Electrical Wiring & Rewiring

Electrical Rewiring:

Sometimes, older homes have been wired entirely using an older standard of wiring, called, knob and tube. At the time, it was a practiced industry standard, however, now the Ontario Electrical Safety Code requires all electrical contractors to use the newer NMD90 wiring for the home, and NMWU for underground wiring.

Customers don’t have to rewire the entire home all in one go. It’s entirely up to the home owner how much of the home they would like to have upgraded to the new standard while keeping to their proposed budget. Customers sometimes ask if they can upgrade to the new wiring in their basement only, as they are looking to renovate the basement and turn it into an apartment. This is absolutely do able, and we recommend proceeding in this manner if you plan on performing these upgrades in stages.


When thinking about these stages, what do we actually mean? Typically, clients will want to renovate/upgrade a single level at a time, say, the top floor. When performing the electrical work, our electricians will fish the new wiring from the electrical panel (typically in the basement) to the second floor and begin wiring the new circuits. This process is then repeated as many times as necessary until the stage is completely upgraded. After completion of the stage, we will have an ESA inspector verify the work and provide a certificate of inspection for that address and the level that was worked on. It is up to each client to decide when the time is right to begin upgrading the next stage, in accordance with their financial abilities.

Some additional information regarding houses built in 1960’s or earlier:

  1. If your home was built around or before 1960, the electrical wiring powering the home was installed accordingly. Back then, most homes usually had 1 or 2 TV’s, several table/bedside lamps and a small, central light fixture in the living rooms, bathrooms and most bedrooms. Nowadays, we use high efficiency appliances, however, their temporary power consumption is still quite high compared to what the older wiring is able to carry.
  2. Aluminum wiring:

    Aluminum wiring

    Aluminum is a flexible, silver colored conductor that is commonly found in homes today. Our power distribution companies use aluminum wires to transmit power across the country, province and locally inside towns and cities. Between 1965 and 1970, there was a nation-wide copper shortage, which caused builders to switch from copper wiring to aluminum in order to fully wire homes. While aluminum was used for some large appliances such as heat pumps, electric furnaces, and kitchen ranges safely, the aluminum wiring really presents a problem to home owners where there are splices or connections that were not installed properly. In situations like this, it’s possible that at splice and connection points that sparks can form, cause heat to build up and potentially cause electrical fires. In our modern day era, we rarely see problems with aluminum wiring to larger appliances, however, we have seen issues where aluminum wiring is connected to light switches and outlet receptacles that were designed to function with aluminum, and where said switches and receptacles are replaced with “copper only” devices (such as the switches and outlets found at most hardware stores). In circumstances where aluminum wiring is connected/spliced with copper wiring, it is important to use a special wire connector that employs a corrosion inhibiting compound to prevent it from corroding and falling apart. While solutions exist to mitigate the dangers associated with aluminum wiring, we recommend upgrading your home wiring to copper wiring throughout so as to bring it up to code and make installing switches, dimmers, and power outlets (to name a few) simple, safe and efficient to install.

  3. If your home has 2-prong outlets:

This type of outlet can only be wired with a hot and neutral connection with no provision for grounding. While most lamps and simple electronics work with this type of receptacle, high-tech appliances or electronics with a metal shell such as desktop computers, fridges, or laundry machines require a separate ground. Also called a “safety ground”, the device ground “bonds” the metal components of the appliance to the ground bar in the electrical panel. Using this bonding, the exposed metal areas of these appliances cannot become energized as a result of malfunction or wear and tear. What to do about it? Our electricians are trained to resolve issues like these by either rewiring the circuit using application specific cabling, or by performing a grounding connection from that junction to the panel, and replacing the old outlet with a newer one that will have that third, grounding prong.

CFI ELECTRIC LTD. offer Electrical Wiring & Rewiring Services across the Greater Toronto Area including Mississauga, Rexdale, Etobicoke, North York, York, East York, Toronto, Scarborough, Leaside, The Beaches, Guildwood, Markham, Pickering, Ajax, Oshawa, Port Perry, Richmond Hill, Thornhill and Uxbridge.