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blac1175
Unidentified pipe/conduit in wall

Can anyone help me identify what is this pipe/conduit could be in my wall? The picture is through the hole where the old electrical box used to be.

I don't really need to do anything with the pipe, I just found it while working on replacing an old electrical box in the bathroom. So I'm just wondering what this pipe is. Also, I'm not sure it has to do anything with plumbing, but since it's a "pipe", I had no better idea which forum to use. Please feel free to redirect me.

I was working on replacing an old electrical box in the bathroom, and I found a horizontal pipe, about 2 inches diameter, running in the wall, about 44 inches high from the floor. This is the wall between the two bathrooms. While most walls in my home are using 2x4 studs, this wall is using 2x6. Most of the cross section of the stud is sawn out to let this unidentified pipe pass through.

I don't see more than a few inches of this pipe. One end is going towards the outside wall, but there is nothing on the outside of my house that would help me identify this pipe. The other end is going towards the cabinet where the furnace is, but there is nothing visible inside the cabinet. The furnace is gas, but the gas pipe is attached from the bottom, through the crawl space. So I don't think the pipe I'm seeing would be gas.

To my untrained eyes, the material looks like EMT tubing, but I'm unsure.

The house does not have knob-and-tube, it has 12/2 ungrounded cables, so I don't think the pipe is related to electrical either. On the picture you also see a bare copper wire, that was (I think) used as makeshift grounding for the old metal electrical box, and probably goes to some water pipe.

The house was built in the 50's, and this is in California.

Thanks for all the tips,
Balint

JLMCDANIEL
Re: Unidentified pipe/conduit in wall

Your guess is as good as mine, but the pipe looks like it is brass in which case it may be a plumbing vent pipe.

jack

johnjh2o
Re: Unidentified pipe/conduit in wall

From the height of the pipe my guess would be it's a vent line. Horizontal vents must run 6" above the flood rim of the highest fixture which puts them at 42" or more. It's evidently an older home using galvanized pipe for the waste and vent system.

dj1
Re: Unidentified pipe/conduit in wall

This pipe looks galvanized, which was commonly used years ago. Being 2" galvanized, it has to be a vent or a vent connection.

The loose copper wire in the picture could be a grounding wire like you thought, or could be just a scrap wire left behind.

blac1175
Re: Unidentified pipe/conduit in wall

Thank you all. I can totally accept the vent explanation. I just was not aware, that a vent can go horizontal. I thought those are always vertical right through the roof. But now it makes complete sense: the pipe is probably running between the two sinks in the two neighboring bathrooms, so that there is probably just one pipe to the roof for the two sinks. Thanks!

dj1
Re: Unidentified pipe/conduit in wall

blac1175,
Horizontal vents are widely used for connecting between 2 vents and as offset vents in places where a vertical vent is practically impossible (window, header in the way, etc).

Fencepost
Re: Unidentified pipe/conduit in wall

You could always cut into the pipe.

  • If sparks fly, it's electrical conduit
  • If you get wet, it's water
  • If you get scalded, it's hot water
  • If it stinks, it's a vent pipe
  • If you get wet and it stinks, it's a sewer pipe
  • If your house explodes, it's a gas pipe
  • If money comes out, it's the vacuum tube for the bank's drive-up window
  • If you hear voices, it belongs to the NSA

You're welcome. Always glad to help.

t_manero
Re: Unidentified pipe/conduit in wall
Fencepost wrote:

You could always cut into the pipe.

  • If sparks fly, it's electrical conduit
  • If you get wet, it's water

You're welcome. Always glad to help.

You forgot two things . . .
(1) Shut off water so if it's water, you won't have 50 gallons in the house before you find the main shutoff (assuming it isn't frozen).
(2) Then, call an appropriate service who will make the repair for $300 to $3,000 -- keep it less costly by doing the wall repairs and repainting yourself.

dj1
Re: Unidentified pipe/conduit in wall

tmanero, fencepost was just being funny. Don't worry, it's not a water pipe under pressure. 2" pipes are not used to deliver water in a regular size house. Could be used in a mansion...with 8 bathrooms.

t_manero
Re: Unidentified pipe/conduit in wall

I wasn't throwing rocks at fencepost . . . one can take his "directions" to very interesting places.

blac1175
Re: Unidentified pipe/conduit in wall

Thanks :) I think I'm going to print and frame this answer for future reference :)))

Fencepost wrote:

You could always cut into the pipe.

  • If sparks fly, it's electrical conduit
  • If you get wet, it's water
  • If you get scalded, it's hot water
  • If it stinks, it's a vent pipe
  • If you get wet and it stinks, it's a sewer pipe
  • If your house explodes, it's a gas pipe
  • If money comes out, it's the vacuum tube for the bank's drive-up window
  • If you hear voices, it belongs to the NSA

You're welcome. Always glad to help.

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