If your house was built or re-roofed before the 1980s, there is a real chance the shingles contain asbestos. You cannot confirm it by looking. Only a lab test on a sample can, and that sample should be taken by a professional. The good news: asbestos shingles in good condition that nobody disturbs are generally not a significant health risk, so you do not need to panic or rip anything off. You do need a plan before anyone cuts, drills, scrapes or tears off the roof.
This guide explains what asbestos shingles look like, how to judge the risk, how testing works, and what Ontario and Ottawa rules mean if you decide to remove them.
TL;DR
- Two kinds of shingles can contain asbestos: rigid asbestos-cement shingles and older asphalt shingles reinforced with asbestos fibre. Age and appearance give clues, but only a lab test confirms.
- Intact, undisturbed asbestos shingles can generally stay in place. The danger starts when they are broken, cut, sanded, scraped or torn off.
- Do not sample or remove suspect shingles yourself. Hire a professional to test and, if needed, a qualified specialist to remove.
- Asbestos waste is construction waste: it does not go out with regular garbage in Ottawa and has its own handling rules in Ontario.
- Get the test result before you sign a re-roofing contract, so the quote reflects the real scope.
Table of Contents
- Why old roofs still matter
- What asbestos roof shingles look like
- Are asbestos shingles dangerous if left alone?
- How to test suspect shingles safely
- Leave it, cover it or remove it?
- What the rules say in Ontario and Ottawa
- What removal costs
- Questions to ask before you hire
- Our approach at HMJ
- Perspective: what we tell Ottawa homeowners about shingles
- FAQ
- Sources
Why old roofs still matter
The manufacture, import, sale and use of asbestos-containing products are now prohibited in Canada. That ban does nothing for the roofs already on houses. Health Canada notes that asbestos may still be found in older building materials, including shingles, tar paper and felt.
Ottawa has plenty of this housing stock: post-war bungalows in neighbourhoods like Alta Vista and Carlington, older homes in the Glebe and Hintonburg, and farmhouses and cottages across Renfrew County. Many have had one or two re-roofs, and some still carry original layers underneath newer shingles. That is where surprises happen.
What asbestos roof shingles look like
There are two main types, and they behave very differently.
Asbestos-cement shingles
These are rigid, hard, usually grey (often painted) tiles in rectangular, diamond or hexagonal profiles. According to one identification guide, they were popular for residential roofing from about 1920 to 1960 and stayed in production into the early 1980s. They often get mistaken for slate, and they tend to snap rather than flex when bent. Over decades they weather to a mottled, mossy surface, which is why homeowners often believe they have a slate roof.
Asbestos-reinforced asphalt shingles
These look identical to ordinary three-tab asphalt shingles. The asbestos sat inside the mat as reinforcement, so colour, pattern and granules give nothing away. That is the main reason visual identification is unreliable. Related materials on the same roof, such as asphalt-based felts and roofing mastics, may also contain asbestos.
Clues that raise the odds
None of these confirms anything, but each is a reason to test before work starts:
- The house was built or last fully re-roofed before the 1980s.
- The roof is a hard, brittle grey tile that looks like slate but sits on an ordinary house.
- There are several layers of roofing and nobody knows what is at the bottom.
- The shingles crack or snap rather than bend when a loose one is lifted by a roofer.
- Records, permits or a previous inspection mention the original roof material.
Modern shingles sold today are made with fibreglass and contain no asbestos, but a new-looking surface tells you nothing about what lies beneath it.
Can you tell by age or colour alone?
No. Age raises the probability, and a rigid grey tile from the 1950s is a strong suspect, but colour and shape do not prove content in either direction. Treat age and appearance as the reason to test, never as the answer.
Are asbestos shingles dangerous if left alone?
Health Canada says asbestos is not considered a significant health risk when the material is in good condition, tightly bound and left undisturbed. Health risks come from inhaling fibres, which happens when materials are disturbed by drilling, sawing, sanding, scraping or breaking apart. Breathing in fibres released during renovation or demolition can cause lung cancer, asbestosis and mesothelioma.
For a roof, that means:
- Weathering and rain are not the main problem. The hazard is physical disturbance.
