THE’fire broke out in the Wang Fuk Court residential complex, located in the Tai Po neighborhood Hong Kong (China), caused at least 65 deaths and approx 279 missing: while the death toll continues to rise and firefighters work tirelessly to put out the flames that have engulfed 7 of the 8 buildings, the authorities have opened an investigation to clarify the causes of the accident. In the residential complex – consisting of 8 skyscrapers and around 4,000 tenants – work was in progress renovationfor which external scaffolding had been used in bamboo.
But why is bamboo still used for external scaffolding in one of the most advanced metropolises in the world? In reality, it is a material used historically in the construction sector in Hong Kong: bamboo, in fact, is economiceasily transportable And fast to install. Also for this reason, it is sometimes used in other areas of China and throughout East Asia. But its use also brings with it gods risksespecially if some safety criteria are not respected.
In any case, as also confirmed by some experts contacted by Geopopthe presence of bamboo scaffolding may have been a flame propagation acceleratorbut cannot be considered as the main cause of the fire outbreak.
Reasons why bamboo is still used in Asia: advantages of the material and traditions
As numerous local newspapers have highlighted – including the South China Morning Post –, despite Hong Kong being one of the most modern metropolises, the bamboo is a material distinctive of this territory and was heavily used as scaffolding during the construction of the skyscrapers that today characterize the city’s skyline.
The use of bamboo in scaffolding, in fact, has its roots in local tradition dating back over a century, but still persists today thanks to a series of technical and economic advantages, to the point of being quite widespread even in some parts of continental China, India, South-East Asia and South America.
First of all, bamboo ensures extraordinary speed in assembly and disassembly cycles of scaffolding: it has been estimated that building a bamboo structure requires approximately half the time necessary to create an equivalent steel scaffold. At the same time, the overall cost for transportation and installation is significantly lower, which guarantees a significant economic savings. Scaffolding is usually held together by tightly knotted plastic bands or steel brackets and then anchored to buildings.
Among other things, from a structural point of view bamboo has a good strength-to-weight ratio: a pole made of this material is light enough to be carried up a ladder, but is also strong enough – if reinforced and tied correctly – to support workers.
In short, bamboo is still used today in Hong Kong for 3 main reasons: it is quick to assemble, easily adapting to even the narrowest buildings (an indispensable factor in the high urban density of Hong Kong), it is extremely economical compared to the metal alternative and is a material traditionally used in this area.
Risks and problems of bamboo scaffolding
Despite these benefits, the use of bamboo for scaffolding presents two major problems: the first certainly concerns thehigh flammability of the material. In fact, in an interview with the South China Morning Post Raffaella Endrizziprofessor at the Faculty of Architecture at the Chinese University of Hong Kong, underlined how bamboo is a material that is partly resistant to combustion, as it retains a considerable amount of humidity within it.
In the specific case of the Wang Fuk Court residential complex, the scaffolding had been erected last July: it is therefore possible that, over these months, bamboo has annoyedtherefore becoming an ideal material for the propagation of flames.
The second problem has to do with the fact that bamboo is a organic material and, as such, is heavily influenced by atmospheric agentswhich can compromise its integrity over time. Also for this reason, the Hong Kong Building Department has drawn up some guidelines clear for the construction of bamboo scaffolding, imposing specific criteria for the use of this material, including:
- age of bamboo;
- diameter of the rods bamboo;
- degree of drying of bamboo;
- the presence of steel brackets to connect bamboo canes;
- The authorities, then, must implement frequent inspectionsespecially before bad weather.
Returning to our specific case, the causes of the fire have not yet been confirmed by the authoritieswho are also investigating the presence of polystyrene on the windows and on the possibility that the fire spread protective net placed around buildings. John Lee, governor of Hong Kong, declared the opening of discussions for the gradual replacement of bamboo scaffolding with metal ones.
