knob & tube... should it stay, or should it go?

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sw_ross

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http://forums.mikeholt.com/attachment.php?attachmentid=18573&stc=1&d=1506126584

what's your perspective on using existing k&t wiring?
looked at a job today. my initial inclination is to not use it. I don't like the potential issues down the road from failures of splices.
I know it's been in the building for close to a hundred years. it's served its purpose!

see splices in pic above meters!
 

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Even if those flying splices are moved in boxes, and it passes Megger with building permits & inspections, it is not insurable.

There's been no property insurance for years, and new buyers can't get a fire insurance carrier, much less mortgage insurance, for original Knob & Tube construction, without negotiating cost of complete re-wiring first.

However, owners don't need to negotiate the selling price for such a risky property, if a gullible electrical contractor comes along.

With an "Additionally Insured" certificate from a contractor's General Liability (GL) policy, after modifying the electrical service, Mortgage & Fire insurers may bite, since the GL policy is first in line to pay any claims.
 
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ramsy said:
Even if those flying splices are moved in boxes, and it passes Megger with building permits & inspections, it is not insurable.

There's been no property insurance for years, and new buyers can't get a fire insurance carrier, much less mortgage insurance, for original Knob & Tube construction, without negotiating cost of complete re-wiring first.

However, owners don't need to negotiate the selling price for such a risky property, if a gullible electrical contractor comes along.

With an "Additionally Insured" certificate from a contractor's General Liability (GL) policy, after modifying the electrical service, Mortgage & Fire insurers may bite, since the GL policy is first in line to pay any claims.
Click to expand...

In my area there are hundreds, maybe thousands of insured structures with knob and tube wiring.
 
Here it's a crap shoot, although more and more insurance companies are not insuring a new owner if the home has knob and tube. No insurance =no purchase with mortgage unless rewired.

Probably due to the increased risk of fire due to so many homes that have been insulated around a wiring method not designed for be encapsulated in insulation.
 
mopowr steve said:
Probably due to the increased risk of fire due to so many homes that have been insulated around a wiring method not designed for be encapsulated in insulation.
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K&T was tested and evaluated for encapsulation in the common insulations used before the development of foam insulations. The NEC did not restrict insulation contact with K&T until the 1984 NEC was adopted. The restriction is not retroactive.

In the colder climes, dwellings were already insulated by 1984. As long as the insulation is not a foam, there is no issue in my Metro Area of many 10s of thousands of dwellings with K&T in service in insulation. The only reason these dwellings are not insured is because the owner is not paying for it.
 
I was inspecting a large home that was gutted and rewired except for three rooms in the back on the top floor. Even though the walls were open and his electrician was really pushing for it the home owner refused to rewire those rooms. When it was pointed out the difficulty in getting insurance coverage he laughed and said that was the business he was in and there would be no problem. He later decided to rewire those rooms and told us that the only company wiling to insure the home with knob and tube was Lloyds of London.
 
RICK NAPIER said:
I was inspecting a large home that was gutted and rewired except for three rooms in the back on the top floor. Even though the walls were open and his electrician was really pushing for it the home owner refused to rewire those rooms. When it was pointed out the difficulty in getting insurance coverage he laughed and said that was the business he was in and there would be no problem. He later decided to rewire those rooms and told us that the only company wiling to insure the home with knob and tube was Lloyds of London.
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Interesting. While it has some cachet, insurance obtained through Lloyds isn't necessarily more expensive than any other firm. It's curious that American firms are unwilling to write against this risk. They must have reams of data covering hundreds of thousands of homes that had K&T wiring at some point.
 
Where do you all actually see knob and tube in that picture?

JAP>
 
Above the right hand electric meter, sticking through the plywood backboard, there is a vertical column of ten branch circuit homerun K&T conductors. They are spliced in open air with tan wirenuts to NM extensions.
 
al hildenbrand said:
Above the right hand electric meter, sticking through the plywood backboard, there is a vertical column of ten branch circuit homerun K&T conductors. They are spliced in open air with tan wirenuts to NM extensions.
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Shouldn't each conductor be coming through a separate penetration? It looks like you have a K&T pair coming through each hole.
 
It probably is but it seems like a lot of speculation to me.

Especially from the picture.


If it is, all we may possibly be seeing is the "Tube" portion at best.

JAP>
 
jap said:
It probably is but it seems like a lot of speculation to me.

Especially from the picture.


If it is, all we may possibly be seeing is the "Tube" portion at best.
Click to expand...

Correcting myself, the splices between the NM and K&T are by barrel crimps under translucent covers.

There are a lot of questions that come out of this photo that pertain to the premises. Why four meter sockets, and two unused? Why three Cutler Hammer service centers?

I count five plastic jacketed NM extensions from the crimp splices to the panels. Each plywood hole, in the column of ten, has a loom "tube" extending from them. There is an absence of the NEC required "birdseye" transition fitting, NEC 300.15(F), at the end of the five NM cable sheaths and the contained conductors that go from cable to "open"

In the OP photo, I see an assembly of an apartment building service center in a building that was originally wired with a central electrical service at this same photo'd location. The service upgrade, that we see, only refed the existing dwelling branch circuits as evidenced by the number of single pole breakers in the visible panel. Here, in my area, I would expect the upgrade work to have been done in the Sixties. And the original premises wiring method was K&T.

Edit to add: I'd expect each unit to be a museum time capsule of early 1900s electrical outlets and luminaires.
 
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