Knob & Tube Maintence etc.

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MrHopper

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My boss and I have an older K&T home to do the electrical part of a rather large remodel.

Question is: where say a door is going where K&T once ran through a wall what to do to extend and run around a different direction which will need more wire and routed a different direction.

I believe I read once in the code book you couldn't run grounded (say 12-2 W/G) to extend K&T plus we would then need to use junction boxes for the romex. I know we can run K&T but not real familiar with the system, solder, friction tape etc. K&T is from a whole nother era, not mine. Basicly what do other companies do to tie these systems back in.

Also, say a piece of abandoned K&T comes out of the floor joists above, is tied around a knob and is now dangling. Is it ok to continue it around that knob, back-wrap around itself and tape it if I can't see or get to where it originates from.
 
Anything new needs to comply fully with the nec in effect in your area,that includes spacing ,gfci,afci.Only way i know of going around areas is to do a change over within a legal box and run romex.I highly suggest a visit with the inspecter before you even touch this job.
 
77401 said:
With K&T I never tie to any thing existing.
Anything not needing to be demo'd or touched can stay.
Anything cut gets rewired new
Anything new is all new wiring on new circuits.
The more of the K&T you can get rid of the better
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Where within reason i agree.Sometimes that could cost hundreds an not needed.Where within easy doing back off of any old wiring.
 
I understand this, I don't think I was clear enough or you didn't quite understand the question.
The area is a bathroom. We are going in, removing all K&T we can. All wiring will be new romex 12-2 w/g, GFI protected, being that the plans call for a fan/lite over the tub we will also GFI protect the lighting circuit. There will be a wirlpool so that will be fed from a dedicated circuit protected by a deadface. The question was not should I tie into or not. These will all be new homeruns as will all our old work.

The question is this. There is a finished basement below. The bathroom in question is on the first floor, with a second floor above. There was a K&T circuit run from the ceiling through a wall feeding the basement as well as some first floor recepticles. But the plan has a door where the wires go through the floor. So, what to do with feeding that circuit? The wires are now cut. Can't access from above or below.

I believe I only have one option which is to add K&T to re-connect that circuit (NOT TIE INTO IT)? Is vinyl tape acceptable or does it have to be Friction? Can THHN be used or is it something different. Like I said I'm from a different time. Thanks in advance
 
OK answer this,would this result in new wiring ?If so i think we have a problem.We can no longer create any new wiring in K&T.I think you need to do change over between the two boxes.
 
You need to get what ever K&T that you wish to remain, and work it in to a box that can be used as a JB. This could be a light, a receptacle, or something you're willing to put a blank face plate on (that would not be my choice, personally) - and then work it back to the other K&T you wish not to rip out.

The bottom line is that you can not install any K&T. It's the K&T brought in to a JB - again, working it back to some convienient spot, and then running an accepted wiring method per the NEC - most likely NM.

Hope this clarifies the question you ask. I understand there's now a door cut in where some K&T was run - but you need to work each end to a JB - then connect with a "new fangled" wiring method.

Brett
 
MrHopper said:
My boss and I have an older K&T home to do the electrical part of a rather large remodel.

Question is: where say a door is going where K&T once ran through a wall what to do to extend and run around a different direction which will need more wire and routed a different direction. Add more wire...

I believe I read once in the code book you couldn't run grounded (say 12-2 W/G) to extend K&T plus we would then need to use junction boxes for the romex. You could do that, but only if it were GFI protected. I know we can run K&T but not real familiar with the system, solder, friction tape etc. K&T is from a whole nother era, not mine. Basicly what do other companies do to tie these systems back in. I re-do it in it original method...

Also, say a piece of abandoned K&T comes out of the floor joists above, is tied around a knob and is now dangling. Is it ok to continue it around that knob, back-wrap around itself and tape it if I can't see or get to where it originates from. Yep, this is a good way...
Click to expand...

