Is Knob-and-Tube *Always* Dangerous?

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I'm sure this question has been posted and answered a thousand times here, but a family member who routinely asks me to walk-through homes she is interested in buying (because, as a walking Typhoid Mary of Money Pits, I have hard-earned knowledge) has asked me to jump on a particularly desirable (location, location, location) multi-unit this AM.
One half of this duplex has knob-and-tube.
I have read conflicting estimates of the integrity and safety of knob-and-tube on this group and other web sites. But I'm scheduled to go through the home in two hours and thought I'd post and maybe get some fresh insights.
>From the street, and as far as the exterior foundation goes, this home is an absolute steal (new roof, great landscaping, has it all). My family member needs a place to run to as the result of a divorce and won't be able to take on both the mortgage and a complete rewire at the time of sale; hence, my post.
Thank you as always for your responses.
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knob and tube is ungrounded, as was lots of Romex installed in the 50's and 60's . In some places its unprotected and subject to mechanical damage. The stuff is OLD, but in my experience, most of the K&T I've seen, has been in excellent condition, unlike rubber covered conductors of BX cables from the 40's and 50's, which breaks down and crumbles from heat. I would ultimately replace it, but I wouldn't feel in any hurry to do it yesterday
> I'm sure this question has been posted and answered a thousand times > here, but a family member who routinely asks me to walk-through homes > she is interested in buying (because, as a walking Typhoid Mary of > Money Pits, I have hard-earned knowledge) has asked me to jump on a > particularly desirable (location, location, location) multi-unit this > AM. > > One half of this duplex has knob-and-tube. > > I have read conflicting estimates of the integrity and safety of > knob-and-tube on this group and other web sites. But I'm scheduled to > go through the home in two hours and thought I'd post and maybe get > some fresh insights. > >>From the street, and as far as the exterior foundation goes, this home > is an absolute steal (new roof, great landscaping, has it all). My > family member needs a place to run to as the result of a divorce and > won't be able to take on both the mortgage and a complete rewire at the > time of sale; hence, my post. > > Thank you as always for your responses. >
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probably CANT get homeowners or a mortage with K&T most insurance wouldnt cover it as a fire hazard.
connections are soldered in the wall, without a box surrounding it. unlike today all coinnections are in boxes.
after many years and heavy loads the solder weakens and the connection can overheat and cause a fire, that happened to a buddy of mine fortunately in his open basement cieling he smelled smoke and put it out.
in a closed wall the house will go up in smoke.
have friends whos homeowners inspected their home and REQUIRED rewiring for just this reason.
deduct cost of rewire from home sale price and for futher savings get a home inspector they arent perfect but every trouble they find is money in your pocket.
call your insurance agent and ask about K&T and please report back here what they tell you...
K&T would be safe IF the connections had been made in BOXES but back then no one thought of it
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I'm working on a clients house that has K&T. It's a very large house and the entire 2nd floor and part of the first is K&T and on one breaker! These people were running an ac unit and 3 TVs plus all the lights. The problem with replacing this stuff is that all the connections are buried and hard to find. I've had to make large inspection holes to make sure I've pulled out all of the connections. I've also had a neighbor not quite completely close a hot water radiator bleed vent. The dripping water from the second floor ran down a major junction of mineral coated K&T in the kitchen. It started a fire in the wall where there were 5 switches. The responding firemen had to completely chop out the wall and part of the ceiling to make sure the fire was out. Richard
snipped-for-privacy@aol.com wrote:

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snipped-for-privacy@gmail.com in

never seen that, maybe that's the older knob and tube. i've seen 50's stuff that was connected properly in boxes with the short piece of "loom" thru box holes. (as well as i recall)
i've also seen separate ground wire for old two-conductor romex (kitchens) that had twisted and soldered connections. i guess if ground wire went into rare effect (lots of current) accumulated debris in wall could light up.
older houses had no insulation, so if adding insulation, i think you'd have to replace wiring or guess (!hahahaaaaaa) at how far to derate current for knob and tube.
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snipped-for-privacy@aol.com wrote:

The only way that the solder will fail on Knob and Tube wiring is if the circuits were fused with improperly sized fuses. If the circuits are protected with properly sized fuses K&T will last for decades.
--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
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OBVIOUSLY you dont know enough about solder, over LONG times it wiskers and detoriates. now K&T is likey 50 years old or more, and quality of metals and solder wasnt great way back then.
I fix office machines for a living, at one time did tv and other appliance repair. in that time every now and then would find a bad solder joint, that had workewd forever. frequently in low power circuits where it wasnt and couldnt be overloaded.
Insurance doesnt like K&T because it cost them too much in fire losses,,,,,,,
otherwise they wouldnt care!!
you go right ahead thinking K&T is safe, all those insurancer companies just dont know what they are talking about:(
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snipped-for-privacy@aol.com wrote:

