When roughing in a sink, how far should I extend the 1.5" PVC into the room (i.e. through the drywall). Seems like if it goes past the framing, the drywallers are going to have to cut the hole before putting up the sheet. Is there a length that's too long/short?

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    If you have to glue it, make it way longer than you think you need. Drywallers cut around obstacles all the time. If you can leave the last joint unglued, then the drywallers can pull off the last bit of drain and make a very tidy cut. (But that also introduces the risk of getting construction crap lodged in your drain...) – Aloysius Defenestrate Jun 24 '16 at 4:25
  • Have you looked at the instructions for your sink? They will say that it should hit, then add whatever is from the finished wall to the drain connection. – Chris Jun 24 '16 at 4:31
  • Home depot has pressure caps which is like plug to glue inside the end of the pipe so they wouldn't have to cut bigger then the pipe diameter and thats what dry wallers do all the time and its no problem for them. – aofkj Jun 24 '16 at 12:47
  • I would assume that all of the parts need to be glued, else how would you glue them once the drywall is up? I looked at the pressure caps, but it says that they are solvent welded? Wouldn't that mean I'd need to cut it off later to attach for the sink? – 2 Left Thumbs Jun 24 '16 at 16:11
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    @2LeftThumbs You can use a test plug to block it off for drywalling. The plug goes inside of the pipe, and then a screw in the middle of the cap will make it expand and be air tight. Once that process is done, it can be easily removed by loosening it and you can simply pull it back out without having to cut the pipe. A stub should be 4-6" past the finished wall to ensure that a proper fitting can be installed later on. During the final plumbing install, the pipe can be cut to the exact length needed. – Jason Hutchinson Jun 24 '16 at 16:33

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