Old Electrical Wiring: Warning Signs, Risks, and What a Home Warranty Covers

Older homes have a certain allure, but outdated infrastructure can make them especially prone to costly problems. If you live in an older home with wiring that has not been modernized, a little knowledge of your electrical system can help you keep costly repairs, frustration, and safety hazards in check.

Types of Old Wiring Found in Older Homes

If your home dates to the mid-20th century or earlier, it’s possible that the electrical wiring doesn’t meet modern standards. Here are the types of wiring that were prevalent 50+ years ago and are still in homes today.

• Knob-and-tube wiring. This type of wiring was developed in the 19th century and was used in home construction until the 1940s. The basic design featured unsheathed wires running through ceramic knobs and tubes. Notably, this system lacks a ground wire, making it incompatible with the three-prong outlets we use today. 
• Aluminum wiring. In the 1960s and 1970s, aluminum was often used as an alternative to copper to manufacture electrical wire. In this application, aluminum was initially beneficial because it is inexpensive, but aluminum expands and contracts more than copper with temperature changes. Over time, this expansion and contraction loosens wiring connections, increasing the risk of fire.
• Armored cable. Some wiring, even wiring used today, features a steel cover over the wire for protection. While modern armored cable is up to code, older versions often lacked a ground wire, instead relying on the metal covering for a ground path. If and when that metal covering corrodes, there’s no safe path for excess current in the event of a power surge, putting your appliances at risk.
• Cloth-wrapped wiring. Some older wiring types featured a covering made of a rubberized cloth. This covering is prone to deteriorating over time, posing a variety of hazards and failure points.

The Real Safety Hazards of Outdated Home Wiring

Old electrical systems can pose serious safety risks because of outdated technology, deteriorating materials, and the inability for old systems to manage the demands of modern appliances and lifestyles.

Fire is the most serious concern, and it’s one of the biggest aluminum wiring hazards in particular. Decades-old wiring tends to have loose connections, which makes the wires prone to overheating. This is doubly true when the system is working overtime to sustain the large electrical load of TVs, computers, kitchen and laundry appliances, and charging devices all running simultaneously. If the overheating wires come in contact with anything flammable, it can spark a fire.

Electrical shock is another hazard, particularly when the electrical system is missing a ground. Modern wiring uses a ground wire to send electrical current to the earth in the event of a fault. Without a ground, that current can run through a person instead.

How to Tell If Your Home Has Old Electrical Wiring

You might be able to check if your home has outdated wiring by inspecting any parts of the house that have exposed wiring. These locations could include a crawlspace, garage, or unfinished attic or basement. Compare the wiring you see against images of aluminum wiring, knob-and-tube wiring, and mid-century armored cables and cloth-wrapped wiring.

If you can’t locate any exposed wiring, be mindful of persistent electrical problems that could suggest your system need updating. These include:

• Flickering or dimming lights, especially when you run an appliance
• Frequently tripped breakers
• Discolored, warm, or charred outlet and switch covers
• The smell of something burning, even if it comes and goes

There are also some in-home electrical features that almost certainly point to outdated wiring. Modern electrical systems use three-prong outlets to accommodate the ground wire. If you have any two-prong outlets in your home, you should have your system assessed. You should also confirm that your electrical system includes a circuit breaker panel rather than an old-fashioned fuse box, which has been obsolete for decades. If your home still features a fuse box, you should inquire about an electrical panel upgrade and wiring update.

If you’re still in doubt about whether your electrical system is up to modern codes and standards, you can schedule an electrical inspection. A licensed electrician can assess the age and health of your system in no time.

Rewiring vs. Upgrading: What Your Options Actually Cost

Whether your home needs a full rewire or just some targeted upgrades depends on the type of wiring you have and its current condition. 

A total rewire involves replacing all wiring throughout the home, and it is no small job. For an average single-family home, this could cost between $8,000 and $15,000, though this number inflates quickly for larger homes with more square footage and complicated layouts. When the job is complete, you will also need to replace any torn down drywall and repaint or reapply wallpaper. Many homeowners also choose to tackle additional home updates at the same time, since it makes sense to replace any outdated plumbing or insulation as long as the walls are open to run new wire. This makes a rewire part of a larger renovation project, and costs can balloon into the tens of thousands quite quickly.

If the wiring is in acceptable condition but specific components need attention, targeted updates may be appropriate. You could upgrade to GFCI outlets for a few hundred dollars per circuit, for example, or an electrician might be able to modernize your aluminum wiring by upgrading the connection sites and outlets with copper wire in a process called pigtailing. At $3,000 to $5,000 for a full upgrade, pigtailing isn’t necessarily cheap, but it is less expensive than replacing all wiring in the home.

What to Ask Before Hiring an Electrician for Old Wiring Work

Not every electrician is comfortable or familiar with working on outdated wiring systems. As you look for a qualified contractor, consider posing these questions:

• What wiring types do you have experience working on? Have you worked with this type of wiring before?
• Are you licensed and insured in this state?
• Will this work require permits?
• Will a panel upgrade or targeted updates bring my system up to code? Is a full rewire necessary?
• Do you have recommendations for professionals who can handle the drywall repairs, repainting, and any other work that follows the electrical updates?

How Homeowner’s Insurance and Home Warranties Treat Old Wiring Differently

Homeowner’s insurance covers sudden, accidental damage and, under normal circumstances, would pay out in the event of an electrical fire. If the home has a known issue with old wiring, however, insurance companies may decline to provide coverage or they may charge much higher premiums. If you know your home has old wiring and haven’t disclosed that information to your provider, your claim may be denied if an accident does occur.

A home warranty does not cover accidental damage but instead works as a service contract to repair and replace home equipment that breaks down. While a home warranty is unlikely to cover a total rewire, it can help you pay for minor repairs, panel issues, outlets, and switches, even if you live in an older home. Liberty Home Guard, for example, includes electrical system coverage as standard in our major plans, and it can help you prevent small issues from turning into large ones. To learn more, call (833)-543-7699.