Learning Objectives Describe the types of construction demolition work. Identify the various types of hazards and their control measures in demolition work Describe demolition management process and general controls

1. Dammam Community College
Safety Technology Program
Construction Safety Training
SHORT COURSE
Instructor: Mr. Muizz Anibire, MSc
Tel: +966501296203, Email: muizzanibire10@gmail.com

2.  Describe the types of construction demolition work.
 Identify the various types of hazards and their control
measures in demolition work
 Describe demolition management process and general
controls
Learning objectives

3. Introduction
 Demolition is one of the most hazardous construction
operations and is responsible for more deaths and major
injuries than any other activity.

4. Introduction
 If a demolition project is well planned the risks of injury and
death can be minimized.
 It should be emphasized that the planning and execution of a
demolition project should only be done by appropriately
competent persons.
 The work should be supervised by someone with sufficient
knowledge of the particular structure being dismantled and an
understanding of the demolition method statement.
 For complex demolition work, expert advice from structural
engineers will be necessary.
 The Health, Safety and Environment authorities must be
notified before work begins if it is to last for 30 days or more than
500 person days are involved.

5. Principal hazards of demolition work
 The principal hazards associated with demolition work are:
o falls from height or on the same level
o falling debris
o premature collapse of the structure being demolished
o dust and fumes
o the silting up of drainage systems by dust
o the problems arising from spilt fuel oils
o manual handling
o presence of asbestos and other hazardous substances
o noise and vibration from heavy plant and equipment
o electric shock
o fires and explosions due to flammable/explosive substances
o smoke from burning waste timber
o pneumatic drills and power tools
o the existence of services, such as electricity, gas and water
o collision with heavy plant
o plant and vehicles overturning.

6. Pre-demolition investigation and survey
 Before any work is started, a full site investigation must be
made by a competent person to determine the hazards and
associated risks which may affect the demolition workers and
members of the public who may pass close to the demolition
site.
 The competent person is often a specialist structural engineer
who will also advise on the temporary support of adjacent
buildings and the correct method of dismantling or demolition.

7. Pre-demolition investigation and survey
 The investigation should cover the following topics:
 the construction details of the structures or buildings to be
demolished and those of neighboring structures or buildings
 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 the
building being demolished and adjoining buildings
 falls of materials and people
 the location of any dangerous machinery
 the presence of asbestos, lead or other hazardous or radioactive
substances and any associated health risks
 environmental issues, such as dust, water pollution and noise

8. Pre-demolition investigation and survey
 The investigation should cover the following topics (contd.):
 public safety, the provision of high fencing/hoardings
 manual handling issues
 the location of any underground or overhead services (water,
electricity, gas and sewage)
 the location of any underground cellars, storage tanks,
chimneys, balconies or bunkers particularly if flammable or
explosive substances were previously stored

9. Common hazardous substances in demolition work
Lead – is most dangerous when it is in the air as a fume or dust (e.g.
cutting steelwork coated with lead-based paint or dismantling of
tanks containing lead-based petrol)
Asbestos – where possible it should be removed before any other
demolition work starts and must always be removed by a licensed
contractor. Asbestos may be found in sprayed coatings, thermal
and acoustic insulation materials, fire resistant walls/partitions,
asbestos cement sheets or flooring materials
Polychlorinated Biphenyls (PCBs) – a toxic substance found in
electric transformers and capacitors, refrigeration and heating
equipment
Silica – occurs in stone, some bricks and concrete aggregate. Any
demolition of structures constructed from these materials will give
rise to dust containing silica.

10. Case Study – Asbestos Hazards in Homes

11. Demolition method statement
 There are two forms of demolition:
 Piecemeal – where the demolition is done using hand and
mechanical tools such as pneumatic drills, cranes and
demolition balls, hydraulic pusher arms or heavy duty grabs
and
 Deliberate controlled collapse – where explosives are used to
demolish the structure. This technique should only be used
by trained, specialist competent persons. This is the most
economic form of demolition but it is the most hazardous and everyone
must be at a safe distance at the time of the collapse.

12. Demolition method statement
 A written method statement will be required before demolition
takes place. The contents of the method statement will include
the following:
o details of the method of demolition to be used including
the means of preventing premature collapse or the
collapse of adjacent buildings and the safe removal of
debris from upper levels to prevent overloading due to
the debris
o details of site access and security
o details of the location of any underground or overhead
services
o details of protection from falling materials arrangements
o details of equipment, including access equipment,
required and any hazardous substances to be used

13. Demolition method statement
 A written method statement will be required before demolition
takes place. The contents of the method statement will include
the following:
o arrangements for the protection of the public and the
construction workforce against noise and whether
hazardous substances, such as asbestos or other dust, are
likely to be released
o details of personal protective equipment, such as hard
hats, which must be worn by all personnel on site
o first aid, emergency and accident arrangements
o training and welfare arrangements
o arrangements for waste disposal

14. Management of the demolition and general controls
 Demolition hazard control involves implementing measures
which reduce the risk at the demolition site.
 There is a recognized hierarchy of controls in health and safety
ranging from the most to the least effective. This hierarchy can
be applied directly to the demolition process.
Elimination is the most effective control measure. This
involves removing the hazard or hazardous work practice
from the site, by the following actions:
o disconnecting services to the demolition site
o ensuring there are no sparks or ignition sources,
where a risk of fire or explosion exists
o ensuring separation between the public and
demolition activities
o excluding unauthorized persons from the site.

