Scaffolds

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Scaffolds

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Title: Scaffolds

1
Scaffolds

OSHA Subpart L
1926.450-454

2
Subpart L - Scaffolds(1926.450 - 454)

Scaffolds above 10 ft. - Fall protection

Scaffold access
Aerial lifts - Body belt and lanyard
Scaffold platform construction
Training for employees using scaffolds
Most Frequently Cited FY 2004
3
Subpart L - Scaffolds(1926.450 - 454)

Scaffolds above 10 ft. - Fall protection

1088
451(g)(1)
Scaffold access
904
451(e)(1)
Scaffold working levels - Planked or decked
Standard - 1926.
857
451(b)(1)
Aerial lifts - Body belt and lanyard
813
453(b)(2)(v)
Training for employees using scaffolds
510
454(a)
4
Subpart LScaffolds(1926.450 - 454)

Scaffolds above 10 ft. - Fall protection

Scaffold access
Aerial lifts - Body belt and lanyard
Scaffold working levels - Planked or decked
Training for employees using scaffolds
Most Frequently Cited FY 2003
5
Overview

About 65 of construction workers work on
scaffolds frequently
There are many scaffold-related accidents each
year
4,500 injuries
50 deaths
90 million in lost workdays
In a recent BLS study, 72 of injuries were
attributed to
Planking or support giving way, or
Slipping or being struck by a falling object.

6
Overview

RECENT CHANGES CLARIFICATIONS
10 foot trigger height for fall protection on
scaffolds.
38 inch minimum guardrail height where guardrail
is primary fall protection.
36 inch minimum guardrail height where fall
arrest systems are primary fall protection.
A competent person determines feasibility of
providing fall protection for built-up scaffold
erectors and dismantlers.
Crossbracing may be used as a guardrail, under
certain conditions, in lieu of either a midrail
or a toprail.

7
Subparts/Overview

450 Scope, Application Definitions
451 General Requirements
452 Additional Requirements
453 Aerial Lifts
454 Training requirements

8
1926.450

Scope, Application
Definitions

9
450 Scope, Application Definitions

(a) Scope Application
Subpart applies, except for
Crane/derrick suspended personnel platforms
Aerial lifts criteria, which are exclusively at
1926.453

10
450 Scope, Application Definitions

(b) Definitions
SCAFFOLD
SUPPORTED SCAFFOLD
SUSPENDED SCAFFOLD
COMPETENT PERSON
QUALIFIED PERSON

11
1926.451

General Requirements

12
1926.451

(a) Capacity

13
451 General Requirements
(This section does not apply to aerial lifts)

(a) Capacity
Each scaffold component must be able to
support 4 x max. intended load, with some
exceptions
(1) Fall Protection - see 1926.451(g)

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15
451 General Requirements

(a) Capacity
(2) Direct connections to roofs/floors,
counterweights that balance adjustable
suspension scaffolds
Must be able to resist the tipping moment imposed
by the scaffold in operation, at whichever rate
is greater
4 x Rated Load of Hoist
1.5 (min.) x Stall Load of Hoist

16
451 General Requirements

(a) Capacity
(3)(4) Suspension Ropes ( hardware)
6 x max. intended load of rope
For adjustable suspension scaffolds, intended
load is based on scaffold operating at greater
of
Rated Load
2 (min.) x Stall Load
(5) Hoist Stall Load
Max. 3 x Rated Load

17
451 General Requirements

(a) Capacity
(6) Design Construction
(See Appendix A for examples/criteria)
Designed by qualified person
Constructed loaded accordingly

18
1926.451

(b) Scaffold Platform Construction

19
451 General Requirements

(b) Scaffold Platform Construction
(1) Gaps
Full planking/decking between front uprights
guardrail supports
Max. 1 space between units unless demonstrable
need
(Then max. 9 ½ decked as fully as possible)
Exceptions
Platforms used solely as walkways
Platforms used solely during erection/dismantling
of scaffolds

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21
451 General Requirements

(b) Scaffold Platform Construction
(2) Minimum Widths
18 Most scaffold platforms walkways
12 Certain scaffold types ladder jack, top
plate bracket, roof bracket, pump jack
0 Boatswains chairs
Exception for demonstrable need, and then
As wide as feasible
Fall protection provided

22
451 General Requirements

(b) Scaffold Platform Construction
(3) Min. Distance from workface
Greater distances require fall protection
3 Outrigger scaffolds
14 - Generally
18 Plastering lathing

