Independent tied scaffolds must be tied to the building but do not rely on it for strength. They consist of uprights, ledgers parallel to the building, and transoms perpendicular to the building face. Uprights must be spaced evenly and ledgers and transoms fitted properly. Scaffolds require bracing and ties to the building to prevent movement and collapse. Working platforms need guardrails and toe boards to prevent falls over 2 meters. Suspension scaffolds used on tall buildings carry platforms suspended from outriggers, tracks, and parapet hooks and require secure counterweights.

1. CONSTRUCTION SAFETY PART II
AVINASH KUMAR GUPTA
EE (TRANING)
CCW

2. SCAFFOLDING
• Temporary structures to support platforms as a
workplace/storage of materials.
• prevent fall of workers and materials.
• Properly constructed of sound material of
adequate strength to support weight and stress.
• Securely anchored and stable
• Erected ,altered or dismantled by competent
persons
• Inspected at least once a week , written report of
inspection to be kept.

3. Independent tied scaffolds
An independent tied scaffold which does not rely on the building for its
strength. It has inner and outer rows of uprights or standards

4. Independent tied scaffolds
• It must be tied to the building but does not rely
on its strength.
• Consists of uprights/standards, ledgers( parallel
to building),and transoms(90degree to building
face)
• Uprights be placed on firm and level ground, base
plates should rest on timber sole boards. Never
use bricks, broken paving stones.
• Uprights to be equidistant, ledgers to be fixed
inside ,joints in ledgers to be staggered.
transoms on top of ledgers

5. continued
• For 38 mm boards ,transoms to be so spaced
that no scaffold board overlaps more than
150mm or less than 50 mm.
• Ledgers and transoms should not project
beyond the outline of scaffold to cause danger
to pedestrian or passing vehicles.
• Bracing is essential to stiffen the scaffold.
• Removing of bracing only within one lift if
required for passage of workers.

6. TIES
• Scaffold is to be tied to building to prevent
movement /collapse.
• Area of scaffold should not be more than 32
sqm per tie.

7. Working platforms and gangways
• Each board should have three support to prevent
bending or sagging.
• Where the ends of board meet, transoms must
be doubled, no board overhangs four times its
thickness.
• Width of platform ,
i. 60 cm for footings
ii. 80 cm for stacking of materials
iii.110cm for supporting a trestle platform

8. Guard rails and toe boards
Working platform showing guard-rail and toe board with wire mesh
filling between them and the closely boarded platform

9. Continued
• Where fall is more than 2m provide guard rails
and toe boards
• Guard rails 90cm to 115cm , toe board 15 cm
• Prevents falling accidents

10. Single pole/putlog scaffold
A single pole or putlog scaffold, with a single outer row of uprights or
standards and which is partly supported by the building

11. • For small jobs, platform resting on horizontal putlogs fixed at 90
degree to wall.
• Flattened inner of putlog rests on the wall/holes in the wall.
Scaffold can not stand without support of structure.
• Mostly in use for brickwork.
• Base plate of upright rests on timber sole board. Sole board to
support at least 2 uprights.
• Uprights not more than 2 m apart, and 1.3 m from wall to support
5 board platform.
• distance between ledgers not more than 2 m. Distance between
putlogs not to exceed 1.5m
• Tying to building and bracing to full height is required.
• Prevent children from climbing a scaffold after close of the working
day.

12. Protection From falling Materials
Protection of scaffold from falling
materials – scaffold fan and debris
netting

13. continued
• Provide sheeting,
boarding,netting, fans or brick
guards to prevent materials
falling from the scaffold into
street or public place

14. DEBBIGUARD

15. Brickguard

16. • Mobile tower
scaffold-wheels
should belocked when
in use; ladder access
shouldbe inside the
tower
Mobile TOWER

17. Tower Scaffold
o Consists of a platform resting on horizontal ledges connected
to four uprights
o Devised for painters.
o Accident happen when tower topples over.
• Ratio of the height of the tower to the width of the base in
excessive.
• Top of working platform is overloaded.
• Ladder is placed on top of platform.
• Mobile tower is moved with persons/ materials on top of
platform.
• Tower is not tied to building.
• Access to the platform is via outside of the tower.

18. Tower Scaffold
o Height – ratio of Ht : base, (indoor) 4:1≯
(outdoor) 3:1≯
Static free Standing Height 12m≯
Mobile free standing 9.6≯
Tied to building 12.0m≯
o Structure –
• Vertical, single platform, firm & level base (base plates)
• Corner standards 1.2m.≮
• Caster wheels die 125mm.≮
• Wheels with locks & breaks.
• Breaks applied when stationery.

19. Tower Scaffold
o Platform –
• Cover on the opening with a latch.
• Handhold on cover.
• Guard rails & toe boards.
• Ladder inside.
o Movement – Never move when persons or
materials on platform.

20. TRESTLE SCAFFOLD
A trestle scaffold suitable
only for light work such as
cleaning or painting

21. Trestle Scaffold
• Light work of short duration
• Working platform 430mm inside.≮
• 1/3 of height of trestles should be above
platform.
• When working platform > 2m, provide guardrail
& toe board.
• Adequate bracing.
• Board 38mm, distance 1.35≯
• Board 5mm distance 2.45m≯

22. SUSPENSION SCAFFOLD

23. Suspended scaffold

24. Suspension Scaffold
- Tall buildings
- Suspended platforms (hinged/ independent)
- Cradles
- Suspended form building/ structure by means of
outriggers, tracks and parapet hooks.
Accidents
- Difficulties in getting in/ out
- In sufficient counter weight/ secured.
- Failure of ropes.
- Poor maintenance.

25. UNSAFE Cradles

26. Safe cradles