A qualitative exploration and a Fuzzy Delphi validation of high-risk scaffolding tasks and fatigue-related safety behavioural deviation among scaffolders.

Background: Most construction mishaps were caused by scaffolding incidents despite implementing various safety measures, and the association with human factors like fatigue has been widely reported. This study aims to identify all high-risk task sequences involved during the erection of the most commonly used scaffold; the deviation from the standard protocol led to a substandard fatigue state, followed by content validation using the Fuzzy Delphi Method.

Methods: Qualitative exploration was conducted via focal group discussions (FGDs) involving 30 certified experts. The findings generated from FGDs were further validated by utilising the Fuzzy Delphi Method (FDM) by consulting 19 experts with extensive practical experience and leadership roles in scaffolding safety.

Results: The FGDs identified a total of 7 constructs and 50 items for task sequences involved in the tubular scaffold erection, namely construct Instruction (3 items), Preparation (3 items), Foundation (10 items), First Lift (8 items), Working Platform (7 items), Guardrails (5 items) and Second Lift (14 items). In the FDM validation process, the experts' consensus for each construct was fulfilled with a threshold value (d) ≤ 0.2; thus, all constructs were accepted. Experts' consensus for all items achieved an expert agreement of 75 % and above. Items ranking was conducted using average fuzzy numbers. The highest average fuzzy number documented was 0.8, while the lowest was 0.588. None of the items with the lowest ranking was discarded as all items perfectly fulfilled the second prerequisite and obtained excellent experts' agreement.

Conclusions: The tool generated will help guide the development of a protocol for scaffolding safety management.