Is plaster in an older Glebe house something to test before repairs?

Health Canada lists cement and plaster among the older materials that may contain asbestos, along with surface treatments such as paint, putty, caulking, sealants and spackling. Its advice, for a house built before 1990, is to hire a professional to test before renovating or remodelling.

Health Canada also says there are no significant health risks if materials containing asbestos are left undisturbed and in good condition. Drilling, sawing, sanding and scraping are among the actions it lists as releasing fibres, so the test comes before any of those, whether the repair is one crack or a larger patch. A positive result is abatement work for a qualified asbestos removal specialist (ottawaabatement.com), not plaster or drywall work.

Before a contractor starts:

• Tell the contractor the age of the house and share any test results.
• Ask whether the quote includes arranging the test, or whether you arrange it first.
• Ask the contractor to explain in writing what they propose to use on the plaster and how they will finish it to match the surrounding surface.

On permits, the City's lists do not name plaster or drywall patching; if the repair is part of bigger work, ask the City's Building Code Services. Published Toronto and Ontario contractor prices put a small patch at about $150 to $600 per patch, read October 1, 2026; these are not Ottawa prices.

If you have no test result yet, book the test before you book the contractor, and give the contractor the written result.