Older house wiring puzzle

Whatever the condition from the OP, that is not a reflection on K&T in general, as you want to claim.

Still missing - evidence that K&T is an intrinsic hazard. Or that it is more of a problem than, for example, early 2 wire Romex.

obviously anything thats been around this long is obsolete, lacks new safety upgrades, and is great risk of hack repairs over its life.

have you called statre farm to confirm they wouldnt write new policies for K&T homes?

As in 'early' 1950s installations of domestic electricity here! Meter in the halfway, 115 volt two wire service, no ground, two cartridge fuses probably 20 or 30 amps fuses, one in the neutral and one in the live, one ceiling light (with a pull cord) in the kitchen with everything, small radio, fridge, and when required an electric iron (replacing the ones you used to heat on top of the stove) plugged into it with extension cords. Quite often a water pump under the sink, unless one still 'dipped' water from the well outside. Later on maybe a single outlet for the big wooden TV set (only one channel until

"Home Run" K&T wiring was not that uncommon way back when. Called "common buss" also I think, generally more often used with low voltage DC "farm power" setups (delco plant, Winco etc). where fusing was generally NOT in a common distribution panel The Positive "buss" was a heavy wire, bar, or pipe down one side of a house, and the negative down the other side. Circuits were strung across the building. If someone was familiar with that kind of wiring and then wired a house to a main panel, it could get very interesting - not to mention a REAL BUGGER to sort out!!!!

So are you too lazy or too stupid to edit out this garbage?

"Obviously" is not proof. Obviously missing - evidence that K&T is an intrinsic hazard. I don't believe electricians in this newsgroup agree with you.

What evidence is there *hack* repairs are common on K&T? I don't remember ever seeing any.

Is *hack" wiring more common than with other wiring methods?

Your opinion doesn't count. Where is a source? Never anything but opinion and anecdotes.

In the link supplied previously an insurance company did not provide evidence when challenged. Insurance companies employ lots of actuaries to determine risk. I see no reason to believe insurance companies have determined such a risk.

Have you read that in Minnesota State Farm (probably) had a surcharge on older services and the state insurance regulator ordered the surcharge dropped.

Because an insurance company does something does not necessarily mean there is a rational basis. Where is your evidence?

I see no reason to believe State Farm is not redlining.

would yopu be happy to pay say 100 bucks more a month for homeowners insurance so homes with K&T and other obsolete systems can have insurance?

are YOU stating the CURRENT NEC regulations havent made new installs safer?

K&T requires good soldering skills. thats not common today, worse connections arent in boxes so a failing joint that overheats can easily cause a fire.........

Still too lazy/stupid.

That begs the question of whether K&T is significantly more hazardous than other wiring. You have still not provided a reliable source that says it is. The only relevant link in this thread is that an insurance company, which employs actuaries to get casualty information, did not show K&T was a hazard when challenged.

Where is your evidence. All you provide is FUD.

Also begs the question of whether existing K&T is significantly more hazardous.

I have read that K&T has been 'recently' used in areas subject to flooding because it dries out faster. K&T is allowed to be used by "special permission".

ght it)

you ignored my questions and failed to respond to the specific issue.

would you pay more for homeowners insurance so people with K&T could get insurance

please supply a link to the info of K&T being used today. does it have a ground conductor? GFCI? arc fault breaker? boxes for connections?

Still too lazy/stupid.

You continue your compulsive FUD.

The links to state agencies that have been provided say:

- an insurance company did not provide any justification for not insuring a house with K&T

- an Illinois investigation of insulation around K&T found no record of hazard - apparently you think they ignored the intrinsic hazard of the K&T???

You have provided no reliable evidence that K&T is hazardous.

It is a red herring. Where is the casualty information that K&T is more hazardous. Maybe you could call your buddies at State Farm and get it.

All I have read is that it was used 'recently'.

when anyone wit K&T decides to sell their home would they please report back here with what happens?

I asked a realtor about this question yesterday, they had sold my oms house, I bumped into them at the grocery store.

they said its not very common here anymore, at least partially because you cant get homeowners insurance. at home resale time house must be rewired to current code, or no insurance no sale.

he did report one derelict home sold, the buyer paid cash for a home under 20 grand. he said the new owner had a home fire, not caused by wiring and lost his entire life savings. owner was attempting to heat house in winter totally by fireplace, chimney failed.

everyone should have homeowners insurance

my moms house

There is no possibility houses have to be rewired to the 2008NEC. AFCIs on most circuits? Kid-proof receptacles in most locations? Receptacles at current spacing requirements? Ufer earthing electrode required? Boxes have light fixture or fan rating? All wiring has a ground? All grounded receptacles? Eliminate almost all of the GFCI exceptions? Replace old stove/dryer circuits that have a neutral but no ground? Garages must have a ground wire in the feeder? Everything meets the UL standards in effect now?

Either you misunderstood the agent or he is as wacked-out as you are.