23
451 General Requirements

(b) Scaffold Platform Construction
(4)(5) End Extension
Min. 0 - If restrained (with cleats/hooks/equiv.
)
Min. 6 - Generally (beyond centerline of
support)
Max. 12 - Platforms lt10 long
Max. 18 - Platforms gt10 long
Unless designed installed with guardrails or
sufficient cantilever

24
451 General Requirements

(b) Scaffold Platform Construction
(6)(7) Platform Lengthening
Abutting requires support surface for both ends
Overlapping may occur only over supports
Min. 12 overlap unless restrained (such as by
nailing)

25
451 General Requirements

(b) Scaffold Platform Construction
(8) Platform angles
Where platform changes direction
(such as turning a corner)
Lay first any platform that rests on a bearer at
an angle other than a right angle
Lay on top any platform resting at a right angle

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451 General Requirements

(b) Scaffold Platform Construction
(9) Wood Finishes
No opaque finishes on platforms
Except ID markings on edges
Coatings may not obscure top/bottom wood
finishes. Examples
Wood preservatives
Fire-retardant finishes
Slip-resistant finishes

28
451 General Requirements

(b) Scaffold Platform Construction
(9) Multiple Manufacturers
Components may only be intermixed if
They fit together without force and
Structural integrity is maintained
Components may only be modified if
A Competent Person determines structural soundness

29
451 General Requirements

(b) Scaffold Platform Construction
(10) Dissimilar Metals
Components may only be used together if
A Competent Person determines safe levels of
galvanic action

30
1926.451

31
451 General Requirements

(c) Criteria for Supported Scaffolds
(1) Tipping Restraint
Height to base width ratio gt 41 requires
bracing with guys, ties, braces /or outriggers
At locations which support inner outer legs,
scaffold ends, horizontal intervals, and any
eccentric loads or cantilevered work platforms
Per manufacturer recommendations or per code

Need some bracing? Were your guys!
32
451 General Requirements

(c) Criteria for Supported Scaffolds
(2) Firm Foundations
Footings must be level, sound, rigid able to
support the loaded scaffold without settling or
displacement
No unstable objects as platforms or supports
No equipment (such as front end loaders) may be
used as support, unless specifically designed to
do so

33
451 General Requirements

(c) Criteria for Supported Scaffolds
(3) Stability
Poles, legs, posts, frames uprights must be
Plumb
Braced to prevent swaying displacement

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36
1926.451

(d) Criteria for Suspension Scaffolds

37
451 General Requirements

(d) Criteria for Suspension Scaffolds
(1) Support Surface
All suspension support devices must rest on
surfaces able to support the load imposed by the
scaffold in operation, at whichever rate is
greater
4 x Rated Load of Hoist
1.5 (min.) x Stall Load of Hoist

38
451 General Requirements

(d) Criteria for Suspension Scaffolds
(3) Stabilization
Inboard ends of outrigger beams must be
stabilized by
Bolts or other direct connections to the floor or
roof deck
Counterweights (not allowed for masons
multi-point adjustable types)

39
451 General Requirements

(d) Criteria for Suspension Scaffolds
(3) Stabilization
Inboard ends of outrigger beams must be
stabilized by
Bolts or other direct connections to the floor or
roof deck
Counterweights (not allowed for masons
multi-point adjustable types)
Of non-flowable material (e.g., not sand, gravel,
etc.)
Secured to beam by mechanical means and not
removed until the scaffold is disassembled

40
1926.451

(e) Access

41
451 General Requirements

(e) Access
(451(e)(9) covers access requirements during
erection dismantling)
(1) Types
When scaffold platforms are gt2 above/below a
point of access
Use appropriate ladders, stairs, ramps, walkways,
etc.
Do not use crossbracing as a means of access

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43
451 General Requirements

(e) Access
(2) Hook-on attachable ladders
Positioning must not tip scaffold
Bottom rung lt 24 above scaffold supporting level
Rest platforms at max. 35 vertical intervals, if
used that high
Min. rung length 11½
Max. rung spacing 16¾ (uniformly spaced)

44
451 General Requirements

(e) Access
(3) Stairway-type ladders
Bottom rung lt 24 above scaffold supporting level
Rest platforms at max. 12 vertical intervals
Min. step width
16
11½ for those on mobile scaffolds
Slip-resistant treads on all steps landings

45
451 General Requirements

(e) Access
(4) Stairtowers (scaffold stairway/towers)
Bottom step min. lt24 high
Stairrail on each side w/toprail midrail
Toprail/handrail provided, with adequate handhold
Surfaced to prevent injury
No projection hazard
Min. 3 clearance
28-37 high (measured at facing edge of riser)

