Toilet/WC above Shower?

[Martin F]

I'm trying to get a wall hung toilet installed in my condo but my application got rejected because as I understand it, that the wet vented drain for the WC has to be at the same elevation or lower than other wet vented plumbing group fixtures such as the shower (I assume it is to prevent risk of siphon the p-trap for the shower).

Review Comment: "Bathroom, relocated toilet, not as per FBC 912.1.1, (other fixture drains shall connect at same of above WC elevation, see SH)"
Code Reference: https://codes.iccsafe.org/content/FLPC2023P1/chapter-9-vents#FLPC2023P1_Ch09_Sec912

I'm on the top floor of the building and have 26 showers below my WC so I am thinking it must be possible using the right venting for the shower which might be different for the showers below me since they are allowed to be under a WC.

Could adding a (dry?) vent for the shower (see red dashed line in drawing) that connects above the lavatory/sink which is the last fixture connected before what would considered the dry vent(?) (where the existing vent stack from units below also connects) fix the issue? or is there another (better/right) way of doing it?

(shower drain is 1-1/2" and not 2" as indicated).

Hope someone out there can help.




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Picture attached shows an isometric drawing from a unit below that have a wall hung toilet installed and where the permit was accepted - however I find it difficult to fully understand what is going on (fixture locations are not correct - should be same as mine) as it shows the shower connects below lavatory/sink (B) and both connects below the WC but also have a dry vent connecting to the vent stack. Also the actual drain connection for the shower is not shown (so be aware it might not provide any help as to how units below are actually connected).

 

[Jeff H Young]

First drawing showing the shower coming off the 4 inch soil stack with dotted red line depicting a vent is correct go with 1 1/2 vent question for you I guess its around 27 story is this all cast iron ? never heard of pvc that high .

 

[Sponsor]

 

[Martin F]

First drawing showing the shower coming off the 4 inch soil stack with dotted red line depicting a vent is correct go with 1 1/2 vent question for you I guess its around 27 story is this all cast iron ? never heard of pvc that high .

Thanks for your reply - I really appreciate it.
It is the only part of my permit application that failed review and I wasn't sure about the right way to fix it.

I was afraid it wouldn't be possible to fix it so my whole design/layout for the bathroom would fall apart :-/

Currently it is Cast Iron, but it will be replaced with PVC from floor slab to ceiling slab.
The building is 14 story where 13 is below me and there is 2 units/groups per floor connected to the stack.

 

[Martin F]

I have made a new isometric drawing to submit for permit review - is it correctly understood?

The 1-1/2 Dry vent (previously marked with red) is connected above the lavatory and the vertical vet went to hopefully fix the problem highlighted in the failed review.

The 4" stack that was previously marked as S.S (Soil stack) has been split into the upper part being a Vent stack and the part below the highest fixture / lavatory is the Soil Stack.