New Studor vent needed?

[Rice]

Hi,

We added a powder room under a stairway on our main floor and installed a Studor vent to the sink drain. Just recently, we tapped into those same supply lines and drain for a new double vanity directly above the powder room on the second level.

Do I need to add studor vents for the vanity on the second level or does the studor vent on the main floor (which the drains from the upper level tap into) function for sinks on both levels?

Thank you in advance for your advice!

Ryan

 

[phishfood]

Yes, you do need to add a vent for the lavatories on the second floor.

The problem I see with your arrangement (studor vents on both drains) is that there is nowhere for positive pressure to be released. There is the possibility that pressure built up ahead of the drainwater from the second floor will disrupt the trap on the first floor. Is there any way that you can run a conventional vent for the second floor and perhaps revent it into an existing vent line?

 

[Rice]

Thank you for your answer! I am glad I asked. I have a dropped ceiling in this bathroom and could vent to existing vent line but it would require about a 4' section of near-horizontal vent line in the plenum. Is that acceptable?

Thanks!

 

[phishfood]

Yes, as long as the horizontal section of vent is above the vanity basin, that is acceptable.

 

[Rice]

Great, thanks for all your help phishfood - it is greatly appreciated. I know how I'll be spending Saturday!

Thanks again!

 

[Rice]

Hi again,

Well I ran a vent stack all the way to what WAS once a vent line for the old sink. But when I cut it to tie my new vent stack into I realized it was simply venting into the attic. Wah wah. So my next question is - can I vent out the wall rather than having to go up through the attic and roof? I would be about 3 feet over the highest window in the house and a couple of feet below the eaves. The eves don't have soffit vents.

Thanks (again) in advance for any information!

 

[phishfood]

The Florida code is based on the International Plumbing Code, so I don't know if it relates to Colorado or not.

But given the conditions you specified, your proposed installation will meet code.