What is Knob and Tube Wiring?

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Knob and tube wiring is an older method of electrical wiring that dates back to before the 1950s. If your home has a construction date between the 1880s to the 1950s, you may have knob and tube electrical wiring throughout your home.

What Is Knob and Tube Wiring?

Are you wondering what exactly is the knob and tube wiring method and if there are safety hazards that come with it? Knob and tube wiring is an old method of electrical wiring. It is now considered a safety hazard because it isn’t up to current codes and doesn’t have a ground wire.

Generally speaking, knob and tube wiring isn’t dangerous on its own. However, it becomes a hazard when your building’s insulation takes over the wiring or if it’s had improper modifications from amateurs.

How Knob and Tube Wiring Works

Knob and tube wiring works differently than the standard electric work you’d see in homes today.

With this type of wiring, there are knobs and tubes. Ceramic or porcelain “knobs” were used as anchor points for wires. These knobs fasten to the wall so you can run copper “tube” wiring coated in cloth insulation through the walls of a home.


What Is Bad About Knob And Tube Wiring

Advantages of Knob and Tube Wiring

Even though knob and tube wiring is an electrical wiring system of the past,  there are some advantages to this type of wiring system.

One of these advantages is that the wiring can allow higher amps than other wiring systems with similar wire sizes.

Another benefit is that the cables and porcelain material used for knob and tube wiring are sturdy and less likely to be affected by puncture wounds from nails attaching them to wall joints.

However, it’s important to note that these advantages are just a few perks to knob and tube wiring. Without inspection, none of the benefits are guaranteed.

Common Problems with Knob and Tube Wiring

Even though there are some advantages to knob and tube wiring, there are also many problems associated with it. If any modifications are done to your knob and tube wiring, which is likely, they create a higher risk for hazards.

Another significant safety hazard with knob and tube wiring is that if any insulation goes around the wiring, it creates the potential for fires. Furthermore, this wiring is also a fire hazard because it lacks ground wire.

Ground wires or grounding conductors lessen the chance of electrical shock and reduce your likelihood of electrical fires, acting as an extra safety precaution.

Since knob and tube wiring is likely an older system, it also naturally has more hazards due to its age. Unfortunately, materials deteriorate, which leads to a need for repair or replacement.

Additionally, if you have knob and tube wiring, you must hire trained electrical professionals for repairs. If you hire amateurs, you increase the chance of adding more improper modifications, which can cause electrical fires and other safety hazards.

Our team of trained electricians at Attic Projects knows how to solve the common problems with knob and tube wiring to give you peace of mind.

How To Maintain Your Knob and Tube Wiring

If you decide to keep the knob and tube wiring within your home or building, you must have a licensed inspector and electrician perform regular maintenance. This is arguably the best way to maintain your wiring. Generally speaking, electricians have certifications and checklists to ensure that your system is entirely safe.

The experts at Attic Projects will look at any area of your home. For example, we check the insulation to ensure that the wiring is safe. We will also post any warning signs in the meantime to help homeowners or building owners meet safety compliance requirements.

Frequently Asked Questions (FAQs) – Knob and Tube Wiring

If you still feel confused about knob and tube wiring, you’re not alone. There’s a reason homeowners hire qualified and trained electricians. When in doubt, check out these frequently asked questions about knob and tube wiring, and don’t hesitate to contact the Attic Projects team with any further questions.

Should I Worry About the Knob and Tube Wiring?

Knob and tube wiring can present some hazards to your electrical system. However, there is no need to worry when you hire professionals.

Instead of worrying, take action by having our team check out your system. Then, we’ll see if you need rewiring.

Our trusted professionals and qualified electricians at Attic Projects will confirm if your system is in okay shape. If anything needs to be replaced, we can follow up with the proper maintenance to ensure your system is working effectively.

Can You Get a Mortgage on a House with Knob and Tube Wiring?

You can get a mortgage on a house with a knob and tube wiring electrical wiring system. If you fall in love with an older home and decide to have your home inspected by a professional inspector, you will find if you have knob and tube wiring. If so, the inspector will outline the maintenance or safety repairs required.

What Is Bad About Knob and Tube Wiring?

One bad thing about knob and tube wiring is that it isn’t built to run some of the electrical devices we have today with three-prong plugs. However, trusted professionals will provide GFCI, or circuit breaker outlets, to prevent any risk of shock.

However, if you have knob and tube wiring in areas with running water, like the kitchen, laundry room, or bathroom, then you need to make sure you have a ground wire installed due to the high risk of electrical shock. Scheduling an inspection with our team can help you determine whether your knob and tube wiring is safe or presents any risks.


Call us today for a free quote on your knob, tube wiring, and any other electrical needs! Contact us via our convenient online form or call Attic Projects at 858-246-742. Instead of wondering what knob and tube wiring is and if it is safe, you can get all the answers you need.

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