Understanding Knob and Tube Wiring

Closeup of a porcelain knob in a residential knob and tube wiring system.

What do you know about your home’s electrical wiring? Older or overworked systems can pose serious safety hazards, including fire and electrocution. This is especially true with knob and tube wiring. Read on to learn about the dangers associated with this type of system, how to tell if your home has one, and the importance of having it replaced.

What Is Knob and Tube Wiring?

Knob and tube wiring (K&T) is an outdated, indoor electrical wiring method and was the standard system used in North America from 1880 to the 1940s. It features insulated copper conductors run through wood framing via protective porcelain insulating tubes, with nailed-down porcelain knobs providing support along the length. And at points where wires are pulled into a wall or enter a wiring device (i.e., a lamp or switch), flexible cloth or rubber insulation known as “loom” is used to protect them.

How to Tell If Your Home Has K&T

K&T is generally easy to identify: Look in your basement and attic for the white porcelain knobs and tubes with wires snaking through. However, while the knobs are typically nailed to exposed joists, they can also be hidden in the walls by previous remodels/renovations. It’s recommended to contact a professional electrician to check for K&T by opening the walls or using a camera.

Why Is It Dangerous?

A K&T system isn’t inherently dangerous, but improper modifications, old age, and the potential for building insulation to engulf the wires create a severe safety/fire hazard. Additionally, it has no ground wire and is thus unequipped to safely handle modern three-pronged appliances and electronics.

Schedule Knob and Tube Wiring Replacement with Stafford

Homes built before 1950 were likely wired with a K&T system. Rely on the local, expert electricians at Stafford for knob and tube wiring replacement to ensure your household is safe and equipped to handle all power needs.

We’re currently offering a deal for $100 off a knob and tube wiring inspection. Claim your promo HERE, and then contact us to learn more and schedule service.



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