Although my experience is limited, the times I have seen crumbling wire insulation with K&T is where it joined ceiling light fixtures, and that was because of the heat (over heating) due to the fixtures.
In some such cases it was possible to (properly) solder a replacement extension onto such a wire and then use a sleeve to cover that, followed by the installation of a junction box to hold the wire safely in place and connect to the fixture.
Whenever possible I replace K&T, but when not reasonable to replace, I would be sure the circuit is on a 15A max breaker. Usually receptacles, which is where the greatest loads exist, and where a ground is especially desirable, can be more easily rewired with romex.
http://www.waptac.org/sp.asp?idq90 http://www.maine.gov/pfr/ins/hearing_2003-13680.htm
These links are especially interesting and deserve a full reading. My comments are just my own opinions and ideas. --Phil
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Phil Munro wrote:

Great links, probably not read by hallerb.
I agree that K&T is basically reliable. IMHO insurance denial for K&T (and some other causes in this thread) is in fact redlining.
I have seen 2 failures of soldered joints. Both were bad when made. One was K&T, one was BX in a metal box.
I have read, don't know if it is true, that K&T are still installed where flooding is a problem because it dries out better.
bud--
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Tom Horne, Electrician wrote:

I won't disagree, but will point out that it has been in place for decades- at least 6 of 'em, if not more.
D
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No. Fuses and circuit breakers prevent that.
Nick
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Fuses and breakers protect against overcurrent situations - not overheating due to deteriorating connections.
Bob
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Would you have any evidence that solder connections deteriorate over time, if they are not overheated?
Nick
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No
Bob
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Never heard of such a thing. All over the NE houses have K&T, and they all have insurance. AFAIK, the NEC still recognizes K&T, so I can't imagine why insurance companies would have any problem with it
> probably CANT get homeowners or a mortage with K&T most insurance > wouldnt cover it as a fire hazard. > > connections are soldered in the wall, without a box surrounding it. > unlike today all coinnections are in boxes. > > after many years and heavy loads the solder weakens and the connection > can overheat and cause a fire, that happened to a buddy of mine > fortunately in his open basement cieling he smelled smoke and put it > out. > > in a closed wall the house will go up in smoke. > > have friends whos homeowners inspected their home and REQUIRED rewiring > for just this reason. > > deduct cost of rewire from home sale price and for futher savings get a > home inspector they arent perfect but every trouble they find is money > in your pocket. > > call your insurance agent and ask about K&T and please report back here > what they tell you... > > K&T would be safe IF the connections had been made in BOXES but back > then no one thought of it >
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RBM wrote:

<SNIP>
It's true, nonetheless.
This is one of many citations regarding it:
http://info.insure.com/home/knobtube.html
Jim
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> Never heard of such a thing. All over the NE houses have K&T, and they all > have insurance. AFAIK, the NEC still recognizes K&T, so I can't imagine why > insurance companies would have any problem with it >
I've been hearing stories about K&T related cancellations for several years.
Bob
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I read what Jim sent, which makes sense for any potential fire hazard. Any wiring in poor condition would be a risk for an insurance company

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As it happens I've just been updating my list of issues that affect underwriting in Chicago and Suburbs, based on conversations with local agents. The most common issues are:
Roofs obviously near end of their useful lives.
Porches or stairs with missing or damaged railings.
Coverage of large areas with ivy or other similar plants (for example, State Farm).
EIFS or Dryvit synthetic stucco over *frame* construction.
Frame buildings in close proximity to another structure (especially a problem in Chicago).
Any fused (as oposed to circuit breaker) based systems, even if 100A in good conditon.
Knob and Tube wiring
For some companies, *any* electrical service less than 100A (or example, Hartford).
Generally, for pre-1900 construction some companies (for example, Hartford) expect to see major updating of systems such as electrical and HVAC.
If an applicant states that there has been recent updating some companies (for example, Allstate) may request to review receipts for the repairs, and expect that these will be from a "licensed contractor".
Previous claims or inquiries discovered during a CLUE search, especially for water damage.
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snipped-for-privacy@yahoo.com says... > As it happens I've just been updating my list of issues that affect > underwriting in Chicago and Suburbs, based on conversations with local > agents.
As an insurance agent, I wish more home inspectors were aware of what conditions can lead to insurance problems.
Insurance companies aren't just worried about gross deficiencies, they're worried about anything that significantly increases the risk of loss. A house can be fully code-compliant and structurally sound, but still be very difficult to insure.
There's nothing more frustrating than telling a first-time home buyer that their dream house doesn't qualify for standard insurance. Almost inevitably, the first words out of their mouths are, "But it passed inspection!"
--
snipped-for-privacy@phred.org is Joshua Putnam
<http://www.phred.org/~josh/
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