Knob & Tube Replacement
What Is It?
In Boston from 1880’s it was widely used through the 1930’s. In some locations throughout Massachusetts, it has been installed into the late 1950’s. Years ago there were few electrical appliances, electricity usage and loads were limited. Knob & Tube was the best and only option.
The wires were spliced and soldered together inside walls, without junction boxes and then wrapped with electrical tape. Wiring was rubber and cloth covered #14 copper mounted on porcelain Knobs nailed to the wood studs and joists. When required to pass through these members porcelain Tubes were inserted in holes with the conductors inside. Knob and Tube wiring therefore never touched the wood structure or plaster. Heat from load or overload dissipated in the air space between rafters and partitions. These circuits originally could be fused by 20 Amp plug fuses. Do not use fuses or breakers over 15 Amp today.
Visual inspection of conductors and splices can determine state of K&T integrity nowadays. Conductors with bare or dry, crumbling or stiff insulation should be replaced. These conditions resulted from over-current, shorts, improper fusing, or high temperatures. Problems are usually found in switch, plug, and junction boxes, in attics, furnace or boiler rooms and above the lights especially.
Why Replace It?
Massachusetts homeowners should have any active knob and tube wiring inspected for safety. We recommend the removal and replacement of all knob and tube wiring to upgrade to current electrical standards. Our professional electricians can do this electrical inspection for you and provide an expert opinion on replacement of your knob and tube.
As an Electrician in Boston we are familiar with replacing Knob and tube wiring.