K & t...

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jxofaltrds

Inspector Mike®
Location
Mike P. Columbus Ohio
Occupation
ESI, PI, RBO
I am confused.

394.10(1) say that you can add extentions. 394.2 (handbook) sends you to 398.12. 398.12 says you can not conceal.
So how would you add to K&T?
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
I am confused.

394.10(1) say that you can add extentions. 394.2 (handbook) sends you to 398.12. 398.12 says you can not conceal.
So how would you add to K&T?
Actually, 394.2 Handbook explanatory text just says that K&T is different than Open Wiring on Insulators (398)
Open wiring on insulators (Article 398) is required to be exposed, whereas knob-and-tube wiring is allowed to be concealed. Conductors used for knob-and-tube work may be of any general-use type specified by Article 310.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
So how would you add to K&T?
The real issue, IMO, is whether the existing branch circuit is overloaded, or not. If the connected load is light enough, then one can splice in another wiring method for the extension.

In my area, there is a history of local ordinance that applies pressure to improve existing Premises Wiring (System)s by saying that any dwelling with a 30 Amp service has branch circuits that are, by definition, overloaded and no extensions are permitted until a service upgrade occurs. After the service upgrade is in place, then a 15 Amp branch circuit is permitted to supply no more than 600 square feet of floor space.
 

e57

Senior Member
Conductors used for knob-and-tube work may be of any general-use type specified by Article 310.
Including THHN with "approved splicing devices", or if so inclined and skilled - a "mechanically and electrically secure" splicing method and solder as laid out in 110.14(B) - Truthfully I trust it more than a Wago on MWBC neutral in a box...
 

mivey

Senior Member
And Saddam Hussein had weapons of mass destruction we still have yet to find.... Hype...
WMD is not limited to nuclear weapons, as it includes any weapon that can kill large numbers of people or cause mass destruction of man-made objects or damage large chunks of nature. WMDs are nuclear, chemical, biological, etc. and I would even consider the MOAB to be a WMD.

Iraq possessed and used WMDs and were acquiring more. This is historical fact. Whether or not that had nuclear WMDs is another matter, but they were definitely trying to acquire them at the least. This is also historic fact.

Don't water down your argument with examples not based on fact as it can make your point look weak.

That said, I agree with most of the rest of your post and that there is a lot of hype about k&t as well as other things like aluminum wire.

add: I re-read your post and am noting that it could be read a different way. If you were saying that the hype was stating that there were no WMDs, I am retracting the noodle-whipping portion of my post.
 

mivey

Senior Member
That's weird. I edited my post to add and it created a separate one.

Add: thanks iwire.
 

MarkyMarkNC

Senior Member
Location
Raleigh NC
Here we go again - semantics... Telling someone there home will burn down simply because there is K&T in it - is a lie...

Which does not make you a liar - just misinformed - because you believe that to be true... The day you come to your senses, and still say it - then and only then will you be a liar... ;)

Since most of the housing stock build prior to the 40's was wired in it - if wired, and wired with it when it was - and they all did not burn down makes the standard you set the last thread on the topic - wrong... And willingly or not - telling someone that their home will burn to the ground because of the presence of K&T is an act of fraud. Which also does not make you a fraud...

There are also people out there that tell customers their home is in danger just due to the fact that they have fuses, or FPE panels. Then again - the Ford Pinto was on the road for a long time before it was doomed to hysteria... And Saddam Hussein had weapons of mass destruction we still have yet to find.... Hype...

My point is you need to be objective - a building with any energized wire is an electrical fire hazard... Even one with all of the wiring in MI cable. To what degree? Truthfully I feel homes with ungrounded AC cable, and early cloth versions of NM cable would be more of a hazard than K&T.

Over a long enough timeline, telling someone their house will burn to the ground because it has K&T in it is not necessarily a lie.

K&T is past its useful lifetime. It is a MUCH greater hazard than PVC sheathed romex. Rip it out and throw it in a museum with the buggy whips and rotary phones.
 