46
451 General Requirements

(e) Access
(4) Stairtowers
Landing platform
Min. 18 x18 provided at each level
Stairway
Min. 18 wide
Slip-resistant treads landings
40-60o angle
Guardrails on open sides ends of landings
Uniform riser height (within ¼)
Except for top/bottom steps of entire system
Uniform tread depth (within ¼) for each flight

47
451 General Requirements

(e) Access
(5) Ramps walkways
Guardrail systems required above 6
Max. 13 slope (20o from horizontal)
If gt 18 slope, planks must be cleated
Max. 14 apart
Securely fastened

48
451 General Requirements

(e) Access
(6) Integral prefabricated scaffold access frames
Must be specifically designed constructed for
use as ladder rungs
Min. rung length 8
If rung length is less than 11½, may not be used
as a work platform without fall protection
Rest platforms at max. 35 vertical intervals
Max. rung spacing 16¾
May be non-uniform if caused by joining end
frames together

49
451 General Requirements

(e) Access
(7) Alignment
Ladder/stairway access must line up vertically
between rest platforms
(8) Direct access
Max. distance for direct access between scaffold
another surface
14 horizontally
24 vertically

50
451 General Requirements

(e) Access
(9) Erecting/dismantling
Safe means of access
Where feasible does not create greater hazard
As determined by Competent Person
Based on site conditions type of scaffolding
Cross bracing on tubular welded frame scaffolds
may not be used for access/egress
Ladders installed ASAP
Hook-on or attachable ladders installed as soon
as safe to do so

51
1926.451

(f) Use

52
451 General Requirements

(f) Use
(1)(16) Loading
Do not exceed greater of
Max. intended load
Max. rated capacities
Platforms shall not deflect more than 1/60 of the
span when loaded

53
451 General Requirements

(f) Use
(2) Shore or lean-to scaffolds
These may not be used
(3) Inspections
By competent person
Before each work shift
After any event possibly affecting structural
integrity

54
451 General Requirements

(f) Use
(4) Damage
Impairment by damage/weakening requires
Repair
Replacement or
Removal
(5) Horizontal movement
Forbidden while employees are on scaffold, unless
Specifically designed to do so by registered
professional engineer
The scaffold is a properly operated mobile type

55
451 General Requirements

(f) Use
(6) Power lines
Scaffolds must be protected from energized power
lines, by
Distance (see chart) or
Properly deenergizing, relocating or protectively
coating the lines

56
451 General Requirements

(f) Use
(7) Competent person
Scaffolds may only be erected, moved, dismantled
or altered under the supervision or direction of
a competent person

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451 General Requirements

(f) Use
(8) Slippery conditions
No working on scaffolds covered with snow, ice,
etc., except to remove them
(9) Control of swinging loads
Hoisted swinging loads that might contact
scaffolds must be controlled by tag lines or
equivalent

59
451 General Requirements

(f) Use
(10)(11) Suspension ropes
Must be of sufficient diameter for brake hoist
mechanisms to function
Must be shielded from heat-producing processes
Must be resistant to acids corrosive substances
used on a scaffold, or protectively
shielded/treated

60
451 General Requirements

(f) Use
(12) Storms/winds
Scaffold work during storms/winds is prohibited,
unless
Competent person determines it is safe and
Employees are sufficiently protected by
Personal fall arrest systems or
Wind screens

61
451 General Requirements

(f) Use
(13) Debris
No accumulation on platforms

62
451 General Requirements

(f) Use
(14)(15) Adding height
Makeshift devices (boxes, barrels, etc.) may not
be used to increase height of working level
Ladders may only be used on large area scaffolds
under these criteria
Secured against any sideways thrust
Platform units secured to scaffold
Stabilization against unequal platform deflection
(e.g. ladder legs on same platform)
Ladder legs secured

63
451 General Requirements

(f) Use
(17) Welding
Precautions must be taken against arcing of
welding current through suspension wire rope,
such as
Insulation
Grounding
Temporary shut-off of welding machine

64
1926.451

(g) Fall Protection

65
451 General Requirements

(g) Fall Protection
NOTES
451(g)(2) covers fall protection requirements
during erection dismantling.
Subpart M covers fall protection requirements
for installation of scaffold support systems on
floors, roofs, and other elevated surfaces

66
451 General Requirements

(g) Fall Protection
(1) Per type of scaffold
(i) Boatswains chair, catenary scaffold, float
scaffold, needle beam scaffold, or ladder jack
scaffold
Personal fall arrest system
(ii) Single-point or two-point adjustable
suspension scaffold
Personal fall arrest system and
Guardrail system

