DIY sink drain connection in half bathroom

[MattBD]

I have a slip joint coupling coming out of the wall (cast iron to a PVC stub to the coupling) and am trying to connect the drain from a new sink to it. I purchased this P-trap kit and discovered that the space between the tailpiece and the wall tube was too tight to fit the trap bend.

I got a tailpiece extension and a 45° elbow, but discovered the elbow left me with a thread-to-thread joint that I cannot connect. Current state of affairs.

What part do I need to make this connection? Is this the wrong approach? If so, what should I have between the wall tube and the tailpiece?

 

[Reach4]

I've seen worse.

I don't guess the trap adapter and tailpiece are exactly in line, are they?

 

[Sponsor]

 

[Terry]

A 45 at the wall allows you to swing back and pick up the lav.
If it's a plastic fitting in the wall, sometimes something like a RamBit can drill the pipe out and you can start over. Or there may be enough room on the pipe from the wall for a street 45 there.

Reed Reamer, the pipe that you have is 1.5"

 

[MattBD]

A 45 at the wall allows you to swing back and pick up the lav.
If it's a plastic fitting in the wall, sometimes something like a RamBit can drill the pipe out and you can start over. Or there may be enough room on the pipe from the wall for a street 45 there.

Thanks Terry,
I did almost exactly that. A 90 seemed to fit better. I made a union slip joint with the scrap piece from the trap arm, so it's basically one extra joint. I did that so that I didn't have to cut the pipe at the wall. That trap said it's a reversible J-bend. It passes the initial leak test (1 min running water and about an hour of water in the trap). Anything not legit about this installation?

 

[Jeff H Young]

Terry's Idea is how you do it! I think though you can cut the PVC and still have room to glue on a fitting without a ram bit. looks like you have a threaded fitting at the wall as well so there is other option to unscrew the plastic at wall It appears

 

[John Gayewski]

Yeah I think starting over from the beginning and changing what you have at the wall would be simpler.

 

[Reach4]

Thanks Terry,
I did almost exactly that. A 90 seemed to fit better. I made a union slip joint with the scrap piece from the trap arm, so it's basically one extra joint. I did that so that I didn't have to cut the pipe at the wall. That trap said it's a reversible J-bend. It passes the initial leak test (1 min running water and about an hour of water in the trap). Anything not legit about this installation?

View attachment 81237

Water seal is supposed to be between 2 and 4 inches.

Look at dimensions A and B. Ignore the hand-written note.

 

[wwhitney]

It passes the initial leak test (1 min running water and about an hour of water in the trap).

Another leak test I like to do is to fill the sink to the brim with water and then pull the plug, wide open.

Cheers, Wayne

 

[John Gayewski]

Another leak test I like to do is to fill the sink to the brim with water and then pull the plug, wide open.

Cheers, Wayne

I've regretted that test before, but it's revealing. Lol

 

[MattBD]

Water seal is supposed to be between 2 and 4 inches.

Look at dimensions A and B. Ignore the hand-written note.

Looks like I hit dimension B at 4"

 

[James Henry]

A backwards trap always leaks sooner or later. Don't do it.

 

[MattBD]

Next time I get to the store, I'll pick up a street 22.5, 45, and 90, a new slip joint adapter and a new trap arm. That ought to get me what Terry showed in the first place. I have about an inch left on the PVC coming out of the wall so I should be able to make one more connection once I cut it.

 

[Jeff H Young]

Yep Mattbd that's how I'd do it don't think you need the ram bit you got plenty there to glue to

 

[Terry]

I don't understand why the trap is reversed. You're extending the drain downward, but why?
You have added an extension, which drops it too far down, you can cut plastic pipe and shorten things up, and flip the trap to where it should be.

 

[MattBD]

I don't understand why the trap is reversed. You're extending the drain downward, but why?
You have added an extension, which drops it too far down, you can cut plastic pipe and shorten things up, and flip the trap to where it should be.

I couldn't remember why so I tried it again. The slip joint nut with the trap the right way is up against the 90 so I can't tighten it. Even if I did, it would flex the tailpiece to the side-it's that close. The extension+reversal gets the joint out of the way.

 

[Jeff H Young]

Looking at it it looks like you did it just to mess with our heads Mattbd . i think you can turn trap around sometimes I hack the ears off

 

[Reach4]

If it doesn't leak, I would leave it. But that cutting-the-ears-off does seem like a good idea.

 

[MattBD]

Proof that I actually listened to the experts here. Still needed the extension but only just barely.

 

[Jeff H Young]

looks way better!

 

[MattBD]

Bumping for new problem. The sink is leaking at the drain. Water stands between the drain and the sink and, despite following the installation directions to use a silicone sealant, leaks onto the threads of the drain, then down the tailpiece and extension. How do I fix this?