I have a 1 1/2" drain pipe coming out of the wall in my upstairs bathroom, and I am trying to install a new sink that has a 1 1/4" trap... how do I link them? I don't know how to do this without ripping apart the entire wall and then down to the main drain downstairs? This is holding up the completion of my bathroom. Thanks in advance!

There is a simple reducer that can be added to your drain pipe. You could also buy a trap made for 1 1/4 and 1 1/2 pipe, set one end for 1 1/2 and the other for 1 1/4. They use different plastic washer/spacers to make the conveersion.

Nooooo, don't tear up your wall ! Get 1 1/2" nut with 1 1/2" x 1 1/4" washer. You can do all this job for $2.00 !

Milo...I'm sure you meant an 1.5" x 1.25" washer...yes?

Teamtamara... you will need an 1.5" x 1.25" pvc desanco fitting or you can purchase an 1.5" x 1.5" pvc desanco fitting with 1.5" x 1.25" reducing washer as in my picture below... as long as pipe is PVC... ;)

Should connect together much like my 2nd picture below...

Otherwise, if pvc pipe I might also have you install this job 1.5" pvc pipe and 1.5" p-trap and then connect onto the 1.25" tailpiece from the pop-up assembly using the 1.5" tailpiece from the pop-up assembly using the 1.5" pvc desanco fitting... I recommend the union type ptrap... see last picture (you will need an 1.5" pvc coupling too).

If this is copper pipe or threaded pipe come back and let us know as this will require a slightly different approach!

Good day all...

MARK

To clarify the part about compression fittings,(desanco). This fitting can be 1 1/2" but you will get two nylon gaskets with it. One 1 1/2 X 1 1/2" and the other 1 1/2 X 1 1/14" . So this fitting can be used on kitchens and olther sinks as well. I use a desanco fitting on a washer stand pipe to make the drainage a closed system and to prevent backups. Just my two cents worth!
Tom