# Knob and Tube 101



## Wpgshocker

Gut and re-wire. There is little point doing anything else.

Tell her to find a good drywaller!


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## FrunkSlammer

Knob and tube is pretty safe stuff.

Anywho.. insurance companies hate it and homeowners don't understand it.. and you're an electrician and you don't even get it. So basically it's 2 wires run throughout a house.. the hot and the neutral and they rarely come together. The way it was installed is nothing like how we install wiring these days. 

If she wants it gone, just leave it in tact.. kill the source of it, remove what you can, and fish in new wires.. it's going to be a massive job.

In my opinion, and it's not necessarily the consensus.. but just update wiring as rooms get renovated. The problem with it seems to be insulation breakdown.. it's so old, it's all brittle and just cracks and falls off. So if you take a switch out, expect to re-insulate the conductors. 

Hope this message helps and is a start.. replacing is just a personal thing, unless liability requires replacement. Just let her know it's going to cost a lot of money and it's going to make her house a difficult place to live for a while and there will be repair work needed after.


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## Hack Work

It's good that she is asking you, this way she already knows the dangers and you won't have to sell her on it.

Replace it all, give her a modern electric system.

If she has an attic and basement you can do almost all the work without opening walls.


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## headrec

FrunkSlammer said:


> Knob and tube is pretty safe stuff.
> 
> Anywho.. insurance companies hate it and homeowners don't understand it.. and you're an electrician and you don't even get it. So basically it's 2 wires run throughout a house.. the hot and the neutral and they rarely come together. The way it was installed is nothing like how we install wiring these days.
> 
> If she wants it gone, just leave it in tact.. kill the source of it, remove what you can, and fish in new wires.. it's going to be a massive job.
> 
> In my opinion, and it's not necessarily the consensus.. but just update wiring as rooms get renovated. The problem with it seems to be insulation breakdown.. it's so old, it's all brittle and just cracks and falls off. So if you take a switch out, expect to re-insulate the conductors.
> 
> Hope this message helps and is a start.. replacing is just a personal thing, unless liability requires replacement. Just let her know it's going to cost a lot of money and it's going to make her house a difficult place to live for a while and there will be repair work needed after.


Yeah this is kind of the vibe I got from the little I read. Seems like if the wiring wasn't messed with then there wouldn't be much to worry about. She is planning to redo a few of the front rooms in the house and I think at the least she should redo the wiring while she is in there. 

I should add I most likely won't be doing the work...nor want to. She is a real estate agent so she is somewhat aware of certain knowledge about housing and construction. She does have a basement and attic so it won't be a terrible job but very extensive.


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## Sparky J

Also remember if left intact, no insulation around it. From what I've herd it's supposed to be free air so it could have major issues in attics and exterior walls if insulation was/is going to be installed. 
The last house I removed it in had more butchered wiring problems than the knob and tube. Had it been left alone it would have been pretty sound.


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## HARRY304E

FrunkSlammer said:


> Knob and tube is pretty safe stuff.
> 
> Anywho.. insurance companies hate it and homeowners don't understand it.. and you're an electrician and you don't even get it. So basically it's 2 wires run throughout a house.. the hot and the neutral and they rarely come together. The way it was installed is nothing like how we install wiring these days.
> 
> If she wants it gone, just leave it in tact.. kill the source of it, remove what you can, and fish in new wires.. it's going to be a massive job.
> 
> In my opinion, and it's not necessarily the consensus.. but just update wiring as rooms get renovated. The problem with it seems to be insulation breakdown.. it's so old, it's all brittle and just cracks and falls off. So if you take a switch out, expect to re-insulate the conductors.
> 
> Hope this message helps and is a start.. replacing is just a personal thing, unless liability requires replacement. Just let her know it's going to cost a lot of money and it's going to make her house a difficult place to live for a while and there will be repair work needed after.



Thanks for pointing out the lack of equipment grounding in a K&T wiring system.


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## Hack Work

headrec said:


> She does have a basement and attic so it won't be a terrible job but very extensive.


Then she can upgrade it whether the room is being renovated or not.

Even if the wiring itself is fine, chances are there aren't many receptacles and there are too many rooms on each circuit. Why run extension cords and stress the old wiring/splices? Nevermind the fact that there is no grounding.

If she is asking your opinion, it should be that she should upgrade to a modern system. I'm surprised her homeowner's insurance didn't require it.


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## HARRY304E

headrec said:


> I just had a friend who bought a house that has knob and tube wiring in the majority of the house. She wanted me to come look at it and give my opinion. I took a look but I honestly know almost nothing about it. Just did a little google search and before today had only seen pictures of it and heard horror stories from coworkers.
> 
> Just wondering if you guys can give me a run down on it. She's looking to replacing all the wiring because she's worried about the potential fire hazard. Wondering if that is really necessary or if there is anything I should help advise her on. Thanks guys! :thumbup:



Jay take a good look at this picture.










As you can see that is BX cable with BX to K&T change over connectors .

The BX WAS installed between 1899 and about 1950 when they figured out that and equipment ground was needed,many K&T systems were wired this way so that , That BX IS not grounded to the service.


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## Hack Work

Even if that BX was grounded to the service, it's still not suitable for use as an equipment grounding conductor. 

Rip it out.


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## wendon

Most likely it's not just k&t. It probably has some old romex or bx added to it. The biggest problem IMHO is when someone tried to tie a new circuit into the k&t and did a poor job of it. I think the old romex is the most dangerous, brittle wire and brittle insulation.


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## Galt

Yes it should all be rewired .but knob and tube was a very good wiring method.The conductors are a foot apart most places.If they had better insulation back then a lot of it would still be in service.when you think about it it's kind of dumb to wrap conductors tightly together then apply a potential difference between them. Always reminded me of two cars going sixty miles an hour in opposite directions separated by a yellow line.


