The Dangers of Knob and Tube Wiring
There are many dangers of knob and tube wiring. Knob and tube wiring was an early standardized method of electrical wiring that was commonly used in buildings in North America from about 1880 to 1940. Because it is known to be a safety hazard, it is no longer a popular method of wiring, although it may still be present in older buildings. This article will provide an in-depth look at the dangers of knob and tube wiring.
Dangers of Knob and Tube Wiring
Although it was considered ‘state of the art’ when it was common to install such wiring, there are many dangers of knob and tube wiring. They are as follows:
- Because knob and tube wiring is two stranded, with just a hot and neutral wire, it is not grounded. This means there’s no protection in the case of an electrical fault and shock and fires are more likely to occur.
- Knob and tube wiring uses sheathing for insulation. This type of insulation can disintegrate over time. New wiring uses stronger, safer materials for insulation.
- Knob and tube wiring uses a 60 amp service which is fused with 15 amps. That means more current is flowing through the wire than the wire is meant to handle. This can result in excessive heat and fire.
- Older electrical systems don’t carry ampacity loads. These extra loads can cause the insulation to become brittle resulting in exposed wire that can overheat and cause fire.
- Knob and tube wiring uses two prong receptacles which are also not grounded, increasing the chances of electric shock and injury, especially in areas like kitchens and bathrooms, where water is present. Two prong receptacles also restrict the use of small kitchen appliances.
How Do I Know If I Have Knob and Tube Wiring?
Because of the dangers of knob and tube wiring, it’s important to be able to identify if this type of wiring is present in your home or office. If this is the case, you may want to think about having the wiring replaced. Not only is this type of wiring dangerous, but there are not many insurance companies who provide insurance to these older homes.
If you home was built in the late 1800’s to early 1900’s, there’s a good chance you have knob and tube wiring. To inspect for this type of wiring, it may be a good idea to investigate in the attic or basement. You will be more likely to find exposed wiring in these areas. You may have to clear out some insulation to be able to see the wires and be careful not to step on wires and damage them.
If the wires are connected to little pieces of ceramic, this is a sign that you have knob and tube wiring. Also, you will only have two wires as opposed to three, because the ground wire will not be present. If this type of wiring was found in an attic, and you also have a basement, you may want to inspect there as well. In basements, wiring will be in the floor boards that can be found overhead.
Knob and tube wiring may also be hidden in the walls and ceiling of most houses. The only way you will be able to determine this is by inspecting your electrical box. This is very dangerous as there are many live wires in that box which can cause severe electric shock. Inspection of the electrical box should only be done by a trained professional or after an electric company has turned off all power to the home.
A sign of knob and tube wiring in your electrical box will be wires that only have two strands. If you do find knob and tube wiring in your house, it is best to have a trained professional replace that wiring. They will also be able to replace two pronged circuits with grounded three prong circuits.
What I Should Know About Replacing Knob and Tube Wiring in My House
If you do decide to have the knob and tube wiring replaced in your house, they will run new circuits and replace fuses with modern circuit breakers. The price of rewiring your home can be costly, but it is worth it to know you home is free from the dangers of knob and tube wiring.
You may have to have the electricity in your house turned off completely while the work is being done, so be sure to plan in advance. A good contractor will keep any holes that have to be made minimal, with the size of these not exceeding that of a hardball. They will also keep your home clean and provide you with a warranty for the work done.
Insurance and Knob and Tube Wiring
Most insurance companies will not provide insurance for old electrical systems because they are aware of the dangers of knob and tube wiring…and if you can’t get insurance, you can’t get a mortgage. That is why you should make sure that wiring is up to date if you are buying or selling a house.
Companies that do provide insurance are likely to charge more and also require that the old wiring is removed prior to closing or within 30 days after closing. Some insurance companies may also provide insurance if the system is inactive. If this is the case, they are likely to require the wiring to be removed and replaced 30-60 days after the policy inception.
So we can see that there are many dangers of knob and tube wiring. If you are living in an older home, it is important to safely inspect your home to see if it has knob and tube wiring. If you find this to be the case, it is best to get the wiring replaced. This will not only provide a safer atmosphere for yourself and your family, but it will reduce complications when you are looking to sell your home. Identify knob and tube wiring to keep the dangers associated with electrical shock and fire minimal.