1. S U B M I T T E D B Y ,
A K H I L E S H . A
P R O D U C T I O N O P E R A T O R ( T R ) ,
F O R B E S B U M I A R M A D A L I M I T E D
SCAFFOLDING

2. What is a scaffold?
 A scaffold is a temporary structure specifically erected to
support access or working platform. Scaffold are commonly
used in marine & offshore construction work so that
workers have a safe, stable platform on which to work when
work cannot be done at ground level or on a finished floor

3. HAZARDS
 Scaffolding collapse
 Eletrocution ( Work near over head electric lines)
 Mixing components from different scaffold systems.
 Falls from heights
 Falling objects
 Manual tasks
 Bad planking

4. Assessing the risk
 The type of scaffold to be used
 The height of scaffold to be erected
 The scheduling of scaffolding work
 The layout of the workplace, including proximity to public areas
 The surface on which the scaffold will be erected
 The number of people involved
 Local weather condition
 Exposure that might occur( radiation , gases)

5. Controlling the risks
 Usage of mechanical aids if required
 Use fall protection devices, proper construction
 Safe system of work
 Providing proper personal protective equipment

6. Types of scaffolds
 Birdcage scaffolds
 A birdcage scaffold is an independent scaffold that consists
of more than two rows of standards in both directions and
is connected by ledger and transoms. It is mainly used for
work that is to be carried out on a single level such as
ceilings

8. Tower scaffolds
 A tower scaffold is an independent scaffold consisting of
four vertical members connected longitudinally &
transversely
 Construct with modular frame or tube and coupler
scaffolding.
 Use alternative height to base ratios or extra support if the
scaffold is sheeted, loaded with heavy equipments,
supporting a ladder
 For eg: height of tower outside the building height to base
ratio is 3.5:1

9. Mobile scaffolds
 A mobile scaffold is a tower scaffold that is mounted on
castors. Manufacturers and suppliers must provide
information regarding the safe use and erection of mobile
scaffolds
 Where adjustable castors are used, the slope of the surface
should not exceed 5 degrees. Castors fitted to standards
should be locked
 Before moving, check any power lines or other overhead
obstruction, ground should be firm & level, never move the
scaffold in windy condition, ensure guardrail , mid rail, &
toe boards are installed on all working platforms

11. Tube & coupler scaffolds(Modular)
 So named because they are built from tubing connected by
coupling devices. Due to their strength, they are frequently
used where heavy loads need to be carried, or on structures
with unusual design, shape & locations.yhe versatility of
tube and coupler scaffolds enables them to be assembled in
multiple directions in a variety of settings.
 When using tube and coupler scaffolding consideration
should be given to the diameters and strength of the tube
and components being used to form the scaffold. Steel
tubes & Aluminium tubes should not be mixed in the one
scaffold, except for guard rails, mid-rail or other member
that are not structural members

12. A modular scaffold mainly consists of:
 Standards : they come in a variety of length & have
performed connectors welded at fixed distances along their
length.
 Ledgers : they are in varying lengths with connectors
welded to each end.
 Transoms : they are generally made to support scaffold
board and structures.
 Bracings : bracings in each direction are made to fit the
different bay sizes.
 Scaffold boards :they are also called stagings and come in a
variety of lengths, thickness & widths.

13.  Ties : ties are generally formed in tube and fittings.
 Adjustable base plates : they are essential and care should
be taken to establish their safe working loads and weather
they are designed for heavy or light duty use.

15. Frame scaffold
 Frame scaffold is a scaffold assembled from prefabricated
frames, braces & accessories. Frame scaffolds such as ‘A’ &
‘H’ frame trestle scaffolds are commonly used by painters
and for general fit out & finishing work.
 Frame scaffold should be erected and dismantled by a
competent person in a progressive manner to ensure both
the installers safety and the stability of the overall structure
and braces should be attached to the frames.
 Frame scaffold should be stable & erected on a suitable
foundation to ensure it can adequately carry & distribute
the loads such as materials and workers evenly to each
frame

18. Hung scaffold
 Hung scaffold is an independent scaffold that hangs from
another structure, but is not capable of being raised or
lowered when in use.
 The hung scaffold should be designed by a competent
person.
 All vertical hanging tubes are to be provided with check
couplers at the suspension points and underneath the
platform.
 Standards on a hung scaffold should be tension spliced

20. Suspended scaffolds
 A suspended scaffold incorporates a suspended
platform that is capable of being raised or lowered
when in use.
 Ensure a rescue and retrieval procedure is developed
before starting work
 Suspended scaffolding components should be
inspected foe damage, wear & cracks in before use.
 Ensure safe access to and egress from the cradle.