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## MDShunk

I'd live in an unmolested K&T house well before I'd be interested in living in an old cloth-covered Romex house. That old cloth covered romex-type stuff is the dangerous stuff, in my opinion.


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## dspiffy

Cosign everyone saying K&T is perfectly safe when left unmolested. 

Assuming the house has a modern panel with plenty of room . . .

Update any rooms that are already being remodeled, as suggested.

Add modern circuits to other rooms as needed, leaving the K&T alone until those rooms are also remodeled.

You'll probably end up with the K&T being mostly lighting circuits in unremodeled rooms.


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## Shockdoc

Old uninsulated especially balloon framed K & T houses are a breeze to rewire, 6 circuits and your'e done in a day.


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## Hack Work

I don't know why there would even be a question of what to do. The OP's friend is apparently willing to upgrade if necessary. It doesn't sound like an old lady on a fixed income situation in which she was scared by another contractor and just wants to make sure if her house isn't going to burn down. This situation sounds like the homeowner is willing to improve her home.

Since there is a basement and attic, upgrading is easy and doesn't require the rooms to be fully renovated. 

I can't see why any electrician wouldn't recommend an upgrade to a modern and grounded electrical system in this situation.


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## Hack Work

Shockdoc said:


> Old uninsulated especially balloon framed K & T houses are a breeze to rewire, 6 circuits and your'e done in a day.


Why would you only install 6 circuits? Isn't the point of a rewire to bring it up to today's standards?


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## 8V71

HARRY304E said:


> Thanks for pointing out the lack of equipment grounding in a K&T wiring system.


:shifty:


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## Shockdoc

Hack Work said:


> Why would you only install 6 circuits? Isn't the point of a rewire to bring it up to today's standards?


2) kitchen
1) bath
3) lighting

Supersedes what is there and meets the minimum.


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## Hack Work

Shockdoc said:


> 2) kitchen
> 1) bath
> 3) lighting
> 
> Supersedes what is there and meets the minimum.


I don't get it...


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## Wpgshocker

Hack Work said:


> I can't see why any electrician wouldn't recommend an upgrade to a modern and grounded electrical system in this situation.


Agreed. 
It would also be cheaper do do it all at once, rather than piecing it out. Where I live, insurance companies charge a lot more for K&T. Every year it stays in the house is more money she will lose.


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## dspiffy

Does anyone know of even one instance of a fire being attributed to knob and tube, without other factors being involved (i.e. an oversized fuse/breaker on said wiring)?

I've never heard of any and cant find any with a quick google search.


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## jza

Hack Work said:


> I don't know why there would even be a question of what to do.


I don't get it either. There's some real characters on here.


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## pete87

If called for some service work at a K & T Dwelling .

I always advise saving up for the necessary rewire .






Pete


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## cdnelectrician

Knob and tube may be safe if left un-adultered but with all the electronics people use these days its wayyyyy out of date. Not very often I have torn out K&T that was not messed with in some way, I can only think of one instance where it had not been touched.


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## jza

Regardless of if it's been touched or not and how safe it may be, it's still predates the 1940's and it is industry standard to replace it. I couldn't imagine telling a client that a K&T system is unmolested and safe. I'd need to spend days looking over the system before I could make such a claim in good conscience.


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## chicken steve

Art 394 still exists

although the lost art of K&T may not....



~CS~


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## MDShunk

chicken steve said:


> Art 394 still exists
> 
> although the lost art of K&T may not....
> 
> 
> 
> ~CS~


The last throrough article I read on K&T said that it was being done in SanFran up until the early 70's. There's a company in Ohio that still makes the knobs and tubes if you cared to wire that way. I did bid a historical rennovation some years back that was to be wired this way, but didn't get the job.


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## chicken steve

I'd love to read such an article MD

~CS~


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## MDShunk

chicken steve said:


> I'd love to read such an article MD
> 
> ~CS~


Somebody posted it here years back. I can't, at the moment, remember any keywords in that thread that were unique enough that would let me dig it up without taking a ton of time. You might get lucky doing a google for knob and tube san francisco.


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## The_Modifier

HARRY304E said:


> Jay take a good look at this picture.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> As you can see that is BX cable with BX to K&T change over connectors .
> 
> The BX WAS installed between 1899 and about 1950 when they figured out that and equipment ground was needed,many K&T systems were wired this way so that , That BX IS not grounded to the service.


Grounding patent was registered in June 5, 1928 LINK by
Phillip. F. LABRE


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## The_Modifier

dspiffy said:


> Does anyone know of even one instance of a fire being attributed to knob and tube, without other factors being involved (i.e. an oversized fuse/breaker on said wiring)?
> 
> I've never heard of any and cant find any with a quick google search.


Just when the insulation is laying on it. Including the chemically altered paper, it's properties eventually break down and with the improperly fused wiring of the day heated up and started to reduced the structural integrity as well as some of the finer features of the house like keeping the weather out of the house by burning it down. :thumbsup:


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## papaotis

must agree with the posters who think its o. k. for unadulterated k&b to remain. after all, it lasted as much as 140 years without a problem, right? however, whenever there is a chance to upgrade easily, such as a remodel, DO IT! and yes, with newer electronics and appliances, sometimes a GROUND is needed. besides, upgrading gives us more work!:thumbup:


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## Skblay

In my opinion licensed electricians should never tell anybody residential wiring installed pre 1960 is safe without knowing for a 100% sure that it is. So unless you have X-ray vision I would be careful what you say. I know I couldn't live with assuring somebody that something is safe and then they lose everything they own or somebody in a fire.

With that being said as electricians we get pretty comfortable with sketchy wiring and tend to be quick to say something is "probably fine" and that's one thing between us, but another to non electrically educated paying customers or friends.

Just my humble opinion is all. Best of luck!


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## MTW

MDShunk said:


> I'd live in an unmolested K&T house well before I'd be interested in living in an old cloth-covered Romex house. That old cloth covered romex-type stuff is the dangerous stuff, in my opinion.


