Upstairs bathroom to downstairs kitchen sink

[Chadslost]

Greetings,

DIY plumber here getting ready for a rough in inspection in Missouri. I just wanted to make sure this will pass?

It’s an upstairs bathroom sink draining to a downstairs kitchen sink drain through the foundation with the kitchen sink vent above. All 2” PVC.

I really appreciate any feedback and wanted to give a huge thanks to everyone, I’ve learned so much from these forums!!

 

[Chadslost]

One more photo

 

[Sponsor]

 

[wwhitney]

Dry vents may not be horizontal unless 6" or more above the fixture flood rim.

Cheers, Wayne

 

[Chadslost]

Dry vents may not be horizontal unless 6" or more above the fixture flood rim.

Cheers, Wayne

Does that mean above the upstairs sink flood rim or the kitchen sink flood rim? If it’s the kitchen sink then I believe this should work?

I appreciate the feedback Wayne!!

 

[wwhitney]

It's the flood rim of any fixture served by the horizontal vent segment, so in this case the downstairs kitchen sink. If your downstairs vent joins the upstairs sink vent, that joint too must be at least 6" above the fixture flood rim, in this case both fixtures.

As to your picture, I can't tell what the sink flood rim height is, but if your counters are 36" above the finish floor (AFF), and your sink is undermount, then then horizontal vent section should be 42" AFF or higher.

Cheers, Wayne

 

[Chadslost]

It's the flood rim of any fixture served by the horizontal vent segment, so in this case the downstairs kitchen sink. If your downstairs vent joins the upstairs sink vent, that joint too must be at least 6" above the fixture flood rim, in this case both fixtures.

As to your picture, I can't tell what the sink flood rim height is, but if your counters are 36" above the finish floor (AFF), and your sink is undermount, then then horizontal vent section should be 42" AFF or higher.

Cheers, Wayne

Thanks for the crystal clear reply!

One last question I wasn’t able to find a clear answer to in the codes but I did read in a forum that it is ok.

Is one 22.5 degree permitted before the 6”? I want to get the vent pipe in the wall under the counter.

 

[wwhitney]

Per the definition of "vertical" in the plumbing code, any pipe less than 45 degrees from plumb is considered vertical.

Cheers, Wayne

 

[Chadslost]

Per the definition of "vertical" in the plumbing code, any pipe less than 45 degrees from plumb is considered vertical.

Cheers, Wayne

I really appreciate it! I was looking specifically under vents so thank you!

 

[Daniel Collick]

One more photo View attachment 93343

Whitney is correct about the horizontal portion of the downstairs kitchen vent.
Just couple things I see in your pictures:
1. It’s not uncommon to see vents, especially in these scenarios, piped horizontally below the flood rim, but it needs to be treated as a drain until it is above the flood rim. Meaning it needs to be graded 1/4 per foot, and the 90’s that are below the flood rim that change direction from horizontal to horizontal or from horizontal upwards need to be long turn 90’s. It’s likely that an inspection in our area would approve the vent being below flood-rim but I’d expect them to require that it turn horizontally as high as possible instead of down low where you have it currently.
2. Once the vent is piped to the upstairs don’t tie it into any other vents until both are above the flood rim of their respective fixtures.
3. The fitting you used downstairs looks like a sanitary cross and, if so, should not be used to join two horizontal waste pipes. In our area we’re only allowed to use the sanitary cross to tie vents together.

 

[Daniel Collick]

 

[Daniel Collick]

View attachment 93355

Something like this, but I think you get it. Hope it helps.

 

[Chadslost]

Whitney is correct about the horizontal portion of the downstairs kitchen vent.
Just couple things I see in your pictures:
1. It’s not uncommon to see vents, especially in these scenarios, piped horizontally below the flood rim, but it needs to be treated as a drain until it is above the flood rim. Meaning it needs to be graded 1/4 per foot, and the 90’s that are below the flood rim that change direction from horizontal to horizontal or from horizontal upwards need to be long turn 90’s. It’s likely that an inspection in our area would approve the vent being below flood-rim but I’d expect them to require that it turn horizontally as high as possible instead of down low where you have it currently.
2. Once the vent is piped to the upstairs don’t tie it into any other vents until both are above the flood rim of their respective fixtures.
3. The fitting you used downstairs looks like a sanitary cross and, if so, should not be used to join two horizontal waste pipes. In our area we’re only allowed to use the sanitary cross to tie vents together.

I appreciate the clarification on points 1 and 2!

As far as point 3, would this adjustment work pictured below?

Also, it looks like in the drawing you sent shows a clean out below the drains. Is that required?

Thanks for the help with this!!

 

[Daniel Collick]

I appreciate the clarification on points 1 and 2!

As far as point 3, would this adjustment work pictured below?

Also, it looks like in the drawing you sent shows a clean out below the drains. Is that required?

Thanks for the help with this!!

Yessir. That will work. If you can make room for one I’d still try to fit in a clean out where you’ve got a 2” coupling just above the concrete. If you’re required to put a head pressure test on those fittings for inspection you can use a Holdrite test tee that works very well for test.

 

[Chadslost]

I took your advice and added in the clean out.

I appreciate the help guys! Let me know if your every in the Kansas City area, BBQ dinner is on me.