Bathroom rebuild - mini stack with vent?

[Michal Krombholz]

Hi,

I am new DIY in process of rebuilding a bathroom.

The question is about using a mini vertical drain stack with stack vent (essentially a 2x 3"x2": san tees on top of each other with a 2" vent on top - as pictured). The shower and sink will be connect to this mini stack branches. Is this vent and its location OK? There is existing WC downstream from it.

The old bath had a WC and LAV connected to main 3" drain, separately, no vents, only a relief vent downstream and further up the horizontal/vertical stack vent (for the rest of the house). I doubt it was in any code or sanity.

Please, do not make too much fun of my drawing and concept ;-)

Regards,
Michal

 

[MicEd69]

In all codes, a dry vent must be vertical, or no more than 45 degrees off vertical, until it reaches 6" above the flood line of the fixture(s) being served. So, the answer to your question "Is this vent and its location OK?" is no.

 

[Michal Krombholz]

Thanks! I see, there no space for 6" above flood; :-(. Bummer.

Could it all be considered a wet vent?

Would laying out horizontally the joint between shower and sink into a horizontal (ie removing the 'mini stack') and than going into a vent be more acceptable?

out <-- horizontal <-- shower <--- sink <-- horizontal <-- elbow up --> vertical vent

I think this still does not work as there is a horizontal vent area not above flood level. So same problem as before?

Alternatively I could vent from sink p-trap join and then have a wet vent for the shower downstream but this makes the vent location rather inconvenient.

out <-- horizontal <-- shower tee <-- horizontal <-- elbow up <-- vertical <-- sink tee --> vertical vent

 

[Michal Krombholz]

Ah!
"A vent pipe should rise vertically at least 6 inches above the flood level rim of the highest fixture it serves" - the key being "the *highest* fixture" so the vent must be connected to the sink connection.