Demolition contractors glossary

Short, plain-English definitions of the terms you'll meet when choosing a demolition contractor provider in Ontario.

What are PCBs in older buildings?: Polychlorinated biphenyls (PCBs) are synthetic chemicals used in building materials before the 1980s, including caulking, electrical ballasts, and transformers, that pose health and environmental risks and require professional testing and removal before demolition.
What is a demolition permit in Ontario?: A demolition permit is a municipal authorization required under the Ontario Building Code before tearing down or removing a structure, issued by the local building department and distinct from a standard building permit.
What is a demolition shear?: A hydraulic-powered attachment mounted on an excavator or loader that cuts through steel beams, reinforced concrete, and structural members during demolition work.
What is a Designated Substances Survey?: A mandatory pre-demolition or pre-renovation survey under Ontario's Occupational Health and Safety Act that identifies the presence and location of asbestos, lead, PCBs, mercury, and other designated substances in a building.
What is a high-reach excavator?: A high-reach excavator is a specialized demolition machine with an extended boom and arm that can reach 80 to 120+ feet high, allowing controlled dismantling of tall buildings from ground level without requiring crane support or aerial lifts.
What is a hydraulic breaker (hoe ram)?: A hydraulic breaker (hoe ram) is a pneumatic hammer attachment mounted to an excavator that uses repeated impact force to fracture and break concrete, rock, asphalt, and other hard materials during demolition work.
What is a party wall?: A party wall is a shared wall between two adjacent properties, typically found in semi-detached or townhouse configurations, that requires written agreement before partial or full demolition.
What is a pulverizer attachment?: A hydraulic jaw crusher that mounts on an excavator arm to pulverize concrete structures and liberate embedded rebar for material recovery and recycling.
What is a tipping fee?: A tipping fee is the charge per tonne or per load that landfills and transfer stations impose when accepting demolition and excavation debris.
What is backfill?: Backfill is the material, typically soil or engineered fill, placed back into an excavated area after foundation, utility, or footing work is complete to restore grade and provide structural support.
What is construction and demolition waste?: Construction and demolition waste (C&D waste) is debris generated during building, renovation, or demolition projects, including concrete, lumber, drywall, brick, metals, and other materials requiring sorting and disposal.
What is dewatering?: Dewatering is the process of removing groundwater from an excavation site to create dry working conditions before demolition or construction begins.
What is friable asbestos?: Friable asbestos is asbestos-containing material that crumbles, pulverizes, or shreds when handled, disturbed, or subjected to mechanical pressure, releasing asbestos fibers into the air.
What is grubbing?: Grubbing is the excavation and removal of tree stumps, roots, and woody debris from the ground after trees have been felled, leaving bare soil suitable for construction or grading.
What is hoarding (construction)?: A temporary protective barrier erected around a demolition or excavation site to shield the public, secure the work area, and contain dust and debris.
What is non-friable asbestos?: Non-friable asbestos is asbestos bound tightly within a matrix material that resists disintegration and does not readily release fibers when handled normally, requiring Type 2 or Type 3 removal classification in Ontario.
What is Ontario One Call?: Ontario One Call is a free notification service that contractors must contact before excavation work to alert utility companies of digging activity and request location of buried gas, electric, water, and telecommunications lines.
What is selective demolition?: Selective demolition is the targeted removal of specific interior or exterior building components, finishes, or systems while leaving the main structure intact, typically performed during renovation or repurposing projects.
What is shoring?: Shoring is a temporary support structure installed to hold back soil and prevent cave-in during trenching, excavation, or foundation work.
What is soil compaction?: Soil compaction is the process of mechanically densifying soil by removing air voids to increase its load-bearing strength and stability for building and infrastructure projects.
What is topsoil stripping?: Topsoil stripping is the removal and temporary storage of the upper layer of soil, typically 4 to 8 inches deep, prior to excavation, grading, or foundation work on a site.
What is underground storage tank (UST) removal?: Underground storage tank (UST) removal is the decommissioning and extraction of buried fuel or oil storage tanks from a site, followed by soil testing and assessment for environmental contamination.
What is underpinning?: Underpinning is the process of reinforcing, deepening, or replacing sections of a building's existing foundation to prevent or correct settlement, subsidence, or structural instability.
What is waste diversion rate?: Waste diversion rate is the percentage of demolition debris that is recycled, reused, or recovered instead of being disposed of in a landfill.