Knob & Tube

[jxofaltrds]

Not to bring up a long debated topic, but we are having an office debate. 394.12 (5) states that K & T shall not be used in hollow spaces that are insulated.
The debate is not that K & T is permitted, and that insulating over is a good thing, but it is that the code specifically does not state that you cannot insulate over it. The code does not state where insulation is permitted, rather that K & T wiring is not permitted to be installed in an insulated space.
Does anyone agree with this "legal" interpertation of the code?

The code does not tell us about framing, HVAC, plumbing, stairs, I could keep going.

Not sure of your point.

Others have cited the code so I will not repeat.

 

[220/221]

394.12 (5) states that K & T shall not be used in hollow spaces that are insulated.

How can it be hollow if it is full of insulation?

 

[tls]

I don't think that in wall insulation was even available when K & T was being installed. I may be wrong, but I have never seen a house with insulation installed in the 20's and 30's. The closest thing to it was a type of fiber that was put on the outside, nothing in the walls.

I haven't personally seen it in walls, but it existed -- I've seen fairly extensive use of bagged insulation (excelsior, straw, even what appears to be dried seaweed,mostly in old paper cement-bag like bags marked "Cabot") for sound insulation between ceiling/floor joists in 1920s construction in New York City.

With BX from the 1920s spliced on those round metal plates (no box) at every fixture, modified who knows how many times in the intervening 80 years...and little tendrils of grass/seaweed/whatever poking out of the 80 year old paper bag on both sides of the plate. Shudder. Now there's a fire hazard for you.