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Discussion Starter · #1 ·
First time here. Just looking to get some opinions and feasibility on a project I've been meaning to do: replacing one room's knob and tube electrical wiring with standard Romex from the breaker to the existing outlets.

My home, which was built in 1930, has the two wire/cloth wire insulation/knob-and-tube wiring. In two rooms on the first floor, I run a lot of electronics like computers and have been (unfortunately) relying on one powerstrip and plugging a bunch of things into it because of the lack of outlets in the room. I'm hoping to add additional outlets to the room and also replace (or abandon) the existing knob and tube wiring for safety and peace of mind.

My breaker is in my basement is unfinished so I can clearly see where the wires go from the breaker panel (recently replace 200A breaker) to the outlets I want to replace. Since the existing wiring is outdated, I figure I should run up-to-code type of wiring from the breaker to the replacement outlets. I was wondering how feasible this kind of job is for a guy to do on the weekend -- replace two runs of old wiring, adding some outlets, and a junction boxes as needed.

tl;dr - I want to replacing existing old cloth insulation-knob and tube wiring to one room and add additional outlets to that a room or two.
 

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It should fairly simple in your case. You could run all your new cables in the basement and feed them up into the wall from below. No cutting of the wall will be needed except where you want to install your new receptacles.
 

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Very feasible, especially if you have open access to the path the new wiring would need to take. In my experience the most difficult and messiest part of the job is cutting into walls or ceilings in order to physically run the new wiring.

Installing new receptacles and new wiring is conceptually simple but it pays to be neat and orderly, and above all to understand what you're doing and why. (So read up on basic residential wiring concepts beforehand). Some general advice:

Buy more cable than you think you need. That 250' coil may look long but you'll be surprised how quickly it goes--and if you don't need that much now, it'll sit just fine on a shelf until you realize you could really use just one more circuit here or one more light over there.

When cutting new cables to length, give yourself some extra slack to work with at first and then trim the wires down later.

Leave the wires long enough that they reach at least a few inches out beyond the face of the junction box, so you have room to work with them while attaching them to the receptacle terminals. But make them short enough so that there's not a bunch of excess that's just going to get bunched up and take up space in the junction box when you try to push it all back in there.

Get the wires organized before you start attaching any of them to the receptacles: All black wires on the hot side ("small" slot on the receptacle and brass-colored screws), all white wires on the neutral side ("big" slot on the receptacle, silver-colored screws), ground wires neatly connected and pushed to the back.

Buy the deepest junction boxes you can get that will fit within the wall cavity, especially if the box will have more than just one cable entering it. Having a roomier junction box costs a little more but makes it way easier to get the wiring and the receptacle (or light switch) to neatly and safely tuck back into the junction box after everything is connected.

I like receptacles that are labeled "commercial" rather than "residential," because they tend to have good ways for you to easily and securely attach the wiring.

If you're attaching the wiring by wrapping it around the receptacle terminal screw and then tightening it down, wrap the wire in the direction in which you're going to be turning the screw to tighten it.

14-gauge wire is thinner and therefore easier to work with than 12-gauge wire, but must be used only with 15-amp breakers. 12-gauge wire can be used with 20-amp breakers. 12-gauge isn't difficult to work with; it just seems harder if you're used to 14-gauge.

Live power is dangerous. I would recommend opening the electrical panel absolutely last, or hiring an electrician to do it. You can do everything else first--install the new junction boxes, run the new wiring, connect the new wiring to the new receptacles, get the receptacles neatly tucked back into and screwed down in their junction boxes, etc., all without having any of it energized and without having the electrical panel open.

If you're going to be doing that kind of work in any kind of proximity to the knob-and-tube wiring, I would shut that circuit off at the panel first.

If you're going to open the panel, I recommend doing so when you have a lot of daylight (or lots of good battery-powered light or some other such source, set up so that you can see clearly without having to hold the light in your hand and without being in your own shadow), and shutting off the main breaker before you remove the panel cover. Even then, pay close attention to where the big service cables come in and are screwed down on the main lugs--and don't brush against them, don't let tools brush against them, don't let the new wires you're pulling into the panel brush against them, etc. Or hire an electrician to do it, at least the first time, and watch from a safe distance.

Have fun. Be careful.

(One more thing: Don't connect more than one wire to any individual circuit breaker, unless the breaker is specifically designed and labeled for it. Since you have a new 200A panel, you might well have spare spaces in which to install a new breaker to let you run a completely new circuit, and that's a nice clean safe way to do it).
 

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Discussion Starter · #4 ·
Have fun. Be careful.
Thanks a lot for your detailed post! I appreciate all the small tips you put like getting deeper/commercial receptacles boxes, laying out the wiring before finalizing the connections, etc. I have a little background in electrical wiring, but nothing as large as this project. I hope it actually too hard given its only running new wire and just cutting a few holes. But I guess I won't know until I start.
 

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You will no doubt have other questions as you proceed with your project. You should add your location to your profile so that your questions can be answered with an answer that is appropriate for you.
 

