Knob And Tube Wiring

Knob and tube wiring removal has been our specialty since 1996. One of our strengths is in taking ownership of the patching required to repair the holes made by the rewiring. This makes our holes more “patching friendly.” We always aim to complete projects with efficiency and treat your residence as a home and not just a job site.

We start the process with a written, detailed quotation. This has the itemized list of individual costs for your consideration. We always take the time to help you make the right choices.

Old Wiring and Knob and Tube Wiring

Knob and Tube Services in Toronto

When choosing Langstaff and Sloan Inc for your aluminum knob and tube wiring needs, we are committed to:

  • Being accessible through phone during business hours to schedule an appointment for a quotation
  • Arriving on time for the quotation
  • Providing a written and detailed quote
  • Scheduling a specific start and finish date
  • Dispatching a sufficient team to complete the project in time
  • Arranging daily communication with our crew leaders
  • Handling all arrangements with the Electrical Safety Authority (ESA) and your Local Distribution Company (LDC)
  • Walking you through your entire home to ensure your satisfaction
  • Treating you and your home with respect and courtesy
  • Encourage you to provide honest feedback for our constant improvement

Knob and Tube Wiring Replacement

Why is Knob and Tube Wiring Dangerous?


Knob and tube were used from the 1880s through the 1940s. If your home is running on this outdated technology, it means your wiring system is from the WWII era at the latest. The difference in electricity consumption from that time to today poses a threat to your home. If you have these installed, chances are these are overloaded and may cause electrical fires.


Insulation is typically installed over knob and tube wiring. That increases the chances for a fire to break out. The extra layer of rubber cloth insulation leaves little space for heat to dissipate. There could be build up when current is flowing through the wires. This can potentially be hazardous and can lead to serious issues with your knob and tube wiring.

Improper Alterations

A lot of issues with knob and tube are due to DIY fixes or an unauthorized handyman. The old wiring system makes it a challenge to find available parts. This often leads to improper solutions and alterations.

Absence of Ground Wire

The absence of ground wire makes the aluminum knob and tube wiring unsafe for modern, three-pronged appliances and devices. This can lead to danger and increase the chances of fire.

Does Not Do Well with Moisture

Aluminum knob and tube wiring is not suitable for moist environments. Exposing it to wet areas can be dangerous, with the possibility of shocking anyone nearby.

Your Aluminum Knob and Tube Wiring Experts in Toronto

Looking for a trusted electrical contractor in Ontario? Langstaff and Sloan Inc has years of experience serving areas in the GTA. We guarantee high-quality service that can ensure your home’s safety.

Contact us today and let our licensed electricians take care of your aluminum knob and tube wiring needs!


  • 1. What is “Knob and Tube” type wiring?
    This is the first generation of wiring in Canada. Shortly after the end of WWII, it was abandoned for “Two conductor/Cloth covered” type wiring. Click here to see photo’s. As you can see, this type of wiring uses ceramic knobs to support individual wires running along the wooden beams, and ceramic tubes to pass through wooden beams. The connections are done by splicing, soldering and taping. This is usually well done, however not very accessible for any future repairs/alterations.
  • 2. Why is it unsafe?
    There is no ground wire. This presents a shock hazard, and could lead to an electrical fire. It has no temperature rating. This is why the wires above ceiling mounted fixtures are so commonly compromised. It is a free air wiring system and was never meant to be covered by insulation.