Homes in Seattle's Capitol Hill, Spokane's South Hill, Tacoma's North End and countless small Washington towns were built between 1900 and 1950 with knob and tube wiring. Much of it is still in service. Here is a clear-eyed look at whether it needs to go.
What knob and tube is
Single insulated conductors run separately through ceramic knobs and tubes, with no ground wire. Splices were soldered and taped in open air rather than inside junction boxes.
The actual risks
- No ground, so three-prong outlets on these circuits are not truly grounded.
- Insulation that has become brittle after 80 to 100 years.
- Heat buildup when attic insulation is blown over the wires, which is very common in Washington after energy retrofits.
- Decades of amateur splices adding modern loads to circuits never designed for them.
Why your insurer asks
Many carriers will not write a new policy on a home with active knob and tube, or require an inspection and partial replacement. Buyers frequently make rewiring a condition of sale.
What a modern rewire looks like
Our whole house rewiring crews fish new grounded copper through existing walls using small, strategic openings, work room by room so you can stay home, and coordinate drywall or plaster patching afterward. The result is a fully grounded system with the dedicated circuits a modern kitchen and home office need.
Aluminum wiring is the other one
Homes built from the mid-1960s to mid-1970s may have aluminum branch wiring, which loosens at connections and overheats. Remediation with approved connectors or full replacement is included in the same service.
Find your local page: rewiring in Seattle, Spokane, Tacoma or any Washington city.