Knob & Tube Hazards
- Insulation over the wiring: If household insulation is installed over knob and tube wiring, a fire is just waiting to break out. The wiring is coated with a rubber/cloth insulation. It needs lots of space to dissipate the heat that builds up when an electrical current is flowing through. If there is no room, because it has been covered with insulation, an extremely dangerous situation is created.
- Excess use: Knob and tube wiring was installed when there were very few electrical appliances in the average home. Nowadays, with TVs, sound systems, computers, washers, and dryers, the system can easily become overheated. Many times, there is an overuse of extension cords, and power bars, as well. Old systems are just not designed to handle the demands for electricity that occur in our modern computerized world. The ground pin (or 3rd prong) on power bars or other electrical items should never be removed to accommodate the two-pin outlets used in Knob & tube wiring.
- Alterations: Most problems occur with Knob & tube wiring because of improper alterations being made to the existing wiring. As it is such an old system, proper replacement parts are not always available, which could be the reason a lot of makeshift handyman fixes are so dangerous. Knob and tube wiring are easily accessed in the basement, which is perhaps the reason why this wiring is often spliced unsafely with modern wiring by home handymen, as opposed to certified electricians.
- Damage: Serious problems can occur when this type of wiring is damaged, either due to wear and tear, handyman fixes, or other types of damage. Porcelain knobs and tubes can crack, and the wires tend to sag and fray over time exposing live wires.
- Brittle insulation: The rubberized cloth insulation on Knob & tube wiring becomes brittle over time and can flake off.
Plugging in a lamp, or even a TV, in your living room or bedroom really does not pose much of a risk when you have Knob & tube wiring. However, in places where there is a possibility of contact with water, for instance, the bathroom or kitchen, this type of the ungrounded system could be extremely dangerous.
Aluminum Wiring Hazards
Identifying Aluminum Wiring
- Aluminum wires are the color of aluminum and are easily discernible from copper and other metals.
- Since the early 1970s, wiring-device binding terminals for use with aluminum wire have been marked CO/ALR, which stands for “copper/aluminum revised.”
- Look for the word “aluminum” or the initials “AL” on the plastic wire jacket. Where wiring is visible, such as in the attic or electrical panel, inspectors can look for printed or embossed letters on the plastic wire jacket. Aluminum wire may have the word “aluminum,” or a specific brand name, such as “Kaiser Aluminum,” marked on the wire jacket. Where labels are hard to read, a light can be shined along the length of the wire.
- When was the house built? Homes built or expanded between 1965 and 1973 are more likely to have aluminum wiring than houses built before or after those years.