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Knob and Tube Wiring: What It Is and Why You Should Replace It


Knob and Tube Wiring
Schenectady NY home Inspections Knob and Tube Wiring

Knob and tube, also referred to as K&T wiring, is the first form of electrical wiring ever used, making it considerably old. During the construction of homes that were built between 1880 and 1950, this wiring design was widely used across the United States. While rather aged, the knot and tube wiring can still be found in some residences today. Even in homes that have areas of updated wiring, oftentimes the K&T is still found in tight spaces such as attics and crawl spaces. Due to the age and design of the knot and tube wiring, it is typically considered a hazard by today’s safety standards. So, if you are looking at purchasing an older home and find that it has this type of wiring, be sure to have it thoroughly inspected.


What Is Knob and Tube Wiring?

Knob and tube wiring is designed with aluminum or copper wiring that is encased in black rubber tubing. The encased wiring was installed along the wood framing and then was attached to a ceramic cylinder, i.e. knob to hold the wiring in place. Unlike modern wiring, the knob and tube wiring does not include a grounding wire. Instead, it consists only of black and white wire strands that without grounding wire could potentially increase the risk of fire or shock if a fault occurs.


The Issues of Knob and Tube Wiring

While knob and tube wiring does not necessarily pose an immediate danger, it does degrade over time. Whereas modern-day wiring has flexible plastic sheathing and a grounding wire, the wiring of that era was encased in rubber and sometimes a cotton-based sheath, both of which deteriorate over time. Additionally, the knob and tube wiring was designed for a much lighter use of electricity versus the electrical load required in most homes today.


If the knob and tube wiring were installed correctly and has not been tampered with, sometimes the integrity of the wiring remains safe, overall. But, if the wiring is beginning to degrade the signs will be fairly evident with noticeable cracks in the tubing and/or visibly frayed or exposed wires.


Yet another issue with the knob and tube wiring is that many insurance companies will not insure a home that has it. This is because of its design to handle a lower electrical capacity, making it easy to overload. When you mix that in with the factors of age and absence of any grounding wire, it obviously raises concern. However, there are exceptions to this, which include the location and condition of the wiring in the home. Oftentimes, most insurance companies will base their decision on coverage upon hearing the opinions of a certified inspector.


So, if you are considering the purchase of an older home in the Schenectady, NY area, contact us and we will be happy to inspect it for you. We will communicate with you every step of the way and happily answer any questions for you.



The Author Schenectady NY Home Inspections LLC is a locally owned and family operated Home Inspection Company. Schenectady NY Home Inspections is located in Schenectady NY and has performed over 6500 Inspections Book online Phone: 1-800-603-5194


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