Single to Double Vanity P Trap

[Jeremiah]

Pre Happy New year everyone one! I am changing a single sink vanity into a duel. My wall intake in on the far left of the vanity. I plan on doing this in the picture to connect both then a P-trap right before it goes into the wall intake. Any concerns?

A heads up, I know most people do the tubular but I don’t like them so I still use glue and

 

[Geofd]

Pre Happy New year everyone one! I am changing a single sink vanity into a duel. My wall intake in on the far left of the vanity. I plan on doing this in the picture to connect both then a P-trap right before it goes into the wall intake. Any concerns?

A heads up, I know most people do the tubular but I don’t like them so I still use glue and

You would need to trap both sinks and vent both you can use one vent as long as you are code compliant

 

[frodo]

NO, You can not, nor do you want to do what you are attempting

what size is the pipe protruding out from the wall where the old sink was?

you can not use 1 1/4'' pipe it has to be 1.5'' sch 40 pvc glued

 

[havasu]

Where are the vents? Do you need two or just one for a dual sink set up?

 

[frodo]

just the one if it is within the 30''

go beyond the 30'' and then everything changes

 

[Jeremiah]

Thank you for the replies. The wall pipe is 1 1/2, I’m using all 1 1/2 pipes here to connect easily. The sinks are more than 30 so I’ll trap both. I’m unfamiliar with the venting rules. Would I have to cut into the wall and connect to the vent pipe for one of them?

 

[GReynolds929]

Show us a picture of the current setup. You cannot have two traps on one trap arm, they have to be individually vented. Once we can see your setup we can advise further.

 

[frodo]

The pipe in the picture is not 1.5'' it is 1 1/4'' and can not be used
the tee you are using is a pressure tee it is not a DWV tee
the p trap you have is a 1 .5 trap connected to a 1 1/4 pipe with a reducer that is turned backwards
and you can not use a 90 on top of a trap to offset.

I can tell you how to do it the right way, but if you are just going to blow it of and install 1 1/4'' pipe I really do not have the time to fool with it

 

[Jeremiah]

The pipe in the picture is not 1.5'' it is 1 1/4'' and can not be used
the tee you are using is a pressure tee it is not a DWV tee
the p trap you have is a 1 .5 trap connected to a 1 1/4 pipe with a reducer that is turned backwards
and you can not use a 90 on top of a trap to offset.

I can tell you how to do it the right way, but if you are just going to blow it of and install 1 1/4'' pipe I really do not have the time to fool with it

That picture is old, I went back and got the same set up all in an inch and a half

 

[frodo]

 

[CT18]

View attachment 27055

Frodo i think what i got from his post is the drain is all the way to the left and not in the center between the sinks. If thats the case at my house i would run 1 1/2" across the back of the cabinet and use a wye for the trap at the sinks and if there is room put a cleanout fitting at the end. I would also use a tee with a aav run up as high as i could as aav's are legal here in between the 2 sinks. I am more on the industrial side of plumbing and has been close to 30 years since i did house plumbing, Frodo is your go to guy here.

 

[Jeremiah]

Here’s the layout, I wanted to turn right and put it through the two by fours but it’s going to be too wide of a hole to be code. Don’t know how I want to do it now.

 

[frodo]

 

[Jeremiah]

Awesome thank you for the diagram! Both sinks will be to the right of the vent pipe. That left cut out is a towel cabinet, not the vanity. I just read about the sheet metal shoes that will allow me to cut holes in the 2x4s, how high above the drain pipe of the sinks do I need to put in that vent arm? I’d like to cut as little as possible of the wall to get to the area to put them in.

 

[GReynolds929]

This would work. Vent cannot go horizontal before it is 6” above flood level of the sink. the horizontal section needs to be graded 1/4” per foot just like a drain.

 

[frodo]

Awesome thank you for the diagram! Both sinks will be to the right of the vent pipe. That left cut out is a towel cabinet, not the vanity. I just read about the sheet metal shoes that will allow me to cut holes in the 2x4s,



how high above the drain pipe of the sinks do I need to put in that vent arm? I’d like to cut as little as possible of the wall to get to the area to put them in.

42'' is typical

 

[Jeremiah]

Perfect diagram, getting pipes and cutting today! I’m looking at other pictures and see the use of the different Ts. I would use a sanitary T to both vent connections then the wye and 1/8 bend to connect the middle vent? Or can I just T them all or one of them? Looks like previous stack connection was just a T

 

[frodo]

use a tee in the vertical and a combination on the horizontal

 

[Jeremiah]

Thank you so much! I’ll upload a picture once I have it done

 

[TomFOhio]

Make sure the tee in the wall for the vent is up side down.