Knob & Tube – Should I Worry It’s In My Home?

Knob & Tube is an old wiring we find in homes. It was generally installed from the 1880’s to the 1940’s. Many people have heard about this wiring, and maybe have even seen it, but may not fully understand what it is or what it means to be present in your home. The wiring was ungrounded and had a hot and neutral wire running independently. The knobs were used to change direction and the tubes would insulate the wires when going through wood and other building materials. It may seem like it’s not too dangerous, the wires are separated, and it has been in your home for typically at least a hundred years right! So, what makes it something you should worry about?

  1. It’s probably been altered. Originally the connections were soldered together. Your home has gone through many changes over the years. While the original installer may have taken great care, we often see modern Romex wiring spliced into the wiring and other very poor connections. This is not a safe practice and may lead to a fire in your home.
  2. Insulation. We love tight homes and energy efficiency in today’s world. Knob & Tube is an open-air system, meaning it is designed to dissipate heat by having space and air movement around the wires. While insulation installers typically know this, they can’t see into the walls and we constantly find Knob & Tube covered in insulation. This can lead to overheating and again fire.
  3. It’s ungrounded. A ground serves multiple purposes; it can help protect the user against shock and help trip a breaker if a fault is occurring. An ungrounded circuit poses a shock and fire hazard, especially with the larger demand we put on wiring today.
  4. It is often associated with Asbestos. Some wiring had Asbestos used in the wiring materials and we also see Knob & Tube fuse panels insulated with Asbestos. Asbestos presents its own hazards but is just another downside to this aged wiring system.
  5. IT’S VERY OLD. Typically, 100 years or older wiring can’t last forever. Yes, it’s been around a long time, but it is getting more brittle and more susceptible to fire as time goes on. It expands, contracts, gets hot, and dries out over time. I think it’s pretty fair to say it has lasted long enough and should really be replaced.

In summary, I personally don’t think this should be much of a debate. If you want one system of your home in really good shape, it’s your electrical system in my opinion. For whatever reason, aged wiring is one of the more overlooked issues with homes today and many people choose to ignore these issues. I understand it’s expensive to update or replace your electrical system but having Knob & Tube wiring can even make it difficult or not possible to get insurance from many insurance companies these days. That alone is reason enough because insurance companies do this because they know it poses a large risk.

Don’t put your family at risk by putting off the replacement of this old wiring.