That's strange that you singled out cloth covered romex. Old unbonded BX is far more dangerous than cloth covered romex and K&T. With BX you have a bunch of potential heating elements in the walls and ceilings. No such danger exists with K&T and cloth romex.


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## LARMGUY

MDShunk said:


> I'd live in an unmolested K&T house well before I'd be interested in living in an old cloth-covered Romex house. That old cloth covered romex-type stuff is the dangerous stuff, in my opinion.


Between what years was this cloth covered Romex installed? 40's, 50's?


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## papaotis

not sure but i thionk it goes back to the late twenties


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## Wpgshocker

LARMGUY said:


> Between what years was this cloth covered Romex installed? 40's, 50's?


My house is mid sixties and have the fibre cover. Still in great shape.


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## FrunkSlammer

papaotis said:


> must agree with the posters who think its o. k. for unadulterated k&b to remain. after all, it lasted as much as 140 years without a problem, right? besides, upgrading gives us more work!:thumbup:


Yeah k&t was bad for business because it's probably the best wiring method devised. 

Good thing our current wiring methods won't last 20 years. :laughing:

BUSINESS IS BOOMING!


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## captkirk

papaotis said:


> not sure but i thionk it goes back to the late twenties


My house was built in the early 20s and there was evidence of k t.


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## Pharon

My house was built in 1890 and I think I have every type of wiring situation ever invented. My basement is a horror show. I will try to post pics.


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## retiredsparktech

MDShunk said:


> The last throrough article I read on K&T said that it was being done in SanFran up until the early 70's. There's a company in Ohio that still makes the knobs and tubes if you cared to wire that way. I did bid a historical rennovation some years back that was to be wired this way, but didn't get the job.


 I would find it hard to believe that SanFran used K&T, that late.
When did The NEC, require every receptacle, used in residential, to be the 5-15 grounding type?
Even back then, it was highly labor intensive!
I do remember seeing a home remodeling show, where a late 40's, early 50's home was still wired in K&T.


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## oldtimer

I have seen many houses that were originally wired with K and T .

The main problem is (was) when homeowners replaced light fixtures with fixtures that draw more than the original .

Example : a closed in glass fixture that was meant to have a maximum of a 40 watt lamp , which was replaced by a 100 watt lamp .

The K and T was passed through factory holes in a three inch round pan box . Sometimes there is (was ) a crowsfoot to hang the fixture from , and other times the fixture was just bolted on with the 8/32s .

Of course , in the totally enclosed fixtures the wiring was toasted by the extra heat from the higher wattage lamps .

The original concept of K and T was good , and I M O , if left as it was originally intended , was safe !

IF LEFT AS ORIGINALLY INTENDED !

(another little gem of wisdom from an old curmudgeon)


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## Military Veteran

Saw this stuff in Australia in very old houses,usually wired by American sparkys after WW1 saw 4 bare wires thought it was telephone stuff, was there to fit a tv antenna found out the hard way,415 volts 3 phase no grounds talked the old cat guy into rewiring the house.


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## chicken steve

Our American Electrician handbook details how K&T is to be put together

Despite what you may have witnessed of this wiring method's demise after a century of abuse, it really was _something_ of an art

Yesterday i just took 30 odd K&T splices out of a local attic

My apprentice and I laid them all side by side to _realize _the meticulous and repetitive nature of the splicing they did

I put it forward that, if we were half as scrutinizing of our _own_ methods, instead of subscribing to the speed we're pushed to achieve, we'd really be something


~CS~


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## LGLS

dspiffy said:


> Does anyone know of even one instance of a fire being attributed to knob and tube, without other factors being involved (i.e. an oversized fuse/breaker on said wiring)?
> 
> I've never heard of any and cant find any with a quick google search.


 Errr... enough fires are attributed to "electrical fault" when no other cause can be found to take those reports seriously.


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## retiredsparktech

chicken steve said:


> Our American Electrician handbook details how K&T is to be put together
> 
> Despite what you may have witnessed of this wiring method's demise after a century of abuse, it really was _something_ of an art
> 
> Yesterday i just took 30 odd K&T splices out of a local attic
> 
> My apprentice and I laid them all side by side to _realize _the meticulous and repetitive nature of the splicing they did
> 
> I put it forward that, if we were half as scrutinizing of our _own_ methods, instead of subscribing to the speed we're pushed to achieve, we'd really be something
> 
> 
> ~CS~


They were still teaching these wiring methods in the trade school I attended in the late 50's, early 60's. They were still issuing the old RH type wire, that was obsolete back then.
Splice, solder and tape, both rubber and friction tape. The pig-tails were dip soldered and the tap and western union splices, were soldered with the old soldering copper, using No-corrode soldering paste and 50-50 solid core solder. Not a wire-nut in sight!


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## [email protected]

*K+T*

I wired houses in Ohio in early "60's". We drilled a million holes for tubes, it was very labor intensive. All splices were soldered and taped and a knob was required within 3" of a splice. You could tap off a conductor at any point as long as the tap had a knob within 3". We paralleled runs and each wire had a tube when going through a stud or joist. When going into a steel box, each conductor was in varnished cambric tubing called "loom". We used T and TW conductors supported on knobs every 4', when parallel with studs. It was a very safe system and the conductors, if overloaded, had a large space area to dissipate heat as in the wall insulation was slim to none. It was a good system for the "times". What eased it out of favor was high labor cost, as it was very laborious to install. Romex replaced it in the mid "60's" as it was much less labor intensive. The labor unions in Ohio cried and moaned and protested and even sabotaged rough in's that used Romex. A year or so went by and the unions grudgingly accepted Romex and things settled down. It was an interesting time to be in the trades.


