Supported Scaffolds
Scaffold User Training
Ladders and Scaffolds
Scaffold Hazards
The danger of falling is most common.




9% of construction deaths are
scaffold-related
Scaffold falls injure 29,000
workers every year.
47% of all scaffold catastrophes
and deaths are caused by
defective scaffolds.
Any missing or defective part
makes a scaffold less safe.
X&L
Ladders and Scaffolds
1926.450 Subpart L - Scaffolds
 1926.450:
Scope, application and
definitions
 1926.451: General requirements
– Covers the basic variables
 1926.452:
Specific requirements
– For each type of scaffold
 1926.453:
Aerial lifts
 1926.454: Training
– Anyone who works from a scaffold or who
erects scaffolds must have training.
15
How Do We Know a Scaffold Is Safe?
 Supported
features:
scaffolds must have these
1926.452(w) "Mobile scaffolds"
1926.452(b) “Tube & coupler scaffolds”
1926.450 definitions applicable to
subpart
 Competent
person means one who
is capable of identifying existing and
predictable hazards in the surroundings
or working conditions which are
hazardous or dangerous to employees,
and who has the authorization to take
prompt corrective measures to eliminate
them.(CPL 2-1.23)
SUBPARTS
X&L
Ladders and Scaffolds
.451 General Requirements
For All Scaffolds
(a) Capacity
– Support its own weight and 4 X the
Maximum Intended Load (MIL).
– Designed by a Qualified Person and built
and loaded to design.
– Some Criteria listed in Appendix 'A'
17
SUBPARTS
X&L
Ladders and Scaffolds
(b) Platform Construction

Platforms fully planked or decked

Maximum 1” gaps

Maximum openings of 9½” if necessary
Platforms and walkways minimum 18” wide
 Guardrails and/or Personal Fall Arrest
System (PFAS) for < 18” wide


Planks laid at angles other than 90º laid first
under planks laid over supports at 90 º
20
9 1/2 ”
1” MAX
SUBPARTS
X&L
Ladders and Scaffolds
What Makes a Safe Platform?

Fully planked with scaffold-grade wood or
metal.
21
Scaffold Platform Construction

Front of scaffold no more than 14 inches from face of
work

For outrigger scaffolds 3 inches

Unless secured platforms extend minimum of six
inches over support
6"
NOT CLEATED OR TIED
(b)(7)
12”
(b)(3)
14”
MAX
18”
OR MUST HAVE GUARDRAIL
OR FALL PROTECTION
SUBPARTS
X&L
Ladders and Scaffolds
Platform Construction

Don’t paint wood, except ID on
edges
Fully planked between front
upright & guardrails
 Don’t mix scaffold components
used unless compatible &
strength is maintained
[Competent Person decision]
 Don’t modify mixed scaffold
components
to make them fit [C.P. decision]
 No components of dissimilar
metals without Competent
Person approval

Inspect, Inspect, Inspect
27
SUBPARTS
X&L
Ladders and Scaffolds
Tie-Ins to the Building
This 6-tier scaffold is
is anchored to the building
with rope through windows.
A solid strut anchor is better,
especially if not dependent upon
friction attachments at both ends.
30
1926.451 (c) Supported Scaffolds
 Guys,
ties or braces required at the
4:1height ratio
 Repeated
every 20 feet for scaffolds
three feet wide or less
 Every
26 feet wider than three feet
 Installed
at each end of the scaffold
 Horizontal
spacing not to exceed 30 feet
1926.451 (c) (1) (ii)
30 feet
30 feet
SUBPARTS
X&L
Ladders and Scaffolds
34
Plumb, Level, Square
You can visually check scaffold alignment.
Plumb:
Vertical
members stand
perpendicular to
horizon.
Level:
Horizontal
members are
parallel to
horizon.
Square:
Horizontal and
vertical
members form
right angles
where they
connect.
SUBPARTS
X&L
Ladders and Scaffolds
Foundation and Load
Distribution?
35
Supported Scaffolds
 Bracing
required to prevent tipping for all
eccentric applied loads
 Scaffolds
must bear on base plates and mud
sills or other firm foundation
 Footings
rigid with no settling or displacement
1926.451 General Requirements
(c) Criteria for supported scaffolds
(2) Base plates mud sills
Base plate
Mud sills
1926.451 (c) Supported Scaffolds
 Unstable
objects
shall not be used to
support scaffolds or
platform units.
 Unstable
objects
shall not be used as
working platforms.
1926.451 (c) Supported Scaffolds
 Poles,
legs, posts,
frames, and
uprights plumb
and braced
SUBPARTS
X&L
Ladders and Scaffolds
37
What’s the Best Way
to Load the Scaffold?
Distribute loads evenly. Point load over uprights.
Evenly
distributed –
A good practice!
An unsafe practice!
Point Loading When necessary, it should be
done over uprights.
1926.451 (e) Access
 Scaffold
more than two feet above or below a
point of access ladders, stairs, ramps or other
similar access provided
 No
cross braces for access!
 Hook
on ladders positioned so as not to tip
the scaffold
 Bottom
rung within 24 inches of supporting
level
 Over
35 feet, rest levels every 35 feet
1926.451 (e) Access
 Hook-on
ladders compatible
with scaffold used
 Minimum
rung width of 11
1/2 inches
 Rungs
uniformly spaced
 16
3/4 inches maximum
rung spacing
 Slip
resistant treads on
stairs and landings
1926.451 (e) Access
 Prefabricated
scaffold access:
– specifically designed and constructed for
use as ladder rungs;
– Have a rung length of at least 8 inches
– Uniformly spaced
– Max. spacing 16 3/4 inches
** fixed ladders must have fall protection if length
of climb is 24’ or greater.**
** landing ‘rest’ platforms required on fixed ladders at
maximum intervals of 50’**
Use
 No
loading in excess of intended or rated
load
 Lean-to
 CP
scaffolds prohibited
to inspect for defects each shift
 Damaged
braced
scaffold repaired, replaced or
SUBPARTS
X&L
Ladders and Scaffolds
USE
 No
makeshift devices to increase height
– The 'Drywall Bucket Rule'
 No ladder to increase height except on
'large area' and:
– Side thrust countered, platform secured
– Ladder legs on same platform & secured
 Platforms not to deflect > 1/60 of span
47
Use
No moving of scaffolds with employees on them
unless designed by PE for such
 Must decend mobile scaffolds prior to moving, and
lock casters when in position.
 Safe distance from electric lines:
– Insulated lines:

