What are some of the problems associated with knob-and-tube wiring?
Knob-and-tube wire covering tended to deteriorate over time, get brittle, crack and even fall off, leaving the wire exposed. The wires were connected and soldered together, and usually wrapped with electrical tape. Over time, the electrical tape had a tendency to fall off as well. A lot of the wiring is usually concealed in walls and ceilings, and even covered with the home’s insulation, and therefore cannot be fully evaluated.
Poor connections and unsafe modifications were also a very common problem with the wiring. The older systems used a 60 amp service, but the wire is only fused with 15 amps. With more current flowing through the wire than it could handle, this lead to overheating and possibly even fire. Additionally, not having a ground wire for protection also increased the risk of shock or fire.