I finally found the water leak in my condo. I cut and cap a 1/2in pipe and the hissing sound of water went away. Now I have to figure out how to install a bypass because I lost the cold water in both the bathrooms sink. I still have hot so no hurry to fix. My neighbor has a leak too and a plumber is coming tomorrow for an estimate. I'll ask how much to install my bypass but for now I'm assuming I have to do it. I cut the dry wall and took pictures.

The bypass: I want to go from the water heater inlet to the right as shows in the picture with the water heater.The details are as follow:

Detail B: I'll remove the right angle that connects the pipe with the gate valve and install a "T". This is all 3/4" pipe. The valve and pipes goes back to the original position. The top of the "T" will have a reducer (3/4" to 1/2"), street elbow, etc. to extend the pipe towards "detail c".

Detail C: Cut the cold water line (this goes to the bathrooms sinks). Install a couple of elbows (need to stay away from hot pipe). Drill a hole through the stud (is this OK?) and extend the pipe to join the one from detail B. This pipe is not really long (~2 ft) so it will be a single piece. I'll have to make sure all the fittings are fluxed and ready before I start to solder. Done.

Detail A: This just shows how I disconnected the 1/2" pipe. I had a cap and pipe so I shoved it inside the reducer while heating the whole thing. It was really painless. It doesn't look pretty but I'll fix it later. I get the idea that there will be water trapped inside that will never move.

Does my bypass idea look OK? Thanks.


detail b

detail c

detail a

  • Wow, you got the elbow out, and more importantly, got a pipe short to seal in that old fitting. Nice work. Drill the stud, yes. But then there's supposed to be a protection plate. Pre assemble some shorts on the elbow so you don't set it on fire. Make the hole big enough so that assembly will make the curve while being inserted.
    – Mazura
    Jan 28, 2022 at 0:52
  • I'm curious what it is that you're bypassing. Is there a section of pipe that's leaking and you're bypassing that? Also, yes, it's perfectly fine to drill through studs, that's how all your plumbing and electrical was installed in the first place. I believe that the maximum hole size is 1/3 the thickness of the board you're drilling through, and that holes next to each other must leave solid wood twice the diameter of the hole between the holes. However, wait for someone to confirm that. It's not a bad idea to put protection plates on the studs to ensure no screws go through the pipes.
    – FreeMan
    Jan 28, 2022 at 13:48
  • 1
    TBH, I'd be a bit concerned about the notched stud in Detail B. A hole would have been better. (Not your work, I'm sure.)
    – FreeMan
    Jan 28, 2022 at 13:49
  • Yeah, the notch really weakens it. I'd replace the pipe with a section of 2x4 fitted into those notches if possible, that should help things. Plus, I don' like the pipe-on-pipe contact.
    – Jamie M
    Jan 28, 2022 at 13:52
  • You don't need a protective plate if the pipe is more than 1-1/2" from the face of the stud.
    – Ecnerwal
    Jan 28, 2022 at 15:17

1 Answer 1


You should be fine drilling a hole. I see it all the time.


Drilling. Any stud shall be permitted to be bored or drilled, provided that the diameter of the resulting hole is not more than 60 percent of the stud width, the edge of the hole is not more than 5/8 inch (16 mm) to the edge of the stud, and the hole is not located in the same section as a cut or notch. Studs located in exterior walls or bearing partitions drilled over 40 percent and up to 60 percent shall be doubled with not more than two successive doubled studs bored.

BTW: Are you in an earthquake zone? Is that why all the strapping is in place?

  • I knew 33% seemed too small when I made the comment. Thanks for correcting me and including a reference.
    – FreeMan
    Jan 28, 2022 at 15:35
  • Earthquake zone yes: California, USA. The strap is required but mine has double because the water heater is not actually touching the walls. I wished I had used the removable straps but at the time I was low in money and the stuff I used was very cheap. Thanks.
    – Rodo
    Jan 28, 2022 at 19:25

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