Knob and Tube Wiring - Isolation

Detail ID 2.0301.2
High Voltage (50 volts or more)
Desired Outcome

Prevent electrocution and reduce fire hazards

SF Single Family Site-Built Housing
MH Manufactured Housing
MF Multifamily Housing


  • SF
  • MF
Specification Objective

Maintain a minimum of 3" of clearance around live knob and tube wiring

Prevent fire hazards

  • SF
  • MF
Specification Objective

Mark all live knob-and-tube wiring with caution tape that is visible from at least 5' away and post appropriate signage

Provide essential safety and maintenance information and maintain safe operation of knob-and-tube wiring