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## MTW

[email protected] said:


> I wired houses in Ohio in early "60's". We drilled a million holes for tubes, it was very labor intensive. All splices were soldered and taped and a knob was required within 3" of a splice. You could tap off a conductor at any point as long as the tap had a knob within 3". We paralleled runs and each wire had a tube when going through a stud or joist. When going into a steel box, each conductor was in varnished cambric tubing called "loom". We used T and TW conductors supported on knobs every 4', when parallel with studs. It was a very safe system and the conductors, if overloaded, had a large space area to dissipate heat as in the wall insulation was slim to none. It was a good system for the "times". What eased it out of favor was high labor cost, as it was very laborious to install. Romex replaced it in the mid "60's" as it was much less labor intensive. The labor unions in Ohio cried and moaned and protested and even sabotaged rough in's that used Romex. A year or so went by and the unions grudgingly accepted Romex and things settled down. It was an interesting time to be in the trades.


K&T in the early 60's? :001_huh: I'd venture to say that many areas of the country had switched over to cloth romex long before that.


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## sbrn33

FrunkSlammer said:


> Knob and tube is pretty safe stuff.


This is an ignorant statement. 75 years ago it was fine. In this day with all the added loads and blown in insulation it is easily the biggest cause of electrical fires in this day and age if you take out portable heaters. 
This kind of attitude from someone who calls himself an electrician is really kinda sad. 
This does not even bring into account the issue of open conductors under 7 foot in basements.


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## chicken steve

[email protected] said:


> I wired houses in Ohio in early "60's". We drilled a million holes for tubes, it was very labor intensive. All splices were soldered and taped and a knob was required within 3" of a splice. You could tap off a conductor at any point as long as the tap had a knob within 3". We paralleled runs and each wire had a tube when going through a stud or joist. When going into a steel box, each conductor was in varnished cambric tubing called "loom". We used T and TW conductors supported on knobs every 4', when parallel with studs. It was a very safe system and the conductors, if overloaded, had a large space area to dissipate heat as in the wall insulation was slim to none. It was a good system for the "times". What eased it out of favor was high labor cost, as it was very laborious to install. Romex replaced it in the mid "60's" as it was much less labor intensive. The labor unions in Ohio cried and moaned and protested and even sabotaged rough in's that used Romex. A year or so went by and the unions grudgingly accepted Romex and things settled down. It was an interesting time to be in the trades.


Thanks for posting this cajuray & know that i'm just as interested in hearing from your era of wiring as i was as an apprentice 3 decades ago

Please, stick around

~CS~


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## MTW

sbrn33 said:


> This does not even bring into account the issue of open conductors under 7 foot in basements.


Which is a non-issue.


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## Bkessler

sbrn33 said:


> This is an ignorant statement. 75 years ago it was fine. In this day with all the added loads and blown in insulation it is easily the biggest cause of electrical fires in this day and age if you take out portable heaters. This kind of attitude from someone who calls himself an electrician is really kinda sad. This does not even bring into account the issue of open conductors under 7 foot in basements.


As long as it's fused properly what's the issue? If there is damaged wiring it should be replaced but I've seen some knob and tube that's in great condition.


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## chicken steve

As have I

yet the insurance cabal has apparently issued an APB on K&T ......~CS~


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## sbrn33

chicken steve said:


> As have I
> 
> yet the insurance cabal has apparently issued an APB on K&T ......~CS~


As they should. When was the last time you witnessed a K&T job that was fused properly and had no additions or insulation added since it was installed.
This is you boys trolling, next thing you will say is how good the pushmatics are.


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## FrunkSlammer

I've seen more mint condition K&T than bad K&T. I think it's because people don't understand it, so they can't screw with it as much as modern NM cables. 

People altering K&T, overloading it or stuffing insulation around it isn't the fault of K&T, it's the fault of the people. 

This is like a anti-gun thread.. K&T doesn't kill people, people kill people!


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## chicken steve

sbrn33 said:


> As they should. When was the last time you witnessed a K&T job that was fused properly and had no additions or insulation added since it was installed.
> This is you boys trolling, next thing you will say is how good the pushmatics are.


My stance is the level of craftsmanship in the K&T era can't be touched by our _'git~r~done'_ philosophy sbrn

They had bit & brace, as well as truck forges

they had to THINK about the circuitry layout, or it cost them labor _vs_. our almost effortless advantage of simply drilling another hole to pull NM thru

~CS~


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## retiredsparktech

MTW said:


> K&T in the early 60's? :001_huh: I'd venture to say that many areas of the country had switched over to cloth romex long before that.


I lived in and owned three old homes in the city of Milwaukee.
They were wired for electricity, sometime in the 1920's. They were wired with the old style BX. The only homes that were wired with K&T, were the homes that were wired for electricity, when originally built. Many of them had the watt hour meters and the branch circuit fuses in the attic.
Milwaukee County did not allow Romex wiring until 1972. Also, I don't remember seeing SE cable used either. :blink:


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## Next72969

sbrn33 said:


> As they should. When was the last time you witnessed a K&T job that was fused properly and had no additions or insulation added since it was installed. This is you boys trolling, next thing you will say is how good the pushmatics are.


 mother in law has pushmatics. Told her keep it


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## markore

chicken steve said:


> As have I
> 
> yet the insurance cabal has apparently issued an APB on K&T ......~CS~


Think the worst offenders to the scare rep are the tin knockers and sears furnace repairmen running around panning joists for air returns, tapping into the K&T and energizing all their cloth aluminum ducts right and left.


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## five.five-six

FrunkSlammer said:


> People altering K&T, overloading it or stuffing insulation around it isn't the fault of K&T, it's the fault of the people.


Common sense would dictate that we error on the side of caution and ban all K&T, its for the safety of the children. 




Sent from my iPad using Tapatalk


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## chicken steve

I can get it dealt with for $295

I'll even throw in a set of steak knives!

:jester:


~CS~


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## FrunkSlammer

five.five-six said:


> Common sense would dictate that we error on the side of caution and ban all K&T, its for the safety of the children.


Who's we? And why hasn't the NEC or CEC banned all K&T in the interest of child safety and erring on the side of caution? I'm guessing the evidence just isn't there.