• Less than 300 volts = 3 feet
• 300 volts to 50 kilovolts = 10 feet
• Over 50 kilovolts = 10 feet plus .4 inches for each additional
kV; or twice the length of the line insulator but never less
than 10 feet
Use
 Scaffolds
erected, moved, dismantled, or
altered only under the supervision and
direction of a competent person qualified in
scaffolds
 Access
scaffolds with snow/ice only to
remove
 Swinging
lines
loads near scaffolds must use tag
Debris
shall not be
allowed to
accumulate
on
platforms.
SUBPARTS
X&L
Ladders and Scaffolds
.454 Training Requirements

Your employer must train you.
73
SUBPARTS
X&L
Ladders and Scaffolds
48
Fall Protection
 Required
at 10 foot height
 PFAS instead of guardrails on some
 Fall protection required when scaffold is
greater than 14” away from work surface
 PFAS for erectors/dismantlers where
feasible
 Toprails height = 38” to 45”
 Crossbracing ‘X’ as top or midrail
depending on height
(g)(4)(xv)
Top
38”- 40”
48” Max
Mid
20”- 30”
Cross bracing in Guardrail Systems
SUBPARTS
X&L
Ladders and Scaffolds
Guardrails
 Guardrails
prevent work falls.
Only 33% of the scaffolds
involved in accidents had
guardrails.
─ Ideal height is 38
inches above work
platform.
─ OSHA requires fall
protection on
platforms 10 feet or
higher.
Top rail must withstand a force of 200 pounds (or 100
pounds on suspension scaffolds).
49
1926.451 (g) Fall Protection
 Guardrail
systems shall
be installed along all
open sides and ends of
platforms.
 Guardrail
systems
installed before scaffold
is released for use by
employees other than
erection/dismantling
crews.
SUBPARTS
X&L
Ladders and Scaffolds
(h) Falling Object Protection
 Hardhats
required
 Protect employees below
 Barricades to exclude working below
 Toe boards at edges of platforms
 Allows panels and screens
 Canopies allowed
53
SUBPARTS
X&L
Ladders and Scaffolds
54
Toeboard Options
Using extra planks on edge:
– Wire in place
– Maintain max. gap of ¼"
– Wire or nail ends in place
Job-made w/1"x 6" lumber:
– Wire/nail/cleat in place
– Lighter, easier to handle
SUBPARTS
X&L
Ladders and Scaffolds
54
Electrical Hazards
Scaffolds shall remain a minimum
of 10 feet away from energized
power lines.
All power tools and equipment
shall be plugged into a GFCI
Temporary lighting shall not be
connected to the scaffold system
by metal components
SUBPARTS
X&L
Ladders and Scaffolds
Mobile Scaffolds3
 Plumb;
 Cross,
Level square; Braces secured
horizontal & diagonal braces to
prevent racking or collapse
 Mobile scaffolds must comply with other
frame requirements
 Castors - positive lock on wheel and/or
swivel
58
SUBPARTS
X&L
Ladders and Scaffolds
Mobile Scaffolds2
Horizontal and
diagonal bracing
required to prevent
“racking”.
Most manufacturers
provide with fixed
length.
59
Fatal fact
Bricklaying crew working
on the upper floor of a
three-story building built a
six-foot platform spanning
a gap between two
scaffolds. The platform
was correctly constructed
of two 2”X12” planks with
standard guardrails;
however, one of the
planks was not scaffold
grade lumber and also
had extensive dry rot in
the center. when a
bricklayer stepped on the
plank it disintegrated and
he fell 30 feet to his death.
Fatal fact
Two employees were installing
aluminum siding on a farm house
when it became necessary to
remove a 36-foot high metal pole
CB antenna. One employee
stood on a metal pick board
between two ladders and
unfastened the antenna at the top
of the house. The other
employee who was standing on
the ground, took the antenna to
lay it down in the yard. The
antenna made electrical contact
with a 7200-volt power
transmission line 30 feet 10
inches from the house and 23
feet 9 inches above the ground.
The employee handling the
antenna received a fatal shock
and the other employee a minor
shock.
SUBPARTS
X&L
Ladders and Scaffolds
71
Protect Yourself With
Good Practice
Don’t allow tools, materials, or debris to collect
on scaffold.
 Never, never throw or drop tools, materials, or
equipment.
 Make sure connections are in place and
completely tight.
 Do not stand on ties.
 Do not stand on guardrails or plank
extensions.
 Do not overreach outside of the guardrails.
