knob and tube wiring

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highendtron

highendtron

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An insurance agent wants me to fix one of his rental houses. The house has a 100 amp GE panel mounted in the basement. Thieves tried to steal his copper and removed all the basement branch circuits. They tried to remove the panel but were unsuccessful. All of the basement runs are or were knob and tube. Short of rewiring the whole house what is the best way of rewiring a knob and tube basement. Is it acceptable to place 1900 boxes close to the knobs and use open splices to the knobs? Or should I remove the knobs and make a splice in handy boxes? Any constructive thoughts?
 
highendtron said:
Is it acceptable to place 1900 boxes close to the knobs and use open splices to the knobs?
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I do this quite often - pipe in a bunch of 4sq's near to where the knobs are - them loom into the box from the knobs. (FYI you can only take one wire per hole in this method to the 1900 bx per code)

I would also suggest that you investigate whether or not the home was using switched neutrals (popular pre 1960) +/or wired in a 3-wire style (circa late 60's ~ 1970's indicators of this can be colored TW wire insulation) If done in the 40's or prior it is usually safe to say they were all single phase 2-wire circuits - and you should re-feed them that way preferably from only one phase in case there was other work. But tracing the whole whouse is not a bad idea.....

And if the wires are too short - western union some additional length to it by putting a knob on both sides of the spice withing 6" - then loom into a box.....

Check this out: It may have more answers to more questions - or just create more questions....
http://www.markhellerelectric.com/wusplice.pdf
 
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e57, What do mean by three wire style? The reason I ask I ran to that today. The wire was TW but there were three wires, two black and they used a orange wire for thr neutral. I thought they just did not know what they were doing. This was in the basement, rest of the house T &K.
 
highendtron said:
An insurance agent wants me to fix one of his rental houses. The house has a 100 amp GE panel mounted in the basement. Thieves tried to steal his copper and removed all the basement branch circuits. They tried to remove the panel but were unsuccessful. All of the basement runs are or were knob and tube. Short of rewiring the whole house what is the best way of rewiring a knob and tube basement. Is it acceptable to place 1900 boxes close to the knobs and use open splices to the knobs? Or should I remove the knobs and make a splice in handy boxes? Any constructive thoughts?
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i wouldnt really try to reuse the knob and tube since its at the end of its time and needs an upgrade. i would just replace whatever was in the basement and try to sell him a house rewire.
 
Thanks!!! I wish I could walk away but I like the challenge. In any case I put 1900 boxes up but I realize, after reading the site you sent me to, that I need to go back and put my spice in the box.
 
Jim W in Tampa said:
You now are rewiring like it or not and now arc faults and gfci come to play.I hope he has deep pockets.
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only if the jurisdiction has adopted 05 or 08. we're still on 02.
 
guschash said:
e57, What do mean by three wire style? The reason I ask I ran to that today. The wire was TW but there were three wires, two black and they used a orange wire for thr neutral. I thought they just did not know what they were doing. This was in the basement, rest of the house T &K.
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Not quite sure what you have there - but it may be the same......

Around here we have a number of these.... Sort of 'Frank Loyd Wright' "Styled" or influenced homes and buildings that were popped up here and there during the late 50's though early 70's. Most of them were wired with TW or early thermoplastic wiring in a K&T style. The colors on the wire differ because the coloring obviously did not stand the test of time. White often seems a yellow color, and red was often white wire that the manufacturer colored red with some sort of dye. As it is not usually too consistent and doesn't go all the way through - sometimes it fads and looks orange... Black seems to hold up rather well...

The main difference from other earlier K&T wired buildings was the use of Edison style circuits - 3-wire circuits using one conductor of each phase, and only one neutral. Where as most ealier versions used only 2-wire branch circuits... Many of these later 3-wire K&T buildings also had ground conductors splices simularly to K&T, but no knobs or tubes - just stapled right to the framing, with the grounds taken to water lines here and there in the building.

One of the reasons you'll find so many late K&T buildings here is that SF shunned cable methods for quite some time. An additude that I believe spread across a good part of the SF Bay Area with certain people - because I see them deep into the suburbs in areas where I know they also allowed cable methods at the same time.

Either way - it is always a good idea to fully understand what you are dealing with by tracing out the circuits completely.
 
I will add that in most areas, an act of vandalism like this would not trigger "Re-wiring" the whole building. As to many this would be a repair of existing. A decision by the AHJ...

Where I am - they might ask for the kitchen and baths to have GFI devices - but would not ask for AFCI's unless the whole circuit was new.
 
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