How to Safely Inspect Your Home’s Knob and Tube Wiring


Knob and tube (K&T) wiring was an early standardized method of electrical wiring used in buildings in the United States from about 1880 to the 1940s. This old wiring system is still present in many older homes, but it presents safety issues compared to modern electrical wiring. As a homeowner, it's important to inspect your home's knob and tube wiring to identify any potential hazards. This article provides a comprehensive guide on safely inspecting K&T wiring in your home.

Background on Knob and Tube Wiring

Before jumping into the inspection process, it helps to understand what K&T wiring is and why it can be dangerous.

What is Knob and Tube Wiring?

Dangers of Knob and Tube Wiring

There are several factors that make K&T wiring dangerous:

- Fire hazard - The risks above make K&T wiring a potential fire hazard.

Preparing for a Knob and Tube Inspection

Inspecting your home's knob and tube wiring yourself involves some preparation and precaution.

Safety Gear

Turn Off Power

Turn off all breakers and unplug all appliances prior to inspection. Use the non-contact voltage tester to confirm power is off.

Remove Covers

Inspecting Your Home for Knob and Tube Wiring

With safety gear on and power disconnected, thoroughly inspect your home for K&T wiring using the following tips:

Locations to Check

Light fixtures, outlets, switches, walls, attics, and basements. Key locations include:

Signs of Knob and Tube

Documenting and Mapping

As you find K&T wiring, thoroughly document and map it out:

Dealing with Knob and Tube Wiring Hazards

If you confirm your home has potentially dangerous K&T wiring, here are your options:



Load Management

Insurance Issues

When to Call an Electrician

While you can safely inspect your own home's wiring with precautions, it's best to call a licensed electrician under certain circumstances:

Their expertise can provide thorough evaluation and solutions to K&T hazards.


It's critical to inspect your older home for hazardous knob and tube wiring. Follow safety precautions, thoroughly check common locations, identify K&T, map it out, and address any risks found. If wiring is in poor condition or poses challenges for DIY inspection, don't hesitate to call an electrician. Taking action to deal with K&T wiring will make your home safer.