There are some key points that should be known:

What is this stuff anyway? Knob and Tube wiring, sometimes abbreviated K&T, was a standard wiring method that was implemented as far back as the 1880s, and was used up until the 1940s and 50s. It is called Knob and Tube, because the single-conductor wires are supported by cylindrical ceramic nailed-down knobs, and passed through studs or joists via ceramic tubes which helped to insulate the wires. Splices were usually made by soldering the wires together and then just wrapped up with cloth tape. These were left in “open air” without the splice being contained in an electrical box (a requirement today). Where conductors would enter a switch or outlet box, the wire would be protected with a cotton cloth covering saturated with asphalt, called “loom”.

As I mentioned above, many insurance companies will not insure a house that contains this type of wiring method (or even a fuse panel).

The National Electrical Code prohibits the use of insulation of any sort installed in walls or ceilings where Knob and Tube wiring exists. This is because of a potential fire hazard. If any sort of insulation comes into contact with the conductors, they can’t disperse heat properly as they were originally designed to.

The cloth-like or rubber insulation breaks down after time. This may cause the conductor to be bare and unprotected – a real shocker!

This old style of wiring was mainly used to power things such as electric lamps, not modern equipment such as air conditioners, refrigerators, computers, space heaters, etc.

A lot of times the “neutral” wire was switched instead of the “hot” wire. This dangerous practice is against modern electrical code, but was a common practice in the era of K&T.

There is no equipment grounding conductor with this type of wiring system. Grounding is arguably the most important part of a sound electrical system. A tell-tale sign that an electrical outlet might be fed with Knob & Tube is that the receptacle is only a “2-prong” version, missing the 3rd prong on the bottom which is for the grounding conductor.

The problem With Old Wiring

A bad situation: I have heard of a report of someone hanging a metal clothes hanger on an exposed piece of knob and tube wiring located in the ceiling in the basement. Then, when they went to grab the metal hanger while doing some laundry in their bare feet, they literally got quite a shock. Fortunately, the person was OK and just shaken up a bit. In the right set of circumstances, this could be a deadly situation.

What can be done? We are always glad to come out and consult with you about your options. Your expert team at McCurdy Electric can quickly diagnose, and if necessary, upgrade the antiquated wiring system to current safe code standards. The wiring method that we install will more than likely be installed for the next 100 years or more, just like the Knob & Tube has been. We have many years of experience working in the older New England homes that are still utilizing the old wiring methods, therefore, we already know what to look for.

The cost of our diagnostic evaluation is $250. This includes a 2 hour session with two of our team members. The licensed electrician will look at any switch outlet boxes, receptacle outlet boxes, lighting outlet boxes, and any accessible K&T wiring to determine how much needs to be replaced. We will refund half of the $250 evaluation fee when you sign the proposal to perform the work needed.

Please feel free to contact us with any questions or concerns that you might have.

More Dangerous Electrical Wiring To Be Aware Of

Outdated wiring.
Safety standards exchange as technological know-how changes. How historical is the electrical wiring in your home? When used to be the closing time you had it professionally inspected? If you can’t be aware (or don’t know!) when your wires were inspected, then there’s a threat you’re at risk.

Poor wiring is the largest electrical danger facing any home. Faulty, old, or broken wiring leads to fires, electricity surges, arc faults, and more. The older the wiring, the greater the risk; especially if you haven’t had it inspected. If you notice discolored outlets or a continual burning smell, you ought to appear into upgrading your home’s wiring. If you don’t be aware of how historic your wiring is, schedule an inspection right away!

Overloaded stores and electricity strips.
We get it. It’s handy to have all your science plugged into a single strip. It’s so convenient! Unfortunately, that convenience is a little too top to be true. If you have too many units plugged into a single strip, you may want to overload it and start a fire.

Make certain you’re not worrying more voltage from your retailers or strength strips than they can handle. If your outlet utilization ever journeys circuit breakers or other fail-safes, think about unplugging a few devices. You ought to additionally recognize how old your electricity strips are and keep away from using any that are too ancient to measure up. When it’s time to change your power strips, look for strips that consist of a circuit breaker and other safety measures.

Outlets or electronics that are too close to water.
Take a seem around your home. Do you have any outlets that are dangerously close to a water source? Water conducts electrical energy very easily, so even stray voltage may want to arc via water. If a source of electricity is too close to a supply of water, it’s an awful lot greater possibly to shock you, start a fire, or harm equipment.

Be very cautious not to place any electronic gadgets too shut to water sources. Never use a hairdryer whilst standing on a wet floor. Don’t carry your smartphone or any other digital machine into the bath. Make certain all of your home’s retailers are definitely dry all the time. Basically, hold electrical energy and water as separate as viable as frequently as possible.

Light bulbs with too much wattage.
All light bulbs use a certain amount of wattage (energy) whilst turning on and operating. Every mild fixture is rated to take care of a sure quantity of wattage. If a lightbulb uses more wattage that than its fixture can handle, the bulb could overload the fixture’s wiring.

When a bulb overloads a fixture’s wiring, the wiring overheats. Over time, this heat could melt equipment and damage the fixture or wiring itself. In some cases, it ought to even start fires! Luckily, this precise electrical hazard is convenient to avoid. Use light bulbs that are equal to or less than the maximum wattage the fixture can handle. The most wattage will be listed on the lamp or fixture socket.