67
451 General Requirements

(g) Fall Protection
(1) Per type of scaffold
(iii) Crawling board (chicken ladder)
Personal fall arrest system
Guardrail system (gt200 lb. toprail capacity) or
Securely fastened handrails (¾ grabline/equiv.)
(iv) Self-contained adjustable scaffold
Guardrail system (gt200 lb. toprail capacity) and
Personal fall arrest system (if platform is
supported by ropes instead of frame structure)

68
451 General Requirements

(g) Fall Protection
(1) Per type of scaffold
(v) Walkway (located within a scaffold)
Guardrail system (gt200 lb. toprail capacity)
Within 9½ of walkway
Along at least one side
(vi) Supported scaffold bricklaying
At all open sides/ends of scaffold
(non-bricklaying)
Personal fall arrest system or
Guardrail system (gt200 lb. toprail capacity)

69
451 General Requirements

(g) Fall Protection
(1) Per type of scaffold
(vii) Supported scaffold general
At all open sides/ends of scaffold
(non-bricklaying)
Personal fall arrest system or
Guardrail systems per paragraph (g)(4) upcoming

70
451 General Requirements

(g) Fall Protection
(2) Erection/dismantling
Competent person must determine fall protection
feasibility safety
Employer must provide fall protection where
installation and use not a greater hazard

71
451 General Requirements

(g) Fall Protection
(3) Lanyards Lifelines
Requirements in addition to 1926.502(d)
Personal fall arrest systems on scaffolds must be
attached by lanyard to
Vertical lifeline
Horizontal lifeline or
Scaffold structural member

72
451 General Requirements

(g) Fall Protection
(3) Lanyards Lifelines
(i)(iv) Vertical Lifelines
Prohibited when overhead components are part of a
single-point or two-point adjustable suspension
scaffold
Fastened to a fixed safe point of anchorage
Independent of scaffold
Protected from sharp edges abrasion

73
451 General Requirements

(g) Fall Protection
(3) Lanyards Lifelines
(i)(iv) Vertical Lifelines (contd)
Vertical lifelines, independent support lines
suspensions ropes, may not be attached to
Each other
The same point of anchorage
The same point on the scaffold or personal fall
arrest system

74
451 General Requirements

(g) Fall Protection
(3) Lanyards Lifelines
(ii) Horizontal lifelines
Must be attached
Secured to 2 or more structural members of
scaffold, or
Looped around both suspension independent
suspension lines (on scaffolds so equipped) above
the hoist brake attached to the end of the
scaffold, but not
Attached only to suspension ropes

75
451 General Requirements

(g) Fall Protection
(3) Lanyards Lifelines
(iii) Lanyards
When connected to horizontal lifelines or
structural members on a single-point or two-point
adjustable suspension scaffold
Scaffold must have additional independent support
lines automatic locking devices capable of
stopping scaffold fall if suspension rope(s) fail
Independent support lines must be equal to
suspension ropes in number strength

76
451 General Requirements

(g) Fall Protection
(4) Guardrail systems
(See also Appendix A specifications)
(i) Installation
Must be installed along all open sides ends of
platforms (except during erection/dismantling)

77
451 General Requirements

(g) Fall Protection
(4) Guardrail systems
(ii)(viii) Top edge height
Limits
38-45 - Post-2000 supported scaffolds
36-45 - Pre-2000 supported scaffolds
45 - When conditions warrant system
meets remaining criteria
When load-tested in a downward direction, top
edge may not drop below minimum limit

78
451 General Requirements

(g) Fall Protection
(4) Guardrail systems
(iii)-(vi),(ix),(xv) Sides
Must be installed between the top edge
platform.
Usual types are midrails, screens, mesh,
intermediate vertical members, solid panels
equiv.
Crossbracing is acceptable as a midrail when
The crossing point of two braces is 20-30 above
the work platform and
The end points at each upright are no more than
48 apart

79
451 General Requirements

(g) Fall Protection
(4) Guardrail systems
(iii)-(vi),(ix) Sides
Placement
Midrails at approx. mid-height
Screens mesh along entire opening between
supports
Intermediate members at lt19 spacing
Must resist specific outward/downward forces
75lbs. Systems with 100 lb. toprail
capacity
150 lbs. Systems with 200 lb. toprail capacity

80
451 General Requirements

(g) Fall Protection
(4) Guardrail systems
(vii) Toprails
Able to withstand downward/outward force
100 lbs. Single-point or two-point adjustable
suspension scaffolds
200 lbs. Guardrail systems on other scaffolds

81
451 General Requirements

(g) Fall Protection
(4) Guardrail systems
(viii) Toprails
Crossbracing is acceptable as a toprail when
The crossing point of 2 braces is 38-48 above
the work platform and
The end points at each upright are no more than
48 apart

