Asbestos was widely used as a building material in Canada from the 1920s through the late 1980s. If your home was built before 1990, there is a reasonable chance it contains asbestos-containing materials (ACMs) somewhere in its construction. Most of the time, those materials pose no immediate risk — until you renovate. Here's where asbestos hides, what it looks like, and what you need to know before you disturb it.

Why Asbestos Was Used

Asbestos is a naturally occurring mineral fibre with remarkable properties: it's heat-resistant, chemically stable, strong, and cheap. For decades, it was considered an almost ideal building material and was incorporated into dozens of products — insulation, flooring, roofing, ceiling texture, pipe wrap, and more. Canada was actually one of the world's largest asbestos producers and exporters well into the 1980s.

The problem is that when asbestos fibres are disturbed — cut, scraped, broken, or deteriorated — they become airborne. Inhaled fibres can lodge permanently in lung tissue and, after a latency period of 20–50 years, cause mesothelioma (an aggressive cancer), asbestosis, and lung cancer. There is no safe level of asbestos fibre inhalation.

Canada finally banned most uses of asbestos in 2018. But the material is still in millions of existing homes.

Where Asbestos Is Commonly Found in Canadian Homes

Popcorn / Stipple Ceilings

Textured spray ceilings — commonly called popcorn or stipple ceilings — were almost universally applied with asbestos-containing compounds through the 1970s and into the early 1980s. This is one of the most common asbestos finds in Ontario homes. The texture is typically non-friable when intact, but the moment you scrape, sand, or drill through it, fibres become airborne. Many homeowners inadvertently expose themselves and their families during DIY ceiling removal.

Vinyl Floor Tiles (9" × 9")

The classic 9-inch square vinyl floor tile — extremely common in basements, kitchens, and rec rooms of homes built before 1980 — was frequently manufactured with asbestos. The adhesive (mastic) used to install it often contains asbestos as well. Intact tiles in good condition are generally not a risk. The hazard comes from breaking, cutting, or sanding them, or from removing them in a way that disturbs the adhesive layer. Even tiles that appear solid may crumble at the edges.

Pipe and Duct Insulation

Older homes with boiler heating systems or original plumbing often have pipe lagging — a wrapping material applied to hot water and steam pipes to retain heat. This insulation was commonly made from or contained asbestos. Deteriorating pipe wrap is particularly hazardous because it becomes friable over time, releasing fibres simply from vibration or air movement. Duct wrap on older HVAC systems can also contain asbestos.

Drywall Joint Compound

Joint compound (also called mud) used to tape and finish drywall seams was manufactured with asbestos through roughly 1977 in Canada. Homes built or significantly renovated before that date may have asbestos in the drywall compound — including in walls that otherwise look perfectly modern. Sanding old compound for a renovation is a known exposure route.

Vermiculite Attic Insulation

Loose-fill vermiculite insulation poured into attics was common through the 1980s. The majority of vermiculite sold in Canada during that period came from the Libby Mine in Montana, which was contaminated with tremolite asbestos — one of the most hazardous asbestos fibre types. If your home has loose, grey-brown granular insulation in the attic that looks like small pebbles, assume it contains asbestos until tested. Do not disturb it or enter the attic without proper PPE.

Exterior Siding and Roofing

Asbestos cement board was used as exterior siding ("transite" siding) on many homes built from the 1940s to 1970s. Asbestos was also used in older roofing shingles. These materials are generally low-risk when intact and painted, but cutting, drilling, or demolishing them without proper precautions creates fibre release. They also require special disposal — they cannot go in a regular dumpster.

Fireproofing and Insulation Boards

Furnace rooms, mechanical spaces, and areas around fireplaces in older homes sometimes contain spray-applied asbestos fireproofing or asbestos millboard (insulating panels placed around heat sources). These materials are often friable and represent the highest-risk category of asbestos material.

Older Electrical Components

Electrical panels, wiring insulation, and certain heating components manufactured before 1980 can contain asbestos. While this is less commonly encountered, it's a reason why licensed electricians working in older homes should be aware of the risk — and why an asbestos assessment before any renovation should include electrical areas.

How to Tell If a Material Contains Asbestos

You cannot identify asbestos by appearance alone. Asbestos fibres are microscopic — you can't see them with the naked eye, and the materials they're mixed into look like any other drywall compound, floor tile, or insulation. The only way to confirm the presence or absence of asbestos is through laboratory analysis of a bulk sample.

A qualified assessor takes small samples from suspected materials and sends them to an accredited lab for polarized light microscopy (PLM) analysis. Results typically take 3–5 business days. This testing is required before any Type 2 or Type 3 removal work under Ontario Regulation 278/05.

When Is Asbestos Actually Dangerous?

The key concept is friability — how easily a material can be crumbled or broken to release fibres. Intact, well-bonded asbestos-containing materials that are not being disturbed generally do not pose a health risk. The danger arises when materials are:

Cut, drilled, sanded, scraped, or demolished
Deteriorating with age (crumbling, peeling, flaking)
Damaged by water, impact, or vibration
Disturbed during renovation or demolition without proper containment

This is why older homes with intact asbestos materials in good condition are often left undisturbed — with proper management documentation — rather than undergoing costly removal. The removal itself creates the hazard if not done correctly.

What Homeowners Should Do

If your home was built before 1990, the practical approach is straightforward:

Before any renovation or demolition — have suspected materials assessed and tested. This is not optional under Ontario law for contractors, and it protects you.
If you find deteriorating insulation, crumbling ceiling material, or damaged pipe wrap — don't disturb it. Seal off the area and call a professional assessor.
If you're buying an older home — consider including an asbestos inspection as part of your due diligence, particularly if renovation is planned.
If you've already disturbed suspected material — stop work, leave the area, and contact a professional. Air testing can determine whether fibres have been released.

At Green Life Restoration Services, we identify, assess, and safely remove asbestos-containing materials throughout Toronto and the GTA. Contact us for a free on-site assessment — before you start any renovation work.

Asbestos in Older Homes: Where It Hides and Why It's Still a Problem