• Knob and Tube Wiring –

Knob & Tube wiring was the first wiring brought into houses. This was used from around the 1900’s – 1930’s. It was installed by running the hot and neutral wires separately. Typically, one black and one white, although most I see appear black at this point in their life. Ceramic knobs affix to the structural members, (a joist, for example) while the tubes are inserted into holes drilled through the members. The wiring was then run through the tube, or clamped to the knobs, fed to the outlets, and tied in at the main service panel. Viola, we had power.

Knob & Tube wiring, in and of itself, is not inherently, a problem. Agreed, it is lacking a ground conductor, as are many houses built up to, and as recently as the 1960’s.
(Lets face it. A two-prong lamp plugged into a receptacle lacking a ground conductor is no less safe than a two-prong lamp plugged into a receptacle with a ground conductor. Dining rooms, bedrooms, living rooms usually are not serving equipment with grounds anyway, with the exception of media and computer equipment, which should be grounded.) Knob & Tube becomes a problem because of what has, in many instances, occurred over the life of the system.

During the time that these systems were installed, the electrical usage in houses was not nearly that of a modern house. As such, there were far fewer circuits and receptacles in these houses, resulting in Little Johnny not being able to use his “Quadraphonic Orbital Spaceship Enterprise III system”, (with the optional hand held “Bug Blaster”) from the toilet in his private bathroom (which used to be a closet). And, seeing as how Bart, next door, can… Little Johnny’s dad… ya see where I’m going with this?

So what has happened over the years in many cases, is the general electrical circuits in the house have been expanded beyond what they were rated for when first installed, resulting in those *#&@*% fuses blowing. Great idea!! Let’s put in a bigger fuse…that’ll fix ‘er. Of course, in “fixin ‘er” we’ve over-fused the circuit, creating a fire hazard. As the wire and the insulation wrapped around it gets hotter, it dries out and becomes brittle.

Also, in many cases, Earl, after watching HomeTV’s, “You Kin Doit, Too!” decided to throw a few additional outlets in on a Saturday morning (after throwing down a few Silver Bullets. ((Hey, it’s 12 o’clock somewhere!).
• Your first clue could be the duct tape, (or even Scotch tape) wrapped around the splices. (If he even used tape)
• Gobs of romex wiring strung and wrapped, inside, outside, upside-down, only to poke out the baseboard somewhere downstream and run around the perimeter of the room, up the wall, and back in behind the cleverly (half) mounted electrical box (lacking a cover plate).
• You may find 8 or 9 outlets in one bedroom and only 1 or 2 in the others.
• Also, “strange placement” of outlets. For instance, mounted into the top jamb of a door. (Yes, I did happen to find one there once.)

These are all signs that the electrical system has been, how say, fiddled with.

Bottom line, where there’s Knob & Tube, the odds are in your favor that at some point, someone stretched the system out.

Also, in many instances, I’ve found the vast majority of the wiring to have been upgraded, leaving a Knob & Tube circuit in the attic, or basement. Again, have your electrician look closely at the wiring to insure it’s not suffering the effects of aging. (Don’t have an electrician, don’t call Earl.)

My feelings are usually, “If’n it ain’t broke, don’t fix ‘er.” HOWEVER, with knob & tube, I do strongly urge you to consider upgrading.

Aluminum Wiring (Single strand) –

• This type of wiring had a short surge in popularity in the late 1960’s – early 1970’s. The cost of copper was through the roof, so it was decided to give this less costly wiring its day in the sun. Unfortunately, much like the sun, it has this not particularly good habit of causing things to burn. Here’s how it happens. We’ll use an outlet where a lamp is plugged in for example:
  o When the lamp is turned on, the aluminum wire heats up. Aluminum expands when it is heated, contracts when it cools back down. Because it is soft, when it expands against the attachment screw on the outlet, it tends to flatten out a bit. A couple hours later, the lamp is turned off, and the aluminum cools, and contracts. Here’s where the problems start. Now that it has contracted, there is a very small gap between the wire and the screw. Multiply this occurrence by hundreds of on and off cycles with the lamp, and this gap grows and can begin to corrode and arc. This action can overheat the outlet, and may eventually cause a fire.
  
• The good news is, houses that were built with aluminum wiring do not have to be completely rewired or torn down. Over the years, the problems with this type of wiring have been addressed to the point where the wiring system can be modified to allow,
  o The existing wiring to remain in place,
  o The fixtures, receptacles, switches and breakers to be provided with replacements that will eliminate the dangers associated with this type of wiring in the past.
  o Repairs that will allow copper and aluminum to be connected together with special wire nuts designed for that purpose.
  
• Recommendation 1 –
  o If you have a house built in the later 60’s – early 70’s, have an electrician in to determine if it has aluminum wiring on 110 Volt circuits.
  
• Recommendation 2 –
  o Don’t buy into the, “It’s been this way all these years, some it must be OK”, school of thought. This problem occurs over time, so it may be an accident waiting to happen.
  
• Recommendation 3 –
  o Feel you switches and outlets. If they feel warm, or have an unusual odor coming from any of them, don’t wait. Get an electrician in now for further evaluation. An ounce of prevention…

Federal Pacific Service Panels and Equipment –
This brand of service panel was also used in the 1960’s up through the 1970’s. The “Stab-Loc” breakers found in them have been linked to fires in several cases. There have been several studies done over the years, along with recalls and discontinuation of production, finally resulting in the manufacturer closing the door and selling the company. The Consumer Protection Safety Commission also did a study, and concluded that these were problematic, although they did not feel that they had the funds to perform a full-blown investigation.
So, I guess it’s up to us home inspectors. The problem, as we see it, is the design of the equipment. First off, it’s older stuff, and electrical equipment doesn’t improve with age. These breakers have been known for their “failure to trip” when placed under an overload, which is a cause for overheating and possibly a fire. As a general rule, we do not like this equipment. While some of this information may be disputed, our recommendation is to consider having the panel replaced when we encounter them.
For more in-depth information related to Federal Pacific equipment, visit fellow ASHI inspector, Dan Friedman’s website at http://www.inspect-ny.com/fpe/fpepanel.htm