How to Safely Replace Knob and Tube Wiring in Your Home

How to Safely Replace Knob and Tube Wiring in Your Home

What is Knob and Tube Wiring?

Knob and tube wiring was commonly installed in homes built before the 1950s. It consists of individual hot and neutral wires that are separated from each other, rather than bundled together like modern electrical wiring.

The hot wire is insulated and supported by ceramic knobs, while the neutral wire is suspended in air on porcelain tubes. This type of wiring does not include a ground wire.

While knob and tube wiring was suitable for the time when it was installed, it can be unsafe by today's electrical standards due to the lack of a ground wire and insulation that has degraded over time.

Dangers of Knob and Tube Wiring

There are several dangers associated with old knob and tube wiring:

Signs You Still Have Active Knob and Tube Wiring

Here are some signs that your home likely still has active, live knob and tube wiring:

If unsure, have an electrician inspect your home's wiring to verify if knob and tube circuits are still in use.

Options for Replacing Knob and Tube Wiring

There are two main options for dealing with knob and tube wiring:

1. Remove and Completely Replace

This is the recommended option for safety. It involves:




This involves leaving the old knob and tube wiring in place but splicing it to new wiring that connects to outlets and fixtures.



I do not recommend this shortcut method as it leaves the base fire risk still in place.

Safety Tips When Rewiring a Home Yourself

If you plan to DIY the rewiring work, keep these safety tips in mind:

Rewiring an entire home is complex. Unless you are experienced, it may be safer, faster, and more cost-effective to hire a licensed electrician.

Cost to Professionally Replace Knob and Tube Wiring

The cost to fully replace knob and tube wiring in a home often ranges from $8,000 to $15,000 or more, depending on:

Get quotes from licensed electricians to understand the exact costs for your unique situation. Many homeowners find the peace of mind and increased home value are worth the investment.

Replacing hazardous knob and tube wiring greatly improves safety for your home. Follow local building codes, get necessary permits, and consider hiring a professional electrician for this complex project.