ImmoMulti — direct buyer of income properties on the North Shore — regularly meets owners of older plexes who discover, mid-transaction, asbestos in their materials or vermiculite in their attic. The good news: these materials do not block a sale. According to Health Canada, an asbestos-containing material left undisturbed and isolated poses no significant health risk. The real risk — to your price and to health — comes when these materials are disturbed carelessly, or when a buyer discovers them by surprise. The winning seller's strategy comes down to three words: manage, test, disclose.
Where does asbestos hide in a plex built before 1990?
According to the CNESST, asbestos is found in flocking, thermal insulation, floor finishes and glue, ceiling tiles, vermiculite, asbestos-cement pipes and plaster. The use of asbestos-containing flocking was banned in 1990, and thermal insulation in 1999.
If you own a plex — duplex, triplex or quadruplex — built before the 1990s on the North Shore, asbestos is probably part of its history. It was not a marginal material: it was used for its insulating and fireproofing properties in a wide range of building components.
According to the CNESST, the materials in a multiplex likely to contain asbestos include:
- flocking and thermal insulation (fire or heat insulation, often around piping and the furnace);
- floor finishes and the glue under vinyl tiles;
- drop-ceiling tiles;
- plaster on walls and ceilings;
- asbestos-cement pipes;
- vermiculite, as attic or wall insulation.
The CNESST notes that asbestos is present in many materials of buildings and infrastructure built mostly before 1990. The Government of Québec adds that it is still found in some public and residential buildings built or renovated before 2011.
Source: CNESST — Safe Management of Asbestos and Government of Québec — Effects of asbestos on health.
What is Zonolite vermiculite and why watch for it?
According to the Government of Canada, vermiculite ore mined at the Libby Mine in Montana from the 1920s until 1990 could contain asbestos and was mostly sold in Canada under the Zonolite brand. Not all vermiculite contains it, but it is reasonable to assume old vermiculite insulation could contain asbestos.
Vermiculite is a lightweight, granular insulation, greyish-brown to golden in colour, often found loose in the attics and sometimes in the wall cavities of older plexes. The problem is not vermiculite itself, but the fact that part of the ore sold as insulation came from a mine whose deposit was contaminated.
According to the Government of Canada, some vermiculite contains tremolite asbestos. The best-known brand, Zonolite, was widely distributed in Canada — but the product may also have been sold under other names. That is why any vermiculite insulation installed before 1990 should be treated as potentially contaminated until proven otherwise.
Do not test it yourself, blindly
Taking a sample of vermiculite releases the very fibres you want to avoid. Have a qualified person do the sampling and laboratory analysis. The Government of Canada offers an information line at 1-800-443-0395 regarding vermiculite.
Source: Government of Canada — Vermiculite insulation containing tremolite asbestos.
What are the real health risks of asbestos?
According to the Government of Québec, inhaling asbestos fibres is associated with asbestosis, lung cancer and mesothelioma. These diseases generally appear 15 to 40 years after exposure begins. Québec has set an exposure standard of 0.1 fibre/cm³ of air.
The risk of asbestos is real, but it is conditional: it depends on fibres being released into the air. According to Health Canada, exposure to airborne asbestos fibres does not occur if the material is left undisturbed. Vermiculite insulation sealed behind walls, under a floor or isolated in an attic — and a product that is tightly bound and in good condition — poses no significant health risk.
The activities that create the danger are those that break, sand, cut or move these materials: renovation, demolition, maintenance. That is precisely what distinguishes a plex lived in peacefully from an improvised, careless worksite.
"Between 75% and 95% of deaths due to occupational disease in Québec between 2005 and 2015 were linked to asbestos exposure. Of 116 deaths from occupational disease in 2020, 90 were linked to asbestos."
— Government of Québec, Effects of asbestos on healthThese figures are not meant to alarm an owner whose plex contains intact asbestos: they explain why handling must be controlled. A well-managed material is one that does not release fibres.
What are your CNESST obligations during renovation or demolition?
According to the CNESST, before any work likely to produce asbestos dust, you must verify its presence, train workers and control dust emissions. For asbestos removal or demolition involving asbestos, a worksite notice must be sent to the CNESST, and an "Asbestos – Danger" sign posted for moderate- and high-risk work.
