Materials and contaminants to consider before demolition
The goal is to know when to stop and test — not to identify hazardous material visually or explain removal.
Potential asbestos
When the flag is raised
- older house or materials
- tiles, plaster, insulation, fibre cement, mastics or older heating systems
- work that will cut, drill, tear out or demolish material
Prudent action: Do not identify by sight. Test suspect materials before disturbance and use qualified specialists if confirmed.
Lead-containing paint or dust
When the flag is raised
- older paint
- sanding, stripping or demolition
- children or vulnerable occupants
Prudent action: Avoid creating dust before checking the material and planning appropriate containment, cleanup and disposal.
Vermiculite insulation
When the flag is raised
- lightweight granules in attic or walls
- insulation or electrical work in the area
Prudent action: Do not disturb or vacuum without assessment; some historic vermiculite may be associated with asbestos.
Mould and wet materials
When the flag is raised
- musty odour
- visible growth
- materials wet for an extended period
- water loss
Prudent action: Find and correct the moisture source before rebuilding. Large areas or contaminated water: specialized restoration.
Silica dust
When the flag is raised
- cutting or grinding concrete, brick, stone or mortar
Prudent action: Plan dust controls, ventilation and appropriate respiratory protection; avoid uncontrolled dry cutting.
Radon
When the flag is raised
- any Canadian home
- energy retrofit that tightens the enclosure
- occupied basement
Prudent action: Measure with a long-term test. A regional map or construction year cannot determine the level in a specific home.