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Go and find thee Smartbox style of boxes that screws to the side of the studs. Much more secure than old work boxes in plaster.
 

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Live power is dangerous. I would recommend opening the electrical panel absolutely last, or hiring an electrician to do it. You can do everything else first--install the new junction boxes, run the new wiring, connect the new wiring to the new receptacles, get the receptacles neatly tucked back into and screwed down in their junction boxes, etc., all without having any of it energized and without having the electrical panel open.
Vinsond, you gave lots of great advice. I just want to clarify one, possibly very important thing - even when turning off the main breaker, the power feeds into the main panel will still be hot and can most certainly kill you. As long as you are careful, you will be just fine. Just don't forget! Best of luck.

**Nevermind, I saw where you already mentioned this near the end of your post**
 

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Leave the wires long enough that they reach at least a few inches out beyond the face of the junction box, so you have room to work with them while attaching them to the receptacle terminals.
Code calls for a minimum of 6 inches of wire, measured from where the cable enters the box.

The “few inches beyond the face” may come up short.
 

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The conductors should extend at least 3" past the face of a standard device box.
 

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Code calls for a minimum of 6 inches of wire, measured from where the cable enters the box.

The “few inches beyond the face” may come up short.
The conductors should extend at least 3" past the face of a standard device box.
Thanks, gentlemen. I was not aware of the code requirement but that makes sense. My comment above was just based on problems I've run into with existing wiring in my own homes over the years...some have been noticeably too short, others noticeably too long.
 

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retired framer
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I wouldn't think room by room I would be thinking circuit, where ever that takes me.
Are you going to bring it up to code with the number of outlets or the distance between them?

Working in a cavity is easier if you can get a hand in there so I would remove the old boxes and replace them with old work boxes that can be installed from outside the wall.
https://www.homedepot.com/p/1-Gang-14-cu-in-Old-Work-Box-B114RB/100404027
 

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First time here. Just looking to get some opinions and feasibility on a project I've been meaning to do: replacing one room's knob and tube electrical wiring with standard Romex from the breaker to the existing outlets.

Personally, there is not much else that I would be working on until all the knob and tube in my house was replaced.
 

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Working in a cavity is easier if you can get a hand in there so I would remove the old boxes and replace them with old work boxes that can be installed from outside the wall.
https://www.homedepot.com/p/1-Gang-1...14RB/100404027
If the old box was on a stud, I prefer an old work box that will hang on the stud, not the dry wall.
The Madison smart box
https://www.homedepot.com/p/Madison-Electric-Products-Smart-Box-1-Gang-Adjustable-Depth-Device-Box-MSB1G/203340257
The Arlington F101
https://m.platt.com/Products.aspx?pid=651477
 

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Discussion Starter · #15 ·
I wouldn't think room by room I would be thinking circuit, where ever that takes me.
Are you going to bring it up to code with the number of outlets or the distance between them?
The room I'm working in isn't too big so I don't think I would need to bring it 100% to code (the room is like 12ft x 10 ft in a small corner of the house). I am double checking to see if I can bring it as close to code as possible without doing any extra work I don't need to do (just replacing an outlet and adding 2 more outlets right now for a small room).


If the old box was on a stud, I prefer an old work box that will hang on the stud, not the dry wall.
The Madison smart box
https://www.homedepot.com/p/Madison...g-Adjustable-Depth-Device-Box-MSB1G/203340257
The Arlington F101
https://m.platt.com/Products.aspx?pid=651477
Oh, I was not aware of these kinds of boxes that screw into the studs. I may decide to go with these instead of those existing/old work boxes. Since the outlet I wanted to upgrade was in the wood baseboard of the room, instead of a couple inches off the ground in the plaster, I was just going to put the new outlets into the existing baseboard and secure them to the baseboard. Thanks!
 

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Into the baseboard is good choice for the existing receptacles, since you won't need to replace the baseboard.
Add any new ones up in the wall on the studs.

Another option to this work is to remove the baseboards and run the cables through the studs. Then replace the baseboards. This style of baseboard usually does not have the plaster behind it, so once the boards are off, you have access to the stud bays.
 

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The room I'm working in isn't too big so I don't think I would need to bring it 100% to code...
That's not how code works.
You may or may not have to get a permit to do this. Better check with your town.
You may or may not have to bring everything on that circuit or in that room up to code. When replacing knob and tube, it's easier to replace the whole circuit than to tie in to it.
If you have the opportunity to fix something, fix it. Don't halfass it. Remember that the code is the minimum standard you can legally build. You can and should do better than the bare minimum.
 

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Oh yeah, knob and tube isn't as dangerous as some people think. The problem with K&T is that it is ungrounded and if you insulate the walls the K&T has a harder time dissipating heat. Back when knob and tube was installed, it was usually done by professionals who did it well so it holds up well. As long as nobody has tapped into it or added blown in insulation K&T isn't much of a hazard. ...other than the lack of ground.
It's still a good idea to replace it, but it's not like you should go running from any house with K&T like it's about to blow up!
 
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