Replaced my sink. faucet, disposer and all the underneath plumbing. Used a typical P trap/white plastic parts from HD. All pieces of pipe fit or were cut to the correct length so that they all butt into their connections. Nothing leaks.

However, when I was inserting the new piece of white pipe into the existing wall drain threaded stub out to see how long I needed to make the pipe, I simply inserted it into the black opening until it stopped. I then cut it for the length I needed to attach to the extension leading to the P trap.

But I'm wondering... if I simply inserted the new pipe all the way through the entire wall drain, have I now butted it up against the far side of the vertical pipe? Thus, I've essentially blocked the end of the white pipe up against the vertical of the drain? The water drains from the sink fine (I guess).

Do the wall drain black pipes have some sort of stop/collar in them to prevent this exact thing of pushing a new pipe all the way through them?

Do I need to remove the new white pipe and somehow measure how deep the opening is of the black wall pipe before it drops down into the basement, then cut the white pipe to that depth? House was built in 2006.

Make sense?



Edited 4 times.

assuming you have a slip joint adapter on the end of the black ABS pipe the tubular white PVC needs 1-2" total insertion - your 'gut' re: blockage may very well be correct

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

You only need to cut it long enough so it fits into the pipe from the wall. You do not have to shove it ALL the way in.

OK thanks all. I pulled it apart and with a flashlight, realized the drain inside the wall does have a bit of a slope at the the top so that helped prevent the pipe from pushing all the way through to the opposite side. That said, I decided to cut about 2" off the pipe so I had a little room to work with it when I reassembled it. Seems to work great now.

Thanks!

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

It appears like you inadvertently put the new white pipe all the way through the black wall drain pipe. It is recommended to hire a plumber who can evaluate the unique configuration of your plumbing system to see if there is a stop or collar inside the black pipe. They will be able to examine the problem and advise you on the best line of action. Before cutting the black pipe to the right length, it may be necessary to remove the white pipe and measure the depth of the opening in the black pipe. A plumber can provide the skills required to guarantee that your plumbing system is properly installed and working.



Edited 1 times.