What control measures can be used to minimise the risk of people and materials from falling?
- Chutes used to ensure debris reaches the ground safely in piecemeal demolition
- Netting around scaffolding
- Toe boarding and guard rails to prevent accidental knocking
- Brick guards, debris netting and sheeting to contain materials that do fall
- Scaffold and access stairs kept in safe and good condition, for as long as possible
- Fall protection provided
- Warning signs
- Hard hat wearing in the area
What are the main hazards associated with deconstruction and dismantling work?
- Premature collapse
- Falls and falling materials
- Vehicles and plant overturning
- Manual handling
- Dust and fumes
- Noise and vibration
- Existence of services
- Hazardous substances
- Dilapidation
What would be the typical scope of a pre-demolition survey?
The presence of adjoining or adjacent properties
• The type of structure and its key elements
• The condition of the structure
• The need for temporary works or shoring
• Confined spaces, such as old tanks or process vessels
• Overhead or underground services
• Health hazards, such as asbestos
• Suitable access for the proposed method of demolition and vehicle access for the removal of waste
What is the purpose of pre-demolition, deconstruction, or refurbishment survey?
Prospective contractors must ensure that the information with which they are provided is sufficiently detailed to allow identification of any structural problems and the risks associated with any flammable or hazardous substance.
What are the 3 principal ways of demolishing a structure?
- Take it down piecemeal
- Knock it or push it down
- Blast it down using explosives
What would influence the size of an exclusion zone?
- Materials used in the structure
- Structure’s condition
- Extent of any planned pre weakening
- Explosives to be used
- Site’s topography
- Proximity of surrounding structures
- Effects of ground vibration or the attendant shock waves
- Dust
- Noise
When would an “exclusion zone” be particularly used during demolition activities?
When explosives are to be used in a demolition, an exclusion zone must be put in place at a safe distance from the structure that is to be demolished. Everyone, apart from the shot firer, must be outside the exclusion zone when the demolition is to be activated. An explosives engineer should design the exclusion zone, and everyone must be kept outside the zone until all clear signal has been given.
