DEMOLITION AND DISMANTLING - NEBOSH Quick Revision Sheet

Demolition and/or Dismantling Hazards and Controls
Introduction
A High Risk Construction Activity
For every one fatality in the manufacturing industry there are five fatalities in construction and three of these will be fatalities due to demolition work
Not uncommon for multiple fatalities to occur – Didcot Power Station 2015 saw 4 Fatalities
Demolition Definition / Dismantling Definition
“The deliberate pulling down, destruction or taking apart of a structure, or a substantial part of a structure” / “The taking down or taking apart of all, or a substantial part of a structure”
Pre-Demolition Survey
  • CDM Regulations apply to all demolition & dismantling works
  • Previous use may present hazards to workers
  • Survey is required before any work begins to ensure demolition work can go ahead
  • Protection of work force & surrounding property
  • Client is responsible for ensuring any building to be demolished is adequately surveyed
  • Issues to be considered include:
  • The construction details of the structures or building (pre-stressed beams, materials, fragile roofs, general weakness etc.) and those of neighbouring structures
  • The previous use of the premises
  • The load carrying capacity of adjoining land including the presence of underground culverts
  • The need for possible temporary support structures for building being demolished or those adjacent.
  • Falls of materials and people
  • The location of any dangerous machinery
  • The presence of asbestos, lead or other hazardous or radioactive substances and the associated risks
  • Environmental issues – dust, water pollution, noise etc.
  • Public safety including the provision of high fencing or hoardings
  • Manual handling issues
  • The removal of waste
  • The location of any underground or overhead services (gas, electric, water, sewage)
  • The location of any underground cellars, storage tanks, chimneys, balconies or bunkers particularly if flammable or explosive substances were previously stored
  • The means of access to the site
  • The details of any traffic or pedestrian routes through the site
  • The provision of welfare facilities
  • The proximity of neighbours
  • The location of public thoroughfares adjacent to the structure or building
  • Any local authority building regulations that might apply to the building or structure
  • Legal covenants or disputes which could affect operations on the site.
  • Consideration must be given to the previous history of the site & the presents of:
  • Asbestos
  • Chemical contamination
  • Lead
  • Large drains (Weil’s disease)
  • Dust (pigeon droppings)
Type & Sequence of Demolition will Need to be Considered
  • Piecemeal Demolition
-Preliminary to other methods
-Done using hand held tools
-Can be begun or completed by machine
  • Pre-weakening and controlled collapse:
-Controlled collapse involves pre-weakening
-Removing key structural members (key stones)
-Remaining structure collapses under own weight
Problems
  • Collapse may be greater than expected
  • Could leave structure hazardous & insecure
  • Debris projection
  • Debris left after collapse may present risks to those that move it
  • Use of explosives
-HSE must be consulted
-Compliance with Control of Explosives Regulations 1991
-Experienced explosives engineer required
  • Ground Zero” Technology
-Remote controlled demolition arm
Isolation of Services
  • Isolate at furthest point from demolition
  • Don’t assume isolated
  • Remember some systems store energy even after isolation:
  • Electrical capacitors
  • Compressed oils / air
  • Stored water
Protection of Public & Others
  • Boundaries fenced or boarded 2.5m high
  • Clearly marked with adequate warning notices
  • Boundaries must be maintained
  • Inspected daily by competent person
Waste:
  • Do not allow waste to accumulate
  • Disposal must be undertaken using relevant waste transfer notes (non-hazardous waste)
  • Use only recognised landfill sites
  • Considerations for hazardous waste such as asbestos and receipt of consignment notes
Specific Issues
  • Avoiding premature collapse
  • Protection from falling materials
  • Protection from Noise
  • Control of dust
  • Use of plant & machinery
  • Environmental protection
  • Competence of workforce

Demolition Method Statement
  • Details of the method of demolition to be used.
  • The means of preventing premature collapse (including adjacent structures)
  • The safe removal of debris from upper levels
  • Details of site access and security
  • Details of the location of any underground services
  • Details of protection of falling materials arrangements
  • Details of equipment to be used (access equipment, hazardous substances etc.)
  • Arrangements for the protection of the public and workforce (noise, asbestos, dust etc.)
  • Details of isolation methods for any services
  • Details of any temporary services required for the site
  • Details of PPE to be worn
  • First aid, emergency and accident arrangements
  • Training
  • Welfare arrangements
  • Arrangements for waste disposal
  • Names of the foreman and those who will have responsibility for health and safety and the monitoring of work
  • The coordination of all work activities on site
  • The expected level of competence of site workers
  • Relevant risk assessments covering COSHH, PPE, manual handling etc
  • Good practice to have a site waste management plan to ensure that the legal duty of care for waste is complied with. Hierarchy of control within the site waste management plan should be:
  • Eliminate;
  • Reduce;
  • Reuse;
  • Recycle;
  • On site separation and segregation and responsibly dispose of using licensed carriers
Protection from Falling Materials
  • Protective screens should be set up around demolition
  • Brick guards, debris nets & sheeting to contain falling materials
  • Demarcation zones with specific risk
  • Head protection essential
Protection form Noise and Dust:
  • Protective screens should be set up around demolition
  • Brick guards, debris nets & sheeting to contain falling materials
  • Demarcation zones with specific risk
  • Head protection essential
Environmental Protection
  • Ensure waste being transported from site is sheeted
  • Provide wheel wash
  • Consider road sweeper
  • Consider contamination of sewers (oils etc)
  • Establish interceptor pits to prevent contamination of water