Inspector's perspective needed

Specific Inspection Topics Electrical Inspections
1

I have been living in my 1966 built home (Cleveland, Ohio suburb) for around 10 years. Even though it’s only 40 years old, the home was constructed using knob & tube wiring. Nonetheless, they actually ran grounding wires for all the circuits, so I have 3 prong outlets, all fed with three wires (no bootleg grounds). The 100A panel (properly fed from the meter with 2 AWG Al) is fused, containing two block pullouts with cartridge fuses. One of the pullouts controls the electric range and contains 40A fuses; this circuit is wired with 6 AWG (not 8 AWG) Cu in flexible conduit. The other pullout contains 60A fuses and controls the 8 branch circuits as well as a subfeed (which goes outside to the fused disconnect for the outdoor condensing unit). Of the 8 branch circuits, 6 are fused at 15A and 2 are fused at 20A (all using Type S fuses). I’ve confirmed that the two 20A circuits use 12 AWG Cu entirely.

Prior owners have done some tapping into the K&T (for example, to add ceiling fans in the bedrooms, which originally had no ceiling fixtures). I’ve gone through the house and fixed all these improperly done additions by undoing the splices and redoing it all in junction boxes. The wiring is in excellent condition (looks new, actually), and in the ten years I’ve been here, have never had any fuse blow. Given recent developments in the area of insuring K&T wiring and fused systems (which I feel, if properly installed, are actually safer than breakers (witness FPE)), I’m concerned that I’m going to have problems selling the home. How would an inspector approach these circumstances?

2

Mr. Martin,

First let me say…and I am sure others may not agree but to have K&T in a home that is only 40 years old lends me to think it may have been remodeled 40 years ago but may be older…but again that might be just me thinking this…anyway…

When dealing with K & T you have to consider many things as todays standards as far as NFPA see’s it would not require changing it but it sounds like many things associated with it are being changed in the structure which causes a problem…you analysis of K & T is valid to a point but the bad thing about K & T is when it starts to be altered past is original ( common netural ) approach by home owners to meet their current needs of today…ie: continuous and linear v. non-linear loads the problems become compounded on the shared neutral structure of K & T.

As you know insurance companies will march to the beat of their own drum as will their UWer’s who back the policy so they can change or add stipulations as they deem fit…Are you going to have problems when you see…well it depends entirly on the following-

1.) Are the upgrades made compliant to safety standards…irrespective to NEC standards…Safety is the foundation of the NEC via NFPA.

2.) Can the home be insured on a NEW policy versus a ongoing one that may have grandfathered the existing coverage…the prospective buyer will have to check that out…if bought right out with no mortgage quite possibly their choice if they want to buy without insurance…then again a carrier may have no problem with it…really depends on the inspection and review.

Their is a proper way to transition from K & T to modern day wiring but I just happen to be one of those electricians who believe you should just not splice in willy nilly and consider it upgrading anything…it has to upgrade to the distribution point to be a true fix…

Taking exposed wires lets say in an attic that are K & T and placing them in a box…provided the proper fitting and insulators are used is not an upgrade…only a enhancement and it really does not reduce the shared properties of the system wiring itself.

The concept of K & T being safer I guess came from the fact it has no ground…thus giving no equal grounding reference point…but in your case that is no longer the case…so it really should be evaluated by an electrical contractor that KNOWS knob …one who can review the changes being made…much like a structural eng. will review truss alterations and suggestions on compliance approvals.

The dangers of K & T are not always the same as in modern wiring…but some are like overloading the shared netural, fuses that can be altered wrongly and mostly unprotected wires that can be exposed to damage…making sure they stay min. 3" apart from each other and 1" from the surface.

I just dont think an inspector can tell you how the sale will go but we all will write it up as K & T and suggest it being reviewed by a licensed electrical contractor for obvious reasons…does that mean it has to be changed…we no unless other remodeling has been done and it is perfectly allowed to splice to other methods of wiring but must be inside a box and so on…

Now…with all that said is K & T allowed today…well in new constructon obviously not…but it is allowed for adding onto existing dwellings that use K & T as well by special permission from the AHJ…good luck on that ever happening…

Conclussion- The best thing to do is see if the insurance company that will carry the insurance to the new buyer will cover a K & T installation…or in a situation where the buyer pays cash…they obviously will need to know it is K & T and live or DIE with their choices…

Hope this helps any…others may have different opinions on it but again all HI’s will call this out and it will freely be in every report submitted as sub-par wiring and not to the safety standards of today not just simply because it is K & T…but because of what the HI also CANT see…

3

Paul’s post is right on.

Having performed insurance inspection/appraisals for a major carrier, I can state that the underwriters taks a long look at electrical issues. Some carriers are reluctant to write policies where fuse panels are in use. While this may seem silly, it is their dime. If the home burns down from faulty electric, they have guaranteed to fix or replace it. They make the rules as to what is acceptable.

Paul’s point as to renovations is also on-point. The AHJ may permit the non-affected areas to remain, but it is doubtful that he/she will allow modiifcations to an existing system. Wiring for the renovated area will likely start at the panel, with new home runs, installed in a manner consistent with current code requirements. Once a certain percentage of the dwelling is renovated, the AHJ may require the entire dwelling be upgraded.

4

Thanks for the considered responses. A couple of clarifications/questions: the house was indeed built in 1966. You have not been the first to express surprise at the use of K&T to wire a home at that point in time. Second, there do not appear to have been been any additions/renovations to the home. (The only alteration of the original wiring appears to have been the tapping of the K&T to add ceiling fixtures in the bedrooms (as noted in my OP) and another ceiling fixture in the family room.) Nor do I consider “fixing” the post-construction splicing to be an “upgrade.” (BTW, I did not disturb the original installation’s soldered and taped splices.) My big question relates to what you refer to as a “shared neutral approach.” Are you saying that K&T installations were done such that there is a possibility that a single neutral could return current to the panel from more than one circuit on the same leg, thus allowing the possibility of overloading the neutral? That indeed would be a major hazard. Would that not have been contrary to code by 1966, if not well before? In any event, as far as I have been able to determine, the circuit distribution in the attic and elsewhere has a neutral accompanying each hot. I believe, but am not certain (and now I’m gonna check) that the main panel has an equal number of ungrounded and grounded conductors. Thanks again.

5

Mr. Martin,

I can’t say for sure YOUR situation is the same or different than some installs but what I can say is OLDER K & T installs did use a shared neutral approach many times and did most certainly have different circuits sharing the same neutral…in fact it is done today as well just frowned upon more than other things…lol…

Now while I am shocked at the K & T being used in a house built in the 60’s I guess it is entirly possible as well as I do not know when the NEC was changed to not allow it in new construction…only as I have stated before.

I am not implying you made any upgrades…just wanted to explain the concept behind it and what takes place…in terms of being allowed and how a insurance person would look at it…

I happen to know first hand on one thing…I was going to buy a 12 apartment complex…but the branch circuit wiring was aluminum…now I was buying it…they knew I was an electrician and when I would fix it but it had tenants in it…currently and the insurance company i spoke with would not insure it unless I kicked everyone out and rewired it all…

Ok…I dont want to get into Aluminum wiring…thats a whole new story but these people were paying good rent…their was no option to fix one apt at a time…all or nothing…even if I know how to fix it to be safer…all or nothing so I did not buy it…could not get insured…

Point is in many cases here…the insurance company and UW’s hold all the cards in issues that you bring up.

As you stated…their are inherent issues with K & T…overloading them with todays applicances and conviences are a major concern when dealing with K & T