As a licensed electrician working across Ontario, I often get calls from homeowners in older homes who discover they still have knob and tube wiring. If your home was built before the 1950s or early 1960s, there’s a good chance this type of wiring is still hidden behind your walls and ceilings.
Knob and tube wiring was common for decades and was considered safe at the time. However, today it often doesn’t meet modern electrical demands or safety standards. That’s where knob and tube rejuvenation or a full rewire comes in, and why I always recommend homeowners have their system assessed.
What Is Knob and Tube Wiring?
Knob and tube (K&T) wiring is an older style of electrical system that uses single wires supported by ceramic knobs and tubes. The hot and neutral wires are separated, and insulation is limited compared to modern wiring methods.
While it was sufficient for the small electrical loads of early 20th-century homes, it wasn’t designed for today’s technology-heavy lifestyles. Modern homes run multiple high-powered appliances, computers, EV chargers, hot tubs, and more—all of which can overload an old K&T system if it hasn’t been upgraded.
Why I Recommend Knob and Tube Rejuvenation
Knob and tube wiring itself isn’t inherently unsafe—but over time, connections can deteriorate, insulation can become brittle, and modifications or additions may have been done improperly. This is where rejuvenation comes in.
During a knob and tube rejuvenation, I:
- Inspect all connections for wear or damage
- Replace or secure wiring where necessary
- Add modern receptacles and switches using approved methods
- Ensure proper grounding and bonding of circuits
- Apply approved connectors and insulating techniques to maintain safety
Rejuvenation allows the original K&T wiring to continue safely supporting your home while reducing the risk of overheating or other electrical hazards.
When a Full Rewire Is Needed
Sometimes, rejuvenation isn’t enough. If the wiring is extensively degraded, has been improperly modified, or simply cannot handle modern electrical loads, I recommend a full rewire.
A full rewiring project typically involves:
- Removing old knob and tube wiring
- Installing modern copper wiring with proper insulation
- Upgrading the electrical panel if necessary
- Adding circuits, outlets, and lighting to meet current electrical needs
- Ensuring the system passes inspection by the Electrical Safety Authority
This approach brings your home fully up to today’s safety standards and makes it ready for any electrical demands now or in the future.
Insurance Considerations for Knob and Tube Wiring in Ontario
Many insurance companies in Ontario are hesitant to insure homes with active knob and tube wiring, or they may require an electrical inspection before providing coverage.
A proper K&T rejuvenation or rewiring project not only improves safety—it also satisfies insurance requirements, giving homeowners peace of mind and simplifying the process of getting coverage.
Signs Your Knob and Tube Wiring Needs Attention
When I assess homes with K&T wiring, I look for signs that indicate the system may need rejuvenation or replacement:
- Flickering lights or frequent blown fuses
- Warm or discoloured receptacles
- Signs of modifications or additions done without permits
- Homes with high electrical demand that the original system can’t safely handle
Even if your home hasn’t shown problems yet, an assessment is always a smart step, especially if you’re planning renovations or increasing your electrical load.
Protecting Your Home and Family
Knob and tube wiring has served Ontario homes for decades, but it needs careful maintenance or upgrading to remain safe today. Whether I perform a rejuvenation to preserve the existing system or a full rewire for long-term safety and capacity, the goal is always the same: to protect your home, your family, and your investment.
By having a licensed electrician evaluate your K&T system and complete the necessary work, you ensure your home meets modern electrical standards and passes inspections through the Electrical Safety Authority. This brings peace of mind and allows your home to safely meet today’s electrical demands.
Call us for a FREE In home quote today!
Enrico’s Electrical Company
Your Ajax Electrician
Toronto & GTA
416-455-5796
Durham Region & Kawarthas
905-239-0077
Trust your knob and tube to a professional
A letter from a Customer
We purchased a 100-year old semi in downtown Toronto, and had a few concerns with the electrical in the house. Home inspection revealed knob and tube in the master bedroom, and visually the outlets seemed old and misplaced. Light switch boxes were in strange locations, and the second bedroom didn’t have a ceiling light fixture. Enrico was so thorough, so patient explaining all the work he suggested should be done (not in a pushy way – in a “if this was my house” way), and the quote came back with options … I was very very impressed with the process, with his professionalism, and his knowledge – especially of older homes. I hired him immediately upon receiving the quote.
Enrico was scheduled to come in the following week, so I never had to wait for the work to be done. He was super punctual. They were the most conscientious workers. Booties over their shoes, drop sheet where they kept the tools, and even bags taped to the wall under areas they had to cut/drill to minimize dust. They even cleaned up afterwards!
My impression was that Enrico went above and beyond what was quoted for my job. I had knob and tube removed from the master bedroom. The house has no attic, so there were holes cut out in the walls to fish out the wires. But then Enrico plugged the walls back up and put drywall compound over it to patch it right back up! Completely unexpected and done in a professional manner. They installed a ceiling light outlet in the second bedroom where there was none. Perfection.
They replaced an old macgruber hack job in the upstairs hallway (outlet with three plugs…?! from previous owner’s “electrician”) with an updated plug and again, they filled in the hole that was left. It was cut into the wainscoting, and Enrico even put a groove in the plastered area to make it look like the wainscoting was intact where they had cut. Amazing!!!
They installed an astronomical timer for my front porch light (automatically changes on/off time according to almanac/longitude/latitude), and changed my front hall 3-switch panel that had been installed INTO the doorframe into a standard 3-switch panel outside the doorframe … And then yep, you guessed it, they patched up my doorframe with some putty to keep the frame intact. As I said, above and beyond!
Now the best part… It only took two days! These guys are machines. Enrico – THANK YOU
Toronto, ON