What is wrong with knob and tube? | GEN3 Electric & HVAC

For many people, the process of buying a home is an exciting one. There are a lot of steps involved in the process, and it can be difficult to keep track of everything. One of the most important things to remember is that your new home may have some outdated wiring systems known as knob and tube. While knob and tube wiring is not inherently dangerous, there are some things you should know about it before purchasing your home. Keep reading to learn more!

  • Knob-and-tube wiring is an out-of-date type of wiring found in homes built before the 1940s.
  • Knob-and-tube wiring consists of wires passing through ceramic tubes in the joists and other wooden parts of the house, held up by ceramic knobs. The wires string together from tube to tube and are usually rubber insulated.
  • This type of wiring was used because it was less expensive than other options available at the time, such as conduits, armored cables, and metal junction boxes.
    • However, knob-and-tube wiring is dangerous because:
    • The basic insulation (rubber) decays over time.
  • It isn’t grounded, which can create a dangerous situation in the event of a power surge or electrical fire. o If a home has had modern wiring put in alongside the rubber wires of knob=and=tube setups (which is against code), this combination can be dangerous as well.. 
  • Even if this type of wirind were safe—which it is not—we recommend replacing it entirely because:
    • The demand if many modern appliances simply too much for this wireing to handle.