Demolition, Renovation, and Site Cleanup
This domain tests safe demolition and renovation practice plus the cleanup and waste handling that follows. Expect questions on hazardous material surveys, demolition sequence, dust control, utility disconnection, waste segregation, and housekeeping.
Before demolition starts
- A designated substances or hazardous materials survey is completed before work begins; typical findings include asbestos, lead paint, silica, PCBs, mould, and ozone-depleting refrigerants.
- Confirm permits, engineered shoring or demolition plans for structural work, and utility disconnection by the owner or utility.
- Complete locates and mark services that remain live.
- Establish exclusion zones, signage, and protected pedestrian routes.
Sequence and structural safety
- Demolish from the top down; never undercut a structure or pull a wall over onto a person.
- Remove hazardous materials before general demolition so dust and debris do not spread contamination.
- Shore or brace remaining structure as directed by an engineer; monitor for cracking and movement.
- Use covered debris chutes or lower material mechanically; do not throw debris from height.
- Control dust with water or extraction, and never dry sweep or use compressed air on dust.
Waste, salvage, and cleanup
- Segregate waste at source: concrete and rubble, metal, wood, cardboard, and hazardous materials such as asbestos-containing debris.
- Hazardous waste moves under the required documentation and to an approved facility.
- Salvage reusable material before demolition where the contract requires it.
- Maintain housekeeping daily: clear walkways, remove trip hazards, secure cords, and cover or contain loose material.
Worked example
A crew is gutting a house built in 1965. The survey identifies asbestos in floor tile and mastic and in vermiculite attic insulation, plus lead paint on trim. Those materials are removed by trained workers with containment, wet methods, and respirators before any general demolition. Only after clearance does the crew remove partitions top-down, using a chute for debris and separating metal and wood for recycling. Dust is controlled with water, and the hazardous waste is manifested to an approved facility.
Traps that cost marks
- Assuming a small residential job needs no hazardous materials survey.
- Dry sweeping or blowing dust out of a doorway.
- Mixing hazardous debris with general waste.
- Pulling a wall over instead of demolishing it in a controlled sequence.