SCOSS says that it has been concerned for some time at the use of structural fixings where these so called 'minor' items have not received the attention they deserve, given their safety critical nature.
Four ceiling failures have been reported by CROSS (Confidential Reporting on Structural Safety) this year. It says the Boston "Big Dig", where a concrete ceiling panel fell on a car killing a passenger and a Swiss swimming pool roof collapse where there were multiple fatalities demonstrate the seriousness of the situation.
SCOSS urges designers to consider the following robustness issues:
Having sufficient redundancy in the system such that one isolated failure does not result in the excessive overloading of other fixings leading to progressive collapse.
Choosing the appropriate material specification where this is relevant to load patterns, substrate condition or corrosion control due to environmental conditions.
Noting that fixings working in shear usually have a greater robustness against certain short-comings compared to fixings working in pure tension.