1. Chapter 3: Scaffold Safety
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

2. What Are The Hazards Of Using Scaffolding?
Falls from elevation—caused by slipping, unsafe access, and the lack of fall protection. Scaffolding over 10 feet in elevation must have guardrails, or other fall protection measures.
Struck by falling tools/debris
Electrocution—from overhead power lines
Scaffold collapse—caused by instability or overloading
Bad planking—giving way
Ensuring that scaffolds are properly constructed can prevent injuries and deaths on construction sites.
Falls are a major hazard on all construction sites, and they are the leading cause of death on residential construction sites. Approximately 1 in 5 fatalities from falling are associated with work on scaffolding. Of workers injured in falls from scaffolding, 25 per cent had received no scaffolding safety training, and 77 per cent of the scaffolds involved were not equipped with guardrails.
Other hazards include injuries from falling materials, electrocutions from touching energized wires, and the collapse of scaffolding or platforms due to unstable foundations, or overloaded platforms.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

3. Scaffolding in Residential Construction
Ladder Jacks
This training will cover the most common scaffolds used in residential construction: tubular welded frames, pump jack scaffolds, and ladder jack scaffolds. We will also briefly discuss aerial lift platforms.
Suspended
Tubular welded frame
Aerial Lift
Pump Jacks
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

4. The Competent Person Required on all sites where scaffolding is used
Must be qualified by training and experience
All scaffolding must be erected and used under the supervision of a “Competent Person.”
Qualifications of the Competent Person
Be designated by the employer.
Have knowledge of the standard and experience to identify existing and predictable hazards in the surroundings or working conditions.
Have the authority to take prompt corrective measures to eliminate hazards.
Have past field experience in safely using the types of scaffolding found on-site
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

5. 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.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

6. 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
Safely constructing a scaffold begins at ground level. On tubular frame scaffolds, assure that the first tier of frames have a solid foundation. Always use base plates, and if the ground is not level, use adjustable base plates. Whenever there is a chance that the soil beneath a scaffold may settle or shift, use a mudsill in addition to the base plate.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

7. Plumb and Level Check that initial row of scaffold frames are plumb
Use screw jacks on base plates to raise or lower frames
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

8. Examples of improper foundations
Ensure that foundations for scaffolding are solid, and will not collapse or shift position.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

9. Scaffold Height
20’
The height of the scaffold should not be more than four times its minimum base dimension unless guys, ties, or braces are used
The stability of scaffolds must be assured as they increase in height. When the height to width ratio exceeds 4 to 1, the scaffold must be secured using guy wires, ties, or braces. 4 5’ 1
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

10. Brace scaffold using ties & guys
ANCHORS & GUYS
TIES
WIDE BASE
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.
Ties, guys, and braces for a scaffold must be installed according to the scaffold manufacturer's recommendations.
If the specifications are unknown then the standards at 29 CFR (c)(1) must be followed. Which state:
The location of the guys, ties, and braces depends upon the width of the platform:
For Scaffolds < 3 feet wide, secure vertically every 20 feet or less and
For Scaffolds > 3 feet wide every 26 feet or less.
Secure Horizontally at end, and at intervals not to exceed 30 feet from one end.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

11. Prior to setup: Inspect the site for electrical lines
OSHA minimum clearance distances from overhead power lines:
Less than 300 volts—clear by 3 feet
300 volts to 50,000 volts—clear by 10 feet
More than 50,000 volts—10 feet
plus
4 inches for every 10,000 volts
over 50,000 volts
De-energized?
Most residential construction will involve voltages of 300 volts or less, leading to the house. However, high voltage lines may be in the vicinity, and may be contacted by extension ladders, or supplies being moved or carried. Note also in this photo that the worker is likely in violation of the fall protection requirement, beginning at 10 feet elevation.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

12. Guardrails and Crossbracing
Toprail—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.
Midrails—Must be halfway between top rail and platform.
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.
Reference (g)(1), (g)(4), (b)(3), and Appendix A, paragraph 1d.  
38 inch minimum guardrail height where guardrail is primary fall protection.
36 inch minimum guardrail height where fall arrest systems are primary fall protection.
Protect from falling between the top rail and surface, by using midrails, screens or mesh.
Protective barriers must be strong enough to support a falling employee. Wood, chain and wire rope may be used for top rails and midrails.
Top rails inches tall when using the midpoint of the crossbrace as the top rail
When crossbracing is used as a midrail, it must be between 20 and 30 inches above the work platform.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

13. Fatal Fact – Ice & No Guardrails
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
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