- Pressure washing, wire brushing and scraping moss break the surface and spread fibres. Do not do these on a suspect roof.
- Cutting a vent, adding a skylight or mounting solar panels all disturb shingles, even if the job feels small.
- Hail, falling branches and ice damage can crack shingles. Cracked or crumbling pieces on the ground should be left in place and assessed, not swept up or bagged.
A roof that is leaking, crumbling or badly broken is a different case from a sound one. At that point, removal or an engineered repair plan usually makes more sense than patching.
How to test suspect shingles safely
The only reliable method is a sample analyzed by a laboratory. Health Canada’s advice is to avoid disturbing suspected materials yourself and to hire a professional to test. Breaking off a corner to mail to a lab is exactly the kind of disturbance that puts fibres in the air, on a roof, where wind carries them toward your yard and neighbours.
Here is how a professional test usually goes:
- Inspection. The assessor looks at the roof, its layers and its condition, and decides how many samples are needed. Different layers or sections may be different products.
- Sampling. The sample is taken with the material wetted and the area controlled to limit fibres, then sealed and labelled.
- Lab analysis. A laboratory analyzes the sample and reports whether asbestos is present. Ontario’s regulation sets out that the method for establishing asbestos content must follow a named standard.
- Report and recommendation. You get a written result you can show to roofers, insurers and future buyers.
HMJ Contracting publishes testing and lab analysis at $300 to $600 CAD. That is a small number next to the cost of finding out mid-tear-off that a crew has been spreading asbestos over your lawn. For a wider look at when to test, see our guide on testing for asbestos before you tear anything out and the signs that suggest you need removal before renovating.
Leave it, cover it or remove it?
There are three realistic paths once you know you have asbestos shingles.
| Option | Best when | Watch for |
|---|---|---|
| Leave in place | Shingles are sound, the roof does not leak, no work is planned | Keep records. Avoid washing, scraping and drilling. Re-inspect after storms. |
| Repair or cover | Minor damage, and a qualified contractor confirms the approach for your roof | Any fastening or cutting is disturbance. Get the method in writing. |
| Remove | The roof is failing, you are re-roofing, or work will disturb the shingles | Licensed handling, containment, waste rules and cost |
Health Canada’s position is that intact asbestos shingles can generally remain in place, and that any renovation or disturbance should come only after professional testing and, if necessary, removal by a qualified specialist. If you plan a re-roof, a new layer over the old one is sometimes proposed. Ask the roofer how the new layer will be fastened, because every nail through an asbestos shingle is a disturbance, and ask for that answer in your contract.
What the rules say in Ontario and Ottawa
Who may do the work
If asbestos is suspected or found, hire a qualified specialist before work begins. In Ontario, any worker on an asbestos abatement project must have received appropriate training. Ontario Regulation 278/05 sets out Type 1, Type 2 and Type 3 operations, which are classed by how much dust a job is likely to create and decide the precautions required. The regulation text defines them. Which class applies to a particular roof depends on the material, its condition and the method, so ask your abatement contractor to state it in the quote.
We cover the owner’s side of this in more detail in Avoid Fines: Ottawa Asbestos Disposal.
Where the waste goes
Tear-off material is not household garbage. In Ottawa, waste from building construction, renovation or demolition is not collected with regular garbage and is directed to the Trail Road Landfill Site or another landfill. Asbestos adds its own layer: Ontario Regulation 86/16 under the Environmental Protection Act defines asbestos waste to include waste from removing asbestos-containing construction or insulation materials and related handling. Sites that accept it can face specific conditions, and a provincial approval for one transfer operation included mandatory airborne asbestos testing.
The practical rule for you: never put suspect shingles in a bin, a trailer or a pickup bed on your own. Let the abatement contractor bag, label, transport and dispose of them, and ask for the disposal paperwork afterward. For the rest of a roofing or renovation job, plain construction debris such as packaging, wood and underlay that tested clean can go through ordinary construction debris removal, as long as it is kept separate from anything that tested positive. Our notes on renovation waste in Ottawa explain what to ask the city before you haul.
