Knob and tube wiring is what you see in houses that predate the 1950’s. Compared to modern wiring, knob and tube wiring does not have a ground wire, which means that it is not compatible with any three-pronged electrical devices. This translates into a greater shock risk as well as fire.
Another difference is that the black and white wires run separately, whereas in today’s wiring the black wire, white wire, and the ground wire run through a single cable.
The last of the major difference is the wire insulation. Know and tube wiring uses a rubber insulation, and modern wiring is insulated with plastic. One of the biggest deficiencies of know and tube wiring insulation is that the rubber insulation breaks down over time, which results more frequently in overheating or mechanical abuse.
As mentioned above, the first indication is the age of your house. Even though you may have a house that was built after 1950, there is still a chance you have know and tube wiring.
Go down to basement. Do you see wires running through porcelain cylinders or tubes going through holes in the wood floor joists? If you do, then you have knob and tube wiring.
For further indication, can you see if the wires are insulated with a rubberized cloth fabric? There may also be porcelain knobs that help secure the wire and keep them from touching the wood.
Keep in mind that even if you don’t visually see the described attributes mentioned above, it doesn’t mean that you don’t have tube and knob wiring. Previous home owners could have concealed the wiring in walls or ceilings, whether intentionally or not. Sometimes this is known as spider wiring. Unfortunately, the only way to tell is by opening up the walls or ceiling.
Houses in the Wolseley and River Heights neighborhoods have a better chance of having know and tube wiring.
The obvious answer is yes – you should probably start planning to replace all your old wiring with new modern wiring materials and techniques.
Obtaining home insurance may be a bit trickier, or at least more expensive. There may be exclusions in your plan if you have knob and tube wiring.
If you ever want to plan any renovations, this type of wiring can also cause you unforeseen headaches. For example, knob and tube wiring cannot have any insulation around it, apart from its own, since it runs hot and need air around it to cool.
At the time of writing this, there is no requirement in the Canadian building code that say a homeowner must replace knob and tube wiring. However, it is considered obsolete.
You should never attempt to do any electrical renovations if you are not a licensed Winnipeg electrician.
Not only is it not safe, but it can also invalidate home insurance and take away the possibility of selling your home without changing everything over first, which will be to your disadvantage as most home-buying prospects will use it to their advantage in negotiating.