14. 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, hook-on, attachable, stairway type, and built-ins
Stair towers
Ramps and walkways
May use building stairs and come out window
(e)
Access requirements for employees erecting and dismantling supported scaffolds -- Must have a safe means of access provided when a competent person has determined the feasibility and analyzed the site conditions.
Direct access to or from another surface shall only be used when the scaffold is not more than 14 inches horizontally and 24 inches vertically from the other surface.
Portable, Hook-on, and Attachable Ladders - position to not tip the scaffold.
Hook-on and Attachable Ladders - must be specifically designed for the type of scaffold with which they are used.
Ramps and Walkways - must have guardrails which comply with [ (b)] 1926 Subpart M if more than 6 feet above lower levels.
Stairway-type Ladders and Stair Towers - bottom step no more than 24 inches above the level on which the scaffold is supported.
Built-in Scaffold Ladders - must be specifically designed and constructed for use as ladder rungs.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

15. Scaffold Access Never access by crossbraces
May use end frames if designed for access
This tubular frame scaffold (on left) is designed to provide access.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

16. Scaffold Access Prohibited
Rungs on this tubular frame scaffold can NOT be used for access
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

17. 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
Reference (a) and (b)
How wide does the work area need to be on scaffolding?
Each scaffold platform and walkway must be at least 18 inches wide.
When the work area is less than 18 inches wide, guardrails and/or personal fall arrest systems must be used.
Employees on a walkway located within a scaffold must be protected by a guardrail system installed within 9 1/2 inches of and along at least one side of the walkway.
Planking should be graded and marked as scaffold planking.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

18. Decking Decking designed to fit between uprights, with no overlap
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

19. Planking Planks must be designed for use with scaffolding
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

20. Overlap planks at least 12 inches
Note toe boards also on this platform. Toe boards must be at least 3.5 inches in height and resist 50 lbs of force, horizontally.
Overlap planks at least 12 inches
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

21. Scaffold Platform Construction
Each abutted end of plank must rest on a separate support surface
Overlap platforms at least 12 inches over supports, unless restrained to prevent movement
Reference (b)
Front edge of all platforms
- 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
Platforms 10' and less to extend at least 6" but not more than 12" past support unless designed and installed and/or guarded properly
Platforms greater than 10' no more than 18" past support unless designed and installed and/or guarded properly
Plank ends are not properly overlapped
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

22. 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
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

23. 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 subpart X—Stairways and Ladders, except:
Job made ladders can NOT be used to support ladder jack scaffolds;
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

24. Ladder Jack Scaffolds – cont.
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.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

25. Ladder Jacks: Fall Protection > 10 feet
The requirement to provide fall protection above more than 10 feet applies to ladder jacks, as well as other forms of scaffolding. Because standard railings and personal fall arrest systems are difficult to use with this type of scaffold, it is recommended that these systems be used only at heights less than 10 feet.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

26. Pump Jack Scaffold Erected no higher than 30 feet
Tie off onto building
Plank width minimum 12 inches
Fall protection
Guardrail set up
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

27. Pump Jack Scaffold
Pump jack scaffolds require fall protection above 10 feet. In this photo, a ladder was secured to pump jack brackets and poles giving required strength for a guard rail. However, platform ends must also be guarded.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

28. Pump Jack Scaffold
Guardrails are required at all open sides and ends of scaffolds.
Violation: Ends are not guarded on this narrow scaffold.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

29. 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 devices
A worker may enter or exit an aerial lift (at heights above 6 feet) provided that fall protection (guardrails or a fall arrest system) is used while the worker moves between the lift and the working surface.
During entry to and egress from the lift, a worker may tie-off to the lift (if the lift is designed to withstand the vertical and lateral loads imposed by the employee's movement itself or by an arrested fall) or to an appropriate nearby structure.
Always stand firmly on the floor of the basket, do not sit or climb on the edge of the basket or use planks, ladders, or other devices for a work position.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

30. Aerial lifts: Tie-off
Employees working from aerial lifts must be tied-off.
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 system.
Employees working from aerial lifts must be tied-off.
Tie-off' means the act of an employee, wearing personal fall protection equipment, connecting directly or indirectly to an anchorage.
Lanyards and vertical lifelines which tie-off one employee shall have a minimum breaking strength of 5,000 pounds.
Anchorages to which personal fall arrest equipment is attached shall be capable of supporting at least 5,000 pounds per employee attached, or shall be designed, installed, and used as part of a complete personal fall arrest system which maintains a safety factor of at least two, under the supervision of a qualified person.
A body belt is permitted only if it is part of a restraint system.
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

31. Fatal Fact – Moving a Lift
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
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module

32. Summary 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
General References:
 OSHA Publication 3150, A Guide to Scaffold Use in the Construction Industry:
 OSHA Construction Scaffolding eCAT
Other standards that apply to scaffolds
-- the responsibility to initiate and maintain programs ( (b)(1))
-- exposures to dusts and chemicals ( , , , , & )
-- hand and power tools ( )
-- electrical ( )
-- personal fall arrest systems ( )
-- ladders ( )
Chapter 3: Fall Protection/Scaffolding
Instructor’s Module