Was your home built before 1950? There’s a good chance you have knob-and-tube (K&T) wiring. This early method of wiring was most common in North America from around the 1880s to the 1940s as American’s used less energy and electricians were less skilled.
As years passed and more energy is consumed by televisions, computers, air conditioners, and more, it’s difficult for these wires to sustain the load. While it’s not necessarily dangerous, the system has been considered obsolete for decades and, in some cases, can pose a safety hazard.
What is Knob-and-Tube Wiring?
K&T wiring is self-explanatory. It consists of wiring protected by rubber and porcelain or ceramic tubes for support when passing through wood framing. The ceramic knobs are nailed or screwed to wooden structural components and support the tubes.
Is K&T Wiring Safe?
It can be. This is almost impossible to answer until inspecting the existing system. While your K&T system may be in great shape, there’s an equal chance it needs to be replaced immediately. Why? Here are some reasons why your safety could be at risk.
Inefficient Electrical Supply
K&T wasn’t designed to power modern-day homes, and for a good reason. There was no way to foresee the amount of electricity we currently use daily. Back then, the system powered toasters, coffee percolators, clothes irons, and light bulbs (and later refrigerators and small black and white TVs). Demand has increased significantly over time.
Damage and/or Poor Connections
Over the years, previous owners may have added to the existing systems. Often, these connections were made by splicing wires together and may be dangerous. Essentially, the age of the system increases the likelihood that improper modifications were made.
Age and Brittleness
Time takes its toll on all things, and K&T wiring systems are no exception. The wires back then were insulated with rubber, which can become brittle and deteriorate. Conductors can also stretch and sag over time, and old, damaged wiring can be a fire hazard if installed near insulation.
No Ground Wiring
Modern wiring systems consist of black, white, and ground wires bundled together and encased in plastic. The K&T system has separate tubing for black and white wires, and no ground wire exists. This is obviously a safety hazard, especially in areas close to water.
Do Insurance Companies Cover Homes with Knob-and-Tube Wiring?
Uninsurable? Some insurance companies will not insure homes that use K&T wiring, no matter its condition. Other companies do not mind or will only insure the home if a licensed electrician gives it a passing grade. If you do receive coverage, experts recommend purchasing an extended or replacement policy.
What Should I Do if I Have K&T Wiring?
First, don’t panic. No codes or regulations specifically require K&T wiring to be removed from your home. Many homeowners replace room-by-room as they remodel or update the home. As a result, your K&T wiring may be completely safe, but we highly recommend having it inspected and evaluated annually, considering its age and possible safety concerns.
Knob-and-Tube Safety Tips
- Do not run too many appliances at once, as this may cause a fire.
- If wiring is damaged, replace it immediately.
- Negotiate with the seller if you are buying a home with K&T wiring.
- Never try to fix the wiring yourself. Please call an expert!
- It will not support 3-prong and 4-prong appliances, as they are not grounded.
- Do not place insulation over bare wire and in garages and attics, as this may cause a fire.
Call the Experts!
Don’t let fear keep you up at night but be aware that your K&T wiring potentially places your home and its inhabitants at risk. You owe it to yourself and your loved ones to have it inspected, at the very least.