Best route for sanitary sewer

[Nathon]

I have two options for routing a sanitary sewer system in a childcare center.

Initially I designed the lines shown in pink, but then re-thought it and traced out a new idea in green.

Which is best, and why?

Thanks!

 

[1gibson]

Green looks difficult / impossible to snake if there's a clog.

 

[Nathon]

@1gibson - Thank you!

 

[dicksewerrat]

Pink also gives you a 50/50 chance that half the system will not be out of service. Move the connection point to one side of the door and install a clean out there to open the combined system..

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[dbill74]

Which uses less piping overall? I would guess the green.
Also, when you have multiple locations where the SS exits the building, each point has to be sleeved or otherwise protected from the weight of the building above. More points to coordinate with structure.
As for being able to snake it, I disagree with Gibson, as either can be snaked with properly located cleanouts.
Speaking of cleanouts, I generally try to avoid locating in the middle of main entryway; not always possible but I try.
This appears to be a single floor building, as such all this will be underground and does not need to follow the main 'square' lines of the building. This is because you will be supporting the piping from structure which usually does. Running certain piping NE/SE/SW/NW can save on piping/trenching also.

Either way you go, I suggest running CO locations by the architect to make sure you are not putting them in undesirable locations and coordinate routes/inverts with structure/footings.

IF it were my design, I would probably use the left purple N/S run as my main and have 2 branches run east to pick up fixtures on that side of the building.

 

[Nathon]

Thank you!

I went with the pink, and have moved the clean out away from the door.

I'll consider running diagonally too.

 

[1gibson]

Dbill74, out of curiosity, where and how many cleanouts would you use for the green? Would you put them right above the T's so you can pick which direction to go with a snake? What about potential need to snake from one location, then pick up and move to a different location to make sure everything is cleared?

 

[Nathon]

UPDATE

Here's what I ended up doing. You can read details if you open the attachment.

Will probably add floor drains to restrooms with 2 toilets and wall cleanouts for 1 toilet.

 

[dbill74]

Gibson, refer to plumbing code for cleanout location requirements. In general they should be at the upper end of mains and branches, whenever there is a change in direction that exceeds 45° and at the main where it exits the building, also in a straight run every 100 feet. Eyeballing the picture in the OP, looks like you could get by with about 10. IPC requires cleanouts to be located to facilitate cleaning in the direction of flow. The reason for this is to minimize chance of damage to fixtures and ensure the snake goes where it needs to. If you are snaking against the flow and it comes to a branch, there is no guarantee the snake will go in the correct direction.

Comments on the latest picture:
Taking the cleanouts to the outside is generally not a good idea, reason being same as for not having your sanitary exit in more than one location. Not saying it can't be done, but you need to be sure it is coordinated with structure and is properly detailed.

Noticing runs going past columns and some fixtures are near columns, this needs to be coordinated with structural. Columns on the interior of buildings more often than not have a big 6-8 foot square black of concrete under them. To save on materials, structural engineers like to specify them as shallow as possible which can interfere with sanitary piping. Again, coordinate with the project's structural engineer.

 

[Nathon]

Thanks dbill74!

I turned the outdoor cleanouts into wall cleanouts.

 

[PEDARRIN2]

I couldn't open the initial plans so could not comment

Looking at the pdf you ended up with - I can only say that it likely will not be constructed as shown and will likely get you some unfriendly comments (or weird looks) from the installing contractors.

Depending on where you are, the upstream portions would be considered dead ends and may not be code compliant. Even if they are acceptable, they are not necessary. Plus every foot you have extended upstream would require excavating the trench, laying the pipe, backfilling, etc. - lots of unneeded cost all for putting a cleanout at the end. Since there are not any chases behind the toilets - I am assuming they are floor set. In that case, the plumber would remove the fixture and use the closet flange connection as the cleanout point. The same can be said of the lavatories - the plumber will remove the trap and use this location to run the snake.

If you have to have cleanouts, locate one behind the washing machine in the wall, one under the cabinet for the hand sink located to plan north of the back to back toilets, one on the wall behind the toilet room groups with the water heater and a floor cleanout in the small toilet room at the lower part of the drawing. Of course keep the cleanout at the connection to the site sewer as shown. But you do not need two. It is not required and not necessary. Locating the cleanouts as stated will likely also comply with the 100' minimum distance requirement from code.