09.09.2020By Alex Altuhov

А Fast Guide to Knob and Tube Electrical Wiring and Potential Complications it Can Cause


Security is a very critical problem for every homeowner especially when the family is involved. As beautiful as old houses may be, a lot of concerns can be raised that a wise buyer should worry about before handshaking on a deal.

The root cause of possible issues is mainly old power lines such as Knob and Tube electrical wiring systems and needs to be rewired or replaced. In this article, we will look into what Knob and Tube Electrical Wiring is and how much of a safety hazard it can be to your home.

How Knob and Tube Wiring Works

Knob and tube wiring was used and came into the model aesthetic in the late 1800s and persisted till the 1930s to 1940s. It consisted of two long wires coated in rubber insulators, which run around the walls of the foundation, wound around the ceramic tubes at the joists to keep the wires in place, connected to the keys to avoiding chafing as it could have caused damage to the insulator which could have possibly resulted into an electrical problem, and covered with loom for insulation at main areas to provide protection.

To deal with knob and tube wiring properly, experts such as HandyKith are best to call to ensure that wires are prevented from touching walls and other surfaces.

Advantages of K&T Wiring

Let’s look at some prominent advantages of K&T wiring.

Affordable Prices

Knob and tube electrical wiring were significantly low-cost to build than their counterparts which were usually found to be up to two to three times more costly. Back in the day, prices were up due to electrical components and not because of the salaries of the electricians.

This took a turn however with the advancement of electrical devices and electricians being deemed as professionals, labor costs shot up even more quickly than the cost of electrical equipment. Considering how labor-intensive it is to install a knob and tube wiring system as compared to the materials being used, a decline in popularity was immediately observed.


Porcelain insulators were one of the features in knob and tube wiring that was used and was what made it considerably favorable at the time. It is a highly durable and rare material with an infinite lifespan that offers protection with virtually no expiry date. Porcelain also kept wires from getting too tense while the installation was taking place.

Higher Amperage

Knob and tube wiring has a higher amperage than electrical structures with the same gauge as the hot and cold wires are isolated about 4 to 6 inches from each other, enabling the wires to quickly dissipate heat into the air.

Superior Compared to Romex

It was unlikely that knob and tube wiring would be punctured as they were wired safely away from the casing and so was therefore deemed more preferable.K&T wiring was also only ever installed by skilled electricians.

Disadvantages of K&T Wiring

Time to talk on some cons.

No Ground Wire

While it may be difficult to imagine today as the ground is critical for any power spikes or overloaded circuits, no ground wire in the knob and tube wiring used to be present for configuration. Hot and neutral wires were used up until the 1960s, which then required that any circuit had to receive a dedicated ground cable.

Wiring Insulation

Knob and tube wiring work better when oxygen is present as it needs to cool down and dissipate as earlier mentioned. Covering it with insulation prevents this from happening. In fact, anything that can get piled around the wires to obstruct the flow of air will increase the risk of combustion. Even nowadays, it is prohibited to authorize insulation to be mounted on an active knob and tube.

Worn Sheathing

In contrast to porcelain insulators, asphalt-soaked cotton sheaths or natural rubber inevitable wears and breaks down over time. It is also common for old, brittle sheaths to break down during renovations. This allows wires to be exposed and raises the risk for electrical shocks as well as burning.

Extra Power Supply Required

A standard house in the 1920s would have a maximum electrical power of 60 amps in the main service panel. In modern times, with the use of appliances and more technological devices, especially in smart homes that continue to sprout, the main service panels can go up to 200 amps of power. Knob and tube wiring was never meant to carry or handle loads like this.

Errors in Home Improvement

Homeowners may do a shabby job at trying to modify their house properly on their own which leads them to install certain changes that can actually do more harm than good. In fact, it is common for amateurs to splice K&T wiring incorrectly since it is readily accessible. Unknowingly, little alterations like these can overload a circuit and become more of a hazard especially with the addition of new appliances.

K&T wiring is also not as resistant to modern cable insulation. K&T wiring that tends to be coated with cambric and asbestos are not appraised for sensitivity to moisture either. Older devices that include insulation with additives are capable of oxidizing copper wire as well. If the wires are bent, its insulation can crack and peel away.

