Asbestos
What does asbestos look like in a house?
By ARO Restorations · Updated
Short answer
You cannot identify asbestos by sight. Its fibres are microscopic and were mixed into other materials. What you can recognise is the kinds of product that often contained it, such as vermiculite, pipe wrap, 9-inch floor tiles and textured ceilings. A laboratory test confirms it.
In this guide
Why you cannot see it
Asbestos is a group of natural minerals that separate into very fine fibres. In buildings it was almost always an ingredient in something else: mixed into cement, vinyl, plaster, paper or adhesive. Individual fibres are far too small to see. Two products that look identical can differ, one with asbestos and one without.
So the useful question is not what asbestos looks like but which materials in a house of your age might contain it. This guide goes through them.
In the attic
Vermiculite insulation. Loose, lightweight granules, grey-brown to silvery-gold, like small pebbles with a layered, shiny surface. It pours and lies flat between the joists. Much of the vermiculite sold in Canada came from a mine whose ore was contaminated with asbestos, so all vermiculite is treated as suspect.
Not asbestos: pink, yellow or white fibreglass batts, grey fluffy cellulose, and white blown fibreglass.
In the basement and service areas
Pipe insulation. White or grey wrap on heating pipes. In cross-section it may look like corrugated cardboard, or be a chalky white shell in a canvas jacket.
Fittings. Hard, lumpy white plaster on pipe elbows and valves.
Boiler and furnace insulation. A thick white coating or blanket on an old boiler, and white gaskets and rope seals at doors.
Duct wrap and tape. White or grey paper wrapped round ducts, or white tape over duct joints and at registers.
Cement board. Grey, hard, dense sheets, sometimes with a dimpled pattern on one side, used behind furnaces and wood stoves.
Floors
Vinyl and asphalt tiles. Nine-inch square tiles are the best known, but twelve-inch tiles can contain asbestos too. They are often dark, with streaks or flecks.
Sheet flooring. Older vinyl sheet with a grey or white felt-like paper backing. The backing is the concern.
Adhesive. Thick black glue, called mastic, under old tiles.
Old floors are often hidden under newer ones. A suspiciously thick floor at a doorway or floor register may have several layers.
Walls and ceilings
Textured ceilings. Popcorn or stipple finishes.
Joint compound and plaster. Indistinguishable by eye from modern materials.
Ceiling tiles. Some older acoustic tiles and suspended ceiling panels.
Sprayed fireproofing. A fluffy or rough grey coating on steel beams and decks, mainly in commercial and apartment buildings.
Outside
Cement siding and shingles. Hard, brittle panels, often with a wavy bottom edge or a textured wood-grain face.
Soffits and panels. Flat grey cement sheets under eaves and on porch ceilings.
Roofing. Some old shingles, felts and flashing cements.
Cement pipe. Grey flues, drains and downpipes.
Window putty, caulking and stucco in older buildings.
Friable and non-friable
The word that matters most is friable. A friable material can be crumbled by hand pressure. It releases fibres easily.
- Friable: vermiculite, pipe and boiler insulation, sprayed fireproofing, textured ceiling coatings
- Non-friable: vinyl tiles, cement board and siding, and similar bound products
Non-friable materials are lower risk while intact. They become a hazard when broken, cut, drilled, ground or sanded.
How old is too old?
Use of asbestos declined through the 1970s and 1980s. Materials installed before about 1990 are generally treated as suspect. Canada prohibited the import, sale and use of asbestos and products containing it at the end of 2018, with limited exceptions. The ban did not remove what is already in buildings.
If you find something suspect
- Do not touch, break or sample it casually.
- Look at its condition. Intact and out of the way is very different from crumbling in a walkway.
- Keep children and pets away from damaged material.
- Do not sweep or vacuum debris.
- If it is damaged, or you plan work that will disturb it, have it tested.
- If it is intact and you are leaving it alone, note where it is for future reference.
Testing
A sample is taken with precautions and sent to an accredited laboratory, which identifies asbestos fibres under a microscope and reports the type and percentage. Results commonly take a few days. Have samples taken by someone trained to do it, because taking the sample disturbs the material.
Is it dangerous to have in the house?
Health Canada’s advice is that asbestos poses little risk when it is in good condition and left undisturbed. Health effects are linked to breathing in fibres, mainly with heavy or repeated exposure, and appear many years later. The practical rule is simple: do not disturb suspect materials, and test before renovating.
Questions people ask
Can you tell asbestos by looking at it?
No. The fibres are microscopic and mixed into other materials. You can recognise products that often contained it, but only a laboratory test confirms it.
What colour is asbestos insulation?
Pipe and boiler insulation is usually white or grey. Vermiculite attic insulation is grey-brown to silvery-gold granules. Colour alone proves nothing.
Do 9-inch floor tiles always contain asbestos?
Not always, but they are a common asbestos-containing product, and so is the black adhesive beneath them. Twelve-inch tiles can contain it too.
What should I do if I find something that might be asbestos?
Leave it alone, keep people away if it is damaged, do not sweep or vacuum debris, and have it tested before any work that would disturb it.
Is asbestos still used in Canada?
Canada prohibited the import, sale and use of asbestos and asbestos-containing products at the end of 2018, with limited exceptions. Materials already in buildings remain.