Knob And Tube Wiring Question (how To Remove A Branch Safely) - Electrical - DIY Chatroom Home Improvement Forum

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Old 10-30-2009, 07:13 PM   #1
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Knob and Tube Wiring Question (how to remove a branch safely)

I have knob and tube wiring. One line ( parralell lines about 3 inches apart) in the basement has a point where a white and black wire branch off of this run....they then go into one black insulated sleeve off to a light with a metal pull that turns it on and off.....all of this is visible and accessible - very easy to trace and follow this branch

my question is....can i simply cut the black and white branches and put electrical tape around it and remove the light or maybe cut them and cap them and put them in a metal junction box until the full run can be replaced.....

any thoughts to do this safely.....i can send a pix if it will help visually....

thanks all - john


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Old 10-30-2009, 10:37 PM   #2
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Yes you can cut the wires, tape the still live loose ends individually, and poke the loose ends into a junction box. The box can be put there temporarily until the entire wire segment is removed but the cover of the box has to be accessible at all times. Just be sure the power is off before working on the circuit.

When you cut back a wire to where it branches off (tees off) another wire that is still live, you can cut it off nearly flush and wrap more tape around the cut. Here you do not have to leave a foot or so still branching off for the purpose of being inserted into a box. Usually the joint is soldered so it doesn't come apart. But if the joint does come apart, you have to poke the remaining ends into a junction box before wire nutting them back together.

WHen you cut back the second continuation from what was once a tee joint, the remaining wire, the feed, must be boxed if it has to stay there and stay live.

When you remove the knob and tube feed line leaving the rest of the circuit dead, you do not have to put the downstream loose ends in a box. It would be a good idea to label the loose ends so the next homeowner knows he can simply remove the wires with no further testing. One consequence is that, if you re-energize a dead light or receptacle with a new cable coming from a different direction, you must disconnect all daisy chaining, restringing that, too, with new cable when desired. Otherwise you might energize loose ends in the wall somewhere.

A live knob and tube wire taht tees off somewhere inaccessible can be cut back little by little as other remodeling work progresses. A junction box would be added or moved to each location where the wire ends are cut back to, before the power is turned back on.


The good conscientious technician or serviceperson will carry extra oils and lubricants in case the new pump did not come with oil or the oil was accidentally spilled, so the service call can be completed without an extra visit.

Last edited by AllanJ; 11-01-2009 at 07:58 AM.
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Old 11-01-2009, 05:07 AM   #3
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Thanks .....

I will give it a go.........I appreciate the help....
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Old 11-01-2009, 08:34 AM   #4
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Be careful not to knock off the old insulation . the ole asbestos covering is brittle . If to much is disturbed , you may want to replace more of it .
Watch out for exposed hot wires , once power is back on . I got hit a couple of times from old knob and tube .
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