A re-wiring of your entire house is an expensive project, but in some situations it may be the only safe thing to do. Here are a few of the types of wiring that were used in bygone eras but have more recently been found to be unsafe. If you find any of these types of wiring, ask your electrician to inspect the entire system and make a recommendation about whether you need to get your house re-wired.
1. Knob and tube wiring
Knob and tube wiring uses ceramic "knobs" as insulators, and it actually worked well for its intended use when done right. However, today's lifestyles use so much more electricity that the wires get more current running through them than they were designed for, making it more hazardous than it ought to be. In addition, add-ons may have been made throughout the years to increase the number of circuits or outlets in your home, and since more modern wiring practices often don't mesh well with knob-and-tube, this can add fire hazards as well.
2. Aluminum wiring
Although aluminum wiring isn't necessarily a problem in itself (aluminum is used even today in some limited wiring applications, such as on dedicated circuits for AC units), an old aluminum wiring system can be a big problem. One of the issues is that when aluminum wiring started to be used widely in the US it was a replacement for copper, which was very expensive at that time. But instead of designing new switches and techniques that were adapted to aluminum's properties and behavior, electricians just used the ones they'd always used, which were intended for copper. More recently, equipment that's adapted to the needs of both copper and aluminum has been developed and other workarounds for aluminum's unique properties have been invented, but if your system is old, it may be very unsafe and require retrofitting or replacing.
3. Two-wire sheathed cable
This type of electrical cable encloses two different wires inside one insulating sheathing. The main problem if you find this type of wiring may be its age. Rubber was used as the insulation before 1940, and is only expected to have a working lifetime of 25 years, so if you find original wiring made with rubber, you could have a very unsafe situation. Of course, any wiring that you suspect to be this ancient should be inspected by an electrician.
These three types of wiring from long-ago decades can all pose a great threat to you and to your house. Overworked wiring that's not used to carrying the amount of electricity you use, old wiring with crumbling insulation, and unsafely installed aluminum wiring with incompatible switches can all increase your chances of electrical fire. Contact a business, such as R & R Electric Co Inc, for more information.