21. Trestle scaffold
 Trestles are a simple working platform used in pairs to
support scaffold boards or proprietary staging and are
intended for light work only.
 They must be sited on firm, level ground and be fully open.
 They must not be used where anyone can fall more than 4.5
m
 The top third of trestles must be above the working
platform, scaffold must be at least two boards wide-430mm
 It is available in lengths of up to 7.3 m and has a standard
width of 450mm. Toe boards & guard rails are required
when persons are liable to fall more than 2 m

23. Cantilever scaffolds
 A cantilever scaffold is a scaffold that is supported by
cantilever load bearing members.
 Design & position cantilever beams in accordance with the
engineers requirements and the scaffolding plan
 Ensure a competent person certifies that the supporting
structure can support the cantilevered scaffold.
 Fix the beam to the floor below using a positive fixing
 Use counterweights on the beam
 Install props to the top of the beam and to the underside of
the floor above. Ensure the props are fixed to prevent
dislodgement

26. Base plate

27. Couplers

28. Planning scaffolding work
 Scaffolding work should be carefully planned before work
starts so that it can be carried out safely.
 Planning involves:
 Identifying the hazards.
 Assessing the risks & determining appropriate control
measures in consultation with all relevant persons involved
in the work
 The scaffolding plan should include a site layout plan and
detail the elevations sections of the scaffold. Its to be made
available for inspection at the worksite

29. The scaffolding plan should address the following issues
 Basis of design
 Foundations
 The weight bearing capacity of the surface where the
scaffold is to be erected.
 Size & weight of the scaffold
 Supporting structure
 Access & egress
 Bracings
 Type of scaffold
 Edge protection
 Barricade , symbols & signs

30. Safe work method statements
 Identify the type of high risk construction work being done.
 Specify the health & safety hazards and risks arising from
that work
 Describe how the risks will be controlled
 Describe how the control measures will be implemented,
monitored & reviewed.
 Be developed in consultation with workers and their
representatives who are carrying out the high risk
construction work
 SWMS is required if the scaffold is erected near energized
electrical lines or if there is a risk of a person falling more
than 2m during the erection & dismantling

31. Loadings
 A scaffold should be designed for the most adverse
combination of dead , live & environmental loads that can
reasonably be expected during the period that the scaffold
is in use.
 Consider environmental loads, particularly the effects of
wind & rain on the scaffold.
 Dead loads relate to the self-weight of the scaffold structure
& components including any working, catch or access
platforms, stairways, ladders, scaffolding hoists or electrical
cables.

32. Uniformly varying load

33.  Live load on standards will vary for different bays &
platforms. To calculate the live load on a standard, assume
that each standard in that bay supports one third of the
duty live load on each platform in each adjoining bay. This
is to allow for off center loading of platforms and
concentrated loads placed closer to a standard.
 For eg: consider a medium duty scaffold
 The live load on any one standards based on the worst
possible loading in adjacent bays (4.4kn)
=4.4KN(450kg)/(2/3)=2.9kN(300kg)
Assume that the dead load-3.5KN(350KG)+2.9KN=6.4KN
Assume that ground capacity 2500kg/m2 , timber plank
225mm wide
Soleboard length=[650kg/(2500kg/m2)]/0.225m=1.16m

34. Scaffold working platforms are generally rated as
 Light duty-up to 225kg/bay. Examples include painting,
electrical work, many carpentry tasks and other light tasks.
Platform should be at least two planks wide (approx:450mm)
 Medium duty-up to 450kg/bay. This is suitable for general
trades work. Platform should be at least four planks wide
(approx:900mm)
 Heavy duty-up to 675kg/bay. This is what is needed for
bricklaying, concreting, demolition work and most other work
tasks involving heavy loads or heavy impact forces. Platform
should be at least five planks wide( approx:1000mm)
 Special duty- has a designated allowable load as designed

