I am swapping out an old pedestal sink for a conventional vanity. Currently in place are some 1/4 pex lines that are run through the pedestal. enter image description here

I want to swap the small pex for 1/2” and am fairly handy and I’m pretty sure I can figure out the pex stuff but am not sure what to do with the current shut offs that are in the basement. Is there an adapter that I purchase that will make the shutoff to pex connection?

  • 2
    Adapters are available for virtually any plumbing scenario. Half inch copper to half inch PEX is probably one of the most common. Have you done any shopping? You should probably move the valves into your vanity space for convenience. – isherwood Nov 11 '18 at 14:44
  • 1
    maybe i misunderstood the question, but that looks like 1/4" PE/PP compression tubing, not PEX piping which usually doesn't even get narrower than 1/2". – aaron Nov 14 '18 at 17:59
  • @aaron You'd be correct. PEX does NOT come in sizes smaller than 1/2". As of yet... – BillWeckel Nov 14 '18 at 21:21
  • youtube.com/watch?v=7DZlXJZRmCY – ron Sep 30 '19 at 19:59
  • use a mini close quarters tubing cutter for copper. cut the hard copper pipe cleanly and straight, use fine steel wool to clean and smooth the copper prior to push on valve. consider replacing plastic line to faucet with a braided hose, get an 18" or 24" hose and make one loop between valve and faucet to fit it. – ron Sep 30 '19 at 20:07

Easiest is going to be Push-to-Connect 1/2" Coupling. You will be able to cut the 1/2" copper and then use the SharkBite Push to Connect Coupling to switch to 1/2" PEX the rest of the way up to your vanity. Then you will have to figure out how to connect the 1/2" PEX to the sink and include a shut off under the sink. If you have access to the wall behind the vanity then I like to put 90-Degree Drop-Ear Elbow with a 1/2" Chrome Plated Nipple followed by a 1/2 in. x 3/8 in. Angle Valve.

This Video does a good job of showing it: https://www.youtube.com/watch?v=DL1NL_9Yd1U

enter image description here


enter image description here


enter image description here


enter image description here



I'd leave copper shut offs in place. Assuming you can solder, turn water off, cut copper (leave enough extra room to get a couple inches into vanity...or drain and unsweat valves...cut holes in back of vanity, reinstall new or same valves...pex is cool but if you like secured, solid valves best...that is 1/2" cop x 3/8" compression btw...no need for pex tool...unless your movnng the lines?

  • 1
    I'm confused. You say to leave the valves and then to cut them off. Also, what's with all the periods? One does the job. :P – isherwood Nov 14 '18 at 17:46

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.