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## TOOL_5150

Next72969 said:


> mother in law has pushmatics. Told her keep it


why? they do not have any magnetic trip mechanism, they tend to not operate correctly after being installed and not operated for many years, and sometimes fail to indicate if they are really off or on.

Unless you hate your MIL, then in that case, I understand. :brows:


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## hooch

HARRY304E said:


> Thanks for pointing out the lack of equipment grounding in a K&T wiring system.


knob&tub is safer then what we are installing today leave it ALONE. gfi's are cheeper


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## Going_Commando

I'll rip out BX long before I will properly installed K&T. When not messed with, properly tapped, and not in insulation the stuff is still a fantastic wiring method.

When I went to trade school 2007-2009 we were still taught how to tap K&T with Western Union and T-tap splices. Don't think I've picked up a soldering iron since though :laughing:


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## chicken steve

I've seen BX cause far more problems out there....

~CS~


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## dmxtothemax

What does your home isurance company say about K & T.

That I would check ?

K & T if in good condition and used within it's correct current capacity
is no more dangerous than romex.

If your worried fuse it, and or GFCI it, and then you dont need to worry.


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## Going_Commando

dmxtothemax said:


> What does your home isurance company say about K & T.
> 
> That I would check ?
> 
> K & T if in good condition and used within it's correct current capacity
> is no more dangerous than romex.
> 
> If your worried fuse it, and or GFCI it, and then you dont need to worry.


K&T in good condition, not in insulation is far superior to ungrounded romex. You can't get much safer as far as short circuits and heat dissipation than conductors 12" apart. 

As far as timeframe, my Grandfather started in the trade in 1940. By then BX was on the way out and cloth covered tar coated romex was in. K&T quit around here in 1925-1930, and BX was used in 1930-1940, primarily from what I've been able to gather. The transition from cloth/fiber sheath to thermoplastic was somewhere around 1965-1970. My father, who started working for my grandfather around the age of 12 (1969) never installed cloth/fiber sheathed romex. They also only installed fuse panels until Square-D came out with QO breakers. My grandfather had bought and bench tested, in his own fashion, the breakers that had come out before QO and wasn't satisfied with how long it took them to trip on overloads and short circuits. When he tested QO, he was satisfied, and we have been installing QO only up until 2 years ago, when we started installing Homeline as well. If it ain't broke...


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## chicken steve

dmxtothemax said:


> If your worried fuse it, and or GFCI it, and then you dont need to worry.


afci it

done deal !


right?


~CS~


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## HARRY304E

hooch said:


> knob&tub is safer then what we are installing today leave it ALONE. gfi's are cheeper


In our mass code amendments we can install two prong receptacles when there is no ground available....


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## Alcospark

I have removed and rewired a couple of K&T homes recently and I have to say I'm always fairly impressed with how clean it all looks. Those old guys had it down, it's always straight as an arrow and perfectly spaced. It would be a pain in the ass to have to wedge all those conductor tubes into every hole tho. Also, the power usually always runs to the fixtures and then down to the switches.


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## chicken steve

There was a lot of craftsmanship involved, that we can't take away from them

Even the old K&T fixtures were impressive , to the extent were we're often asked to save and rebuild them


~CS~


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## retiredsparktech

HARRY304E said:


> In our mass code amendments we can install two prong receptacles when there is no ground available....


 Those things, are like five times the price of the of low end Leviton 5-15 devices.
They still use the same internals as the grounding type, less the ground contacts. Only a slight change to the molding dies, to fill in the ground prong hole. :whistling2:


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## Big John

Yeah, I don't get the K&T hate. If you're gonna make me pick an old wiring method, be it K&T, BX, or cloth NM, I'm gonna take knob and tube any day of the week. 

Is it dangerous when screwed up? Sure, but that's true of every wiring system, especially old ones, so they all need to be inspected for safety.

That doesn't mean I think it's better than a new Romex install, but I would never just tell someone it must be ripped out just because.


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## Hmacanada

Big John said:


> Yeah, I don't get the K&T hate. If you're gonna make me pick an old wiring method, be it K&T, BX, or cloth NM, I'm gonna take knob and tube any day of the week.
> 
> Is it dangerous when screwed up? Sure, but that's true of every wiring system, especially old ones, so they all need to be inspected for safety.
> 
> That doesn't mean I think it's better than a new Romex install, but I would never just tell someone it must be ripped out just because.




Insurance companies here do just that big j .
All visible knob and tube has to be removed.
So you end up with a bunch of guys slamming j boxes all over the place.
Like that's supposed to be safer!


Sent from my iPhone using electriciantalk.com


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## chicken steve

We still have a NEC code article for K&T here, not sure why

how 'bout you CEC folks Hma...?



~CS~


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## BuzzKill

Rewire it! That freaking bx plus knob and tube s*cks balls. Fire trap city.


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## Nobaddaysinak

MDShunk said:


> Somebody posted it here years back. I can't, at the moment, remember any keywords in that thread that were unique enough that would let me dig it up without taking a ton of time. You might get lucky doing a google for knob and tube san francisco.


You might get more than your looking for with those search words!


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## MTW

Big John said:


> Yeah, I don't get the K&T hate. If you're gonna make me pick an old wiring method, be it K&T, BX, or cloth NM, I'm gonna take knob and tube any day of the week.
> 
> Is it dangerous when screwed up? Sure, but that's true of every wiring system, especially old ones, so they all need to be inspected for safety.
> 
> That doesn't mean I think it's better than a new Romex install, but I would never just tell someone it must be ripped out just because.


I'll take K&T over old BX any day of the week. Old unbonded BX is genuinely dangerous.


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## chicken steve

It's interesting that the majority of us think so, yet the insurance folks seem fixated on K&T.....

