What You Need to Know About Knob & Tube Wiring

knob and tubeKnob and tube wiring is a common technique used in homes and buildings built in the late 1800’s and early 1900’s. Ceramic knobs support the wire and the ceramic tubes that protect the wire as it crosses the wood framing elements like the floor beams.  

Common Issues Associated with Knob and Tube Wiring

  • Rubber Insulation. The rubber insulation can become fragile. Mechanical abuse or overheating wears out the rubber, making it brittle in high heat spots, even connection above your ceiling lights. This requires replacing the wires
  • It is inclined to stretch and sag over time.
  • No Ground Wire. Ground wire makes an emergency trail for stray electricity so the risk of electrical fire and damage to sensitive appliances and equipment is reduced.
  • Common Hazardous Modifications. The fact that knob and tube wiring is quite old opens the possibility of improper modifications. The age-old systems have insulated wires with varnish and fabric materials that are inclined to deteriorate easily leading to an overheating or short circuit.

If you’re renovating your home, now’s the best and most appropriate time to replace your knob and tube wiring. Doing so will cost you less as the ceilings, walls, and floors are open and accessible. Home remodeling includes adding more receptacles or electrical outlets, ground- and arc-fault circuit interrupters, as well as knob and tube replacement.

Always have a yearly knob and tube wiring inspection to evaluate if it requires changing. Call a licensed electrician at American Air to address any concerns that surround your knob and tube wiring.