Scaffolds
These handouts and documents with attachments are not final, complete, or definitive instruments. This information is for guidance purposes
only. You should independently verify and satisfy yourself as to its accuracy. The AHBSIF does not assume any liability for damages
arising from the use of this information or exhibits and attachments thereto and renders no opinion that any of the terms, conditions,
and/or cited federal standards in this document and the exhibits and attachments should be explicitly followed by the fund member.
Seek specific guidance from the appropriate regulator (OSHA) or professional advisor.
Introduction to Scaffolds

OSHA revised the
scaffold standard in
1997 due to the
following;
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
A quarter of the workers
responsible for installing
work platforms and
inspecting, and assembling
them had no formal training.
Only 1/3 of scaffolds were
equipped with handrails.
Defining a Competent Person


One who is capable of identifying existing and
predictable hazards in the surroundings, or
working conditions which are unsanitary,
hazardous, or dangerous to employees, and who
has authorization to eliminate them.
Scaffolds shall be constructed, altered, or
dismantled under the supervision of a
competent person.
General Requirements
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All scaffolds must be inspected prior to use.
10’ is the point at which some means of fall
protection must be used.
Top handrails should be around 42”, with
the mid-rail about half way at 21”.
Toe boards or other adequate means of
falling object protection must be installed if
there is a possibility of anything falling and
striking someone below.
General Requirements

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All scaffolds must support
their own weight and 4x
the maximum intended
load.
Vertical tie-in or outrigger
support is not necessary on
a free-standing scaffold until
the height exceeds the
minimum dimension of the
base by four times.
General Requirements
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Ladder use on a
scaffold is prohibited.
Platforms must be
kept clear of debris.
Do not load side
brackets. Most are
rated at 25 lbs/ft²
maximum.
Decks And Planking
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All platforms must be fully decked or planked.
Each abutted end of a plank shall rest on a separate support
surface.
Overlap platforms not less than 12” only over supports, unless
restrained to prevent movement, i.e. ”Cleating”.
The working deck should never be more than 14” away from the
working surface.
Decks And Planking

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A scaffold grade plank will be
stamped or marked as such
Plank must be laminated or
solid drawn
A lumber yard 2 x 10 can be
used if it is free of knots or
other defects
Rough Sawn, Full Dimension
Lumber
Nominal Thickness Lumber
Working Load
in lbs/ft²
25
50
75
25
50
75
Permissible
Span in Feet
10
8
6
8
6
6
Overhead Power Lines

The clearance between scaffolds and power lines
is as follows:
Insulated Lines
Minimum Distance
< 300 V
3’
300 to 50 kV
10’
> 50 kV
10’ + 1/2”
for every additional kV
Uninsulated Lines
Minimum Distance
< 50 kV
10’
> 50 kV
10’ + 1/2”
for every additional kV
Frame Scaffolds
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Systems should use only
original parts. Components
from different systems should
not be mixed.
All frame scaffolds must use a
manufactured base pad.
Vertical tubes should never sit
directly on the ground or makeshift mud sill.
X-braces may serve as a toprail or mid-rail, but not both.
If aluminum walking decks are
used, be sure that end hooks
are in place and that the
dimensions match the scaffold.
Frame Scaffolds - Access
OK for Climbing
Must have External
Access
Ladder Frame
Walk-Through
Frame Scaffolds - Access
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Erectors can climb either type,
but provisions for safe access
should be established as soon
as possible.
Bottom rung cannot be more
than two feet high.
Options for access are
manufactured bolt-on ladder
system, stair system, or
extension ladder secured and
sloped properly.
X-braces are not intended for
use as access.
“Stick-Built” Pole Scaffold
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2” x 4” poles free of knots, splits or other defects.
1” x 4” cross-bracing for each section.
2” x 6” or 2” x 8” block under pole if soft ground.
Walk board a minimum 2” x 10” free of knots or other defects.
Walk boards must hang over bearer a minimum of 6”.Walk boards must
overlap each other a minimum of 12”.
2” x 4” top rail, mid rail, and toe board
Stick Built Scaffolds

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Proper overlap
on deck
planking
Top rail and
mid rail
established
after deck
height reaches
ten feet
Adequate
support
between
stanchions
Proper mud
sills under
poles
Is this scaffold
complete?
Pump Jack Scaffolds
 Pump Jack brackets, braces,
and accessories must be
fabricated from metal.
 Each pump jack bracket must
have two positive gripping
mechanisms.
 Poles should be secured to
the structure with triangular
bracing.
 Work benches should not be
used as a working deck.
 If 2x4’s are spliced to make a
pole, mending plates must be
installed to maintain
strength.
Ladder Jack Scaffolds
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Platforms must not exceed 20’
in height.
Job made ladders cannot be
used to support ladder jack
scaffolds.
Ladders that support ladder
jacks must be placed, fastened,
or equipped with devices to
prevent slipping.
Scaffold platforms must not be
bridged to one another.
Werner and Louisville produce
handrail systems for ladder jack
working decks.
Trestle Ladder Scaffold
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Scaffold platforms must
be placed no higher than
the second-highest rung
of the ladder
A conventional step
ladder is not to be used
for this scaffold
configuration
Work platforms must be
secure
All general scaffold and
ladder standards apply
Carpenters Bracket Scaffold
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Typically constructed of wood
Each piece must be properly fitted and
securely joined
Brackets must be no more than 8 ft.
apart
The platform can be no less than two
2’ x 10’ size planks
Attachment must occur in one of
following ways:

