SCAFFOLDING
Introduction
Temporary structure
Can be made of timber (bakau/
mangrove), steel, galvanised metal, metal
alloys, bamboo
Purpose is to provide working platform
Means of material transport
Safe place incorporating safety features
for workers and people passing
underneath
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Types of Scaffolds
Putlogs Scaffolds
Independent Tied scaffolds
Mobiles
Fixed Frame Scaffolds
Suspended
Cantilevered
Putlog Scaffold
Mainly used for constructing or repairing
brickwork structures
Supported in brickworks by putlogs and
ties
Single working platform allowed
Max load on platform is 275 kg/m2 which
is roughly equal to 140 bricks, 25 kg
mortar and 2 men
Maximum safe height of scaffold is 30 m
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Putlog
Putlog Scaffold
End View
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Putlog Scaffold
Putlog inserted at least
80 mm into brickwork
A scaffold tied into a building. 9
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Independent Tied Scaffolds
The whole load of scaffold are carried to the foundation
resting on the ground
Tied to construction to ensure stability
Can deal with 4 working platforms at one time therefore
greater consideration for design
Classified as:
Light duty (only one working platform, max loading of 73
kg/m2)
General purpose (up to 4 working platform and max
loading of 180 kg/m2 on each platform) and
Heavy duty (2 working platforms of higher loading max
of 290 kg/m2)
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Independent Tied Scaffolding
End View
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5
Scaffolding parts and terms
Standard – uprights carry total load of
scaffold including man and material on the
platform
Ledger – horizontal tubes connecting the
standard
Putlog – transverse tube with one end
placed in a slot left in the construction
usually a gap in the mortar joint of a brick
wall
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Scaffolding parts and terms (cont.)
Baseplate – a square metal plate welded
to a short length of tube and fitted to the
bottom of a standard
Soleplate – timber board on which
baseplates rest to avoid baseplate resting
directly on thin surface
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Scaffolding parts and terms (cont.)
Guard rail – an additional ledger connected
between standards where there is a working
platform to form a rail to prevent man falling
from the platform
Scaffolding boards – timber boards placed
across the transoms or putlogs to create the
working platform
Toeboard –timber boards placed on edge
against the standards at the edge of the working
platform to prevent materials or tools falling
over the edge
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Scaffolding parts and terms (cont.)
Toeboard clip – specially shaped clip which
retains the toeboard vertically and in position.
The clip fits around the standards
Coupler – to hold together the various structural
components (i.e. the tubes) of the scaffold.
Should be load bearing
Brace – diagonally placed connections either in
vertical or horizontal plane to ensure stability of
scaffold by removing the possibility of
movement
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Scaffolding parts and terms (cont.)
Tie – a mechanism used to connect and
tie in the scaffold to construction thus
avoiding collapse due to it moving away
from the building
Ladder – mean of access to platform
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Basic Scaffolding Fittings
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Mobiles
Self-contained units
Only one working platform of limited size
Used where work needs to be moved
more frequently
For light loads
Used for maintenance, painting, finishing
interior
Height of towers must not exceed three
times the shortest base dimension
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Mobiles Scaffolding
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10
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Fixed Frame Scaffolds
Easy to install and
mobilise; strong and safe.
Main frame:
high-carbon steel,
762 - 1,219mm wide,
1,524 - 1,930mm tall.
Transverse frame:
to support working
platform
to hold the main
frames
1,829mm long
745 - 1,050mm wide. 35
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Assembling Fixed Frames
Steps:
1. Start with proper assembling of the 1st row, then base
plates and vertical installation.
2. Test for vertical and horizontal levels; apply bracings.
3. Place the transverse frames on the main frames.
4. All base plates must be fixed on the ground supports.
5. Place all pin connectors, interlocks and wall ties.
6. Check all structures for stability.
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Assembling Fixed Frames
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Suspended Scaffolds
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Suspended Scaffolds
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Suspended Multi Level
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Cantilevered Scaffolds (Truss-out)
puncheon
Standards
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Cantilevered Scaffolds (Truss-out)
Restriction on the use of space at the
ground level
Load are transferred totally to the building
Ties are inside window openings
Suitable for height up to 12m
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Power Scaffolds
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Materials for Scaffoldings
The quality for steel tube and coupler must
conform to specification MS (BS 1139 Part 1)
Black steel tube, galvanised steel tube (48.3mm
diam, 4mm thick, 4.37kg/m),
Aluminum aloy tube (48.3mm diam, 4.47mm
thick, 1.67kg/m)
Timber – keruing or wood of equal or higher
strength
Mangrove or bamboo should have the required
strength
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Materials for Scaffoldings
(cont.)
Platform 38, 50, 63mm thick, 225mm
wide, 3.9m long
Mechanical properties – should conform to
the required strength for tensile, yield and
elongation
Approved connectors or couplers
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Safety Features
(MS 426:1994) – Code of practice for safety and
health at work
For a safe and secure structures Adequate
strength of material used
Design load with a safety factor of at least 4
During erections all parts must be securely fixed
Standards are positioned vertically and ledgers
horizontally
Base plates must be used to avoid settlements
of scaffolds 52
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Safety Features (cont.)
Braced diagonally in both horizontal and vertical
planes to prevent swaying and displacements
After erection of scaffolds the structure be
inspected and certified safe by a trained person
A trained and experienced person must inspect
the scaffold once a week
Inspection is also necessary after a rough or
cold weather
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Scaffold Hazards
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Scaffolds Hazard
1. The planks are not cleated or secured against displacement
2. No guard rails and no toe boards 59
3. Gap between building and scaffolds exceed 300 mm
Scaffolds Hazard
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Scaffolds Hazard
Is the scaffolds too
near to the
powerlines?
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Scaffolds Hazard
Unstable
Loaded with blocks
Scaffold is not level
because it was erected
without base plates on an
uneven surface.
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Scaffolds Hazard
Poor foundation: Scaffold end frames,
which have no base plates, erected
on top of scrap wood and unstable
cement blocks.
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Scaffolds Hazard
This is a great example of
what can happen when
construction workers fail to
investigate the site where
their scaffold is being erected,
and base plates are not used.
The scaffold in question (now
taken down) punched a hole
through the downtown
sidewalk. The workers failed
to realize that the sidewalk
was only made from blacktop,
and it had a basement under
it. EXAMPLE OF POINT
LOADING!!
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Scaffolds Hazard
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Scaffolds Hazard
Planking on this platform should be six planks wide, instead of only two.
Also, note that the planks are bowing because the bricks are loaded at 67
one point on the platform instead of being evenly distributed.
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Scaffolds Hazard
Openings between
planks in platform
should not exceed
25 mm
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Scaffolds Failure
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