~CS~


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## Alcospark

It's not the original knob and tube that is the problem. Those old guys knew how to correctly solder and tape a splice. It's the splices that have been added on throughout the years with Romex by homeowners or hack handymen and are buried in walls or under attic insulation that cause fire. That's why it is condemned by the insurance company's.


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## jmellc

MDShunk said:


> I'd live in an unmolested K&T house well before I'd be interested in living in an old cloth-covered Romex house. That old cloth covered romex-type stuff is the dangerous stuff, in my opinion.


I have found BX generally the most deteriorated of all. I have seldom taken sheath from BX without insulation cracking and crumbling with the break. I have seen a lot of cloth Romex in good condition. I have seen a bit of old K/T in good condition despite its age.


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## jmellc

chicken steve said:


> It's interesting that the majority of us think so, yet the insurance folks seem fixated on K&T.....
> 
> ~CS~


I worked in insurance for a time and I think this is how they read things. 

An inspector once told me that officials blame house fires on wiring if they cannot find any other specific cause. Comforting to know isn't it? So, insurance companies keep stats on house fires and official causes. More old houses burn for various reasons but many get the default blame on wiring. Many have K/T, so the insurance co. sees K/T as the cause of a lot of fires.


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## te12co2w

Just put in arc-fault protection. All will be well.


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## EBFD6

jmellc said:


> I worked in insurance for a time and I think this is how they read things.
> 
> An inspector once told me that officials blame house fires on wiring if they cannot find any other specific cause. Comforting to know isn't it? So, insurance companies keep stats on house fires and official causes. More old houses burn for various reasons but many get the default blame on wiring. Many have K/T, so the insurance co. sees K/T as the cause of a lot of fires.


This absolutely is not true. The media many times make assumptions and spread misinformation about cause of a fire, often times speculating before the fire is even out, but fire investigators aren't "guessing" about cause and origin of fires. If the cause of a fire can't be determined it will be put in the report as undetermined. To suggest that fire officials are falsifying documents is insulting to say the least. Sorry, but this is a pet peeve of mine. I hear this nonsense from electricians all the time and it drives me crazy. Fire investigators are professionals. They do their best to determine cause and origin of every fire. Sometimes the damage is too significant and there are no eye witness accounts to go by so they have to classify the fire as undetermined. I have never seen or heard of an investigator guessing it must have been electrical because he can't figure it out. This is just electrician folk lore.


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## jmellc

te12co2w said:


> Just put in arc-fault protection. All will be well.


 
Ha, ha. Joke of the day. LOL:thumbup:


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## jmellc

EBFD6 said:


> This absolutely is not true. The media many times make assumptions and spread misinformation about cause of a fire, often times speculating before the fire is even out, but fire investigators aren't "guessing" about cause and origin of fires. If the cause of a fire can't be determined it will be put in the report as undetermined. To suggest that fire officials are falsifying documents is insulting to say the least. Sorry, but this is a pet peeve of mine. I hear this nonsense from electricians all the time and it drives me crazy. Fire investigators are professionals. They do their best to determine cause and origin of every fire. Sometimes the damage is too significant and there are no eye witness accounts to go by so they have to classify the fire as undetermined. I have never seen or heard of an investigator guessing it must have been electrical because he can't figure it out. This is just electrician folk lore.


Sorry, but I was told this by an electrical inspector who got it from a fire dept official. Just passing it along. This was in the 90's when it was told to me, so maybe things have changed some places since then. I don't say they falsify anything but have a default position if nothing else is found.


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## Big John

EBFD6 said:


> ...But fire investigators aren't "guessing" about cause and origin of fires. If the cause of a fire can't be determined it will be put in the report as undetermined....


 Fair enough. I'm still skeptical as hell about fire-investigation, but I'll admit I have no real facts to back that up, so I'll try to tone that opinion down.


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## chicken steve

EBFD6 said:


> This absolutely is not true. The media many times make assumptions and spread misinformation about cause of a fire, often times speculating before the fire is even out, but fire investigators aren't "guessing" about cause and origin of fires. If the cause of a fire can't be determined it will be put in the report as undetermined. To suggest that fire officials are falsifying documents is insulting to say the least. Sorry, but this is a pet peeve of mine. I hear this nonsense from electricians all the time and it drives me crazy. Fire investigators are professionals. They do their best to determine cause and origin of every fire. Sometimes the damage is too significant and there are no eye witness accounts to go by so they have to classify the fire as undetermined. I have never seen or heard of an investigator guessing it must have been electrical because he can't figure it out. This is just electrician folk lore.



Maybe big city FD's have the budgets for 'investigators' , or dedicated forensics , but most rural ones _do not_ EB

In fact, i'm informed less than 1/2 of federal level stat collecting here iirc sent out actually comes back

Of what does come back are a mosh posh of various forensic levels of expertise

And yeah, it's my pet peeve too, especially since i served on a dept that never lost a cellar hole, but always pointed blame at our trade

~CS~


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## chicken steve

jmellc said:


> I worked in insurance for a time and I think this is how they read things.
> 
> An inspector once told me that officials blame house fires on wiring if they cannot find any other specific cause. Comforting to know isn't it?


Not if you were a sparky on the FD jmellc...........

~CS~


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## LGLS

EBFD6 said:


> This absolutely is not true. The media many times make assumptions and spread misinformation about cause of a fire, often times speculating before the fire is even out, but fire investigators aren't "guessing" about cause and origin of fires. If the cause of a fire can't be determined it will be put in the report as undetermined. To suggest that fire officials are falsifying documents is insulting to say the least. Sorry, but this is a pet peeve of mine. I hear this nonsense from electricians all the time and it drives me crazy. Fire investigators are professionals. They do their best to determine cause and origin of every fire. Sometimes the damage is too significant and there are no eye witness accounts to go by so they have to classify the fire as undetermined. I have never seen or heard of an investigator guessing it must have been electrical because he can't figure it out. This is just electrician folk lore.


Maybe things are different in your neck of the woods, but around here, it seems EVERY fire cause is "solved" and more often than not, it is determined to be electrical. That seems to be the default when no other cause can be determined.


