How to Replace Knob and Tube Wiring

Knob and tube wiring was commonly installed in homes built before 1950. This old wiring system has some safety concerns, so many homeowners look to replace it with modern wiring. Replacing knob and tube wiring completely can be a big project, but it will make your home much safer. Here's an in-depth look at everything you need to know to replace knob and tube wiring.

Dangers of Knob and Tube Wiring

Knob and tube wiring gets its name from the ceramic knobs and tubes that insulate the wires. While it was suitable for the lower electricity demands of the early 20th century, knob and tube wiring can be dangerous by today's standards for several reasons:

These safety issues mean it is highly recommended to completely replace knob and tube wiring in any home where it exists.

When to Call an Electrician

Some homeowners want to DIY knob and tube replacement to save on costs. However, there are some cases where you should call a professional electrician:

For major rewiring projects, hiring a reputable licensed electrician is highly recommended for safety. But some DIYers can handle replacing an isolated section of knob and tube wiring by following important safety precautions.

DIY Safety Tips

If you take on any DIY electrical work, safety should be your top priority. Follow these tips to avoid getting hurt or damaging your home:

Proceed with extreme caution. If you have any doubts or feel unsafe, stop work immediately and call an electrician.

Determining the Scope

The first step for any knob and tube replacement project is to determine the scope of wiring that needs to be updated.

Taking time to thoroughly assess the scope ensures you tackle the most important electrical risks. It also prevents you from overestimating a DIY project if much of the old wiring is inaccessible without major demolition work.

Removing Knob and Tube Wiring

Once you know which wires need to be replaced, the next step is carefully removing the old knob and tube wiring.

Removing knob and tube wires is tedious work, but necessary to make room for new wiring.

Running Updated Wiring

Modern electrical wire comes in 2 common types:

For most homes, NM cable is perfectly suitable for replacing old wiring. Select the gauge (wire thickness) recommended for the circuits you are installing.

Follow these steps to run new wiring:

Take things slowly and methodically to avoid leaving loose wires or making dangerous connections.

Reconnecting Devices and Fixtures

Once new wiring cables are in place, you can start reconnecting devices like outlets, switches, and light fixtures.

Go slowly and double check all devices to make sure new connections are solid. Report any non-working fixtures to an electrician in case the wiring needs troubleshooting.

Important Next Steps

After you replace sections of knob and tube wiring, there are a few important next steps:

Proper follow-up ensures your knob and tube replacement project improves the safety of your electrical system.

Hiring a Professional Electrician

For large knob and tube rewiring projects, the best option is hiring a professional electrician. Although it costs more upfront, there are several benefits:

Although hiring an electrician costs more up front, it is worth it for large knob and tube rewiring projects to ensure a safe electrical system. Carefully check reviews and licenses to find a reputable local professional electrician you trust to get the job done right.