GFCI added to Knob & Tube to protect circuits?

I have an electrician coming tomorrow to look at my newly aquired old house which has some knob & tube in it that I have to update for insurance purposes. The home inspector showed me how it's only the old lighting that now uses the knob & tube, all other electrical has been updated.
The electrician said on the phone that it's possible that he can just add GFCIs to each knob & tube circuit to satisfy the insurance people. This will avoid having to rip plaster walls apart.
Is this an accepted way to resolve the knob & tube issue?
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snipped-for-privacy@gmail.com wrote:

You may need to contact the local code enforcement or insurance people to determine what they want. Just adding GFCI will not change many of the issues some areas and regulations have with K&T.
--
Joseph Meehan

Dia duit
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Actually, K&T wiring is pretty good stuff!
It's reasonably safe even AFTER the mice have eaten the insulation as the "real" insulation is provided by the knobs and tubes.
A GFCI on a K&T circuit would protect the circuit from any significant leakage to ground. The basic nature of K&T is that "shorts" between the two conductors are very unlikely but anything from a nail going to far into the wall to a broken insulator might cause contract between a conductor and some other metal object.
Obviously, you have to do whatever the local authorities and the insurance company demand but when it comes to REAL safety, a GFCI will do the job. Just don't forget to TEST the GFCI once a month or so.
If your GFCI doesn't reset, you may have to tear up the walls anyway but the most likely place for problems is at switches, fixtures, and where you transition from "modern" wiring to the K&T.
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GFCI's are people protectors, not circuit protectors

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I was thinking the same thing....... Why would GFIs do much of anything on lights?
K&T was always a durable means of wiring, and lights really do not need a ground, whereas outlets do. If the K&T is in good condition, I dont see where it needs anything. Lights dont draw any heavy loads.
But inspectors and insurance people generally dont make much sense anyhow.... I'd still like to find even one of them that actually knows how to use a screwdriver.......
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On Thu, 10 Aug 2006 18:18:37 -0400, "RBM" <rbm2(remove

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local question for your electrical permit office. you may first want arc fault main panel protection for your antique wiring. see: http://www.landfield.com/faqs/electrical-wiring/part2 / also partly quoted below: "Subject: What is this weird stuff? Old style wiring
    In the years since Edison "invented" electricity, several different     wiring "styles" have come and gone. When you buy an older home you     may encounter some of this stuff. This section describes the old     methods, and some of their idiosyncrasies.
    The oldest wiring system you're likely to encounter is called     "knob and tube" (K&T). It is made up of individual conductors with     a cloth insulation. The wires are run along side structural     members (eg: joists or studs) using ceramic stand-offs (knobs).     Wire is run through structural members using ceramic tubes. Connections     were made by twisting the wire together, soldering, and wrapping     with tape. Since the hot and neutral were run separately,     the wiring tends to be rather confusing. A neutral often runs     down the centre of each room, with "taps" off to each fixture.     The hot wire tended to run from one fixture to the next. In some     cases K&T isn't colour-coded, so the neutral is often the same     colour as the hot wires.
    You'll see K&T in homes built as late as the 40's.
    Comments on K&T:
        - the people installing K&T were pretty paranoid about          electricity, so the workmanship tends to be pretty good.         - The wire, insulation and insulators tend to stand up          very well. Most K&T I've seen, for example, is in          quite good condition.         - No grounding. Grounding is usually difficult to install.         - boxes are small. Receptacle replacement (particularly with          GFCI) can be difficult. No bushing on boxes either,          so wiring changes need special attention to box entry.         - Sometimes the neutral isn't balanced very well between          separately hot circuits, so it is sometimes possible to          overload the neutral without exceeding the fusing on          any circuit.         - In DC days it was common to fuse both sides, and no          harm was done. In fact, it was probably a Good Thing.          The practise apparently carried over to K&T where          you may find fused neutrals. This is a very bad          thing.         - Building code does not usually permit insulation in          walls or ceilings that contains K&T. Some jurisdictions          will allow it under some circumstances (eg: engineer's          certificate).         - Connection to existing K&T from new circuits can be          tricky. Consult your inspector.         - Modern wiring practice requires considerably more          outlets to be installed than K&T systems did.
    Since K&T tends to be in pretty decent condition it generally     isn't necessary to replace it simply because it's K&T. What     you should watch out for is renovations that have interfered     with it and be cautious about circuit loading. In many cases     it's perfectly reasonable to leave existing K&T alone, and add     new fixtures on new circuits using modern techniques.
    After K&T, they invented multi-conductor cable. The first type     you will see is roughly a cloth and varnish insulation. It     looks much like the romex cable of the last decade or two.     This stuff was used in the 40's and 50's. Again, no grounding     conductor. It was installed much like modern wiring. Its     major drawback is that this type of insulation embrittles.     We've seen whole systems where the insulation would fracture     and fall off at a touch. BX cable of the same vintage has     similar problems. It is possible for the hot conductor to     short out to the cable jacket. Since the jacket is rusted, it     no longer presents a low resistance return path for the current     flow, but rather more acts like a resistance heater. In     extreme cases the cable jacket will become red hot without     blowing the fuse or circuit breaker. The best thing to do with     old style BX is to replace it with modern cable whenever it's     encountered and there's any hint of the sheath rusting.
    This stuff is very fragile, and becomes rather hazardous if the     wires become bare. This wiring should be left untouched as     much as possible - whenever an opportunity arises, replace it.     A simple receptacle or switch replacement can turn into a     several hour long frustrating fight with electrical tape or     heat-shrink tubing.
    After this wiring technique, the more modern romex was     invented. It's almost a asphalt impregnated cloth. Often a     bit sticky. This stuff stands up reasonably well and doesn't     present a hazard and is reasonably easy to work with. It does     not need to be replaced - it should be considered as safe as     the "modern" stuff - thermoplastic insulation wire. Just don't     abuse it too much."
snipped-for-privacy@gmail.com wrote:

