Knob and Tube' Wiring is now on the radar of the Insurance Industry. They have issued this in the Broker Underwriting Guide that specifically states 'We do not insure risks with knob and tube wiring or aluminum'. It is apparent to me that the Insurance Industry of British Columbia may follow the lead of other provinces and reject all knob and tube wiring, regardless of the status of the installation, and only insure a residence once it has been replaced.
Knob and tube wiring is found in older dwellings around 60 years of age and was used for the 120 volt general lighting and receptacles. This wiring may not be apparent in an updated and renovated home, even at the main electrical service panel. Knob and tube is a two wire system consisting of a 'hot' and a 'neutral' wire. There is no bond (ground) wire and it is readily identified by the old style receptacles having only two prongs, where the ground (bond) prong on most modern appliance cords cannot be inserted. Where you have access to the actual wiring itself (usually an attic) both insulated wires are separated and each wire is supported on the wood structure by non conducting insulators, spaced accordingly throughout the runs.
In my previous employ as an Electrical Safety Officer with the electrical regulatory authority of British Columbia, the B.C. Safety Authority, we came across a great array of installations involving knob and tube. It was very rare to find a complete system that had not been altered in some fashion. If found not to be in compliance with the Canadian Electrical Code, we referred to them as safety hazards, they were ordered to be rectified (made safe) by a Registered Electrical Contractor. We found most homeowners were not qualified to deal with the complexities, or understanding, of making this system safe. Most of these non complying installations are what we and the BCSA refer to as 'handyman' alterations, and they were deemed illegal.
Once knob and tube has been tampered with the insulation can be brittle and the cables may show signs of damage, situations where excess heat can create a potential fire, or shock hazard. The Canadian Electrical Code, in Section 26, rule 26-700-8 deals with the use of three prong receptacles used in place of the old two prong. If the wiring is deemed defective, or it does not meet the electrical circuit loads required in the dwelling, (other CEC rules such as Rule 2-200 and 8-104-2 then apply), it must be replaced. All this is to be done under a permit, issued by the BCSA, and a subsequent inspection process is then put into place. At the very least the Insurance Bureau of Canada, in bulletin # AM 96-04, suggest a safety risk inspection by a qualified electrical agency before insurance is denied, but this is only a recommendation. Even if a qualified electrical agency signs off on the installation as safe and in compliance with the BCSA, there is no guarantee the insurance broker has to accept it.
Written by Kenrick Electrical Solutions Ltd. and if you require further clarification or other information, please visit our web site at www.kenrickelectrical.com. or call 250-619-8069.
as seen on http://www.dougbelcher.com/real-estate-blog/february-2008-blog.html