15. Management of the demolition and general controls
 Substitution or replacing a hazard or hazardous work practice
with a less hazardous one could include the following:
o using a controlled collapse technique, in place of
people working at heights
o using power shears in place of grinding or
oxyacetylene cutting, where a risk of fire exists.
 Isolating or separating the hazard or hazardous work practice
from workers and others involved in the demolition area by
the following:
o installing screens on plant to protect from dust and
noise
o installing barriers and fences
o marking off hazardous areas.

16. Management of the demolition and general controls
 Engineering controls by means including the following:
o modification of tools or equipment
o provision of guarding to machinery or equipment
o provision of shatterproof/guarded windscreens on
plant
o provision of falling object protective structures
(FOPS) and roll-over protective structures (ROPS)
on vehicles and plant
o installation of safe working platforms on scaffolds
and elevating work platforms
o installation of edge protection to open edges of
landings, stairways and fixed platforms
o installation of static lines and anchor points for fall
arrest systems
o use of chutes for dropping debris

17. Management of the demolition and general controls
 Administrative controls, including the introduction of reduced
risk work practices. They include the following:
o limiting the amount of time a person is exposed to a
particular hazard
o implementing and documenting safe working
procedures
o for all hazardous tasks
o training and instructing all personnel
o identifying hazardous substances prior to work
commencing
o implementing safe procedures for handling
hazardous substances
o implementing procedures for disconnecting services
to the site

18. Management of the demolition and general controls
 Personal protective equipment should only be considered
when other control measures are not practicable or to increase
the protection given to a person. Personal protective
equipment includes:
o safety helmets (required by legislation)
o fall-arrest harnesses and lanyards
o safety boots
o gloves
o goggles
o respirators
o hearing protectors.

19. Premature collapse
 Premature collapse of the structure is one of the main causes
of serious injury resulting from demolition work.
 The common reason for this type of incident is the lack of
effective planning before the beginning of the demolition.
 Premature collapse usually begins with the structural collapse
of floors and is often caused by plant operating on floors
which are not certified safe and/or back-propped where
required.
 It can also be caused by poor site supervision and a lack of
instruction, training and information for the workforce.
 A fully competent and trained workforce who have been made
completely aware of the hazards associated with a particular
site should lead to a successful conclusion to the demolition.

20. Premature collapse – Mecca Mall, Amman, Jordan

21. Protection from falls and falling material
 Falls at demolition sites can be the result of:
o falling through fragile roofing material
o falling through penetrations or open voids (e.g. skylights,
voids for air-conditioning and plumbing)
o falling from open edges (e.g. stairways, landings, fixed
platforms, scaffolding and edge of roof)
o falling out of elevating work platforms (e.g. scissor lifts)
o failure of plant (e.g. elevating work platforms)
o falling whilst accessing a roof or other elevated area
o falling down lift shafts
o collapse of flooring (e.g. concrete slab and wooden
decking)
o collapse of ground above cellars or pits
o tripping over debris on the ground.

22. Noise
 Some of the effect might be mitigated by replacing noisy
equipment with quieter machinery and ensuring that plant and
equipment are regularly maintained.
 Noise from the processes maybe difficult to control but the
location of noisy plant where it would have least effect on the
neighborhood, the erection of noise barriers, the reduction of the time
taken by noisy operations would help to alleviate the problem.
 The source of noise and vibration on demolition sites will
normally be caused by the use of plant and equipment, falling
debris and/or explosives. Compressors, pneumatic hand-held
tools, front end loaders, excavators and other equipment.
 A noise assessment will be required and workers given ear
defenders.

23. Dust
 During the demolition process, dust is a considerable hazard
which needs to be controlled. Among the possible control
measures are:
o damping the process down with water,
o sheeting of disposal lorries as they leave the site
o provision of filters or covers to site drainage systems to
prevent the risk of them silting up.
o restriction on the speed of vehicles on the site and the
regular cleaning of roads
o mud on the roads which will cause dust can be alleviated by
providing ‘stoned-up’ vehicle routes,
o ensuring that vehicles passed through a wheel wash before
leaving the site,
o designating the vehicle routes to and from the site would
also limit the number of affected roads.

24. Siting and use of machinery
 Examples of some of the hazards that may result from
operating plant and equipment on demolition sites include:
o electrocution due to plant or equipment coming into
contact with live electricity
o plant failure due to its safe working load being exceeded
o accidental dropping of material due to the incorrect
slinging of loads
o plant striking or colliding with persons, particularly
shared access ways
o excessive noise and vibration from machinery, such as
front-end loaders and excavators
o flying particles from pneumatic tools such as impact
hammers
o welding and cutting operations during maintenance work
o the structural failure of steelwork and
o fire and explosions.

25. Siting and use of machinery
 The site supervisor must ensure that all plant and equipment
when delivered to site is in good working order and fitted with
all necessary safety devices, notices and guards.
 He must also ensure that an ongoing maintenance and defect
reporting system is in place. No equipment may be used until
all defects have been rectified.
 The site supervisor will ensure that only authorized licensed
operators are permitted to operate any plant and equipment
used on site.
 All wiring, except where temporary installations are required,
should be disconnected before demolition work commences.
Temporary electrical installations must comply with the
Institution of Electrical Engineers Wiring Regulations and
legislative requirements.

26. Competence and training
 A very important requirement for demolition work is the
provision of training for all construction workers involved in
the work.
 An induction training which outlines the hazards and the
required control measures should be given to all workers
before the start of the demolition work.
 This training should provide information to site workers to
make them aware of the hazards that they will face, the
demolition and control procedures to be adopted and the site
rules. Issues such as first aid and welfare facilities should also
be covered.
 During the demolition process, communications should be
continued using toolbox talks, and posters and signs around
the site.

27. End of Session 07: