Knob & Tube Wiring — What Homeowners Ought To Know

Knob and Tube Wiring

Historical homes can certainly be eye-catching with their vintage-like features, charm, and elaborate craftsmanship, and stained-glass windows, however, since these homes were most likely built in the early 1900s, they most likely contain knob and tube wiring. So, what’s knob and tube wiring, and why does it matter?  Let Wiring Pros LLC help untangle the facts of knob and tube wiring for you.

Do you even know what knob and tube wiring look like and if your home has it? These open wire electrical installations are currently still present in many older homes today. Knob and tube wiring is easy to identify and can be found mostly in the basement or attic of your older home. You’ll notice white, spool-like, ceramic, knobs and tubes that have electric wires coiled through the knobs which support individual strands of wiring. If the wires need to run through joists, then heavy ceramic tubes are used to protect the wires where they run through joists.

What Exactly Is Knob & Tube Wiring?

Back in the day, like; the 1880s up until around the 1940s, knob and tube wiring was the end all be all of the electric wiring, and was quite popular in homes built prior to 1950. Don’t give up searching just because you may not find any visual knob and tube wiring, if your house was built during the previously mentioned time frame, you likely just haven’t located it yet. 

It is also common for electricians back then to install the wiring behind the walls to hide the wires, this is called “spider webbing”. Unfortunately, the only way to locate these types of wiring are to cut holes into the walls or cut a single hole and insert a small camera to see inside the walls.

What You Should Do If You Find Knob & Tube Wiring

If you do happen to locate knob and tube wiring, you won’t be breaking any laws if you leave it, however, you may just want to upgrade for peace of mind. A great option would be to consult a professional electrician, but if you’re in the Phoenix area, Wiring Pros LLC has a great team of professionally trained electricians ready to assist you.

It is recommended that knob and tube wiring be replaced as it could pose a risk of faults and fires inside your home. 

Why Replace Knob and Tube Wiring If It’s Safe?

Knob and tube electrical wiring have become obsolete wiring methods — no longer used in any homes or structures in today’s modern times. Also, the knob and tube wiring that you find would likely not be strong enough to handle all of today’s smart technology and appliances. 

The way that homes were wired in the early 1900s was surely not designed to be able to handle the overabundance of currents — and if you think about it, there were no computers, a/c’s, dishwashers, microwaves etc. back then either. However, the extra load would certainly put a major strain on the knob and tube wires, which would deem the wiring method unsafe and a potential fire hazard.

Other dangers of knob and tube wiring include:

  • Electrical Ground Not Present

Knob and tube wiring consist of two wires:

  1. Hotwire 
  2. A neutral wire

Improperly grounded wires present a great safety risk to your family and your home due to. 

  • Wear, Tear, and Aging Wires — Over time, the rubberized material wrapped around the knob and tube wires becomes cracked, and brittle and may sometimes fall off, leaving exposed wires which could result in hazards such as shock or worse. 
  • Structural Changes Can Affect Safety — Knobs and tube wiring were configured to stay protected by strong ceramic tubes. Take into account, however, that some changes can destabilize this structure, including:

Additional Insulation — Adding insulation to attics and wall cavities can lead to the overheating of knob and tube wires. Covering them also frequently leads to damage from wires being inadvertently walked on.

Inadequate Connections — Since knob and tube wiring are easily accessible and look simple, many homeowners tend to think that they can rearrange the wires themselves, with no proper training. 

When this happens, those improper splices and connections, inclusive of soldering and taping additions without using junction boxes. This is a great safety danger as extensions and modifications like this are not permitted by most electrical and building codes.

What About Homeowner’s Insurance with Knob and Tube Wiring?

Many insurance companies won’t hesitate to deny your homeowner insurance application if your house has knob and tube wiring. It can also be somewhat challenging to secure financing on a home with knob and tube wiring, although with certain upgrades it is likely. 

How to find out if your knob and tube wiring is safe:

  • Have a licensed electrician inspect and verify that your home is wired correctly.
  • Replace all bad circuits that look damaged, are covered with insulation or are not modified correctly
  • Reduce shock and fire risks by installing ground fault protection (GFCI) and potentially arc fault protection (AFCI) to heighten the safety of your knob and tube wiring. An AFCI breaker can also prevent fires caused by improper knob and tube wiring.

Call The Professionals

If you think you may have knob and tube wiring in your older home, contact Wiring Pros LLC today for a free quote and consultation. What better time to ensure the safety of your family and your home? In the meantime, take a look at our blog over here.