Is My Old House Wiring Safe?

Fire Damage From an Overloaded Circuit
Fire Damage From an Overloaded Circuit. Timothy Thiele

The wiring in your home is the highway of power that feeds everything electrical in the home. Over time, like everything else, it begins to break down and may need replacing at some point. But how is one to know? You may not be able to determine the electrical wiring's age, but a qualified electrician can give you a good idea of its age and ability to handle the electrical load within your home. 

Older knob-and-tube and Romex wiring has a way of becoming brittle.

The insulation drys out and starts to crumble, causing the inner wire to become exposed. The cloth insulation around the wire deteriorates with age and eventually becomes unsafe. Knob-and-tube wiring was run as individual wires through joists by using insulating sleeves to protect the wiring. To make the connections, electricians used solder pots.The worst part of knob-and-tube wiring is the lack of  ground wire for the circuit. As a rule of thumb, if the wiring has no problems, is intact, and has not been disturbed, it likely will continue to work for years to come with no problem. However. by adding additional wires and loads to the existing circuit could spell trouble.Take time to have someone check the wiring in your home to be sure it is safe.

When inspecting the wire, if the wire looks intact but just old, it's likely still safe to use. Check splices wrapped in friction tape and be sure that the tape is not unraveling.

If the tape is not loose, these splices should be fine. If, however, the tape is loose, turn of the circuit, remove the existing tape and wrap with new tape. In most instances, if the wires are not disturbed, they shouldn't be damaged. It's when you climb around and pull on them that the brittleness of the wires rear their ugly heads.

Besides these dangers, there is always the fear of loose joints to begin with. Honestly, have you ever crawled around in an attic full of insulation and looked over all of the electrical joints? 

Older knob-and-tube wiring presents a challenge to identify the hot and neutral wires. The neutral wire will have some sort of white tracer on the the wire, although you may have to clean the end of the wire with soapy water. Remember to only do this with the power off. Even then it is likely you may not be able to identify each of the wires due to the amount of time the wiring has been there.

I lived in a home that was built in 1891 and believe me, it needed an electrical update. In fact, that home did not have a 240-volt service that has two hot wires and a neutral, it only had a 120-volt feed, meaning it only had one hot wire and one neutral. With only four fuses feeding the whole house, you can see why I immediately rewired it. Just imagine having no 240-volt appliances like an electric water heater, an electric dryer, central air conditioning, or an electric range. I suppose back in the day, there were few appliances, TV's, VCR's etc. that needed the power that we require today. Imagine having only one outlet in each room!

Now you could fell my pain when i moved in.

The biggest disadvantage of having old wire like knob-and-tube and Romex wiring is that these types of wires didn't implement ground wires. That means that if there is a short to an appliance, let's say, you will become the path to ground and become electrocuted.

If your home has these older versions of wiring, I'd recommend changing it to a grounded style of wiring and updating the amount of outlets in your home. As I would tell you, you can never have enough outlets in your home, garage, or work shed!