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
Hook over a well secured and strong
supporting member
A bolt of no less than 5/8” diameter
extended through the inside of the
building wall
Unit attaches via metal stud or welding
if possible
Hanging Scaffold System
The Wall Walker

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Device meets OSHA
standards
It can be hung on the
inside or outside of the
wall
Fall protection
attachments are
available
The horizontal beam
positional is adjustable
The Wall Walker
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General Framing,
exterior face hanging
on top plate
Handrail System in
place
Setting pre-fab trusses
Aluminum walk deck
locked into place
The Wall Walker
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Cutting tails on rafters
Using inside wall
position from top plate
Easy stow and carry
Unit folds down,
handrail post stores
inside vertical support
Wall Walker Hardware
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Mid Wall Bracket
Hand Rail Brackets
Stabilizer Bar
Manually Propelled Mobile Scaffolds
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Also known as a “Perry” or “Baker”
scaffold.
The casters and wheels must be
locked to prevent movement while
the scaffold is stationary.
An employee may ride this scaffold
under the following conditions:
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The floor is level and free of all
obstructions
The minimum dimension of the
scaffold base is at least half the
height
The wheels are equipped with rubber
or some other resilient material
All tools and materials are secured or
removed prior to movement
Because the wheels and castors must
be locked once the scaffold is set, this
prohibits movement from being a
one-man operation.
Rustgo Manual Work Platform
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All-terrain motorless work
platform with rear steering
capabilities
Can be towed to jobsite
location on a standard hitch
Winch system on each
upright raises and lowers
work platform
Front handrail system is
completely removable
Employees cannot stay on
work platform during
movement
All general scaffold
standards apply
Horse Scaffolds
Members
Horizontal
Bearer
Legs
Dimensions
3 x 4”
11/4” x 41/2”
Braces between
Legs
1 x 6”
Gusset Brace at
top of Legs
1 x 8”
Half Diagonal
Braces

11/4 x 41/2”
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Horses must be spaced not
more than 5 ft. for medium
duty, not more than 8 ft. for
light duty
For stacking applications, must
not exceed two tiers or ten feet
in height
Horses must be inspected for
defects prior to use
All general scaffold standards
apply
Adjustable Scaffolds
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Use is more common to
commercial projects
Pre-shift inspection of all
components is critical
 Hoist Motors
 Outriggers
 All Fastening Points

All general scaffold
standards apply
Crawling Boards / Chicken Ladders
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Crawling board must be at
least 10” wide and 1” thick
Cleats
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Must be at least 1” x 11/2”
Must be as long as the board is
wide
Must be spaced equally at no
more than 2’ apart
If the crawling board
presents a fall exposure, fall
protection must be used i.e.
handrails-harness
Scissor Lifts
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Scissor lifts are not addressed by the
aerial lift provisions of Subpart L.
There are no OSHA provisions that
address scissor lifts, however,
employers must comply with the
applicable provisions of Subpart L,
both general and specific.
Example:

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Scissor lifts are mobile, the specific requirements for
mobile scaffolds standard (§1926.452 (w) - mobile
scaffolds) shall be used.
Scissor lifts do not require a personal
fall arrest system for occupants.
Aerial Lifts
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Occupants of an aerial lift
must use a personal fall
arrest system.
Occupants are required to
stay on the floor of the
basket at all times.
Pre-shift inspection is
critical to insure safe
operation.
The lift may not be field
modified without the
manufacturers consent.
Scaffold Checklist
Stability of the ground or work surface,
proper mud sills when needed
All components from the same
manufacturer
Adjustable screw jacks with base pads
in every post
External ladder access for steel scaffold
bucks not designed for climbing
Erection, dismantle, alteration done
under supervision of a competent person
Complete decking from front to back on
all working levels
Fall protection in place once work deck
reaches or exceeds 10 ft. for
conventional scaffolds
Daily inspection performed by a
competent person before and during the
shift
Scaffold must be designed to hold four
times the intended working load (safety
factor of “4”)
Tie-ins set once the height of the
scaffold exceeds four times the minimum
base dimension
Scaffold grade planking or better for all
work surfaces
Planks overlapped over horizontal
support no less than 12”
Overhead protection for other trades or
personnel below
Pre-shift inspection of all motorized
components, proper PPE in use