Knob and tube.

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nizak

Senior Member
I'm currently looking at giving a proposal to completely rewire a 110 year old house.

About 75% of the house still utilizes original K+T.

A kitchen renovation in the early 70's updated that circuitry but the rest of the house is pretty much untouched.

Surprisingly each room has a fair amount of receptacles and a switched ceiling fixture.

The new owner tells me that she has contacted insurance companies and they are telling her that they will not insure the dwelling with the K+T in service.

It's a two story with immaculate maple flooring upstairs. There is very ornate oak woodwork trim throughout the house. The attic has about 30" of head room at the highest point. Several ceilings are architectural tin, possibly original.The owner would like not to disturb the flooring above to get into the ceiling spaces below to add lighting and fans. And not remove the crown mounding below.

Here's my question.
Would installing GFCI protection to the K+T make it considerably safer?
Would a combo GFCI / AFCI breaker be a better way to go?

Here in Michigan we are not required to have arc fault protection on any circuitry.

I'm looking for a way to appease the insurance company without destroying the home.

Local AHJ is telling me that unless there are signs of deterioration , it can stay as is.

Thanks
 
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
You are caught between a rock and a hard place. K&T was designed for open air, no building insulation. Has there been no insulation added to that house since day one?

Are recall those receptacles the original two wire?

GFCI and AFCI won’t hurt, but IDK how much it will help either. K&T is still K&T no matter how you protect it.

Don’t bid the project.
 

480sparky

Senior Member
Location
Iowegia
Unfortunately, it's gonna run some serious scratch. If the insurance requires it to be replaced / bypassed / removed, it's going to be ugly. And dirty. Yes, AFCI and GFCI can make it safer, but the actuary probably won't go along with it. The HO may need to find another carrier.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
The new owner tells me that she has contacted insurance companies and they are telling her that they will not insure the dwelling with the K+T in service.

I'm looking for a way to appease the insurance company without destroying the home.

Local AHJ is telling me that unless there are signs of deterioration , it can stay as is.

The HO may need to find another carrier.

I agree with 480. Sounds like the house is a Victorian gem. The HO just hasn't approached the carrier that WILL insure the property.
 

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
I've been a spark in K&T central for decades , only the past decade has seen the insurance contingent's wrath over it.

I did convince one insurance company re: afci protection , but that was short lived.

It doesn't matter who you find now, they'll all poo poo it.:happyno: one way or another.....insulation= code violation!


Seems they're up on the fact nothing marketed here mitigates glowing connections

~RJ~
 

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
I also am in a locale with a heavy concentration of existing century+ old dwellings with energized K&T and they ARE insured.

By companies who are obviously lax on inspections.

Of course , you could have some un-insulated dwellings owned by oil exec's out in Minnesota

Then it would all make sense Al :p

~RJ~
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
By companies who are obviously lax on inspections.

Of course , you could have some un-insulated dwellings owned by oil exec's out in Minnesota

Then it would all make sense Al

Hardly.

10s of thousands of insulated structures. The K&T insulation Code restriction was introduced in the 1984 NEC, decades after the last "new" installation of K&T. With the cold winters of Minnesota, it has been a rare dwelling that wasn't LEGALLY insulated already by 1984. Inspectors here understand that K&T is tested and evaluated for insulations, with the exception of foams and glue-set fibers, and is therefore an approved installation. The K&T cannot be exposed and then re-insulated as the re-insulation violates the post-1984 Use Not Allowed.
 

peter d

Senior Member
Location
New England
Would installing GFCI protection to the K+T make it considerably safer?

Not really for the wiring itself, unless the intention was to install 3-wire receptacles.


Would a combo GFCI / AFCI breaker be a better way to go?

I don't consider AFCI protection some magical panacea for making old wiring "safe". Only complete rewiring is the answer to ancient systems for them to be considered safe in my book.
 

Tony S

Senior Member
We have a similar problem with churches. Insurance companies often insist on mineral insulated cable surface mounted, polished it looks quite smart.

It always amuses me that the CoE owns its own insurance company. Does it show a lack of faith?
 

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
Hardly.

10s of thousands of insulated structures. The K&T insulation Code restriction was introduced in the 1984 NEC, decades after the last "new" installation of K&T. With the cold winters of Minnesota, it has been a rare dwelling that wasn't LEGALLY insulated already by 1984. Inspectors here understand that K&T is tested and evaluated for insulations, with the exception of foams and glue-set fibers, and is therefore an approved installation. The K&T cannot be exposed and then re-insulated as the re-insulation violates the post-1984 Use Not Allowed.

