Can drain be downstream of vent?

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Djarchow

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I am finishing my basement. I thought all my rough was done including plumbing and was about ready for sheetrock. My boss (my wife) was looking at the bar layout with her friends last night and wasn't happy with the layout. Would have been nice to have had that feedback before we spray foamed everything in. So I know have a "change order" to rearrange things including the plumbing.

The bar sink is the only drain on this 2" drain line other than the dishwasher which will be next to the sink. The drain line runs horizontally though the wall before tying into the main drain stack. The drain is vented up through the wall with a 2" vent. I have to move the sink and dishwasher either 4-5 feet to the left or to the right depending on how we do the cabinet layout.

Moving the sink to the left would simply mean extending the drain line another 4 feet. Not bad other than the spray foam. With slope this would place the rough drain center at about 18" off the concrete but since there won't be a disposal I think this should be OK with a small undermount bar sink

However, if I move the sink to the right it would place the sink drain and attached dishwasher downstream from the dry vent forming a wet vent). Is this OK since there is no fixture other than the vent upstream of the drain? All I have read around wet vents focuses on multiple drains using the wet vent, not a single.

Thanks for any advice.

Kind regards,

Dennis
 
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Stuff

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Please draw it out as hard to visualize. A dry vent is not normally upstream as it can too easily get clogged.
 

Djarchow

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Please draw it out as hard to visualize. A dry vent is not normally upstream as it can too easily get clogged.[/QU

Thanks for the reply. Here is a picture. The arrows show the directions I could move the drain. The arrow to the right is the one I was concerned about.
 

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Reach4

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Thanks for any advice.
Find out whether you are under IPC or UPC. Iowa- IPC adopted by Local Governments but UPC adopted statewide

If UPC, a 2 inch trap arm (including the path to the U of the trap) max is 8 ft. Max is 5 ft for UPC.


I think that either way, you will probably need to branch off the vent.

No wet venting for bar sinks I think. You could consider an AAV, or just move the vent. I think the vent will have to be downstream of the drain.
 

Djarchow

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Find out whether you are under IPC or UPC. Iowa- IPC adopted by Local Governments but UPC adopted statewide

If UPC, a 2 inch trap arm (including the path to the U of the trap) max is 8 ft. Max is 5 ft for UPC.


I think that either way, you will probably need to branch off the vent.

No wet venting for bar sinks I think. You could consider an AAV, or just move the vent. I think the vent will have to be downstream of the drain.

Reach,

Thanks for the reply. Yes, we are under the 2015 UPC. I should have been more clear above, the 4-5 feet was my developed trap arm length, though I hadn't thought about the length from the wall to the trap weir so that would take up another 3-6 inches of length.

We are not allowed to use Studor valves here.

Regards,

Dennis
 

Reach4

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So teeing or elbowing off the vent, at least 6 inches above the flood level of the served fixture, is your action.
 

Djarchow

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So teeing or elbowing off the vent, at least 6 inches above the flood level of the served fixture, is your action.
Thanks. Yes, I can do that, I just wasn't crazy about hogging out 6 feet of 3" thick spray foam for the vent. I will try to do a charge back to my wife for the extra labor.
 
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