What removal costs
Roof size, number of layers, access and the contractor’s containment plan all drive price, and a roof is usually quoted after inspection rather than from a flat rate. For reference, HMJ Contracting’s published ranges on its abatement page are $1,500 to $3,500 CAD for small Type 1 or 2 jobs, and $5,000 to $15,000 CAD for vermiculite attic removal. Whole-home or Type 3 work has no published price because it depends on scope. Those ranges are for those job types, not a shingle quote, so treat them as context and ask for a written, itemized estimate for your roof. Our Ottawa asbestos removal cost guide breaks down what drives the number.
While you are checking the roof, ask about the attic as well. Health Canada warns that vermiculite-based insulation, which may contain asbestos, should never be disturbed or removed by the homeowner. Roofers working from the attic side can stir it up.
Questions to ask before you hire
- Has the material been tested, and can I see the lab report?
- Is the crew trained for asbestos work under Ontario rules, and is the company insured?
- Which operation type will this be, and what containment will you use?
- Who handles disposal, and will I receive documentation afterward?
- Is the quote itemized so I can see testing, removal, hauling and the new roof separately?
- How will the property be protected and cleaned, including gutters, eavestroughs and the ground below?
A contractor who cannot answer these plainly is not the one to put on your roof.
Our approach at HMJ
We test first, quote second. For an older roof, we arrange sampling and lab analysis, explain the result in plain language and then price the work line by line. If the shingles are sound and nothing is planned, we will say so and tell you what to avoid. If removal is the right call, we handle containment, hauling, disposal and post-job documentation, and we can carry straight on into demolition or reroofing-related renovation work under one roof. You can read about our licensed abatement services and request a free estimate. We aim to get estimates back within 24 hours.
Perspective: what we tell Ottawa homeowners about shingles
After more than 25 years working on Ottawa-area homes, the pattern we see is not people ignoring asbestos. It is people finding out about it too late, usually after a roofer, plumber or electrician has already started cutting. The cost of a test is small. The cost of stopping a job halfway, cleaning a property and re-pricing the work is not.
We also see the opposite mistake: owners who assume any old roof must come off immediately. It does not. A sound asbestos-cement roof can last for years if it is left alone, and spending money to remove it early is not always the best use of a renovation budget. Our advice is to find out what you have, write it down, and decide on your timeline rather than someone else’s.
The third thing we stress is paperwork. A lab report, a written scope and disposal records protect you when you sell, insure or renovate later. Buyers and inspectors increasingly ask for them.
— Jason
FAQ
How do I know if I have asbestos shingles?
You cannot know by looking. Age, a rigid slate-like grey tile, or an original pre-1980s roof are warning signs, but only a lab test of a professionally taken sample confirms the answer. Do not break off a piece yourself.
Is it safe to live under an asbestos shingle roof?
Generally yes, if the shingles are in good condition and left undisturbed. Health Canada does not consider intact, tightly bound asbestos a significant health risk. The risk rises when the material is damaged, cut, scraped or removed.
Can I remove asbestos shingles myself?
Health Canada advises against disturbing asbestos materials yourself and recommends hiring a qualified removal specialist before work begins. In Ontario, workers on asbestos abatement projects must also be trained. A DIY tear-off also leaves you responsible for the waste.
Can I put asbestos shingles out with the garbage?
No. Ottawa does not collect construction, renovation or demolition waste with regular garbage, and asbestos waste has additional handling rules in Ontario. Your abatement contractor should bag, transport and dispose of it and give you the paperwork.
Should I test before buying an older house?
If the roof is original or the house predates the 1980s, yes. Ask the seller for any past testing, and arrange a professional assessment before you close or before you plan a re-roof, so the cost is in your budget.
Sources
- Asbestos and your health, Health Canada
- Asbestos and your health, Health Canada (prohibition and low-risk statement)
- Chemical safety for DIY projects, Health Canada
- Asbestos in the home, CCOHS
- O. Reg. 278/05, Designated Substance: Asbestos
- Special items, City of Ottawa
- O. Reg. 86/16, Waste Management, Ontario
- Environmental Compliance Approval notice, Ontario Environmental Registry
- Asbestos roof shingles: how to identify by home age and style