As soon as you undertake work in a multiplex likely to release asbestos dust — even routine renovation in an old plex — regulatory obligations apply. According to the CNESST, the employer (the contractor, or you if you hire labour) must, among other things:
- Verify the presence of asbestos and the types present before starting work;
- Train and inform workers about the risks and safe work methods;
- Control dust emissions, using a sealed enclosure and appropriate ventilation where needed;
- Provide appropriate respiratory protection equipment;
- Post an "Asbestos – Danger" sign at each access point for moderate- and high-risk work;
- Send the CNESST a worksite notice for removal work or demolition involving asbestos, with methods and a training attestation.
The cost of non-compliance
According to the CNESST, in case of non-compliance with these rules, the Commission can stop the work and offenders are liable to penal prosecution. For a seller, a worksite halted mid-transaction is the worst-case scenario.
Source: CNESST — Asbestos (employer obligations).
Should you disclose asbestos or vermiculite to the buyer?
A prudent seller discloses what they know. The sale of a building in Québec is governed by the legal warranty of quality, and hiding a known problem can expose the seller to a latent-defect claim. Transparency protects the seller better than silence.
Disclosure is strategic. Many sellers fear that admitting the presence of asbestos will scare buyers off. In reality, it is the opposite: what scares off a buyer (or their notary, or their lender) is the surprise and the doubt. A seller who presents a clear test report and an honest declaration inspires confidence.
In Québec, the sale of a building is presumed to carry the legal warranty of quality. Concealing a known defect — or deliberately turning a blind eye — can open the door to a costly claim after the sale. Transparent disclosure is therefore both an ethical and a legal-protection matter.
The "manage, test, disclose" strategy
- Manage: leave in place what is intact and in good condition, rather than disturbing it needlessly;
- Test: have suspect materials and the attic vermiculite sampled by a qualified person;
- Disclose: give the results to the buyer and state them clearly in the seller's declaration.
For the exact wording of your seller's declaration and the promise-to-purchase clauses, consult a notary: every situation is unique, and a well-drafted clause protects you on both sides.
To go deeper on your obligations as a seller, read our guide on latent defects and the legal warranty when selling a plex.
How do asbestos and vermiculite affect price and financing?
There is no official discount scale. The impact depends on where the material is, its condition, the scope of work the buyer plans, and the quality of your documentation. An intact, well-documented material has a more limited impact than an unexpected discovery mid-transaction.
On the financing side, an inspection report mentioning vermiculite in the attic or materials likely to contain asbestos can lead a lender or mortgage insurer to request an additional inspection, a test or a holdback. This does not usually prevent the transaction, but it can lengthen timelines and cool a hurried buyer.
On the price side, the worst-case scenario is the unexpected discovery: a buyer who finds undisclosed vermiculite during inspection will negotiate down, invoke a delay, or walk away entirely. A clean file — test, scope of risk, management plan — defuses that dynamic and protects your value.
| Situation | Typical impact on the sale |
|---|---|
| Asbestos intact, tested and disclosed | Limited impact; the buyer purchases with full knowledge |
| Attic vermiculite, not tested | Doubt; lender or buyer may require a test before closing |
| Material disturbed without precautions | Health and regulatory risk; worksite possibly stopped by the CNESST |
| Unexpected discovery mid-transaction | Downward renegotiation, delays, possible buyer withdrawal |
This is where a direct sale makes full sense. A specialized buyer who purchases multiplexes as-is already factors the possible presence of asbestos or vermiculite into the offer — no need to decontaminate before selling.
Sell your older plex as-is — asbestos or vermiculite in placeImmoMulti buys North Shore income properties without requiring decontamination. Offer within 48 h. →Manage, don't panic
Asbestos and vermiculite do not condemn your plex: they call for a clear-headed approach. Leave intact what is sound, have suspect materials tested by a qualified person, and disclose what you know. This protects your health, keeps you compliant with CNESST requirements if you renovate, and defends your price against a well-informed buyer. And if you would rather skip the tests, financing delays and inspection negotiations, a direct sale remains the simplest option for an older income property on the North Shore.
To place these materials within a full building review, see also our article on the pre-sale inspection of an income property and our dedicated guide to inspecting an old plex (pyrite, asbestos, vermiculite).
Informational content only · Does not constitute legal or tax advice. Consult a notary for your specific situation.