Knob and Tube Wiring

If your home was built in 1950 or earlier, take a look in the basement. If you notice wires running through porcelain cylinders or “tubes” inserted in holes in the wooden floor joists, you have knob and tube wiring. You’ll also see porcelain “knobs,” which keep the wires secure, and prevent them from touching the wood along which the wires run. The wires are usually insulated with a rubberized cloth fabric.

One of the main differences between modern wiring and the old knob and tube, is that there is no ground wire. Therefore, this type of wiring cannot accommodate any electrical items with three pronged plugs, and the risk of shocks and fire is much greater. Also, the black and the white wires run separately, while in more modern wiring, you will see that the black wire, the white wire, as well as the ground wire, are all enclosed in a single cable. Another difference is the wire insulation. Modern wiring is insulated with plastic, while knob-and-tube uses rubber. The breakdown of the insulation over time on knob-and-tube wiring is often the reason it is replaced. It’s important to note that this is frequently the result of overheating or mechanical abuse.

You may have found it difficult to obtain home insurance if your home has k&t wiring. In fact, this type of wiring is not inherently dangerous. Problems arise when the insulation around the wires begins to deteriorate with age, or when home handymen have made alterations to the wiring. Knob and tube wiring should never run through insulation, especially blown-in insulation, as this type of wiring requires open space to keep cool. Any insulation surrounding the wiring can cause serious problems. In fact, this wiring is sometimes referred to as “Open Wiring” which helps to emphasize the importance of maintaining open airspace around the wire at all times to prevent any overheating.

There is nothing in the building code in Canada which states k&t wiring must be removed from existing homes, but it is considered obsolete, and can’t be used in any new construction.

Kitec Piping

Kitec was the “go-to” pipe used in plumbing and heating installations between 1995 and 2007. It was manufactured by a company called IPEX Inc. which still exists to this day.

Kitec is a composite plumbing material made from five layers of metal, plastics and resin adhesives, with brass fittings.

The outermost plastic layer is usually colour-coded to indicate hot water (bright orange) or cold water (bright blue). The label ‘ASTM 1281’ is printed on the outer layer in black lettering.

Starting in the late 1990s, Kitec was marketed as a cost-effective alternative to copper pipe that was also much easier to install. IPEX Inc. and its distributor sold Kitec plumbing under the names Kitec, PlumbBetter, IPEX AQUA, WarmRite, Kitec XPA, AmbioComfort, XPA, KERR Controls, Plomberie Améliorée.

  • Despite layers of protective plastic and resin, both the aluminum layer of the pipes and the brass fittings had a tendency to corrode quickly.
  • Kitec fittings contained very high levels of zinc, which reacted with the chemical composition of Kitec and leached minerals into the pipe. This caused the fittings to degrade quickly and a build up of zinc oxide that restricted the flow of water.
  • The plastic and aluminum layers expanded and contracted with temperature changes, weakening over time until the pipe burst.

Vermiculite Insulation

If your home was built or renovated before the 1990s, it is difficult to guess the method of insulation chosen as there were numerous options: fiberglass batt insulation, blown in cellulose, sprayed polyurethane foam or even vermiculite.

Vermiculite insulation was a popular material in the 1940s and continued with the energy crisis into the mid-1980s. In Canada, it was one of the insulating materials allowed under the Canadian Home Insulation Program from 1976 to the mid-1980s. The CHIP program provided grants to homeowners to increase insulation levels, thereby reducing energy consumption.  Instead of buying batts of insulation, homeowners could buy bags of loose vermiculite and pour them into wall cavities and between joists in the attic.

Similar to mica, if you discover these granules between the joists of your roof, it’s a safe bet to say that it is insulated with vermiculite. If your home was built before the 1990s, your vermiculite may contain amphibole asbestos fibers.

Vermiculite from the Libby mine in Montana, USA (which at its peak accounted for 70% of the worlds vermiculite production) is known to contain high levels of amphibolic asbestos. Extracted from the mine between 1920 and 1990, this vermiculite insulation was sold in large bags mainly, but not exclusively, under the trademark Zonolite® Attic Insulation. The mine was closed in 1990. As well as being rich in vermiculite, this mine had the misfortune of having a deposit of tremolite, a type of asbestos. When the vermiculite was extracted, some tremolite came in with the mix.

