Rewiring Your Old House: Why It’s Important
If you live in or are purchasing an older home – like one that was originally built before 1940, then there’s a chance that it could have its original wiring. Knob-and-tube wiring is characterized by its white color and ceramic, spool-like knobs. It was the electrical wiring of choice from the 1880s all the way through the 1940s – and while it’s not illegal or against any building codes in most cases today, it can present some significant safety issues.
In this post, we’ll discuss why it could make sense to rewire an older home – both from a safety standpoint and a practical one. Here’s a look at what you need to know about rewiring an old house:
When Should a House be Rewired?
As we said, there’s nothing illegal about old knob-and-tube wiring in most municipalities. However, most building codes do say that it should only be used in open-air, non-insulated spaces. And this alone could present some practical issues with outdated home electrical wiring. For instance, if you follow building codes, you can’t insulate walls that have knob-and-tube wiring within them. This could lead to more heat loss in the winter and heat gain in the summer from a lack of insulation, causing your energy bills to increase. On another practical note, old wiring often won’t support three-pronged plugs because this type of wiring often doesn’t support a ground wire. This may limit your appliance options.
Additionally, old wiring can hurt the resale value of a property and make it less attractive to potential buyers if you were ever to put your home on the market. While older homes are high on charm, many buyers may find the electrical wiring too much of a potential issue to take on themselves. Some insurers won’t even insure homes or properties with knob-and-tube wiring due to the potential issues it could cause.
The Rewiring Process
Rewiring a home isn’t cheap, but it’s often necessary. It can be done in a couple of different ways. One is to cut into walls and run new wires, then replace any cuts with new drywall. The other way is more minimally invasive and consists of fishing new wiring through the walls.
Key Dangers Old Wiring Poses
Aside from practicality and resale issues, old wiring can pose a significant safety threat to your property. In this section, we’ll discuss some of the common hazards associated with knob-and-tube wiring and other types of dated electrical work. Here’s a look:
Not Enough Capacity for Modern Homes
Rather than replace old wiring, many property owners will attempt to modify it to meet their current needs. This isn’t a great idea for a few reasons. One, modifications can often overload the wiring, which can lead to a fire risk. And two, old electrical work tends to be unsafe in and of itself. Like everything, electrical wiring has a shelf life. The older it gets, the more modifications property owners make to meet their present-day needs, and the more problems you could have.
No Ground Wire
As we noted in the above section, knob-and-tube wiring doesn’t support three-pronged plugs. This means that this type of electrical wiring doesn’t have a ground wire, and any appliances that are plugged into it are more likely to be damaged due to voltage surges and other issues. This also has the potential to lead to electrical shocks.
No Moisture Rating
Older wiring often isn’t rated for moisture, which can present a shock and fire hazard in areas like the kitchen and bathrooms where water is more common.
Building Codes Often Aren’t Followed
As noted in the opening, knob-and-tube wiring isn’t illegal, but most building codes require it to be installed in open, insulation-free areas. This is because older wiring is designed to release heat, and if insulation or any other flammable building materials are nearby, it could lead to a fire. Unfortunately, building codes aren’t always followed and knob-and-tube wiring may be installed in and around insulation.