This is something I put together as to not have to explain K&T to people under me. K&T

That is if you are allowed (Locally), I am, and do all the time. In most situations it would require much more (Scope of demo) work to a structure that would not be nessesary, or required preservation of special finishes that would not be able to be replicated due to lack of skilled carpentry or materials.
 
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e57,

Nice document.
e57 said:
This is something I put together as to not have to explain K&T to people under me. K&T
Click to expand...
Over my career I've had the opportunity to work on a lot of K&T. Here's my take on MrHopper's question.
All of my citations are from the 2005 NEC.
394.2 Definition

Concealed Knob-and-Tube Wiring. A wiring method using knobs, tubes, and flexible nonmetallic tubing for the protection and support of single insulated conductors.

394.10 Uses Permitted
Concealed knob-and-tube wiring shall be permitted to be installed in the hollow spaces of walls and ceilings or in unfinished attics and roof spaces as provided by 394.23 only as follows:
(1) For extensions of existing installations
(2) Elsewhere by special permission
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MrHopper, for the situation you describe, you are not adding new openings, only re-routing the conductors. That falls under 394.10(1) above.
394.56 Splices and Taps
Splices shall be soldered unless approved splicing devices are used. In-line or strain splices shall not be used.
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In my area, a seven county Metro area, approved splicing devices includes wirenuts. However, I prefer to use the soldered and taped Western Union Splice. e57's document details this splice nicely.
394.104 Conductors
Conductors shall be of a type specified by Article 310.
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Article 310 has a lot of conductor types, including THHN.
300.15 Boxes, Conduit Bodies, or Fittings ? Where Required
A box shall be installed at each outlet and switch point for concealed knob-and-tube wiring.

Fittings and connectors shall be used only with the specific wiring methods for which they are designed and listed.

Where the wiring method is conduit, tubing, Type AC cable, Type MC cable, Type MI cable, nonmetallic-sheathed cable, or other cables, a box or conduit body shall be installed at each conductor splice point, outlet point, switch point, junction point, termination point, or pull point, unless otherwise permitted in 300.15(A) through (M).

. . . .

(F) Fitting A fitting identified for the use shall be permitted in lieu of a box or conduit body where conductors are not spliced or terminated within the fitting. The fitting shall be accessible after installation.
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Note my highlight in red above. Only K&T switches and outlets require a box. . .no mention of K&T conductor to conductor splices.
300.16 Raceway or Cable to Open or Concealed Wiring

(A) Box or Fitting A box or terminal fitting having a separately bushed hole for each conductor shall be used wherever a change is made from conduit, electrical metallic tubing, electrical nonmetallic tubing, nonmetallic-sheathed cable, Type AC cable, Type MC cable, or mineral-insulated, metal-sheathed cable and surface raceway wiring to open wiring or to concealed knob-and-tube wiring. A fitting used for this purpose shall contain no taps or splices and shall not be used at luminaire (fixture) outlets.
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MrHopper,

For your situation you may use any of the wiring methods listed in 300.16(A) to run between the two ends of K&T that you've cut off. The trick is to use a "fitting" that ends the raceway or cable, and allows the contained conductors to emerge in free air through separately bushed holes.

In the past, for this "fitting" I've used plain old two screw die cast 3/8" romex clamps with 1/2" weatherheads that thread onto the 1/2" NPT of the romex clamp.
 
al hildenbrand said:
e57,

Nice document. WhyThank You...

~approved splicing devices includes wirenuts. However, I prefer to use the soldered and taped Western Union Splice. Around here you could only use a wire-nut if in an accessible area. I too prefer a WU Splice, but another method could be a small split-bolt taped well.


The trick is to use a "fitting" that ends the raceway or cable, and allows the contained conductors to emerge in free air through separately bushed holes. A "Monkey face" fitting....
Click to expand...

Monkey face fittings are hard to find these days, the one below is for BX, but were also made for NM, EMT,and RMC.
bxloom.jpg
 
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