Toronto’s Knob and Tube Wiring Experts

Last updated: September 2026

Knob and tube wiring is one of the oldest methods of home wiring. It uses two wires: a live wire and a neutral wire, with no ground wire. The cloth-covered wires are attached to porcelain knobs to hold them in place. Holes are drilled through studs or joists, and porcelain tubes are fitted to protect the wires from touching the wood.

Common Faults Associated with Knob-and-Tube Wiring

A properly installed and maintained knob and tube system doesn’t pose an immediate risk. However, problems can occur over time due to the age of the wiring or changes made by previous homeowners. Improper alterations or repairs can also create new issues or worsen existing ones. We are a licensed electrical contractor serving Toronto and the GTA, specializing in knob and tube wiring replacement, removal, inspections, and home rewiring.

One of the most common issues with knob and tube wiring is its insulation. Unlike modern plastic insulation, it’s made from rubber or cloth, which can become brittle and deteriorate over time. This can leave wires exposed, increasing the risk of short circuits and fires. We perform thorough inspections to identify exposed wires, deteriorated insulation, and other hidden hazards, and repair or replace damaged wiring where necessary.

Wiring Is Never a DIY Task

Knob and tube wiring should always be handled by a qualified licensed residential electrician because of the potential risks. Our skilled team has the experience to safely handle even the most challenging wiring problems. No matter how complex the issue, we resolve it safely and efficiently.

New wiring for knob and tube replacement
Knob and tube wiring exposed in an open wall during rewiring of an older Toronto home

Complete Wiring Replacement

If you notice any cracks or damage in your knob and tube wiring, schedule a knob and tube wiring inspection with a licensed electrician immediately. Using modern tools and materials, we replace the affected wiring with precision and care. Your safety is our priority, and we ensure every replacement is done accurately to prevent future problems.

Rewiring Knob and Tube Wiring

Because of the risks and complexities associated with knob and tube wiring, a complete rewiring or whole house rewiring may be the safest solution. Our team has extensive experience in rewiring homes, making them safer and more efficient while improving overall electrical performance. We replace the old system with modern wiring that meets today’s electrical needs and safety standards. The time required depends on the size of the home, accessibility, and how much wiring needs to be replaced.

Homeowners should be extra careful with knob-and-tube systems, as they can become dangerous if damaged or improperly modified. A trusted residential electrician, like Ontime Electric, has the skills and experience to handle these complex wiring jobs safely.

Knob and Tube Wiring Replacement Cost in Toronto

Replacement cost depends on the size of your home, how much of the original wiring remains, and how accessible it is (finished walls cost more to work in than an unfinished basement or attic). Full home rewiring typically runs $5,000–$20,000+ — because every home is different, Ontime Electric assesses the wiring first and provides a written knob and tube replacement quote before work begins, with no surprises mid-project. Our guide on what it costs to wire your house covers the full breakdown.

Worth knowing: many Ontario insurers may not provide or renew home insurance on a property with active knob and tube wiring, so knob and tube replacement can make a significant difference for insurability.

Knob and Tube FAQs

Knob-and-tube wiring isn’t illegal in Toronto, but it’s considered outdated and a potential safety hazard. It’s no longer allowed in new construction projects.

Knob-and-tube wiring was widely used from about 1900 to the late 1940s. Many older homes across Toronto & GTA may still have this type of wiring.

Knob-and-tube (K&T) wiring is an early electrical system using separate cloth-insulated copper wires. Ceramic knobs hold wires in place, and ceramic tubes protect wires as they pass through wooden beams.

You can sell a house with knob-and-tube wiring, but many insurers may flag it or require removal or proper upgrades before issuing home insurance.

It depends on the home’s size and how accessible the old wiring is. Ontime Electric provides a written, upfront quote after an assessment, and every replacement includes the required ESA notification and Certificate of Acceptance once the work is reviewed and accepted.

If your Toronto home was built before the 1950s or you suspect it still has knob and tube wiring, a professional knob and tube wiring inspection can confirm its condition and identify damaged insulation, unsafe alterations, overloaded circuits, or other hazards. A licensed electrician can then recommend whether repairs or complete replacement are needed.

Yes. Ontime Electric provides knob and tube wiring removal and replacement throughout Toronto and the GTA. Our licensed electricians remove outdated wiring and replace it with modern, grounded wiring that meets current electrical safety requirements.

Yes. Some Ontario insurers may require knob and tube wiring to be inspected, repaired, or replaced before issuing or renewing home insurance. Once required electrical work is completed and accepted, ESA issues a Certificate of Acceptance for the work.