Why cover existing vented drain in a wall and then reroute everything through an S-trap

[Sokolq55]

I was going to put in a cheater vent to fix an S-trap under my kitchen sink. But then I decided to open up the wall just to see as there was a random vent on the roof in nearby location.

Behind the wall, I discovered an existing vented drain that was just hacked off and covered with cabinetry. And also hacked off in the basement. Was a pretty long copper run to the main.

Why would someone cover the existing vented drain and then proceed to run a totally new one into floor? Is this something you guys see?
Just to confirm, I'm assuming my best option is to tie a trap adapter into this existing drain with a shielded coupling and another in the basement or should I just leave it alone and do a cheater vent?

https://imgur.com/GdD8MQM

https://imgur.com/Vm9QcVS

https://imgur.com/A1RwCTH

 

[Reach4]

What is going on at the "Old Vent" label? Copper is capped off, right?

A clogged drain line could have motivated the new line. But if you could put a long sweep and transition into the big PVC, I would think that would work. Making sure the remaining drain copper is clear should be easy enough.

 

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[Sokolq55]

What is going on at the "Old Vent" label? Copper is capped off, right?

A clogged drain line could have motivated the new line. But if you could put a long sweep and transition into the big PVC, I would think that would work. Making sure the remaining drain copper is clear should be easy enough.

No cap there. It's a copper san-tee vented to roof. The connection seems to be sound. I can test it or maybe better to just replace that entire copper san tee with a new pvc long sweep san tee.

The 2" pvc (the new one they put in) runs two bays over from where the copper ran before. So I'll just cut that out and move it over 2 bays.

I mean maybe it was clogged. Dunno. These were flippers. Maybe they just forgot to make an opening in the back of the cabinet before installing and then just said, screw it, let's just drain directly into floor with an s trap and no vent at all. And scrap the 30 feet of 1-1/2 copper for cash?

https://imgur.com/QQhCtx9

 

[Reach4]

No cap there. It's a copper san-tee vented to roof.

The santee is on the picture that has "Vent" and "Basement" labels. It is not in the basement. I was asking about the photo that is in the basement and has the "Old drain" label on the photo.

I mean maybe it was clogged. Dunno. These were flippers. Maybe they just forgot to make an opening in the back of the cabinet before installing and then just said, screw it, let's just drain directly into floor with an s trap and no vent at all. And scrap the 30 feet of 1-1/2 copper for cash?

Maybe that 30 ft of copper was sold by thieves.

 

[Sokolq55]

The santee is on the picture that has "Vent" and "Basement" labels. It is not in the basement. I was asking about the photo that is in the basement and has the "Old drain" label on the photo.


Maybe that 30 ft of copper was sold by thieves.

I see. Yea that’s where they cut off the old drain and did not cap it. Can feel the breeze there and see daylight. I never noticed it before as there were storage shelves stacked to the top.

 

[Reach4]

So if you go to reuse that, you might make the long sweep 1-1/2 pvc. Then it would be easier to couple to the copper with a shielded coupling. Then expand that to the 2 inch. Maybe add a cleanout while you are at it.

On the photo with labeled "Old drain", there is something above where a new bend with the trap adapter will go. The trap arm, the bend, and the trap adapter will all be in the horizontal plane while maintaining the 1/4 inch per foot falling toward the copper santee. Or maybe locate the new bend to the right a bit to get away from the wood.

 

[Sokolq55]

So if you go to reuse that, you might make the long sweep 1-1/2 pvc. Then it would be easier to couple to the copper with a shielded coupling. Then expand that to the 2 inch. Maybe add a cleanout while you are at it.

On the photo with labeled "Old drain", there is something above where a new bend with the trap adapter will go. The trap arm, the bend, and the trap adapter will all be in the horizontal plane while maintaining the 1/4 inch per foot falling toward the copper santee. Or maybe locate the new bend to the right a bit to get away from the wood.

Thank you. For the 1-1/2 "long sweep" could I just use a combo santee and have the back capped for a cleanout?

Yes, I think I will put the new trap adapter bend to the right side of the stud because I'm also adding a garbage disposal and my sink drain is way towards the back of the sink so there won't be much room for a p trap behind the disposal without doing all sorts of acrobatics with bends.

I'm still debating whether to reuse that existing copper santee or cutting it out and putting a pvc one with shielded couplings. Just to be on safer side.

Question about putting a cleanout in the middle of the 30 foot run (I don't have a long enough snake to go all the way from trap to main, lol). Could I use just a regular 2" hub vent tee fitting in the middle of the run so I could snake both ways from mid point?

 

[Reach4]

Thank you. For the 1-1/2 "long sweep" could I just use a combo santee and have the back capped for a cleanout?

That would be the bottom, right? So flow of drainage would be down, out the side leg, and then the straight down leg would be a cleanout? I am pretty sure that is not what you mean.

OK... so the end not nearest the curve could be horizontal. Then that would connect to a pipe that goes thru the rim joist for cleanout from outdoors?

I'm still debating whether to reuse that existing copper santee or cutting it out and putting a pvc one with shielded couplings. Just to be on safer side.

Note that the holes will have to be bigger to clear 1.5 inch PVC. 1-1/2 inch copper is 1.625 OD and PVC is 1.900 OD.

Note that the Fernco 3001-150 / P3001-150 will connect a 1-1/2 PVC pipe with a copper pipe.

Question about putting a cleanout in the middle of the 30 foot run (I don't have a long enough snake to go all the way from trap to main, lol). Could I use just a regular 2" hub vent tee fitting in the middle of the run so I could snake both ways from mid point?

They make cleanouts meant to be able to be used going either way. https://www.supplyhouse.com/Spears-P444X-020-2-PVC-DWV-Cleanout-Tee-w-Standard-Plug

 

[Sokolq55]

That would be the bottom, right? So flow of drainage would be down, out the side leg, and then the straight down leg would be a cleanout? I am pretty sure that is not what you mean.

OK... so the end not nearest the curve could be horizontal. Then that would connect to a pipe that goes thru the rim joist for cleanout from outdoors?

I meant to say combo wye, not santee. Something like this but now thinking about it, there won't be enough clearance between it and wall

 

[Reach4]

How do you access the cleanout plug? Wouldn't that be up against the rim joist?

 

[Sokolq55]

How do you access the cleanout plug? Wouldn't that be up against the rim joist?

You are correct. Not enough clearance. Where would you locate a cleanout? maybe a wye upstairs by trap adapter? or maybe in middle of line like the one you linked.

Would a cleanout like I drew up (combo wye) work where the drain pipe does a 90 turn (horizontal to horizontal) no change in plane. There's a turn like that in the pipe then another 7 or so feet and drops into the main.

 

[Reach4]

All of those places make good sense.

Yes, the combo makes good sense where the cleanout is accessible.

In warmer areas, they might run a pipe thru the rim joist, and be able to rod from outdoors.

 

[Sokolq55]

All of those places make good sense.

Yes, the combo makes good sense where the cleanout is accessible.

In warmer areas, they might run a pipe thru the rim joist, and be able to rod from outdoors.

What would be the proper assortment of fittings to make a test cap cleanout integrated with the trap adapter so I wouldn't have to pull the trap apart to get in there?

 

[Reach4]

Pulling the slip joint trap adapter out and going thru there is not a big deal. Pull out the slip joint trap, and go in. However you will need to make the bend, hit the santee, and hope the snake goes downward. I

You could put a wye or combo into the trap arm path, but that doesn't make things a whole lot better.

You could put a wye (or DWV cleanout) above the trap adapter or below, if you want to have an access to be able to get to that cleanout.