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see AFCI info Consumer Product Safety Commission Preventing Home Fires: Arc Fault Circuit Interrupters (AFCIs) at: http://www.cpsc.gov/cpscpub/pubs/afci.html
snipped-for-privacy@gmail.com wrote:

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Ah so perhaps the electrician was talking about AFCIs or a combination of both? I'll know more tomorrow but thanks for that link!
buffalobill wrote:

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"There are many homes dating back to the 1920's that still have knob-and-tube that has outlasted subsequent wiring technology, such as BX with rubber insulated conductors and early forms of romex. Do AFCI breakers protect existing knob-and-tube wiring systems?
An AFCI circuit breaker will trip and clear the circuit when a line-to-neutral arc occurs (often caused by the melting of the conductor insulation at loose terminals) within three to eight half-cycles, whereas a standard circuit breaker might not open for many hundreds of half-cycles. Note: If the AFCI is dual listed as a GFCI, the two wire receptacle can be replaced with three-wire receptacles and no equipment grounding conductor is required to be run to the receptacles [406.3(D)(3)]."
http://www.mikeholt.com/mojonewsarchive/AFCI-HTML/HTML/AFCI_Questions_and_Answers~20030301.htm
snipped-for-privacy@gmail.com wrote:

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Ask insurance DIRECTLY! Some people cover up the remaining knob and tube so they qualify for homeowners insurance. Like replace everything visible:(
just one minor trouble, if you have a fire in the future the presence of knob and tube will be discovered and inssurance can refuse to cover you. You could lose everything....
The other issue is resale value, rules continue to get tighter. So attempoting to get around the replace K&T today may not work in the future espically when you decide to sell and decrease your homes future value.
I think you should replace all the K&T and get on with life. Nothing lasts forever, how many vehicles have you purchased in a lifetime? how many $$$ have you spent.
Now balance this spending against a INVESTMENT in your home! Homes are investments because they go up in value!
Vehicles go DOWN in value so they arent investments.... more like a money pit:(
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It (AFCI) will provide some protection but nothing's perfect.
K&T is usually not too hard to replace since it is usually installed in accessible areas and the old wire can be used to pull new cable where it is not. Remember the new wire doesn't need to follow the old route at all and some of those fixtures can be tied to other existing branches. Hardest part is retrofitting the j boxes if there were none.
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On 10 Aug 2006 14:52:48 -0700, snipped-for-privacy@gmail.com wrote:

imho:
Talk to your insurance and local code enforcement people.
But.... the GFCI protection protects people from shock, but will not stop a problem commonly associated with K&T. Fire.
later,
tom @ www.Consolidated-Loans.info
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