knob and tube wiring

Does Your Home Have Knob & Tube Wiring?

The first electrical systems, added to homes in the early 1900s, were called knob and tube wiring. These systems stopped being installed in the 1950s, and electrical wiring techniques have advanced far beyond them. However, you may still find knob and tube wiring in your home if built in the 1950’s or previous.

What Does Knob And Tube Wiring Look Like?


knob and tube

In many homes, some of the wiring is visible in the attic or unfinished part of the basement, it looks like electrical wires supported by thick white knob and tubes. These white parts are made from ceramic or porcelain and designed to provide a bit of insulation for the wires.

The tubes surround the wires where they pass through wood, and the knobs are usually mounted onto the wood. If you find exposed knob and tube wiring, don’t touch it.

Should I Get Knob And Tube Wiring Removed?

Yes, you should rewire any knob and tube type wiring. It predates temperature ratings of wire and is a free-air wiring system. Most houses have insulation. Also, it is not grounded which means it is more likely to cause a shock or start a fire.

The Ontario Electrical Code does not recognize knob and tube wiring as a safe method of wiring. It may be rewired, but new Toronto electrical installations cannot involve knob and tube wiring.

If you would like your knob and tube wiring maintained, we suggest that you choose only the most experienced professionals for the job. At Langstaff and Sloan we usually have at least one knob and tube rewiring project on the go. The holes we make for patching are smaller than most, which allows for easier access to these wires. We also complete rewiring jobs faster than other electricians.

Need a new Toronto electrical installation? Contact us at Langstaff and Sloan for expert, professional service.