Extend crawlspace cleanout for added sink drain

[bestman]

First time poster, long time reader.

I would love advice from all you pros on how best to tie in the drain for a small bar sink to our main waste line.

Is it feasible to extend the iron cleanout with PVC to tie in the drain?

Sorry, I don't know all the right terms. I'm more comfortable on the supply side.

 

[James Henry]

That's fine, you'll have to drill the lead and oakum out and insert a doughnut then use a 3x2 combo and install a clean out after that.

 

[Sponsor]

 

[bestman]

That's fine, you'll have to drill the lead and oakum out and insert a doughnut then use a 3x2 combo and install a clean out after that.

Thanks James.

Would it be possible to just unscrew the cleanout "cap" and connect a screw-in PVC then the 3x2, then cleanout?

 

[Mr tee]

Probably the cleanout does not have a standard pipe thread so you won't be able to just screw into it. If the existing line is 4" you need to leave a 4" cleanout on the end of the plastic fitting (wye or combo) that you add.

 

[Terry]

You could also cut the cast further back, and insert a wye in the line using shielded couplings.
Sometimes the old cast is more of a copper size. If you try that, measure the OD of the pipe. Some old 4" cast is 4-1/8" OD, which is the same as copper, and the other side of the coupling would need to be for plastic if you're using ABS.
Or sometimes I pick up a cast no-hub wye for that which takes up less space on the line.