Eric Phillips on Asbestos in Older Houses…

Almost any house built prior to the 1990s will contain some asbestos. This WorkSafe BC link will show you some of the more common places and give an overview of asbestos in the home.
It is interesting that the diagram uses a relatively modern house as its example. Asbestos, as the miracle do-anything product, came into full prominence after our houses were built, but there will still be some asbestos used either during original construction or during subsequent renovations/maintenance. The most common places to find materials which may contain asbestos are in vermiculite insulation (one common brand name is Zonolite, which looks like small brown popcorn), “popcorn” textured ceilings (sometimes called Spray-Tex), duct tape (asbestos tape was used to seal joints on hot-air ducts and also on furnaces and fireplaces), asbestos-board siding, flooring, drywall & fillers, and electrical boxes. We had a local Grandview example where asbestos was found in the plaster as well but it was not clear if it was in the original plaster or came from post-construction renovations (filler with asbestos). The reason for the asbestos concerns is that once disturbed, the fibres will stay airborne for a long time and the long-term consequences of inhaling them will not be immediately evident. To confirm I was not misleading you, I talked to a carpenter friend who has been through the working-with-asbestos course and he gave a few examples. He had a job of re-placing some old flooring. The 9×9 tiles and the adhesives almost certainly contained asbestos. To avoid the cost of dealing with their removal, the tiles were left undisturbed and were covered with floor-leveling compound and then with sheet flooring with the edges sealed. An engineered wood floor could also have been used with the same sealing precautions.
How do you know for sure if there is asbestos in a material to be removed during renovation? Testing in the only way to know for certain. For example, I have some vermiculite insulation in my attic. If I simply wanted to increase the amount of insulation, I could have added more insulation on top but since I needed to move some to get access to wiring, I took some samples to a lab and had it tested. Although my insulation does not look any different from any other vermiculite I have ever seen, it did not contain appreciable amounts of asbestos. While on that topic, if you are planning a renovation, someone in our ad hoc group is completely renovating their house and therefore had samples analyzed but found the City would not accept self sampling and required sample collection by a certified testing group. This is contrary to the information provided on the City’s website.

Eric Phillips
“Amateur House Mechanic”, Grandview Heritage Group