Then Minnesota must have a state addendum for this Al>


394.12 Uses Not Permitted. (5) Hollow spaces of walls, ceilings, and attics where such
spaces are insulated by loose, rolled, or foamed-in-place
insulating material that envelops the conductors

~RJ~
 

growler

Senior Member
Location
Atlanta,GA
The new owner tells me that she has contacted insurance companies and they are telling her that they will not insure the dwelling with the K+T in service.

I've been a spark in K&T central for decades , only the past decade has seen the insurance contingent's wrath over it.

I did convince one insurance company re: afci protection , but that was short lived.

It doesn't matter who you find now, they'll all poo poo it.:happyno: one way or another.....insulation= code violation!


Seems they're up on the fact nothing marketed here mitigates glowing connections

~RJ~


If it's a new owner they should have had a warning during the home inspection process that the house was wired with K&T and possible problems in the future.

If the owner can't find an insurance carrier that will insure the property it's their problem.

If the house has to be rewired they need to work with a GC that's good at renovating old houses so that any cutting and patching can be taken care of by them.

The time for an owner to consult with an electrician on a problem like this is before they buy the house.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Then Minnesota must have a state addendum for this Al

No.

The NEC is a new construction standard. The new (in 1984) 394.12 IS NOT retroactive to pre-1984 concealed K&T that exists and is undisturbed and was installed to the Code of its time of assembly, even when the concealed K&T is enveloped in insulation installed pre-1984.

The pre-1984 NECs are silent about enveloping K&T in insulation, which means it is ALLOWED.

Your generalization "insulation=code violation" is what the insurance company claims, and in so doing the insurance company is writing its own electrical code that is stricter than the NEC adapted into ordinance by the local jurisdiction.
 

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
No.

The NEC is a new construction standard. The new (in 1984) 394.12 IS NOT retroactive to pre-1984 concealed K&T that exists and is undisturbed and was installed to the Code of its time of assembly, even when the concealed K&T is enveloped in insulation installed pre-1984.

The pre-1984 NECs are silent about enveloping K&T in insulation, which means it is ALLOWED.

Your generalization "insulation=code violation" is what the insurance company claims, and in so doing the insurance company is writing its own electrical code that is stricter than the NEC adapted into ordinance by the local jurisdiction.

You're kidding right Al ?

The insurance cabal that basically wrote the NEC & owns the NFPA by proxy would pick their teeth with any local jurisdiction. Your '84 reference is simply where their concern debuted, not to be confused with some grandfathering scheme.

That rationale is no less a 'BX jacket is an EGC' when a 3rd element of circuitry wasn't even around....

~RJ~
 

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
If it's a new owner they should have had a warning during the home inspection process that the house was wired with K&T and possible problems in the future.

what if one hails from a state where no HI qualifications are required?

If the owner can't find an insurance carrier that will insure the property it's their problem.
kinda like blind guys hoping geico will pick 'em up?
If the house has to be rewired they need to work with a GC that's good at renovating old houses so that any cutting and patching can be taken care of by them.
true , unless it's all boon barn....

The time for an owner to consult with an electrician on a problem like this is before they buy the house.
which isn't common

~RJ~
 

Galt

Senior Member
Location
Wis.
Occupation
master electrician and refrigeration service tech.
I don't think knob and tube is as dangerous as most think. Most old homes here have new circuits to the kitchen and baths as well as larger 240 loads. Many knob and tube circuits still in use on second story bedrooms and attics looks as good as the day it was installed.
 

kwired

Electron manager
Location
NE Nebraska
No.

The NEC is a new construction standard. The new (in 1984) 394.12 IS NOT retroactive to pre-1984 concealed K&T that exists and is undisturbed and was installed to the Code of its time of assembly, even when the concealed K&T is enveloped in insulation installed pre-1984.

The pre-1984 NECs are silent about enveloping K&T in insulation, which means it is ALLOWED.

Your generalization "insulation=code violation" is what the insurance company claims, and in so doing the insurance company is writing its own electrical code that is stricter than the NEC adapted into ordinance by the local jurisdiction.

You're kidding right Al ?

The insurance cabal that basically wrote the NEC & owns the NFPA by proxy would pick their teeth with any local jurisdiction. Your '84 reference is simply where their concern debuted, not to be confused with some grandfathering scheme.

That rationale is no less a 'BX jacket is an EGC' when a 3rd element of circuitry wasn't even around....

~RJ~
All that means is the installer may have better chance of being relieved of liability if it was pre 1984.

Insurance can still refuse to offer coverage or offer at a higher premium for anything they don't like.
 
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