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5 Reasons Why Knob and Tube Wiring Needs to Go

knob and tub gilroy

It Is Time to Upgrade Your Home’s Knob and Tube Wiring


If you were to ask modern homeowners, “what is knob and tube wiring,” many would not have a good answer. That is because this style of wiring stopped being used in the 1940s. However, having an older house may put your family at risk without you even knowing it.


At Watson’s Charging Stations & Electric, safety is our top priority. That is why we put together a straightforward guide to help you understand why it is time to replace your home’s old knob and tube wiring. As the leading provider of electrical services in the Gilroy, CA, and Santa Clara Valley area, we have helped countless homeowners update their homes to ensure it runs efficiently and safely. Learn more about how we can help you by contacting us today.


What Is Knob and Tube Wiring?

Homes built before 1950 often employed knob and tube wiring. It was the standard on all homes for decades. If you are unsure if your house has knob and tube wiring, look in your basement or near your circuit breaker box. If you can see wires running through porcelain cylinders inserted in the floor joists, you have knob and tube wiring.


This older wiring method does not have a ground wire like modern wiring, and this kind of setup cannot accommodate electrical plugs with three-prong plugs. Unlike modern wiring that keeps hot and neutral (black and white) wires together, knob and tube wiring run separately.


The way knob and tube wiring works are that it uses insulated copper conductors passing through framing holes via porcelain insulating tubes. The wires are supported along their length by nail-down porcelain knobs. This system was a popular wiring method because the wires had higher amp ratings, were less likely to be punctured by nails, and porcelain had a near-unlimited lifespan. On the other hand, knob and tube wiring installation is so complicated that only professional electricians can install it, and it comes with many risks.


5 Reasons Knob and Tube Wiring Should Be Replaced

Knob and tube wiring may have been the go-to wiring method from the 1880s to the 1940s, but it is far too dangerous to be used today. Here are just some of the reasons knob and tube wiring puts you at risk:

  1. No Ground Wire

Knob and tube wiring does not have a ground wire. Not only does that mean this style of wiring is incompatible with modern three-prong plugs, but it also leads to more significant risks of fires or other electrical problems. Modern electrical wiring consists of three wires: hot, neutral, and ground. The two wires that supply power to your outlets are black (hot) and white (neutral). The bare copper wire is known as the ground wire and acts as a backup plan in case the neutral wire is compromised.


Electricians started using ground wires from the mid-1940s to the early 1950s to protect against electrical fires and electrocution events. While the ground wire is now standard for all new homes, the electrical code does not require older homes to upgrade their wiring. It may not be mandated, but gaining additional safety and convenience is worthwhile.

  1. Old Age Deterioration

Surprisingly, older knob and tube writing is still functional in many homes across the country. However, this setup cannot handle the needs of modern electric appliances and electronics. Modern computers, TVs, washers/dryers, ranges, etc., require more power than before. In fact, as more homeowners move away from using fossil fuels in their homes, electricity is in higher demand. Demanding more power than the wires can handle will result in overloads that pose a severe risk of electrical fires.


More importantly, older knob and tube wiring systems have likely deteriorated and worn down due to their age. The rubberized cloth insulation used on knob and tube wiring becomes brittle over time and can flake off. As wires and insulation break down, the risk of electrical problems goes up.

  1. No Moisture Resistance

Thanks to modern wire designs and sheathing, home wiring can handle various moisture levels that enter the home. Knob and tube wiring does not have this capability, which means this kind of wiring is a poor choice in areas prone to moisture, like kitchens, bathrooms, and outdoor spaces.

  1. Out of Sight, Out of Mind

Knob and tube wiring is often surrounded by insulation and other building materials. Since these wires do not have the same wrappings/coverings as modern wires, being buried can pose various dangers. For example, home insulation can be somewhat flammable, even when treated with fire-retardant chemicals. The heat released by knob and tube wires can put your home at risk. Since these wires are buried in building materials, it is easy to forget that they are even there.

  1. DIY Modifications

Many homeowners balk at the idea of replacing the wiring in their homes. Instead of making the appropriate upgrades, they use their own improper modifications to meet their needs. These modifications can include anything from making unsafe splices to DIY connections. Improper adaptations to knob and tube wiring can be extremely dangerous.


Protect Your Home with Watson’s Charging Stations & Electric

If you own an older home, you do not want to live with the risk of outdated and potentially dangerous knob and tube wiring. The team at Watson’s Charging Stations & Electric can help ensure that your home is running safely and up-to-code. We have been the premier team of electricals in the Gilroy, CA, and Santa Clara Valley area for years, and we are here to help you get the peace of mind you deserve.


Whether you recently purchased an older home or have been in one for decades, give us a call to set up your free consultation. We can help evaluate your home’s electrical needs and prepare a plan to help catch your home’s electrical grid catch up to modern needs, whether it is through replacing your outdated knob and tube wiring, updating your electrical panel, or taking other steps to join the electrification movement. Call today and bring your old home past the present and into the future.