Oil Tanks

Many homes in the Greater Vancouver area built before 1957 were originally heated with furnace oil. When natural gas became available, the oil storage tanks, which were normally located underground in backyards, were filled with sand or capped.

However, as these unused buried oil tanks start to corrode and rust, the remaining oil can leak out and flow onto the rest of the owner’s property, the neighbour’s property, storm sumps and waterways, resulting in contamination of soil and water. Apart from the negative financial impact on the market value of the property, the owner can face substantial legal liability under various statutes and bylaws for such contamination.


Some older homes in British Columbia may have lead-based paint on the walls. Removing, repairing or disturbing this paint through normal wear-and-tear (such as paint on doors, windows, stairs and railings) can expose you and your children to serious health risks: lead poisoning can cause anaemia (a deficiency of red blood cells) as well as brain and nervous system damage.

The risk is greatest for children because they are growing and absorb lead easily. Even small amounts of dust with lead are dangerous to infants and children. Unborn children are also at risk if the mother-to-be consumes lead. Currently there is no known safe level of lead exposure.

Your home probably contains lead-based paint if it was built before 1960. If built between 1960 and 1990, the exterior may contain lead-based paint. The paint on interior surfaces may also contain lead in smaller amounts that could still be harmful, especially to young children. Houses built after 1990 should not contain lead because all consumer paints produced in Canada and the U.S. were virtually lead-free by this time.



Poly B, also referred to as Polybutylene, is a flexible grey pipe used in hot water systems and residential plumbing. It was manufactured in between the years of 1985 and 1997 because of its flexibility, low cost, and ease of installation. It is estimated that in Canada alone there are over 700,000 homes that have had this piping installed prior to it being discontinued.

Eventually and over time the pipe begins to leak and cause damages to homes. One or more of the following are the reasons you may be experiencing poly b issues in your home:

  • High levels or free chlorine exist in the water supply causing leakage throughout the piping system.
  • Improper installation of the piping in homes where fitting were installed too right causing hair line cracks eventually ending with leakage and damages to homes.
  • Improper installation of piping to be bent and put under stress causing leaks and damages to homes.
  • Installation near high heat areas including hot water tanks, in the attic, and other areas of extensively high temperatures.
  • The use of acetal (white or grey) fittings to connect pipes rather than the preferred metal fittings.


Asbestos is a naturally occurring fibrous material that was used in more than 3,000 building materials from the 1950s to 1990s.

When asbestos-containing materials are disturbed, intentionally or unintentionally, asbestos can be released into the air; and exposure to harmful airborne asbestos can cause serious health concerns for anyone working or living on your property.

Asbestos can be found in more than 3,000 common building materials, such as vinyl and linoleum flooring, stucco, loose-blown insulation, roof felt shingles, gypsum board filling compound, incandescent light fixture backings, and deck under-sheeting.

There are no significant health risks if materials containing asbestos are tightly bound in products and in good condition; sealed behind walls and floorboards; isolated in an attic; and left undisturbed

Aluminum Wiring

Aluminum wiring was used extensively in Canada from the mid 1960’s through the mid 1970’s. Initially, aluminum wiring was chosen for its low cost compared to the more expensive copper wiring. Some houses are wired completely with aluminum or copper. Others have a combination of both.

There are two chemical reactions that take place on the surface of pure aluminum. The result of both is exactly the same — the wire heats up and can reach temperatures high enough to ignite nearby combustible materials. The first chemical reaction causes corrosion when two dissimilar metals meet – in this case, between the aluminum wire and the standard brass outlet terminals. (Copper is so similar to brass that corrosion does not occur.) In the second chemical reaction, pure aluminum wire oxidizes as soon as its insulation is removed, exposing the wire to air. Either reaction coats the wire surface with a layer that increases resistance to current and generates heat. When the insulation is stripped from aluminum and the wire is exposed to air, it begins to form a white coloured oxide, which is a poor electrical conductor and causes a resistance to electrical flow.