Double Vanity Reno - 'S' trap in wall

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Tee Jay

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I'm currently renovating a master bath and we are replacing a double vanity with the exact same setup. I took the drywall down to add some new electrical plugs and I came across this drain set up which although appears to have worked on the left, I don't think is up to code.

I don't see an issue with the right side as it is a sanitary tee to the drain which vents straight up. The left on the other hand connects to the drain/vent with a wye and 45 above the cleanout and below the sanitary tee for the right sink. Not a plumber by trade but this looks to me like an s-trap.

The pipe halfway up the wall on the left is the vent from the floor below tying back in.
Vanity Plumbing.jpg


Close up of the wye below the tee. Basically goes wye for cleanout, wye for left sink, sanitary tee for right sink all together in a row.
Vanity Wye.jpg


I am thinking that if I put a couple sanitary tee's in here and tie into the vent from below (it's at 42") then this would be the quick fix that would meet code without having to redo it all. Am I off base on this plan? Or do I need to do a wye-45 at the bottom up to a sanitary tee on the top tying back into the vent? Or is this just completely wrong.

Vanity Plumbing Fix.jpg
 

breplum

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UPC drainage tables say that 1-1/2" can handle both lavs on the vertical but must be 2" when going horizontal.
So, it is much more common to just use a 2 x 1.5 x 1.5 Figure 5 fixture tee.
But, if you don't care about code, then stacked tees mostly will work.
Following the plumbing code is always the best way to go.
 

WorthFlorida

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Double check the double sink traps height for your new sink and vanity. This forum has many posts with DIYers trying to do the final connection only to find the trap is either too low too high. This is especially true when vanities have an open bottom.
 

wwhitney

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To answer the original question, yes adding a revent per the blue line would take care of the improper venting on the left hand sink stub-out.

An upright combo is better for the vent takeoff, and looks like you have plenty of room for it. And the combo should be oriented so that any water that got in the vent would be directed to flow towards the drain.

Cheers, Wayne
 
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breplum

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WW's definitely a good solution.
We never use glue type p-traps.
We would cut out the old traps, add a trap adapter, then use poly slip joint p-traps.
In a case like yours we Rambit out the old glued in pipe from the fitting.

reed-reamer-02.jpg


p-trap-parts-terrylove-01.jpg
 
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Reach4

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It's a small thing, but draw the jog at the bottom of you baby-blue line to/from the right instead of to/from the left.
 

Tee Jay

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WW's definitely a good solution.
We never use glue type p-traps.
We would cut out the old traps, add a trap adapter, then use poly slip joint p-traps.
In a case like yours we Rambit out the old glued in pipe from the fitting.

reed-reamer-02.jpg


p-trap-parts-terrylove-01.jpg
I'll have to look and see if we have these around here. I don't recall seeing them at HD's or Lowe's but they might keep them in a different section away from the ABS. It certainly would make the final hookup easier.
 

Tee Jay

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Thanks everyone. I had a look at the local stores, no one had a double fixture fitting that I could find, just a double sanitary tee. So with that being said, I think fixing the vent on the left hand side is still better than what I currently have.

As mentioned by @wwhitney i will go with the upright combo to fix the vent and have it flow back towards the drain. I'll replace both traps as I need to make the drains centered under the new sinks anyway.

Since I already have the vanity on site, it should be easy to double check the heights and adjust the rough in now if I have to. I think it should be okay though once I recenter the stub as it is just a standard vanity, very similar to what came out of there. Nothing fancy here, just the ol' standard vanity cupboards for sink cabinets.

My picture was done without really thinking but yes I will flip the bottom connection around so if there is any moisture it flows the right way towards the drain. Thanks for the reminder @Reach4!
 

John Gayewski

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I'll have to look and see if we have these around here. I don't recall seeing them at HD's or Lowe's but they might keep them in a different section away from the ABS. It certainly would make the final hookup easier.
You can clean these out easier and address leaks easier. It's all around a better solution.
 

wwhitney

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You can clean these out easier and address leaks easier. It's all around a better solution.
I don't disagree, but as a counterpoint:

A union p-trap (threaded connection between u-bend and outlet elbow) with a trap adapter on the trap inlet also allows access to clean the u-bend. And I think some plumbing codes limit slip joint connections after the trap. IIRC the UPC does or used to limit it to 1 SJ connection. So if any plumbing code limited it to 0, then you'd need to use a glue joint trap.

Cheers, Wayne
 

John Gayewski

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I don't disagree, but as a counterpoint:

A union p-trap (threaded connection between u-bend and outlet elbow) with a trap adapter on the trap inlet also allows access to clean the u-bend. And I think some plumbing codes limit slip joint connections after the trap. IIRC the UPC does or used to limit it to 1 SJ connection. So if any plumbing code limited it to 0, then you'd need to use a glue joint trap.

Cheers, Wayne
I've mostly found them to leak. Sure you can take them apart but they aren't really adjustable like a slip joint, where if glue joints set at at tilted angle there's not much to do other than smear whatever is handy and hope it works.

Plus if you want to get into the piping and have to go in through the union you have very limited effectiveness past a foot or two. Our inspectors consider a slip joint access to the piping and therfore cleanouts are omitted.
 

Jeff H Young

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I started out using glue in p traps threaded union , a bit more hassel but I had no choice thats what we used , now I prefer the tubular traps we used to use threaded brass traps LA pattern on commercial jobs. not everyone can be the boss you have job specs and follow them . on a house I pretty much only use tubular now
 
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