Updated October 16, 2026. Originally published March 19, 2026.
Smiley Electric, Inc. completed a full knob and tube removal project in a Portland, Oregon home. The old wiring ran through ceilings, walls and lighting circuits in several parts of the house. Replacing it meant tracing circuits that ran unpredictably, adding boxes where light fixtures had none, getting new cable through lath-and-plaster walls with few ways in, and coordinating with the drywall crew so the house could be put back together.
The challenges in this house
This Portland home presented several challenges that are common in older construction.
Wiring that ran unpredictably
The old circuits were routed unpredictably through the walls and ceilings, so the first step was identifying every active knob and tube circuit.
Light fixtures with no boxes
Light fixtures in the house lacked electrical boxes, so proper boxes had to be added for them as part of the new wiring.
Lath and plaster with few ways in
The walls and ceilings were lath and plaster, which needed careful cutting, and there were limited access points for running new wiring. Older homes often take more time for routing the new wiring than for the installation itself.
Coordinating with the drywall crew
We coordinated with other trades, including drywall professionals, so the home could be restored after the wiring was installed.
The work
The project was a full removal of the knob and tube wiring and its replacement with modern wiring. Our process included:
- Identifying all active knob and tube circuits
- Safely disconnecting and removing the old wiring
- Installing new grounded wiring
- Adding proper electrical boxes for fixtures
- Running new circuits for outlets and lighting
- Preparing the system for inspection
What knob and tube wiring is
Knob and tube is an early wiring method that uses ceramic knobs and tubes to support and route wires through walls and ceilings. It was commonly installed in homes built before the 1950s, and many older Portland homes still have it. It has no equipment grounding conductor. Because it is decades old and may have been altered over the years, its condition and any alterations need to be assessed by an electrician.
Have knob and tube in your own house? See our knob and tube rewiring service in Portland for how we evaluate the wiring and plan the work.
Smiley Electric, Inc. is licensed and insured, Oregon CCB #227116, and does knob and tube removal, rewiring and electrical upgrades throughout Portland, Beaverton, Hillsboro and surrounding Oregon communities. Contact us to ask about a rewiring evaluation.