

The vent and the sealed pit are all very possible. IF I get this worked out, a shower could be an additional option. Right now, on days when I get reallt dirty, I have to go to the second floor to reach a shower which the wife is not wild about. A shower in the shop would let me keep the house cleaner and confine my mess to my shop.

I like the sealed pit packages from Liberty (P383LE51 or P372LE51). They are all setup ready to go. I just have to get comfortable with the 75' run to the house, any possible freeze issues, frictional loss over the run, and the 36" of head necessary to transit the basement from the entry side that the shop is on, up and over, to the exit side to the sewage outflow to the street.

 

[Michael Young]

My woodshop needs a toilet and sink. The shop sits on a concrete slab 75 feet from the house that was built in 1850. The sewage outflow from the house is only 2 feet below grade and exits through the front wall of the basement to a sewer main in the street that has only about 3.5 feet of cover.

The only way I can make this work is with a sewer ejector.

My question is should I plan the ejector in the shop and depend on the long pressure line to reach the house outflow or do I run a gravity line outside to a pit with a manhole? Our winters are not severe so a 30" freeze line is adequate. The problem is a 75 foot gravity run is going to require too much drop and my water table is down only 15 feet.

Does anyone have experience with long runs on the pressure side for an ejector system? If that works i can have the sump in the shop. With that approach will odors be a problem if the toilet is used infrequently?

Should the pressure line be insulated?

Thanks in advance for any help.

set your sewer ejector right outside the shop. pipe your waste lines to ejector. then run your 2" waste to tie into the existing DWV.

NOTE: you are in a shop. print something large and obnoxious TOILET PAPER ONLY/pumped fixture. You get people dumping sawdust and paper towels, you'll end up replacng that pump.

 

[Jeff H Young]

I was assuming a single family home with detached garage not a machine shop or wood shop with crew. In any case figure out your elevations with a builder level. get the hard numbers . before deciding how to do it.
Wayne had valid idea as well if your sewer is screaming down hill you might be able to pick up some more fall by tieing in closer to street. a gravity sewer is better than pumped . I may need to be corrected but I believe code requires a reason to pump waste rather than build by gravity

 

[Tim MacIntosh]

I have a very similar situation. Freezing is definitely a concern. Older home with some Spaulding on foundation so running pipes under the footing is extra-off-the-table. This is what I was thinking:

 

[Tim MacIntosh]

Someone suggested that the long gentle up situation was not good for a pump. Any thoughts on this anyone? In light of this I did a plan B. But it relies on two pumps; seems like a liability. With no check in between, maybe a cleverly placed vent could allow for the pressure line to drain - no freezing!
Thoughts?

 

[Reach4]

Two pumps seems unnecessary.

It looks like you have three foundation walls you are going through. Is that what those are?

Why insulated heated box? Is it impractical to get the outside run below the frost line?

 

[Jeff H Young]

Tom, What about gravuty drain from workshop to the basement of house and then pump up to the elevation where sewer exits house?
BTW Tim might want to look at his drawing I dont think you can gravity drain w/c on a 2 inch line