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## chicken steve

While they may be good intended, there is no statue demanding reportage to the NFIRS.

It is not even an _unfunded federal mandate _....

However, they became a _statistical focal point _for the creation of>>>>










~CS~


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## Hmacanada

I had regular customer call a couple yrs back to tell me he had lost an old barn on one of his farms to fire .
And the report said electrical was likely the cause , but the reason he called me was to check if I had cut the triplex down feeding it, like he asked me to a couple weeks prior.
And I had cut it off!
Same here though small community no big city budget to waste time on actual cause.
No one was hurt in the fire, so very little effort in looking for cause.
I've heard stories of crows or rats carrying cig butts and stuff into buildings and starting fires.
Really tough job to find cause with extensive damage to buildings!! 


Sent from my iPhone using electriciantalk.com


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## jmellc

Hmacanada said:


> I had regular customer call a couple yrs back to tell me he had lost an old barn on one of his farms to fire .
> And the report said electrical was likely the cause , but the reason he called me was to check if I had cut the triplex down feeding it, like he asked me to a couple weeks prior.
> And I had cut it off!
> Same here though small community no big city budget to waste time on actual cause.
> No one was hurt in the fire, so very little effort in looking for cause.
> I've heard stories of crows or rats carrying cig butts and stuff into buildings and starting fires.
> Really tough job to find cause with extensive damage to buildings!!
> 
> 
> Sent from my iPhone using electriciantalk.com


Wow, this is an eye opener. Wonder what EBFD6 will have to say now?


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## robnj772

We just had an electrical fire here last weekend, burnt the house to the ground.

I had a temp power pole on the job, house was to be torn down.

The newspaper said it was an electrical fire, fire department said it was electric. The country fire marshal even determined it was an electrical fire.

Funny thing about it is, the electric was removed from the house about three months ago, and my temp hadn't been energized yet.


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## jmellc

robnj772 said:


> We just had an electrical fire here last weekend, burnt the house to the ground.
> 
> I had a temp power pole on the job, house was to be torn down.
> 
> The newspaper said it was an electrical fire, fire department said it was electric. The country fire marshal even determined it was an electrical fire.
> 
> Funny thing about it is, the electric was removed from the house about three months ago, and my temp hadn't been energized yet.


I'm loving this!:laughing:


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## EBFD6

jmellc said:


> Wow, this is an eye opener. Wonder what EBFD6 will have to say now?


What do I have to say? 

Mistakes happen. Just like in any industry there will be people who are not good at their job. There are hacks in every industry. As far as the anecdotal stories, I have found in my experience that there is usually more to the story than what is told. These stories generally have some facts left out, some embellishments, and some flat out fabrication. 

My point is this, while there may be a handful of fires that are erroneously attributed to electrical causes, that is the exception and not the rule. Electricity does cause fires. It's not the FD picking on electricians. Electrical malfunctions are the number 3 cause of fires with approx. 25,000 nation wide. Cooking is #1 with approx 160,000, heating equipment is #2 with approx 35,000.

To hear electricians talk you would think that every fire where they don't find a can of gasoline and a match just automatically gets blamed on electrical. That's far from true.


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## LGLS

I have a sneaking suspicion that static electricity, lightning, and spontaneous combustion cause a lot more fires than are attributed. I can pretty much guess what happens when the remains of a burned down home are sifted through and a multitude of extension cords are found, that electrical will be determined the cause simply because nobody around witnessed or could hear the small lightning bolt that appeared out of nowhere from slightly overcast skies. 

Much in the same way some building inspectors don't like the idea of leaving a site without issuing a violation, and police don't like to see the unsolved crime statistic get higher, fire investigators don't like the idea of coming back to the office with too many "undetermined" results on their reports either. Further, whether the report comes back accurate or not, what's the harm in their lying? Whether caused by electrical, spontaneous combustion, cat knocked over kerosene lamp, or lightning strike, the insurance company is still going to pay right? So no harm, no foul...


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## macmikeman

Don't forget to add rodents to this picture. They do the damage , fire burns the evidence. Blame goes to the wiring. Corrosion is another factor in fires. When was the last time you saw a fire report that said the house burned down due to corrosion? But that is the culprit in lots of receptacle outlet connections going glow.


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## jmellc

EBFD6 said:


> What do I have to say?
> 
> Mistakes happen. Just like in any industry there will be people who are not good at their job. There are hacks in every industry. As far as the anecdotal stories, I have found in my experience that there is usually more to the story than what is told. These stories generally have some facts left out, some embellishments, and some flat out fabrication.
> 
> My point is this, while there may be a handful of fires that are erroneously attributed to electrical causes, that is the exception and not the rule. Electricity does cause fires. It's not the FD picking on electricians. Electrical malfunctions are the number 3 cause of fires with approx. 25,000 nation wide. Cooking is #1 with approx 160,000, heating equipment is #2 with approx 35,000.
> 
> To hear electricians talk you would think that every fire where they don't find a can of gasoline and a match just automatically gets blamed on electrical. That's far from true.


 
Ah, but your 1st post said false determinations are "absolutely not true". How the song changes as we go along......


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## EBFD6

jmellc said:


> Ah, but your 1st post said false determinations are "absolutely not true". How the song changes as we go along......


I stand by my original statement. No "song has changed".

This statement is not true:


jmellc said:


> An inspector once told me that officials blame house fires on wiring if they cannot find any other specific cause.


Mistakes can be made in an investigation, assumptions might be made due to incomplete evidence, but investigators are not falsifying documents as your initial quote suggests. Are there a few "bad apples" out there as far as investigators go? It's possible. But to paint everyone in the profession as just blaming electrical for fires on a whim is blatantly false. There are a lot of hack electricians out there. Does that mean that every electrician is a hack?


