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Running romex in same joist space as water? #173970
01/24/08 11:39 AM
01/24/08 11:39 AM
chimo  Offline OP
Joined: Oct 2004
Posts: 16
I'm re-routing some circuits on a residential kitchen project, and was wondering:

Can you place electrical runs in the same wall cavity with plumbing? Good/bad practice? Could this be against code in some areas?

Building Codes & Related References
Re: Running romex in same joist space as water? [Re: chimo] #173971
01/24/08 11:54 AM
01/24/08 11:54 AM
JValdes  Offline
Joined: Jun 2007
Posts: 301
South Carolina
Yes, but I cannot quote an article to back it up. I know it is done all the time and I would not hesitate to do it myself. Someone else may disagree and provide an article for us. But I think the answer is yes.

Re: Running romex in same joist space as water? [Re: chimo] #173972
01/24/08 11:55 AM
01/24/08 11:55 AM
renosteinke  Offline
Cat Servant
Joined: Jan 2005
Posts: 5,316
Blue Collar Country
I don't see anything against doing so, but experience has suggested a few complications you'll need to address.

Pipes take up space. This can mean there's no room for a box, anchoring the cables can be difficult, and that the cables will need additional protection when the piping pushes them too close to the wall.

Re: Running romex in same joist space as water? [Re: renosteinke] #173997
01/24/08 10:16 PM
01/24/08 10:16 PM
excellencee  Offline
New Member
Joined: Sep 2007
Posts: 5
I had a HO/plumber who forbid me from running romex in the same stud/joist space as his copper pipes. He claimed electrolisis (sp?) causing pinholes in his copper. He was/is the only plumber that ever identified this as a problem. BTW I run romex in the same bays as plumbing.

Re: Running romex in same joist space as water? [Re: excellencee] #174007
01/24/08 11:38 PM
01/24/08 11:38 PM
Theelectrikid  Offline
Joined: Apr 2004
Posts: 810
Levittown, PA
Welcome aboard excellencee, from another member from the Commonwealth of PA.

Ian A.

Is there anyone on board who knows how to fly a plane?
Re: Running romex in same joist space as water? [Re: Theelectrikid] #174023
01/25/08 01:50 PM
01/25/08 01:50 PM
macmikeman  Offline
Joined: Jul 2002
Posts: 717
Honolulu, Hawaii
You can. However, if the spacing is tight, you might want to consider the ambient temperature if you find that your cables are physically touching the hot water pipe. In that case de-rating may be required, depending also on the length of the contact.

Re: Running romex in same joist space as water? [Re: macmikeman] #174025
01/25/08 02:04 PM
01/25/08 02:04 PM
Zapped  Offline
Joined: Oct 2002
Posts: 482
Huntington Beach, CA, USA
In the same joist/stud bay? Sure. I've worked with so many plumbers I couldn't begin to take a swing at the number, but I've never heard anything about electrolysis or any such thing like that.

Touching? No. Hot water, cold water, doesn't matter. Not a good idea. Vibrations, heat, cold, etc. There are too many variables to even consider doing this. You can get around them without problem. If not, at least use some pipe insulation jacket between your wire and the pipes.

Good Luck!

Re: Running romex in same joist space as water? [Re: Zapped] #174038
01/25/08 03:50 PM
01/25/08 03:50 PM
pauluk  Offline
Joined: Aug 2001
Posts: 7,520
Norfolk, England
We do it all the time over here, where hot-water central-heating systems are the most widespread so it's common to have copper pipework running all over the house, not just in the kitchen/bathroom areas.

Re: Running romex in same joist space as water? [Re: pauluk] #174216
01/29/08 01:50 PM
01/29/08 01:50 PM
mikesh  Offline
Joined: Jun 2006
Posts: 613
Victoria, BC, Canada
Plumber often wrap BX to prevent electrolosis but romex is no problem as it is insulated. excellencee's HO/plumber was thinking bx but he was a plumber and what does a plumber know about electrical installations ;-)

Re: Running romex in same joist space as water? [Re: mikesh] #174223
01/29/08 07:03 PM
01/29/08 07:03 PM
WireNuts29  Offline
Joined: Jul 2007
Posts: 85
Mass, U.S.A.
I have first hand experience with a hot water pipe going to the shower, melting into the range feed in my parents house.The house was built in early 70's. this happened probably 6 years ago. The problem most likely started as soon as the house was occupied. But over time the romex jacket and conducter jacket was melted. the only reason for finding the problem was a random shock when getting in the shower, and touching any grounded metal around it. I.e the handle, or drain. I've never seen this problem anywhere else. From then on I always maintain a healthy spacing when running romex anywhere near hot water pipes.

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