K&T is code compliant.

Still missing - a reliable source that says K&T is hazardous.

if you cant get homeowners insurance then a major upgrade of wiring is necessary. once its a major upgrade and not just a repair curerent codes must be met...........

as they must with other safety issues.

Any wiring that is in poor repair is hazardous and this is usually the case with K&T.

The idea that you cant get insurance unless the house meets "current code" is more wacko than your comments on K&T. What insurance company requires all the features above?

As I have said several times, Minnesota required State Farm (probably) to drop a surcharge for older services. Insurance companies, at least in some states, are not allowed to do whatever they want.

If wiring is upgraded, only the parts of the system that are modified must meet "current code", just like a "repair".

Existing K&T can be picked up in a rewire - it is allowed by the code. The NEC does not require replacement of K&T. So in your "major upgrade" K&T can remain.

Still missing - a reliable source that says K&T is hazardous.

In many years of doing trouble calls I have not seen that. It certainly was not "usually the case".

The 2 sources in this thread, from state agencies, do not indicate a particular problem with K&T.

Where is a reliable source that says K&T is hazardous.

how many links do you want posted?

heres one, i can flood the board if you like.

sadly bud is living in dreamland, where stuff thats 100 years old is just fine

Knob and Tube Wiring William Kibbel III, The Home Inspector Handy homeowners, critters, and time are enemies of this vintage wiring system

Dear Home Inspector: Our home inspector recommended replacing the knob and tube wiring in our home. But my father-in-law says there's nothing wrong with leaving it alone. What is your opinion of this type of wiring?

When installed correctly knob and tube wiring was, in some ways, superior to current wiring practices.

Unfortunately, this system is rarely intact after 80 or so years of use. Things that happen well after the original installation can cause major problems. For this reason, I agree with your inspector.

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Time, heat, and possibly hungry critters have caused the insulation on this wiring to disintegrate.

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Before I explain the problems, let's examine this old type of wiring. Fairly common in houses built before 1930, the system uses porcelain insulators (knobs) for running wires through unobstructed spaces. Porcelain tubes protect wires that run through studs and joists.

Some of the safety features of the system are:

The porcelain knobs suspend the wire in open air to dissipate heat. The wiring was usually installed along the center of joists and studs away from potential nail punctures. Additional protection is provided by porcelain tubes where it passes through wood. The hot and neutral wires are always separated by at least 3 inches except near a connection to a box or fixture. At these places, an additional protective woven sleeve, or was used from the last knob. Splices were joined by wrapping one wire around another and then soldering the joint. Knobs were then placed within 6 inches of the splices to prevent stress on the connection. Wires were usually never loose or placed on top of joists where they could be easily damaged. The two main weaknesses of this vintage wiring are:

The lack of a ground conductor, and Switches were often placed on the neutral wire, turning off the circuit, but not the current. Improper alterations

Improper alterations are the most consistent problem I find with knob and tube wiring, and they pose a significant safety hazard. Unfortunately from a safety standpoint, the electrical system is one of the few things in a home that can be installed completely wrong and still

Additional branches improperly added to the original wiring is one of the common problems I see. When additional branches or fixtures are added, the fuses protecting the old circuits are likely to blow frequently. Installing larger fuses is an easy, but unsafe, solution. Oversized fuses allow much more current to flow than originally intended, resulting in additional heat in the conductors. This heat causes the insulation protecting the wire to become brittle, and eventually to disintegrate.

Heat and critters

Heat directly above ceiling lights and in un-vented attics can also degrade the wire insulation. Some types of insulation used on knob and tube wiring seem to be a delicacy for the critters that find their way into old homes. They can make short work of the insulation covering the wires.

Thermal insulation problems

Faced with drafty houses and high heating bills, homeowners often add thermal insulation to their attics and walls. Insulation on top of knob and tube wiring is a major fire hazard.

Remember the first good point of knob and tube wiring? The wire suspended in open air allows heat to dissipate. Loose and rolled insulation counteracts the original open air installation of knob and tube wiring.

In 1987, the National Electric Code prohibited the placement of insulation in contact with this type wiring. Later, a couple of west coast states permitted insulation provided the wiring was "certified" by a licensed electrician, foil or paper backed batt insulation was not used and warning signs were placed where the old wiring is concealed by the insulation.

Finally, there seems to be a growing concern about this old wiring from the homeowners insurance companies. I have found one that will not write a policy if there is more than a certain percentage of knob and tube wiring still in use and several will not offer coverage unless it is all replaced.

I would like to agree with your father in law, but my experience has been that previous owners, excessive heat and even critters didn=92t know to "leave it alone".

About the Author William Kibbel III is a home inspector and restoration consultant specializing in historic residential and commercial buildings. He is vice president of Tri-County Inspection Company, serving Southeastern Pennsylvania and Central New Jersey.

Bill welcomes questions for future columns. You may contact him at snipped-for-privacy@oldhouseweb.com