History of Knob & Tube Wiring
Knob & tube wiring (sometimes referred to as K & T) is the original electrical wiring system and is still in use in some homes today. In the 1880’s, knob & tube wiring became very popular. It was inexpensive compared to conduit and other electrical options during that era. These wiring systems consisted of ceramic knobs and tubes that both insulated and guided the conductors. The wires were wrapped with a cloth sleeve for added protection. Although inexpensive, knob & tube wiring was very labor intensive, and over time the labor costs for the electricians themselves exceeded the cost of materials.
Knob & tube wiring remained popular well until after the World War II era when more electrical appliances and devices became available. However, the increase in electrical appliances caused more of an electrical load demand than the knob & tube wiring systems could handle. The increased load also caused increased heating temperatures which created the threat of fires in homes. Over time, the insulation of the wiring systems became dry and brittle. In some cases, they were easily damaged by rodents and/or renovations. As a result, it became an increased hazard to have this wiring system in your home. This is why many insurance companies refuse to insure homes and businesses with knob & tube wiring.
What can I do if I have K & T in my home or business?
If your home was built in the 1930’s or earlier, you may have a knob & tube wiring system installed. We strongly recommend having a qualified electrician evaluate the system and/or replace it. Replacing the electrical wiring would be the best option to ensure your property – and family – is safe for many years to come. We don’t really see much of this kind of electrical wiring here in South Florida. But we have come across it in Coral Gables and some of the other older cities. Below, you can see the the differences between modern wiring and the groundless k & t.
There’s always the possibility of bringing your home up to code without having to replace all the wiring in your home. That is to say, there may be other solutions. If you have knob & tube wiring, and you are looking to update or replace it, give us a call. Our free consultation will have you already feeling safer.
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ALWAYS call and check with a qualified electrician before attempting or acting upon anything you read on this site. Changes are always happening within the NEC, standards and regulations, and State, County, and City by-laws.