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If you’re house hunting, you’ll want to know about wiring.

This is true in older homes – especially those built before 1950.

Homeowners must tell a prospective insurer what type of wiring their home has. Some won’t insure certain types because they are viewed as high-risk. And, if they will insure the home, it will likely be at a much higher premium and require an inspection by a qualified electrician.

The chief cause of electrical fires in Canada is faulty wiring. Although electrical fires can happen in any home through defective workmanship, poorly done DIY projects or normal wear and tear, keeping on top of any issues is an important part of being a homeowner.

Types of wiring systems

Knob and Tube Wiring: Commonly used in homes built before 1950, this type of wiring consists of ceramic knobs that support the wires and ceramic tubes that protect them as they pass through walls and joists. Because it’s single-insulated, it can quickly become hazardous due to fraying. It is also a two-wire system that does not contain ground wiring, which makes it incompatible with modern three-prong appliances. Without grounding, it can also damage your electronics. It can expose people to the risk of electrical shock and is not rated for moist environments such as kitchens and bathrooms. Not designed to handle the electrical demand of today’s home.

PRO TIP: Often, homes are sold saying there is no knob-and-tube present, but it can often be found inside walls, ceilings and under floors. The best approach when dealing with an older home is to assume there is unless documents show the building has been fully rewired and inspected.

Aluminum wiring: This gained popularity in the 1960s and 70s as a cheaper alternative to copper. But it is prone to oxidations, which can lead to loose connections, overheating and fire risks. It can be dangerous because it has a higher rate of thermal expansion. When the electricity passes through cables and connectors, wires heat up and expand. Safety experts say aluminum wiring in homes built before 1972 more than doubles the risk of fire breaking out at connection points.

PRO TIP: Aluminum wiring can also present insurance problems for potential buyers if you’re trying to sell your home. Insurance companies often insist that aluminum wiring systems are thoroughly inspected by a licensed electrical contractor or that wiring is updated.

60 Amp: Today we have more appliances which often need stronger amperage. Older wiring is usually rated for a lower AMP. As a result, this may not be enough to service a home with an electric stove, oven, clothes dryer, air conditioner, and more. This can cause circuits to overload and lead to a fire. Many companies will not insure a home with a 60 amp service. Their rationale is that if the service is 60 amp, the system must be old. If the system is old, it should be upgraded.

PRO TIP: Alberta-based Robarts Electrical Services Limited notes it is becoming more common lately that during negotiation for the sale of a home, the buyer’s realtor will ask for $10,000 off the selling price of the home because of 60 amp service. But the service upgrade to 100 amp by a qualified electrician could cost less than $3,000 depending on the size of your home. It’s wise to find out ahead of time … the upgrade may benefit you.

Copper wiring: This is the standard for electrical wiring used in home construction today. Copper wiring can resist corrosion, which is a major concern in areas with high humidity or salt exposure. It is also highly resistant to heat and wear and tear. It can handle high temperatures without melting or degrading. Highly flexible, copper is easy to bend when wiring the house.

PRO TIP: Copper wiring has a long lifespan and can last for several decades without needing replacement or repair. This allows for savings on maintenance and replacement. In addition, the efficiency and safety benefits of copper wiring can help reduce energy costs and minimize the risk of electrical hazards.

How do I know what type of wiring a house has?

To determine what type of wiring your home has, you must first check what year your home was built.

If by some chance your wiring is exposed, for example in an attic or basement, you can check the color of the wiring to determine its type. Aluminum wiring is silver will be marked with ALUMINUM, ALUM, AL. ALUMINUM, ACM, ALUM ACM, or ALACM.

To be completely certain, hire an electrician to check your home’s wiring. This can also be a good time to assess the condition of the wiring and determine if an upgrade is necessary.

Will insurance cover my electrical panel?

Electrical panels are typically covered by a homeowner’s policy if the damage is the result of a “sudden and accidental” loss caused by a peril such as fire or lightning. However, it won’t be covered if the damage is the result of age or improper maintenance.

Hire qualified professionals

Most insurers see homes with knob-and-tube wiring, aluminum wiring, and 60-amp service as high-risk. Hidden electrical fire hazards may exist in most older houses and homes built before 1975. Many insurers also won’t cover certain wiring issues such as faulty workmanship or repair.

This is NOT the time for a DIY project. Hire a qualified professional electrician so you – and your insurer – know your electrical system is safe. In Ontario, visit the Electrical Safety Authority to find a local technician. If you live in another province or territory, consult your regulatory authority. If you upgrade, be sure to get any documents for your insurer or any future sale.