Knob-and-tube or K&T for short was commonly used in buildings in North America from about 1880 to the 1940s. This system is considered obsolete and can be a safety hazard.
Though not dangerous in itself, dangers can accrue from this system due to its age, improper modifications, and situations where building insulation envelops the wires.
As knob and tube has no ground wire there is no protection against electric shock. Original two pronged outlets will not accept any three-pronged plugs.
It is treated differently in different jurisdictions. In some areas, it must be removed at all accessible locations, while others merely require that it not be installed in new construction.
When comparing knob and tube wiring with its modern counterpart it is much less resistant to damage. Knob and tube wiring is insulated with cambric or asbestos and is not rated for any exposure to moisture. Some older systems contain insulation with additives that may oxidize the copper wire. Knob and tube can become brittle and bending the wires may cause insulation to crack and peel away.
Knob and tube wiring is often poorly spliced with modern wiring, causing the majority of the issues and fire hazards.
This involves carefully identifying and locating all the existing knob and tube wiring throughout the home. Knob and tube wiring is an older electrical system commonly found in houses built before the 1940s.
A comprehensive assessment will be conducted to determine the extent of work required for replacing the knob and tube wiring. This includes evaluating the scope of the project, estimating the time, labor, and materials needed, and providing a breakdown of costs.
In the process of replacing the knob and tube wiring, it may be necessary to remove and reinstall floor coverings such as carpets, tiles, or laminate flooring to access the wiring safely. This ensures that the new electrical system is properly installed without damaging the existing floor finishes.
The outdated knob and tube wiring will be completely replaced with modern electrical wiring that adheres to the current electrical codes and safety regulations. This includes the installation of appropriate wiring materials, grounding systems, and other necessary components.
During the replacement process, it is common to encounter damage to drywall or plaster walls due to the removal of old wiring. Any such damage will be repaired, ensuring a smooth and finished appearance after the new wiring is installed.
We only have one course of action we recommend when facing knob and tube wiring and that is total replacement.
First step will be to spend a little time tracing out all the circuits that are affected by the knob and tube. Many times we see old 2 pin plugs and new light switches both wired on the same knob and tube circuit.
We take care of everything from pulling the permits, completing the work, to patching any drywall damage. We also remove all garbage and dispose of in our recycle bins.