How to Safely Replace Dangerous Knob and Tube Wiring

Knob and tube wiring was commonly installed in homes built before 1950. This outdated wiring can be dangerous due to insulation breakdown and overloaded circuits. Replacing knob and tube wiring with modern electrical wiring improves safety and allows for additional circuits to be added. Here’s how to safely replace knob and tube wiring in your home.

Dangers of Knob and Tube Wiring

Knob and tube wiring consists of two single insulated wires running through the framing of the home. One carries the electric current while the other acts as the neutral return. The hot and neutral wires are separated by about 4 inches and supported by ceramic knobs.

This old wiring is dangerous for several reasons:

For these reasons, knob and tube wiring poses a serious fire and electrocution risk. Replacement should be a top priority for homes that still have it.

When to Replace Knob and Tube Wiring

Here are some signs that indicate your old knob and tube wiring should be replaced:

Preparing for a Knob and Tube Replacement Project

Replacing knob and tube wiring is a major project that requires extensive planning and preparation:

Proper planning makes the replacement process smoother and identifies any special challenges specific to your home.

How to Replace Knob and Tube Wiring

The basic process for replacing old knob and tube wiring involves:



Safety Checks

Do not conceal any work until the necessary rough-in inspections by your local building department have passed.

Considerations for Partial Knob and Tube Replacement

In some cases, full knob and tube replacement may not be feasible due to budget constraints. Partial or staged replacement is an option.

Prioritize the most dangerous wiring first

Use warning labels

Check circuits frequently

With careful prioritization and vigilance, partial knob and tube replacement can provide some improved safety. But keep working towards full removal and replacement for best protection.

Ensuring Electrical Safety After Replacement

Once your old knob and tube wiring has been entirely replaced with modern wiring, there are still important safety steps:

Replacing hazardous knob and tube wiring provides huge safety benefits and peace of mind. Maintain that safety by using your upgraded electrical system properly and scheduling any needed repairs immediately.