Construction-industry representatives warned that the use of metal scaffolding comes with its own risks despite being more resistant to fire than bamboo.

The use of bamboo scaffolding has come in for critical examination following the devastating blaze in Tai Po that claimed, in the latest official count, the lives of 94 and forcing authorities to consider building on a plan for a switch to metal "as soon as possible".

Chau Sze-kit, chairman of the Hong Kong Construction Industry Employees General Union, said on Friday the sector was keeping an open mind on the shift while hoping that people would bear in mind the potential problems from using metallic structures.

"Metal is more fire-resistant than bamboo... On the other hand, if the metal scaffold catches fire, it will get hot. When it reaches a certain temperature, it becomes more prone to collapse," Chau told an RTHK programme.

"Regardless of it being bamboo or metal scaffolding, if there's good management and rules are being followed, it is relatively safe to use either one."

Lawrence Ng of the Hong Kong Construction Sub-contractors Association said bamboo scaffolds should be phased out, but pointed out that metal systems might not be suitable for all renovation projects.

"If we were to use metal scaffolds, it's necessary to have a putlog attached to the exterior of the building. However, metal scaffolds are way heavier than bamboo," Ng said.

"If the building itself is too old... other issues may arise [from the use of metal scaffolds]."