Knob and tube wiring is one of the oldest methods of electrical wiring in buildings and had been a standard method of wiring in North America from the 1880's to the 1930's. This wiring method uses knobs which help hold in copper wires that are insulated by ceramic tubes that run through the joist and stud drill-holes. The actual wire consists of only a hot (black) and neutral (white) wire with no ground wire. Both wires must run separately to fixtures as opposed to those used now which are contained within a plastic sheathing.
Is it safe? It is safe but the downside of this wiring system is that it is too outdated to be used in the modern home especially with all the heavy duty electrical appliances we use these days. In fact several insurance companies are not willing to cover homes that have existing knob & tube wiring, or will do so only at a much higher rate. Do you want to learn more? Visit what is knob and tube wiring.
The wiring can have a few problems under certain circumstances. The insulation used in rather brittle and can't withstand high temperatures like modern wiring. If the knob and tube wiring has been used inappropriately it can cause the insulation to break leaving the wire exposed. Improper splicing can be a hazardous problem too especially because splicing into the knob and tube wiring is not a simple process.
Another problem with this wiring system is that it is not a grounded system. This means it cannot be used to wire modern electrical outlets but only for ungrounded applications. How do you maintain the knob and tube wiring system and ensure safety in your home? If your house was built more than 50 years ago you might have the knob and tube wiring system. It is extremely important to conduct thorough inspection of the wiring system. You can hire the services of an experienced electrician or get an electrical contractor to conduct the inspection for you. A proper inspection will help find the faults with the wiring. Furthermore timely repairs and proper maintenance can ensure longevity of the wiring.
Hire the right electrical contractors to get your upgraded or changed In case you need to get the wiring changed an electrician will be able to replace your existing with copper. In fact you can even get your entire house wiring upgraded to meet all the current electrical codes and standards. There are several highly qualified and experienced electricians and electrical contractors who can run new wires with minimal damage to walls. Look for electrical contractor who offer comprehensive installation services including arranging for all permits and inspection, to even plastering the holes they make in the walls.