Chapter 3: Scaffold Safety

viraginityfumblingSoftware and s/w Development

Nov 2, 2013 (3 years and 2 days ago)


Chapter 3: Scaffold Safety

What Are The Hazards Of Using

Falls from elevation

caused by slipping, unsafe
access, and the lack of fall protection. Scaffolding
10 feet

in elevation must have guardrails, or
other fall protection measures.

Struck by

falling tools/debris


from overhead power lines

Scaffold collapse

caused by instability or

Bad planking

giving way

Tubular welded frame


Aerial Lift

Scaffolding in Residential Construction

Ladder Jacks

Pump Jacks

The Competent Person

Required on all sites
where scaffolding is

Must be qualified by
training and

Duties of the Competent Person

Select and direct employees to erect, dismantle,
move, or alter scaffolds.

Determine if it is safe to work on or from
scaffolding during storms, high winds.

Ensure personal fall arrest system or wind screens
protect employees.

Train employees involved in erecting scaffolds.

Inspect for visible defects.

Base Plates

All scaffolds require
base plates

Base plates are often
combined with screw
jacks to adjust height

On open ground, use
mud sills in addition to
base plates

Plumb and Level

Check that initial row
of scaffold frames are

Use screw jacks on
base plates to raise or
lower frames

Examples of improper foundations

Scaffold Height

The height of the
scaffold should not
be more than four
times its minimum
base dimension
unless guys, ties, or
braces are used








Brace scaffold using ties & guys

It is the responsibility of the competent person to

use the necessary ties, guys, braces or outriggers to
prevent a supported scaffold from tipping.

assure that the supported scaffold poles, legs, post
frames and uprights are plumb and braced to prevent
swaying and displacement.

Prior to setup: Inspect the site for
electrical lines

OSHA minimum clearance
distances from overhead
power lines:

Less than 300 volts

clear by 3

300 volts to 50,000 volts

by 10 feet

More than 50,000 volts

10 feet


4 inches for every 10,000 volts

over 50,000 volts

Guardrails and Crossbracing


Must be between 38 to 45 inches.

when the crosspoint of the crossbracing is used as a toprail, it
must be between 38 and 48 inches.


Must be halfway between top rail and

when a cross point of crossbracing is used as a midrail it must
be between 20

30 inches above the work platform.

Install along open sides & ends before releasing
the scaffold for use to employees.

Laborer was working on the
third level of a tubular welded
frame scaffold which was
covered with ice and snow

The scaffold was not fully
decked, there was no guardrail
and no access ladder

The worker slipped and fell
head first 20 feet to the
pavement below

Fatal Fact

Ice & No Guardrails

Proper Scaffold Access

Provide access when
scaffold platforms are
more than 2 feet above or
below a point of access.

Permitted types of access:

Ladders, such as portable,
on, attachable,
stairway type, and built

Stair towers

Ramps and walkways

May use building stairs
and come out window

Scaffold Access


access by

May use end frames if
designed for access

Scaffold Access Prohibited

Rungs on this
tubular frame
scaffold can
NOT be used
for access

Scaffold Platform Construction

Platforms must:

be fully planked or decked with no more than 1 inch gaps

be able to support its weight & 4 times maximum load

be at least 18 inches wide



Overlap planks at least 12 inches

Scaffold Platform Construction

Each abutted end of
plank must rest on a
separate support

Overlap platforms at
least 12 inches over
supports, unless
restrained to prevent

Plank ends are not
properly overlapped

Distance limits:

platform edge to working face of wall

No more than 14" from the face of the work

3" from the face for outrigger scaffolds

18" from the face for plastering and lathing operations

Ladder Jack Scaffolds

Height of ladder jack platforms
must not exceed 20 feet;

All ladders used to support
ladder jack scaffolds must
comply with 29 CFR 1926.452
subpart X

Stairways and
Ladders, except:

Job made ladders can


used to support ladder jack

Ladder Jack Scaffolds


The ladder jack shall be designed and constructed such that
it will bear on the side rails and ladder rungs alone. If
bearing on rungs only, the bearing area must include a
length of at least 10 inches on each rung;

Ladders used to support ladder jacks must be placed,
fastened or equipped with devices to prevent slipping; and

Scaffold platforms shall not be bridged one to another.

Ladder Jacks:

Fall Protection > 10 feet

Pump Jack Scaffold

Erected no higher than
30 feet

Tie off onto building

Plank width minimum
12 inches

Fall protection

Guardrail set up

Pump Jack Scaffold

Pump Jack Scaffold

Guardrails are
required at all
open sides and
ends of scaffolds.


are not guarded
on this narrow

Aerial lifts and fall protection

Use fall protection (guardrails
or a fall arrest system) when
moving between the lift and
an elevated work surface.

Stand on the floor of the
basket, and never on the edge
of the basket

Do not combine the aerial lift
with planks, ladders, or other

Aerial lifts: Tie

Employees working from aerial lifts must be tied

Wear personal fall protection equipment, connecting
directly or indirectly to an anchorage.

Lanyards, vertical lifelines, and anchorage points
must support 5,000 pounds per employee

A body belt is permitted only if it is part of a restraint

Employee was operating an aerial
lift, with an extendable boom
rotating work platform

The boom was fully extended and
the machine apparently ran over
some bricks, causing the boom to
flex or spring, throwing the
employee from the basket

The employee fell 37 feet to a
concrete surface

Fatal Fact

Moving a Lift


Assign Competent Person

Use proper scaffold construction methods

Ensure stable access

Avoid electrical hazards

Ensure fall protection/guardrails

Secure decking

Apply protections to ladder, pump jack scaffolds,
and aerial lifts