Removing a wall in an old Ottawa house, where could asbestos be?

Where Asbestos Can Hide in an Ottawa Wall Removal

In a house built before 1990, several materials inside and around a wall can contain asbestos, and disturbing any of them without testing first is the point where costs and legal requirements change quickly.

The materials to check, drawn from Health Canada and Ontario's guide to O. Reg. 278/05, include:

• Joint compounds on drywall seams (Ontario's guide)
• Textured paints or coatings (Ontario's guide)
• Plaster (Health Canada lists cement and plaster)
• Construction mastics (Ontario's guide)
• Pipe insulation, including corrugated air-cell or block insulation (Ontario's guide), and insulation around hot water pipes (Health Canada)
• HVAC duct insulation (Ontario's guide)
• Vinyl floor tile or sheet flooring (Ontario's guide) where the wall meets the floor
• Caulking and sealants (Health Canada)

Health Canada advises hiring a professional to test before renovating and a qualified asbestos removal specialist if asbestos is found. A pre-renovation inspection with bulk sampling runs roughly $250 to $1,300 depending on the size of the building and the number of samples taken, based on published prices read in September 2026.

Once a material tests positive at 0.5 per cent or more asbestos by dry weight (the threshold in O. Reg. 278/05, section 3(4)), the removal work is classified as Type 1, Type 2 or Type 3 under that regulation. Which Type applies depends on whether the material is friable and how much of it is disturbed, assessed on site by the contractor. Ask the contractor to give you the Type in writing, because it determines what controls, training and notices the law requires. For Type 3 work, the employer must notify a Ministry of Labour inspector before starting, and clearance air testing is required after the enclosure is dry. O. Reg. 278/05, section 12(5), also says the total area worked consecutively in a room counts as one job, so splitting the work into smaller visits does not change the classification.

Ontario Regulation 347 lets asbestos waste leave the site only for a disposal site whose operator has agreed to accept it, packaged and labelled to the regulation's specifications, transported by a driver trained in asbestos waste management.

Before you agree to a price, ask the contractor to spell out in the quote which Type they are pricing for, whether a clearance air test is included or billed separately, and which disposal site they have arranged for the waste, because those three items are where two quotes for the same wall can differ.