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mivey

Senior Member
Over a long enough timeline, telling someone their house will burn to the ground because it has K&T in it is not necessarily a lie.
Well then, I guess you just made up that statistic on the spot because it is not true (Referencing your sig: "62.584361% of all statistics are made up on the spot")

It will not positively burn down because it has K&T. It might burn down because of poor maintenance, modifications, etc. If you think about it, the insulation could rot and fall off of just about all of the K&T and, because of the wire separation, no fault would occur. The same is not true for other wiring methods.

You don't see the power lines outside burning down because they are on insulators do you? Is there a big safety push to insulate and bundle the power lines into one big "safe" cable"?
 

growler

Senior Member
Location
Atlanta,GA
Here we go again - semantics... Telling someone there home will burn down simply because there is K&T in it - is a lie...


Telling someone that their house will burn because of K&T is a lie. Telling someone that a wood heating system in their house will burn it down is a lie ( many homes were heated with wood and coal for years).

Now telling someone that K&T or a wood or coal furnace is considered a hazard is not a lie because it is considered a hazard by many to include the insurance industry.

If you want to you can say that K&T is as safe as any other wiring method in your personal opinion, that's OK, but there is no industry wide consensus to back that up so it's still just a personal opinion.

I still haven't seen a house wired in K&T that I would be willing to tell the owners that it's perfectly safe. Every house that I have ever rewired I have found some bad wiring, some of it was in walls and ceiling where it couldn't be seen during an inspection.

The real problem with K&T is not that it was a bad wiring method in it's original condition. But many homes here were wired 70-80 years ago when there was little demand for electrical outlets. In those 70-80 years the demand has grown and the system has been altered to meet the demand and often altered with little concern for safety. Sure you could put the system back to original condition but in my opinion that's a waste of time and money because it is just more cost effective to use modern wiring methods. Puting K&T back to it's original condition will not really increase the value of the house but bringing it up to code will. People will pay for a house with original woodwork or stonework but they really are not interested in 80 year old plumbing or electrical.

If a person can not afford new tires for their car they can drive around with much of the tread missing and that is their choice but it's still not as safe as new tires and they just have to understand the chances that they are taking. You can't tell someone with bald tires that they will wreck and kill themselves but you can tell them they are at greater risk.
 

MarkyMarkNC

Senior Member
Location
Raleigh NC
If you look at a home insurance or rental insurance form, the insurance companies are generally only concerned about three things when they insure your home - K&T, aluminum wiring, and fuse panels. I'm assuming they have statistics that back up their concerns.

They are probably part of the 37.415639% that are NOT made up:grin:
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
If you look at a home insurance or rental insurance form, the insurance companies are generally only concerned about three things when they insure your home - K&T, aluminum wiring, and fuse panels. I'm assuming they have statistics that back up their concerns.
Your experience with reports of insurance salespeople's concerns, and even actual direct experience with specific cases where you have first hand knowledge from the insurance company representatives, doesn't mean ALL insurance companies have the same concerns.

I work in an area of 3.5 million souls with a core of houses built prior to 1940. Many, many thousands of houses. I mention "1940" because local ordinances, in several of the inner ring jurisdictions, were added to require an "all-metal" wiring method be used for any new wiring within their jurisdiction. Kinda like parts of inner city Chicago, or some other jurisdictions. All existing K&T was still blessed by ordinance, however.

Most of that K&T is STILL in service today, on the core (original) few circuits, with exception for such dwellings that have had extensive remodeling done.

Virtually all of these dwellings are insured.

Some of the finest dwellings in the State still have K&T in service in them. . . .

What a particular insurance company does with respect to specific policies they offer to "protect" their customers just doesn't have anything to do with any one specific piece of K&T and the state of the insulation on it.

Apples and Oranges, IMO.
 
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LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
If you want to you can say that K&T is as safe as any other wiring method in your personal opinion, that's OK, but there is no industry wide consensus to back that up so it's still just a personal opinion.
As is the opposing point of view.

Every house that I have ever rewired I have found some bad wiring, some of it was in walls and ceiling where it couldn't be seen during an inspection.
Is the same true for every BX or NM-wired house you've rewired?

The real problem with K&T is not that it was a bad wiring method in it's original condition. . . . the system has been altered to meet the demand and often altered with little concern for safety.
Again, the same can be said for other wiring methods, like BX, NM, and even conduit.