82
451 General Requirements

(g) Fall Protection
(4) Guardrail systems
(x) Ends
Suspension scaffold hoists non-walk-through
stirrups may be used as end guardrails, if the
space between them and the side guardrail or
structure does not allow passage of an employee
to the end of the scaffold

83
451 General Requirements

(g) Fall Protection
(4) Guardrail systems
(x)-(xiv) Characteristics
Surfaced to prevent injuries/snagging
No projection hazards from rail ends
No steel or plastic banding as toprail or midrail
Manila or plastic/synthetic rope used for
toprails or midrails must be inspected as
necessary for strength, by a competent person

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85
1926.451

(h) Falling Object Protection

86
451 General Requirements

(h) Falling Object Protection
(1) Elements
General
Hard hats
Small objects
Catch/deflect small objects with toeboards,
screens, guardrail systems, debris nets, catch
platforms
Large objects
Place large, heavy or massive objects away from
high edges

87
451 General Requirements

(h) Falling Object Protection
(2) Provisions
(i) Hazard area below must be barricaded
restricted
(ii) Toeboards are required for sufficient
protective distances along the edge of platforms
higher than 10

88
451 General Requirements

(h) Falling Object Protection
(2) Provisions
(iii)-(v) Where tools, materials, or equipment
are piled higher than toeboard
Paneling/screening for sufficient distance or
Guardrail system with openings sufficiently small
or
Canopy structure, debris net or catch platform of
sufficient strength

89
451 General Requirements

(h) Falling Object Protection
(3) Canopies
Positioned between falling object hazard
employees
When used on suspension scaffolds
Additional independent support lines
Equal in number to points supported
Equal in strength to suspension ropes
Independent support lines suspension ropes must
not be attached to the same anchorage points

90
451 General Requirements

(h) Falling Object Protection
(4) Toeboards
Able to withstand downward/outward force of 50
lbs.
Min. height 3½
Max. clearance ¼
Securely fastened at platform edge
Solid, with max. 1 openings

91
1926.452

Additional Requirements

92
452 Additional Requirements

The following requirements supplement those of
1926.451, apply to these specific types of
scaffolds
(a) Pole scaffolds
(b) Tube coupler scaffolds
(c) Fabricated frame scaffolds
(d) Plasterers, decorators large area
scaffolds
(e) Bricklayers square scaffolds (squares)
(f) Horse scaffolds
(g) Form scaffolds carpenters bracket
scaffolds
(h) Roof bracket scaffolds

93
452 Additional Requirements

(i) Outrigger scaffolds
(j) Pump jack scaffolds
(k) Ladder jack scaffolds
(l) Window jack scaffolds
(m) Crawling boards (chicken ladders)
(n) Step, platform, trestle ladder scaffolds
(o) Single-point adjustable suspension scaffolds
(p) Two-point adjustable suspension scaffolds
(swing stages)
(q) Multi-point adjustable suspension scaffolds,
stonesetters multi-point adjustable suspension
scaffolds, masons multi-point adjustable
suspension scaffolds

94
452 Additional Requirements

(r) Catenary scaffolds
(s) Float (ship) scaffolds
(t) Interior hung scaffolds
(u) Needle beam scaffolds
(v) Multi-level suspended scaffolds
(w) Mobile scaffolds
(x) Repair bracket scaffolds
(y) Stilts

95
452 Additional Requirements

(y) Stilts
Use is allowed only on a large area scaffold
whose
Guardrail system is increased an equivalent
height
Surface level is flat, free of tripping
falling hazards (such as pits, holes,
obstructions, debris)
Stilts must be properly maintained
Any alteration must be approved by the
manufacturer

96
1926.453

Aerial Lifts

97
1926.454

Training Requirements

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99
454 Training Requirements

(a) Training for affected workers
Basic requirements
Provided for each affected employee
Conducted by person qualified to understand
hazards how to control or minimize them

100
454 Training Requirements

(a) Training for affected workers
Content
(1) Electrical, fall falling object hazards
(2) Procedures for
Dealing with electrical hazards
Erecting, maintaining disassembling fall
protection systems falling object protection
systems being used
Proper use of scaffold proper handling of
materials on the scaffold
Other pertinent scaffolding requirements

101
454 Training Requirements

(b) Training for scaffold workers
(Those involved in erecting, disassembling,
moving, operating, repairing, maintaining, or
inspecting scaffolds)
Training
In recognition of hazards associated with the
specific work
Conducted by person competent to recognize
hazards

102
454 Training Requirements