An Evaluation of Supported Scaffold Safety PDF Version PowerPoint Version
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Michael McCann, PhD, CIH, Ken Halperin, PhD, Consultant
CPWR – Center for Construction Research and Training




Fatal Falls from Supported Scaffolds, 1992-98
  • Total # of deaths = 267 (38/year)

    • 217 falls (81%)
    • 47 collapses (18%)

  • 15 deaths (6%) dismantling scaffolds
  • 6 deaths (2%) assembling scaffolds
Source: U.S. Bureau of Labor Statistics data

Research Methods
  • Used a 150-point checklist to evaluate scaffold safety practice

    • Rated scaffolds as acceptable or unacceptable

  • Evaluated 113 scaffolds in 9 areas of Eastern U.S.
  • Also evaluated information on worksite, workforce, and scaffold competent person.
Results
  • 36 of the 113 scaffolds (32%) were unacceptable and posed imminent hazards:

    • danger of collapse
    • missing planking, guardrails, and/or
    • inadequate access

  • 77 scaffolds (68%) were acceptable and posed no imminent danger to the workers.
30 Scaffolds (27%) Had Structural Flaws
  • Missing or improperly supported base plates
  • 17
  • Scaffold not tied properly to building
  • 13
  • Platform not level
  • 6
  • Some runners missing
  • 3
  • Some jacks overextended
  • 2
  • Severe overloading
  • 2
  • Some posts incorrect
  • 1
  • Some braces not tight
  • 1


36 Scaffolds (32%) Had Fall Hazards

  # fall hazards
  • Missing mid guardrails
  • 33
  • Missing top guardrails
  • 28*
      * Also missing midrails  
  • Improper access
  •  
     
  • Climbing scaffold frame
  • 23
     
  • Other severe access problems
  • 5
  • Partially planked platforms
  • 26
  • Substandard planks
  • 3


    Correlation between Structural Flaws and Fall Hazards
    • 36 scaffolds were unacceptable
    • 23 had both structural flaws and fall hazards
    • 10 had fall hazards only
    • 3 had structural flaws only
    Problems of Unacceptable Scaffolds
    • 36 scaffolds were unacceptable

      • 92% were missing guardrails
      • 83% had structural flaws
      • 78% had poor access
      • 72% were insufficiently planked
    Scaffold Competent Person
    • Required by OSHA

      • 29 CFR 1926.451(f)(3) requires inspections by competent person before each work shift and after occurrences which could affect scaffold structural integrity

    • Competent person

      • Recognize hazards
      • Authorized to take corrective action
    Competent Persons on Scaffold Sites
    • 104 sites had workers present
    • 82 (79%) had competent persons
    • 10 sites (10%) said competent person was not present
    • 72 competent persons were interviewed

      • Only 32 (44%) had scaffold safety training
    Need for Competent Person Scaffold Safety Training
    • 32 sites had competent persons who had scaffold safety training

      • 25 scaffolds (78%) were acceptable

    • 62 sites had no competent person or had one without scaffold safety training

      • 24 scaffolds (39%) were acceptable
    Importance of Scaffold Erector
    • 72 scaffolds erected by scaffold user

      • 43 (60%) were acceptable

    • 41 scaffolds erected by scaffold erection contractor

      • 34 (83%) were acceptable
    Effect of Union Status of Scaffold Erector
    • 49 scaffolds erected by union contractors

      • 38 (78%) were acceptable

    • 64 scaffolds erected by non-union contractors

      • 39 (61%) were acceptable
    Effect of Type of Supported Scaffold
    • 86/113 scaffolds (76%) were frame scaffolds

      • 54 frame scaffolds (63%) were acceptable

    • 27 scaffolds (24%) were other types of scaffolds

      • 23 other scaffolds (85%) were acceptable
    Summary of Proper Scaffold Safety Practice -1
    • Unacceptable scaffolds have both:

      • Structural flaws

        • Missing or improperly supported base plates
        • Improper tying off to building
        • Uneven platform slope

      • Fall protection hazards

        • Missing planking and/or guardrails
        • Inadequate access
    Summary of Proper Scaffold Safety Practice - 2
    • Strong correlations with:

      • Presence of competent person with scaffold safety training
      • Use of non-frame scaffolds
      • Scaffold erected by scaffold erection company

    • Slightly weaker correlation with union status of scaffold erector
    Summary of Proper Scaffold Safety Practice - 3
    • No correlation with:

      • Location n Site size
      • Number of workers on the scaffold
      • Trade of scaffold workers
    Recommendations
    • Hire an outside scaffold erector
    • Have competent person on site who has had scaffold safety training
    • Consider whether frame scaffolds are the best choice
    • Perform regular inspections
    Quick Scaffold Inspection Checklist
    • Check for missing planks on platforms
    • Check for missing guardrails
    • Check for proper access
    • Check for proper tying off to buildings
    • Note: The first 3 points find 92% of unacceptable scaffolds
    Missing Planks



    Missing Guardrails



    Improper Access



    Further Information on Construction Safety and Health

    CPWR – Center for Construction Research and Training www.cpwr.com

    This presentation was funded by research grant U60 CCU 317202 from the National Institute for Occupational Safety and Health (NIOSH) through CPWR – Center for Construction Research and Training, Silver Spring, Md. The contents are solely the responsibility of the authors and do not necessarily represent the official views of NIOSH.



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