Plus, in many ways, fuses are safer than breakers.
 

Power Tech

Senior Member
Here we go again - semantics... Telling someone there home will burn down simply because there is K&T in it - is a lie...

Which does not make you a liar - just misinformed - because you believe that to be true... The day you come to your senses, and still say it - then and only then will you be a liar... ;)

Since most of the housing stock build prior to the 40's was wired in it - if wired, and wired with it when it was - and they all did not burn down makes the standard you set the last thread on the topic - wrong... And willingly or not - telling someone that their home will burn to the ground because of the presence of K&T is an act of fraud. Which also does not make you a fraud...

There are also people out there that tell customers their home is in danger just due to the fact that they have fuses, or FPE panels. Then again - the Ford Pinto was on the road for a long time before it was doomed to hysteria... And Saddam Hussein had weapons of mass destruction we still have yet to find.... Hype...

My point is you need to be objective - a building with any energized wire is an electrical fire hazard... Even one with all of the wiring in MI cable. To what degree? Truthfully I feel homes with ungrounded AC cable, and early cloth versions of NM cable would be more of a hazard than K&T.

Here we go with the story telling which I am the bad guy and you are the shining knight hero. Go figure it would turn out that way.

You should get a job writing soap operas.

Here let me make up a story ---- If the house burns down tomorrow and kills somebody ------- you are a fool and a murderer.

It is obvious your knowledge prevents you from seeing clearly.
 

MarkyMarkNC

Senior Member
Location
Raleigh NC
I have no doubt that most K&T houses are being insured. I could probably have a house with K&T hooked up to a fuse panel, with a Federal Pacific sub-panel, utilizing aluminum romex, all wired by an unlicensed hack, and still get home insurance. I would also be paying an arm and a leg for it though.

I used to be of the opinion, like many others here, that as long as you do not disturb K&T, it should be fine. That line of reasoning is usually derived from having seen plenty of K&T installs in good condition, or just having been told that by old-timers, and accepting it as fact. I used to be that way too. Then I saw a house that HAD burned down from a K&T fire that started when home owners piled a bunch of stuff on top of it up in an attic.

Then I read this report about aging residential wiring issues

http://esfi.org/files/u1/AheeAgingResidentialWiringIssues5-05.pdf

And this study done by the NFPA and UL

http://www.nfpa.org/assets/files//PDF/Research/RESAReport.pdf

Then I did some research on the home insurance policies that I alluded to earlier. I have since changed my opinion on K&T.

If asked my opinion by a homeowner, I will tell them every time that they should replace every bit of K&T that is practical to do so. I don't ever scare them into thinking their house is definitely going to burn down, but I print these reports out and let them make their own decision. Knob and tube wiring lowers the value of your home. It is a hazard. It costs you more to insure your home. To me, replacing it is a no-brainer.
 

Power Tech

Senior Member
As is the opposing point of view.

Is the same true for every BX or NM-wired house you've rewired?

Again, the same can be said for other wiring methods, like BX, NM, and even conduit.


Plus, in many ways, fuses are safer than breakers.

I watched a demonstration with fuses vs. circuit breakers. Fuses almost instantly break the load. If we could only reset them.
 

iMuse97

Senior Member
Location
Chicagoland
I watched a demonstration with fuses vs. circuit breakers. Fuses almost instantly break the load. If we could only reset them.

You can. Find the fault or overload. Fix it. Replace the $3-6.00 fuse. Lasts a long time if nothing goes wrong, and then you want it to blow. :)
Lived all my childhood in a fused house (I suppose the K & T had been removed in the 1950's, but they didn't bother replacing the fuse box.)
 

Power Tech

Senior Member
Pulled some wire out of a commercial service I was upgrading. The wire was 3/0. When we pulled it out it was real stiff. I stripped 3' and it was discolored dark red blue.

My point. Electricity flowing through wire changes the molecular structure.

I don't know how it changes it but I am pretty sure it isn't better.

I don't know if copper purity was better back then or not.

I am not a metallurgist and cannot prove this.
 
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