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## LGLS

macmikeman said:


> Don't forget to add rodents to this picture. They do the damage , fire burns the evidence. Blame goes to the wiring. Corrosion is another factor in fires. When was the last time you saw a fire report that said the house burned down due to corrosion? But that is the culprit in lots of receptacle outlet connections going glow.


Exactly. Let's understand that after a total loss, the structure doesn't undergo a forensic autopsy, unless a human being died and arson is suspected. The fire itself destroys the evidence of it's cause. I'm not saying the absolute cause of a fire is never obtainable. I just doubt the accuracy of the success rates and therefore the statistics. 

It would be interesting to see how many fires in the future are determined electrical despite the presence of AFCI protection...


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## jmellc

I still think what the inspector told me was legit. He was an inspector in our city/county for many years and was told this by a fire official in our city. He had no reason to lie.


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## jmellc

IslandGuy said:


> Exactly. Let's understand that after a total loss, the structure doesn't undergo a forensic autopsy, unless a human being died and arson is suspected. The fire itself destroys the evidence of it's cause. I'm not saying the absolute cause of a fire is never obtainable. I just doubt the accuracy of the success rates and therefore the statistics.
> 
> It would be interesting to see how many fires in the future are determined electrical despite the presence of AFCI protection...


For sure. I recall the news video of an Indiana fire marshall stating that AFCI breakers would have prevented an electrical fire started by an arcing receptacle. He said Indiana should require AFCI's like all other states. Mega BS on that. I have replaced a number of burned devices that did not trip an AFCI breaker.


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## chicken steve

Well maybe we should install those afci main breakers then......~CS~


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## chicken steve

Or a big fat afci @ the substation....yeah,_ that's it!_.....the substation! :laughing: ~CS~


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## jmellc

chicken steve said:


> Or a big fat afci @ the substation....yeah,_ that's it!_.....the substation! :laughing: ~CS~


No, let's do AFCI at the main plant, right at the generators. And any power at hydroelectric dams gets GFCI and AFCI at the generators.


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## chicken steve

Well all jocularity aside :lol: i'd like to state that what i've posted is not a kick in the teeth to the FD _(please listen EBFD6) _ 

This is NOT a hard science, and what science exists is being used for the gain of sorts who could care less_ who _burns, or who _runs_ into those buildings that _do_ burn

Hard to get one's head_ around _that, i know....


~CS~


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## LGLS

I don't think AFCI or GFCI protection can protect anything past a transformer that creates a SDS.


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## Aldo Moretti

headrec said:


> I just had a friend who bought a house that has knob and tube wiring in the majority of the house. She wanted me to come look at it and give my opinion. I took a look but I honestly know almost nothing about it. Just did a little google search and before today had only seen pictures of it and heard horror stories from coworkers.
> 
> Just wondering if you guys can give me a run down on it. She's looking to replacing all the wiring because she's worried about the potential fire hazard. Wondering if that is really necessary or if there is anything I should help advise her on. Thanks guys! :thumbup:


I have worked in many old houses that have knob and tube.
I am usually asked if I think that it is safe and legal, should it be replaced or left alone.
I always say that (after looking at the workmanship) it should be left alone, and the cost to replace it all would be astronomical for my work and also the lath and plaster contractors (there are very few of these contractors left) , and many of the older houses have lath and plaster, then we have the asbestos problem too.
The problem is with the insurance companies, many will not underwrite policies on a house that has knob and tube. And, many people that own houses that have knob and tube are older people, often living on a limited fixed income and paid originally $20,000 for their old victorian in S.F. 70 years ago and the house is now worth $2 million on today's market. These people simply don't have the money to upgrade their electrical system, so their insurance company cancels them, but it's not the end of the world.
Some of the problems with knob and tube that I have found is that most often they share the neutral with the black and red phases. And all the wires used are black (for the most part), sometimes the installer dabbed white paint on the insulation of the neutral in the panel.
We all know that it is dangerous (and illegal) to share a neutral with two legs of the same phase, or to share a neutral with more that 2 circuits in a 240 volt single phase system.
From what I have seen, the original installers were careful and did it right, but often a neutral runs wild all over the place and if someone came in and "just grabbed" a neutral at a later date because they were lazy and didn't know what they were doing, it could overload the neutral (which is un-fused).
When replacing panels that have knob and tube, a careful examination is necessary and all the wires must be phase color coded BEFORE un-hooking them, and in San Francisco (they have their own unique electrical code) all wires must be phase coded, even if it is all 12/2 romex. I don't know why they want romex coded, because all romex has a neutral, but I think it is a throwback from the past.
Knob and tube will last forever if it has not been disturbed, and it is still legal and safe, but of course, any new work shall be upgraded.
As far as I know, just because there is no ground, doesn't mean that a person must run a ground to every existing location, only when doing new work. And, I was told by an inspector that if there is no ground in a bathroom or kitchen (near water) that just installing a GFI will satisfy the grounding requirement. This was a few years ago when the inspector told me this, and I don't know if it is exactly true today.


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## The_Modifier

Just curious, do you have to remove the old K&T down south? Up here as long as we remove enough of the conductors to not re attach to the panel, we are good to go. Usually we cut them flush with the overhead flooring so there's no chance to remotely reuse them. After that it's just straight fishing and using the baseboard to avoid damaging the existing lathe and plaster.

With the old strapping being a true 3/4" its tricky but adding devices isn't all that hard once you have your feeders to the devices imho. I takes longer and costs more, but with the money they save on not having to hire a dumbwaller or painter, the majority of clients are more than happy to hire us.


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## Sparky62

Big John said:


> Fair enough. I'm still skeptical as hell about fire-investigation, but I'll admit I have no real facts to back that up, so I'll try to tone that opinion down.


Watch a few episodes of Forensic Files on HLN. They have covered more than a few cases of sloppy fire investigations.


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## Kevin

Sparky62 said:


> Watch a few episodes of Forensic Files on HLN. They have covered more than a few cases of sloppy fire investigations.


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