Waterlogged insulation could have caused Nex cinema duct collapse
The collapse of a ventilation duct in a Nex mall cinema was likely due to waterlogged insulation material whose weight overloaded supporting brackets, according to preliminary findings of the Building and Construction Authority (BCA). The Aug 31 incident in a Shaw Theatres hall left two moviegoers injured.
Investigations are expected to be completed by end-October, said the Ministry of National Development (MND) in a written reply on Monday to a parliamentary question from Mr Melvin Yong (Radin Mas).
BCA had found that "a significant amount of water had accumulated in the layer of acoustic material surrounding the air-conditioning and mechanical ventilation (ACMV) duct". The added weight had likely caused the brackets holding the duct to give way.
The acoustic material surrounding the duct serves to insulate it and prevent water from forming due to condensation, and to muffle noise caused by air travelling through the duct.
BCA has alerted other cinema operators to inspect their ACMV ducts and to carry out maintenance and repair works where necessary, MND added.
BCA will also assess what further measures need to be taken to prevent a recurrence of such incidents, after its investigation has been completed.
Associate Professor Daniel Wong from the National University of Singapore's School of Design and Environment said the water accumulation could come from a leaking pipe, a waterproofing defect, or prolonged condensation due to temperature changes.
He noted that these occurrences are common in poorly maintained or abandoned buildings. To prevent such failures, Prof Wong stressed that scheduled inspections and regular maintenance must be carried out.
When contacted, a Nex spokesman said it is providing assistance to its tenant, Shaw Theatres, to carry out rectification works. The mall, owned and managed by Gold Ridge, said it will "continue to collaborate with the regulatory bodies to ensure that this is resolved as soon as possible and preventive measures are put in place".
Shaw Theatres said it conducted inspections at its six cineplexes following the incident as a precautionary measure, and all were found to be safe.
Golden Village cinemas said it conducted a round of checks with BCA personnel, after recommendations from the authority. This was on top of its scheduled maintenance and inspections. - THE STRAITS TIMES