Enough of a vent for 1 more sink?


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Old 03-08-17, 08:07 AM
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Enough of a vent for 1 more sink?

We added a bathroom to the basement that is fully roughed in (by a plumber) and ready for inspection.

We're thinking of adding a countertop outside the bathroom in the unfinished basement and a slop sink.

The bathroom has a toilet, shower, and sink. The toilet is vented through the waste stack about 20 feet away. The shower and sink are vented as shown in the photo.

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The sink drain is the left leg, the 2" vertical PVC is the shared vent, the drain is to the right.

The question: can I add the slop sink about 30 inches from the right side drain, tapping into it without adding another vent (which is impossible)?

Thanks guys!
 
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Old 03-08-17, 12:32 PM
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Yes you can add to that drain but you will have to add a vent to the sink. No big deal as you tie the new sinks vent into the vent thats there now. Why do you say thats impossible..?
 
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Old 03-08-17, 02:22 PM
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Impossible because the ceiling joists run parallel to the horizontal run of the vent, so it would require boring 3 of them or, it would require boring through 4 studs, some of which are already bored for the drain.
 
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Old 03-08-17, 04:01 PM
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You can tie into that vent as long as its 3 ft above the flood plane of the sink..

You dont want to drill though studs?

Youll have to use a studor vent then.. If you dont vent then the trap for the new sink can/will siphon out and deadly sewer gas will enter the home causing sickness or even death..
 
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Old 03-09-17, 08:22 AM
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Thank you Mike.

I don't want to bore the studs again because they already have a 2" waste pipe through them. Two parallel holes of that size won't leave much strength in the studs. Is that typically done?

I don't know much about a studor vent. Are they effective? Code issues?
 
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Old 03-09-17, 10:18 AM
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Your sink will need its own vent some way or another.

As Mike stated, once it rises over a certain height, you can tie it back into the main vent.

An atmospheric vent (one that goes up through the roof) is definitely preferred over any mechanical vent. Some locales don't allow AAV (Studor) vents, and even if they do, it's mechanical, so it's something that could fail down the road.

In my (now ex-) area of NJ, they did not allow AAVs unless part of an engineered plumbing system. Which basically means, they don't allow them. But NJ is very segmented based on the town, so it really depends on your local codes and inspectors.
 
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Old 03-09-17, 11:35 AM
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Is it a load bearing wall? If not then no worry.
 
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Old 03-23-17, 12:35 PM
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I figured out the least painful way to route the vent, so I have some questions:
  1. The vent will be horizontal for about 5 feet. Am I correct that it needs an 1/8" per foot pitch?
  2. Does tconnection to the existing vertical vent pipe needs a sanitary T sweeping upwards?
  3. At what point do I reduce the drain from 2" to 1-1/2"?
  4. How do I get a sanitary T into that short vertical of the drain going into the concrete? Is there a PVC connector that slides over the pipe or do I have to do a bunch of cutting out?
 
 

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