Please critique my plumbing layout

[atcleveland]

Hello,
I'm planning on adding a full bath, half bath, and utility sink under the mezzanine of my shop. I may want to add a kitchenette upstairs in the mezzanine someday so I want to allow for that in the future too. I'm planning on installing a 4/10 hp sewage pump outside the shop to pump the waste up to my septic tank. This is not going to be inspected but I'd like to make it UPC compliant. Is this vented properly? Comments and advice would be greatly appreciated!
Thanks

 

[James Henry]

It's wrong, do not proceed you'll be sorry.

 

[Sponsor]

 

[wwhitney]

For the UPC:

- No AAVs, so vent the kitchen sink through the roof.
- Wet venting is limited to a single bathroom group, so your second WC is not properly vented, and the utility sink can not be used to wet vent the shower
- Normally the UPC requires the WC to be last on a horizontal wet vent, but WA has amended that away. So that may be useful when you rearrange the drainage connectivity.
- No comment on the ejector pit and vent, as I'm not familiar with those.

A couple different ways to fix the downstairs venting, you could separate the two lav drains and bathroom groups, use one lav to wet vent one WC, the other lav to wet vent the other WC and shower, and then join those two branch drains after all the wet venting is done. Or you could add a dry vent between the upstream WC and the double lav and use circuit venting. Either way the utility sink drain is kept separate and joins downstream of both bathroom groups, e.g. by joining the drain from the kitchenette rather than the shower drain.

Cheers, Wayne

 

[atcleveland]

Thank you for the replies! Does this work?

 

[wwhitney]

Thank you for the replies! Does this work?

Almost. The wet venting is fine (with the clarification that at each lav san-tee, the vent and drain (top and bottom) are 2", which is required for venting the WC).

But your lav venting is off--the vent connection needs to be within one trap diameter of fall from the trap outlet. So that little drop between the trap and the san-tee you show with two 90s is not allowed--you need to use a single horizontal 90 (which as far as I know is supposed to be a LT90 but often a quarter bend is used). Any particular reason you can't just put the san-tee behind the wall penetration so you don't need that 90?

Cheers, Wayne

 

[atcleveland]

Thank you for your help! I really appreciate it.

 

[Reach4]

Usually you would want the kitchenette, on the level above, to drain by gravity.

There is also a way to connect the pump output to the gravity drain, including using a check valve. The line goes up and over, and the flow turns down into a wye to join the gravity line to the septic. This is not a good description, so search for how to do that.

 

[plumb1234]

@atcleveland

Can you tell me what software you used to draw those sketches?

 

[atcleveland]

The software is called SketchUp. It's very intuitive and user friendly.