Is Old Wiring Dangerous?

Old wiring that needs repaired


Electrical fires are always a concern in older buildings. But is old wiring always a health and safety issue? When should you have the electrical replaced? 

What Is The Life Expectancy Of Wiring?


The life expectancy of most electrical wiring can range anywhere from 50 to 100 years. Much of the lifespan depends on the material; copper, for example, can last over 100 years, aluminum a bit less but still well over 50 years. It’s not the metal in the wiring you should be concerned with – it’s the material protecting this metal. 

Electrical wiring is covered in an outer protective sheathing made of a material like plastic; this will degrade much sooner than the copper or aluminum it encases. Much of it depends on what it’s made of – plastic-sheathed wiring, for instance, lasts longer than the fabric-sheathed wiring found in most houses built before 1970. If your wiring is older than 1970, it’s likely near the end of its useful life.


Old Wiring Systems Can Be Dangerous


While the materials can stay useful for many decades, the hazards of older wiring often come from the period it was meant to serve. Most old systems have a lower amperage rating than what’s necessary to run today’s appliances. It can see overloaded circuits, which can lead to a fire

Many house fires start because the design of older electrical systems can’t keep up with modern electronics. Electrical codes and standards have advanced a lot over the years and, if it had pass inspection today, an older building probably wouldn’t meet current safety requirements.


Knob & Tube Wiring Is Dangerous


If your home is a century home, it may still run on an older kind of electrical system known as “knob and tube” wiring. In a knob and tube system, copper conductors supported by knob insulators run inside walls and ceilings, passing through holes that contain porcelain or ceramic tubes. The wiring runs as individual wires – a black hot wire and a white neutral wire – across the entire building. The ceramic insulators keep the wires from touching or the wood, insulation, and other combustible materials.

Since it’s single-insulated, knob and tube wiring systems often become hazardous through fraying with age. The wiring also does not have a ground system for safety. While no grounding isn’t inherently unsafe, it would not have this essential safety feature found on modern wiring systems and contemporary building codes.


What Other Parts Of The Electrical Should I Consider?


Old wiringAge is not the only determining factor of unsafe wiring. There are a lot of details to consider. If the wiring is ungrounded or has damaged protective sheathing, you should have it replaced by an expert. The protective sheathing is going to wear out quicker than the wire it safeguards. As time passes, it can become dry and brittle, eventually degrading and exposing the wiring. 

Ungrounded wiring lacks a bare copper ground wire that grounding the circuit to the electrical panel. Electrical wiring with damaged sheathing may be repairable; however, widespread and severe damage could require partial or complete rewiring.

In the United States, faulty wiring is the leading cause of residential fires. The older a home is, the greater the chances that its wiring is outdated and unsafe. If you’re unsure about the safety of your home’s electrical, call an expert from J.D. Patrick today!

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