I’m looking for a better comment for knob and tube wiring. I don’t feel good about the one I have. This is want I have…
There were signs of old Knob and Tube wiring in the attic, but most of the wiring looked new in the house. Knob and Tub wiring can present potential fire hazards. Recommend consulting the seller’s disclosure about the electrical system to determine if the K & T wiring has been decommissioned or have the electrical system evaluated by licensed electrician.
The electrical code prohibits thermal insulation from being placed around K&T.
394.10 Uses Permitted. Concealed knob-and-tube wiring
shall be permitted to be installed in the hollow spaces of
walls and ceilings, or in unfinished attics and roof spaces as
provided by 394.23, only as follows:
(1) For extensions of existing installations
(2) Elsewhere by special permission
394.12 Uses Not Permitted. Concealed knob-and-tube
wiring shall not be used in the following:
(1) Commercial garages
(2) Theaters and similar locations
(3) Motion picture studios
(4) Hazardous (classified) locations
(5) Hollow spaces of walls, ceilings, and attics where such
spaces are insulated by loose, rolled, or foamed-inplace
insulating material that envelops the conductors
Knob & Tube Wiring
Knob-and-tube wiring was used in residential electrical systems from the 1920s until the 1950s. The name comes from the ceramic knobs that are used to secure the wiring runs, and the ceramic tubes used to protect the wires where they pass through wood joists, studs etc.
Unlike modern wiring systems, where the wires run together in a single sheathed cable, the two knob-and-tube wires run separately and only come together at a terminal (switch, receptacle, fixture, junction box, etc.).
Knob-and-tube wiring is very common in older homes and is considered safe as long as it is in good repair. Unfortunately, due to its age, this is seldom the case. We often see brittle or crumbling insulation, poorly made connections, and amateur modifications, all of which can be hazardous.
Unlike modern wiring, knob-and-tube wiring does not include a ground wire. This means that the outlets served by the knob-and-tube wiring will be the older ungrounded two-slot outlets, which offer no protection from electric shock. Since modern grounded appliances (such as your refrigerator, TV, computer, etc.) typically require a grounded three-slot outlet, it will be necessary to replace some of the knob-and-tube wiring and two-slot outlets at locations where these appliances are to be used.
Knob & tube wiring has become an issue for some home insurance companies. Many companies require a passing inspection by the Electrical Safety Authority (ESA) before they will grant insurance. Some companies simply refuse to insure homes with knob-and-tube wiring. Contact your insurance company with regard to their policy on this.
If the knob-and-tube wiring is in good shape, replacement usually can be deferred until other electrical work is undertaken. However, it would be prudent to engage a qualified electrician to further investigate this wiring. Repairs should be undertaken as deemed necessary by the electrician. In some cases extensive replacement is required, which can be a significant expense.
Here’s one I believe I got from Dan, at least the root of it.
“Knob & Tube wiring was noted at --------- some locations in the home. Although commonly used in older homes, and accepted or “grand-fathered” by many national electrical codes, most electrical systems using this in our area are over 70 years old. Due to its age; its tendency to become brittle with age; and the fact that it has likely been added onto several times by various trades people over the years - Some insurance companies or lenders will not choose to accept it, and may require replacing or upgrading this type wiring. I recommend you verify acceptability with your insurance company and/or lender prior to closing escrow. Also, due to its age, I recommend having a qualified electrician review its condition for safety, etc., prior to closing.”
“Knob-and tube wiring is an outdated type of wiring that has been replaced by NM and BX wiring. This outdated type of wiring can be hazardous and replacement with modern wiring is typically recommended.”
You didn’t check the K&T that you saw to see if it was hot?
If there was insulation around it you need to call that out period.
Observed Knob & Tube wiring spliced with non-metallic wiring (Romex), this is considered a defect and unsafe. Further evaluation and repair of the system is recommended by licensed electrical contractor.
Observed attic insulation was covering knob and tube wiring. This is considered a fire hazard as knob and tube wiring is not insulated and may build up heat or may be frayed thereby exposing the wire to the insulation. Recommend consulting with a licensed electrical contractor and an insulation contractor as to a course of action.
If no significant visible deficiencies noted in it …
Knob & Tube wiring was noted at some locations in the building. Although commonly used in the past, and accepted or grand-fathered by most national electrical codes, most electrical systems using this in our area are well over 65 years old. Due to its age; its tendency to become brittle with age; and the fact that it has likely been added onto several times by various trades people over the years - Some insurance companies or lenders will not choose to accept it, and may recommend upgrading this type wiring. Verify acceptability with your insurance company and/or lender prior to closing escrow. Also due to its age we recommend having a licensed electrician review its condition for safety, etc prior to closing.