35. Safe erection of scaffold
 After enough components of the scaffold have been erected
to support it immediately install:
 A platform at least 450mm wide along the full length of the
section of scaffold.
 Edge protection across the space between the uprights
forming the outer frame of the scaffold at the level scaffold
has reached.
 A means of access to the level the scaffold has reached
 A section of platform may be left open to allow the passing
of planks or other scaffolding components between the
levels

36.  Scaffold fittings & other connections should be securely
tightened.
 All scaffolding components should be installed as the
scaffold is erected
 Obtain certification from a competent person
 Limit the number of workers on a scaffold at anyone time.
 Do not climb on guard rails to gain extra height.
 Implement measures to control the risk of fall by edge
protection, additional scaffold planks to minimise the size of
the internal gap.

37. Scaffold load & size calculation
 Dead load : The dead load(G) shall include the self weight
of the scaffold structure.
 Environmental loads : wind loads , snow loads , rain & ice
loads , earthquake loads in accordance with NZS 4203
 Live loads (Q): the weight of the persons, materials &
debris, tools & equipments & impact forces

38. Duty live loads
 Light duty- a load of 2.2 KN/bay, that includes a single
concentrated load of 1 KN.
 Medium duty- a load of 4.4 KN/bay that includes a single
concentrated load of 1.5 KN
 Heavy duty- a load of 6.6 KN/bay that includes a single
concentrated load of 2 KN
 Special duty- the largest intended load but not less than
heavy duty
 For design purposes, the single concentrated load shall be
assumed in the most adverse position within the bay

39. Inspection of scaffolding materials
 Sufficient material should be provided for and used in the construction
of scaffolds
 Scaffolding material should be free from defects.
 The boards & planks used should be unpainted so that defects should
be visible
 Timber scaffold boards should comply BS 2482 or other equivalent
international standards
 All scaffolding components should comply with BS 1139, BS EN 39 ,BS
EN 74, BS EN 1004, & BS EN 12810
 Hot dipped galvanized, or unprotected tube may be used in scaffolding .
 Tubes end should be free from distortion, corrosion, splits ,undue rust.
 Where tubes have become split at the ends, these should be cut off, cut
should be perpendicular to the axis

40.  The safe working loads for individual couplers & fittings should
comply with bsen12811
 Special attention should be paid to the use of joint pins.
 All couplers & fittings should be free from rust & distortion, worn
threads & damaged bolts & should be maintained in lubricated
condition
 The nuts should be run on their bolts to ascertain that they have
free-running fit . Spanners & podgers should have length as
recommended by the coupler manufacture

41. Dismantling of metal scaffolds
 The dismantling work shall be done by trained workmen under
the immediate supervision of a competent person.
 Sufficient time should be allowed for the dismantling work to be
conducted safely.
 The scaffold to be dismantled should be checked for its strength &
stability beforehand.
 Dismantling sequence should be planned and that sequence of
dismantling sections of the scaffold should be logical and
determined with due consideration of the scaffolder’s safety.
Dismantling work should be carried out according to the plan.
Because changes may have been made in a scaffold structure
during its work, its not safe to assume, to dismantle it in reverse
order.
 If the scaffold is defective ,it should be made good before
dismantling commences.

42.  Scaffold should not be dismantled in vertical sections from one
end towards the other unless special consideration is given to ties
& bracings
 Safe access to & egress from the place of work should be provided
for the scaffolders
 The scaffold to be dismantled should be fenced off at the ground
level/public area to prevent persons entering the work area and
warning notices should be posted up in the vicinity
 Steps shall be taken to ensure that scaffolding materials are not
thrown, tipped or shot down from height, properly lowered in a
safe manner by means of a lifting appliance or lifting gear.
 Every scaffolder involved in the dismantling should have all safety
equipments.
 All the trades on the site should coordinate and collaborate closely
among the members