Demolition

Demolition can be more dangerous than building. Structures may be weakened, hazardous materials hidden, and utilities still live.

• Construction

Before demolition

• Engineering survey by a competent person of the structure’s condition and the risk of unplanned collapse
• All utilities (electric, gas, water, steam, sewer) shut off, capped or controlled, with the utilities notified
• Hazardous materials identified and removed first: asbestos, lead, PCBs, mercury, chemicals
• Floors and walls shored or braced where needed
• Perimeter barricaded and the public protected

During demolition

• Demolish from the top down, following the plan.
• Use enclosed chutes for debris dropped more than 20 feet outside the building.
• Keep floors from being overloaded with debris.
• Keep workers clear of the zone where material and equipment can fall.
• Inspect daily for new hazards caused by weakening.
• Control dust with water; wear required respirators.

Methods of demolition

• Hand demolition: interior strip-outs and selective removal with hand and power tools.
• Mechanical demolition: excavators with shears, grapples and hammers; high-reach machines for tall buildings. See Excavators.
• Explosive demolition: only by licensed specialists, with large exclusion zones.

Hidden hazards

• Asbestos in floor tile, pipe wrap, roofing, drywall compound and plaster. See Asbestos.
• Lead paint on older structures. See Lead.
• PCBs in old light ballasts and transformers; mercury in switches and lamps.
• Live circuits that weren’t on the drawings.
• Weakened floors from fire, water damage, rot or removed supports.
• Silica dust from breaking concrete and masonry. See Silica.

Falls during demolition

Workers fall through floors weakened by demolition, open shafts and holes created as material is removed, and edges where walls used to be. Guard or cover every opening, and use fall protection near unprotected edges. See Holes & Floor Openings.

Daily demolition checklist

• Competent person inspected the structure today
• Utilities confirmed off and capped
• Floor openings and edges guarded
• Debris chutes and drop zones barricaded
• Water spray or dust control running
• Exclusion zone around machines set and respected
• Respirators, eye and hearing protection worn

Last updated: October 1, 2026