4. Construction Activities
Learning outcomes:
1. Identify the main hazards of construction and demolition work
and outline the general principles to control them;
2. Identify the hazards of work above ground level and outline the
general requirements necessary to control them;
3. Describe the safe working practices for common forms of access
equipment;
4. Identify the hazards of excavations and outline the general
requirements necessary to control them; and
5. Identify the hazards to health commonly encountered in small
construction activities and explain how risks might be reduced
4
6. (Stacked goods)
Kept as small as is practical, adequate
space, and should be vertical.
Kept away from walls and off the floor by
using pallets.
Should not block light, obstruct fire detection
and control equipment or block drains.
Separate stack for different types of
containers.
6
7. (Storage – general)
Should not be used for other work activities.
Adequate space for movement (access and egress).
Kept clean and tidy.
Mixed storage :
materials should be separated for easy location and
access.
Incompatible materials should not be stored
together.
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8. (Storage – general)
Warning signs for any special danger or any
special precautions measure.
Adequate fire protection.
Should not permit public access.
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9. (Storage of flammable and
combustibles)
“Require special storage arrangements”
Additional requirements:
Should not be stored with other materials,
separate stores for liquids, solids and gases,
oxygen cylinder stored separately away.
External open-air store (fenced)– 3 meters
from other buildings or activity.
9
10. (Storage of flammable and
combustibles)
Internal stores – of fire resistant material with good
level of ventilation.
At least 2 exit for fire escape and shut / locked when
not in use.
Marked with hazards and precautions information.
Fire risk activities should not be carried out close to
storage area unless with suitable PPE.
10
11. (Storage of flammable and
combustibles)
Electrical equipment in store must not be a
potential source of ignition.
Fire fighting equipment and system must be
in good condition.
Inspected regularly, planned maintenance,
and good housekeeping.
11
12. Construction Activities Risk
factors and risk activities
Main hazards and controls
1. Machinery and vehicles
2. Site security
3. Electricity
4. Slips, trips and falls
12
13. 1. Machinery and vehicles
Machinery hazard: Contact with moving parts, dust,
noise, vibration.
Control: Warning signs, guards, segregate areas,PPE.
Vehicle hazard: toppling over, collision with pedestrian,
other vehicle, structures-collapse.
Control:
Keep people and vehicle separate (sites & building
entrance)
Traffic routes
Visibility
Stationery vehicle safety procedure.
13
14. 2. Site security
Site Hazards: Public access, vandals, thieves, children.
Control:
Entrances locked.
Fencing – 2 meters high.
Other protection measures:
Not leaving ladders lying around.
Disabling equipment.
Covering excavations.
Securely locking tools and hazardous substances at
night.
Provide security staff, cctv, lighting and alarm.14
15. 3. Electricity
Electrical Hazards: trailing cables, live wires exposed,
unsafe equipment, overhead power lines, buried cables.
Control:
Identify buried cable position.
Provide guards
Segregate areas
Equipment properly maintained
Incorporate circuit breaker on equipment
Use low voltage circuit
Substitution other form of power (eg: compressed air)
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16. 4. Slips, trips and falls
(working at height and excavation)
Hazards: Uneven & muddy floor, trailing
wire, holes, falling items.
Control:
Proper manual handling
PPE
16
17. Management Controls
Planning for Health and Safety
Documentation
Selection of Contractors
Control of Contractors on Site
17
18. Construction Activities
Working above ground level (Over 2 metres)
Basic Hazards:
1. Roof (fragile roof- use roof ladder/crawling boards)
2. Deterioration of Materials
3. Unprotected Edges
4. Unstable Access Equipment
5. Weather
6. Falling Materials
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19. Construction Activities
Main precautions to prevent fall and falling
material:
1. Guard rails, fencing and toe boards
2. Working platforms
3. Ladder hoops
4. Fall arrest equipment
5. Protection against falling materials
19
20. 1. Guard rails, fencing and toe boards
Mid rail
missing
Toe boards
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21. 2. Working platforms
Basic Requirements:
Sufficiently wide.
Capable of bearing loads.
Supporting framework should be stable.
Closely boarded to prevent gaps.
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22. 3. Ladder hoops
Prevent falling from height but do not prevent sliding
down the ladder.
22
23. 4. Fall arrest equipment
Boatswain’s Chair
- Light short term work
Safety Harness
-Use when approaching open
edges
23
24. Protection against falling materials
Not stacking materials near edges.
Close boarding of working platforms.
Using hoist to lift or lowering down materials.
or (protect people)
Covered walkways.
Sheeting across scaffold.
Netting to catch falling material.
Designated exclusion zone.
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25. Safe Working Practices for Access
Equipment
Independent Tied Scaffolds
Mobile Towers
Mobile Elevating Work Platforms (MWEP)
Ladders
Cradles
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26. Independent Tied Scaffolds
Scaffolding basic components:
Standards
Ledgers
Transoms
Designed to carry its own mass, material load,
and workers load (use of base plates).
Tied to a building for stability.
Bracing is used to stiffen scaffold framework.
(eg: Façade bracing & Ledger bracing)
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27. Mobile Towers
Used for painting and simple maintenance job.
With working platform and four wheels.
Height limited to 12 metres.
Safety points:
Do not remain on top when being moved - easily
overturn.
Unstable on rough grounds.
Avoid obstacles.
Lock wheels when not in use.
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28. Mobile Elevating Work Platforms
(MEWP)
Precautions:
Firm sound ground.
Sufficient clearance.
Barrier to avoid
collision.
Edge protection for
work platform.
Controls of arm inside
the cradle.
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29. Ladders
Grade 1 – light work
Grade 2 – medium use
Grade 3 – heavy duty work
Metal ladders not be used near unprotected live
electrical circuits
Must be set on solid flat base
Angle 75 degree
Top rest against solid support.
Only one person climb the ladder at a time
Nothing should be carried while climbing
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30. Inspection of Scaffolds
Inspect at regular intervals (once per week).
Inspect when first erect.
Things to check:
Tying and bracing
Edge protection
Ground condition
Access
Loading
30
35. Revision Question
1. What are the requirements for mixed store?
2. What are the requirements for the internal
storage of flammable materials?
3. What are the safe method of working on
fragile roof?
4. What are the main hazards of using
ladders?
5. What measures should be taken to prevent
materials from falling from a height?35
36. Revision Question
6. In respect of scaffolding:
What is the difference between standards,
ledgers and transoms?
What is the difference between tying and
bracing?
7. State the safety precautions which need to
be taken when mobile elevating work
platforms are in use.
8. What is the angle at which ladders should
be positioned?
9. When should scaffolding be inspected?36
37. Revision Question
10. Identify the main hazards associated with
excavation work.
11. What is battering?
12. What are the key elements of shoring?
13. Identify the requirements for crossing
points.
14. How can the hazards of buried services be
avoided?
15. When must excavations be inspected?37