KNOB AND TUBE WIRING: MONSTER IN YOUR HOME OR MISUNDERSTOOD?

Knob and Tube in your home

What is "knob and tube" wiring? "K&T" wiring (as it is known in the industry) was a commonly used system until approximately 1950. It gets its name from the ceramic knobs and tubes that are used to support and protect the wires. There are many reasons why you want to have it removed from your home, but the question everyone asks is, "Is it safe?". Unfortunately, you will get a wide range of answers depending on who you ask. The one constant is that in order to properly eliminate knob and tube, you will need to fully rewire the home - and that is a big and potentially expensive project for any homeowner. Hopefully we can shed some light on this outdated system to provide some answers and a little more information on the wires behind the walls in your home.

The Pros and Cons:

Almost everyone will agree that there are not any benefits to having this wiring system, but if the wiring is intact and working, there is not usually an immediate risk. Because the installation of knob and tube is drastically different from modern wiring methods, we see a lot of modifications made by homeowners, handymen, and even electricians who are unfamiliar with K&T and ultimately do it wrong and increase the risk of a fire.

Even the easy projects can be potentially dangerous. When installing knob and tube, electricians would often switch the neutral wire to a light fixture instead of the hot wire (which is today's standard). This allows the light to turn on/off, but live power is still present at the fixture. If someone is unaware of this, it could make even a simple project like changing a light fixture very dangerous.
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The wires were originally installed with rubber insulation that dries out over the years and becomes brittle. This makes it very susceptible to exposing bare wires to insulation. Any physical contact to the wires by additional insulation or unwanted critters can increase the likelihood of the insulation falling off.

If you don't trust your homes' electrical, you can trust Skyline Electric.

Why you should remove the knob & tube wiring:

You are getting new insulation. Insulation companies cannot (and should not) add insulation to your home with active knob and tube present. The wiring is designed to dissipate heat and covering it with insulation can make the wires overheat, creating a fire hazard.

​You are selling or buying a home. ​Most insurance companies are denying coverage on homes with active knob and tube. It is better to start the process of getting options and specific answers for your home before it comes to the home inspection report and creates a potential problem for the closing.

New technology and appliances. ​We are always adding technology to our homes to make our lives easier and more comfortable, but this same transition to an easier life is putting more stress on these electrical systems. If you have knob and tube wiring, you may have noticed there are on average (2) two prong receptacles per room. Electronics, window A/C units, space heaters, and all the advancements that we now enjoy weren't around when these homes were built, and therefore the wiring system was never intended to sustain the load we now put upon them.

Ungrounded wiring. Ungrounded outlets present a very real risk of shock to people operating the electronics and appliances plugged into the outlet. They can also short out the equipment, rendering your favorite appliances and tools worthless.

Skyline Summary

• Knob and tube is not an immediate danger as a wiring method. The risks come from the age and condition, improper modifications, and situations where the homes insulation makes contact with the wires.
• It is an ungrounded system and therefore cannot service a three-prong appliance (using the two-prong to three-prong adapters are not a safe alternative).
• The outdated wiring system is not designed to accommodate the number of appliances and increased technology we use today.
• Replacements or any modifications that include knob and tube wiring should not be done by a handyman or even an electrician who doesn't have experience with this specific wiring system. Even changing a light fixture can be a costly or dangerous mistake.

If you have any questions about knob and tube in your home, looking to get a whole home remodel, or just grounding for outlets, contact your team at Skyline Electric for honest answers and exceptional service.