How Safe is Knob and Tube Wiring?

In a scenario where the knob and tube wiring is intact, properly maintained, modifications have only been done by professional electricians, knob and tube wiring will still be considered safe today. In most situations, this is usually not the case. Here are some key issues that usually noticed:

The Addition of Electrical Appliances

A modern kitchen consists of 7 to 9 appliances each needing its own socket whereas older homes only used possibly just a simple washing machine and maybe a toaster and iron. K&T networks were not built to supply for the modern wiring in households today, including the fact that new homes have to be grounded for fire hazard prevention.


As mentioned earlier, cloth insulation or old rubber used as insulation in a knob and tube wiring system wears over time and leaves the wires exposed. It is even more dangerous in moist or wet environments such as kitchens and bathrooms.

Connecting K&T Wiring to New Wire

Also mentioned above were unsafe alterations made to cords of modern appliances just for it to be compatible with an outdated, extensively used, and aging electrical system. Marginally and constantly making such changes poses a potential threat. Furthermore, some may even try to combine the knob and tube electrical wiring with modern electrical wiring. If this has not been done by a professional this kind of tampering just makes K&T even more unsafe than it would have been.

Home Insurance

Homeowners may have troubles with their insurance as they tend to deny insurance for those who have knob and tube wiring because of how prone they are to fires. However, there may be exceptions rendered to houses where an electrical is able to identify the system to be secure.

How to Fix K&T Wiring Problems

Let’s dive into the typical wiring problems.

1. Knob and Tube Wiring Replacement

The fastest solution would be the replacement of all ground-fault interrupting outlets. Every GCFI has a breaker included that turns off the power when a ground fault is found, which is an appropriate replacement for actual circuit grounding. Getting a GCFI breaker box instead of keeping an out-of-date fuse box from the initial knob and tube wiring can also get you ground protection.

The safest solution is without doubt the elimination of the existing knob and tube electrical wiring and the replacement of the whole structure with modern copper wiring to meet today’s electrical safety code requirements.

2. CSA approved devices

Another significant safety measure is the replacement of old ungrounded switches and receptacles with licensed CSA equipment. If this has not been implemented, the construction of a new electrical control panel that provides the needs of a normal household today and any future requirements or plans solves any issues involving blown fuses, overloaded circuits, and other safety issues.

3. Licensed Electricians

While it may seem like you would have to break down your walls just to replace your knob and tube wiring, highly-trained electricians such as those found in HandyKith can rewire an old house without bringing down your walls, but rather cut tiny tactical holes to place the new wires. Every trace of a knob and tube wiring does not have to be removed, so long as they are detached and rewired to suit modern standards.


How Easy Is It To Add Extra Plug Sockets?

It is quite easy to add an extra plug socket, if you have even a little experience with electrical repairs. You
simply have to unscrew the faceplate and feed the wires into the mount. This is a task that you can do
yourself. If you can’t, hire a professional.

What Are Warrants of HandyKith Electricians?

The number of sockets that are needed per room depends on the room and its function in the home. For
instance, a living room needs 8 outlets, while the bedroom needs 6 outlets for the main and 4 outlets for the

How can you tell if an outlet is bad?

There are signs to look out for when trying to asses the state of your home’s outlets. You should call an
electrician if the breaker tripped after one appliance was plugged. Also, outlets could feel warm to touch and it
could be a sign of damage if it gets too really hot. This might even cause an electrical fire.

Why is powerpoint in the bathroom different?

The powerpoint in a bathroom is quite different from the ones in other parts of the home. This is due to the
increased exposure of the sockets to water. So, you should use outlets like GFCIs to prevent shocks.

Can a bad outlet make other outlets not work?

This depends on if the outlets are in one circuit together or separate. It is more likely that a bad outlet
would affect others, if this is the case. If separate, the chances are lesser.


Time to Call HandyKith, the Best Team Electrical Team in New York!

HandyKith consists of an incredible team that professionally solves all your installation problems while providing quality assurance and ensures your time is saved. They only work with quality and through legal means so you can trust that your home will be safe in their hands. If you are looking for electricians to replace your knob and tube wiring, there is no one better than HandyKith themselves.


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