In the past, knob and tube wiring was one of the most used wiring systems in homes. It was considered cheap but has been replaced with modern and more secure wiring. 

Now, you will wonder why this outdated system was replaced with other wiring. What are its drawbacks? Don’t worry; we have covered this article from all perspectives, whether it’s related to the knob and wiring advantages or disadvantages. We will also help you with easy tips to fix this wiring issue. Let’s first try to understand its basics;

What is Knob and Tube Wiring?

Knob and tube wiring consist of copper wires covered in rubber. The word “tube” comes from porcelain tubes drilled into the building’s structure to carry the cables. This way, wire passed from the framing without touching it. Resultantly, it saves wires from being damaged by changes in the weather or pressure from the house shifting.

This system was designed according to that time’s building and electrical requirements. When the current passed through the wires, it generated heat, and the porcelain knobs kept them away from the heat. Most installations were built to handle 10-amp loads per circuit securely, and when done correctly, both joints were strong and safe.

Pros and Cons of Knob and Tube Wiring

Now, you will wonder why this wiring system has been replaced or modernized. Let me have a look at its advantages and disadvantages;

Pros

• Durability

Surprisingly, knob and tube wiring can last for decades if installed properly. Some systems installed 100 years ago are still working. It has more longevity than your most modern device, like a smartphone. 

• Heat Release

The wires in knob and tube systems are exposed to air, which helps them release heat more easily. This makes them less likely to overheat than modern wires bundled in insulation.

• Quality Materials

The copper of knob and tube wiring was often of higher quality than that used in modern wiring. It’s like comparing a premium whiskey to a cheap whiskey.

• Visible Joints

The knob and tube system joints and connection are visible. So we can easily identify a problem. 

Cons

• Safety Issues

Contrary to modern wiring, knob and tube systems do not have ‘grounding,’ to redirect extra electricity in an emergency. There are more chances of shocks without grounding, especially in damp areas.

• Insulation Breakdown 

With time, different factors, including weather, temperature, and dirt, may wear down the knob and tube wiring protection. This way, wires are damaged and become dangerous. Usually, they are hidden behind walls and ceilings, and it’s not easy to identify the cracks.

• Overloading Problems

The knob and tube wiring system was designed in the past when we had fewer electronic devices. And now we have more devices to use electricity. This wiring system cannot bear extra electrical power. 

If we use it for modern devices, the system might overload and overheat, which can cause a fire. So, using knob and tube wiring for a modern home is risky.

• Incompatible with Modern Devices

Nowadays, we have high-power usage devices that require a lot of electricity. At the same time, the knob and tube electrical wiring is an outdated wire system and is unable to fulfil the high electricity demands. We cannot rely on this system to use our air conditioners, microwaves, and big TVs.

If we forcefully use this system to supply electricity to these things, it may affect the wires or our advanced devices. 

• Electrical Code Violations

This outdated wiring system does not follow modern electrical codes, so it’s not allowed in new buildings or renovations. If someone wants to replace this system in their old homes, it can cost more money and be complicated.

Tips to Fix Knob and Tube Issues

When Knob and Tube wiring has cracks or is not safe, you can remove or rewire them or connect its parts to new wiring. NEC supports both techniques. However, local codes and insurance may have other requirements. Those who want to connect old wires to modern ones may face high safety risks. And if you choose removal or rewiring, it’s the most secure. Besides your selection, you should also be an expert to try any approach. Even though it’s easier to handle a modern wire system than an outdated wire system, it’s not recommended. 

Conclusion: Knob and tube wiring, a popular and cost-effective system, is now outdated and unsafe for modern homes. Even though it has some advantages, like durability and heat release, its lack of grounding, susceptibility to wear, and inability to handle today’s electrical demands make it risky, especially when used with high-power devices. 

Now, it does not fulfil modern electrical codes, so replacing or upgrading it is important to ensure safety. Whether you rewire the entire system or keep parts of the old one, you should consult a professional to handle the complexities and risks involved. Prioritizing safety and compliance with modern standards is the best way to protect your home and family.