While it is common to find knob and tube wiring (an old type of wiring no longer being installed) in a home, home insurance companies will not insure your home because of it. They ask that it is removed, which can range from $6,000 – $12,000 depending on your home, and permits must be taken out for this. There are some companies that still insure homes with the electrical system containing some knob and tube, but they are not easy to find.

Knob and tube wiring was used in residential construction up until 1945. The name originates from porcelain knobs, which held the wire, and the ceramic tubes that were passed through wood framing. The biggest problem with them is that the coating around the wires breaks down over time and can create a hazard or even fire.

Another wiring problem is aluminum, which was used in the 1960s. It was discovered to be a fire hazard due to the chemical composition and overheating between connections.

While it’s fairly easy to spot knob and tube in unfinished areas of your home, I have found several situations where old wiring exists between hard-to-get-at areas, such as switches to ceiling lights.

A qualified home inspector or electrician should be consulted prior to starting any new additions or remodeling to your home. Also, some provinces and states have passed legislation where only certified electricians can do work on your electrical system, ranging from your panel to a simple light switch. Please make sure that the contractor is using a qualified electrician.
For more information, please visit the Electrical Safety Authority at www.esainspection.net.

cpaulsen@homerenovationguide.com