Bamboo scaffolding, a centuries-old technique that was traditionally ubiquitous in Hong Kong, is under scrutiny for its role in the city’s deadliest fire in more than a century.

At least 55 people have died, and hundreds are still missing since scaffolding at a housing estate in Tai Po district caught fire on Wednesday, according to the latest government figures.

Bamboo is cheap, lightweight, and strong enough to withstand the city’s many typhoons and tropical storms. Hundreds of bamboo poles can often be seen lashed together on the side of a modern office tower.

But could one of Hong Kong’s iconic symbols also have served as the kindling for one of its most horrific tragedies in decades?

How is bamboo scaffolding used?

Buildings or housing estates – like the one in Tai Po district – encased in bamboo during significant renovation projects are not a rare sight in the city-state. Sometimes, the scaffolding can remain up for a year or more.

Bamboo scaffolding is built by speciality workers known as “spiders”. They lash together bamboo poles to build intricate grid-like scaffolding that is then typically covered in additional netting to catch construction materials.

While the use of bamboo has faded in other parts of Asia, it has been hard to replace it completely in Hong Kong, even with options such as metal scaffolding, said experts.

“It’s light, cheap and fast to build with,” Ehsan Noroozinejad, a senior researcher and construction expert at Western Sydney University, Australia, told Al Jazeera. “Crews carry poles by hand, cut them on site, and wrap awkward facades without cranes. That speed and flexibility keep projects moving and costs down.”

Because it is “light and easy to cut”, bamboo scaffolding also fits the narrow living environment of Hong Kong, said Xinyan Huang, deputy director of the Research Centre for Fire Safety Engineering at Hong Kong Polytechnic University.

But there are other reasons, too, why bamboo is hard to replace.

“It [Hong Kong] has a long history, so it is a tradition, and it is not easy to change tradition,” Huang told Al Jazeera by email. “Any change in the construction industry will meet much resistance from current players.”

There are 4,000 bamboo scaffolding workers in the city, Hong Kong Free Press reported, citing union figures, although the industry is on the decline thanks to increased competition from metal scaffolding and an ageing cohort of workers.

Is bamboo scaffolding dangerous?

Prior to the fire, most concerns around bamboo scaffolding have focused on worker safety.

There were 22 fatal workplace accidents involving bamboo scaffolding in Hong Kong between 2018 and 2024, according to government figures. Six accidents occurred while new scaffolding was being built, while the rest took place during repairs.

Besides the fact that bamboo is by its very nature combustible, it is also structurally weaker and less stable than steel, according to Huang. He told Al Jazeera that it should be phased out for larger projects.

“I think the bamboo scaffolding can be used for small-scale applications, such as installing an air conditioning unit and replacing a window of a room. However, the large-scale usage such as covering the entire building facade should be stopped. Perhaps, a maximum area of bamboo scaffolding can be defined in future regulation,” he said.

What role did bamboo scaffolding play in the Tai Po fire?

The fire is the deadliest in Hong Kong in more than a century, since a blaze in 1918 at the Happy Valley Racecourse in British Hong Kong led to the deaths of more than 600 people.

Bamboo scaffolding played a big role in spreading the fire, according to experts like Anwar Orabi, a lecturer in fire safety engineering at the University of Queensland, although it was helped by other materials in the estate.

The fire broke out on the scaffolding of one of the estate’s towers on Wednesday, but the speed with which the fire spread took many observers by surprise. Orabi said the design of the scaffolding made it difficult to keep the blaze limited to just a few floors.

“In my point of view, the scaffolding presented a path for the fire to spread vertically which compromised compartmentation. The fire ‘climbed’ the scaffolding, and ignited the multiple fuel sources in people’s homes,” he told Al Jazeera by email.

“Fire can break windows by imposing a strong heat flux [flow of heat] which heats up the glass and breaks it. It is also possible that many people left their windows open resulting in ingress of the fire. This resulted in a multi-storey fire,” he said. Heat radiation and embers from one building helped spread the fire to the next, he said, ultimately engulfing seven towers.

Hong Kong officials also say substandard construction materials were another contributing factor. The South China Morning Post reported that the netting placed over the scaffolding did not adhere to the fire code, citing local officials.

Senior police superintendent Eileen Chung said highly flammable Styrofoam boards had also been placed in windows in the housing estate’s lifts, public broadcaster RTHK reported, helping the fire spread.

Two directors and one engineering consultant from the company behind the construction have been detained, Chung confirmed.

Hong Kong’s leader, John Lee Ka-chiu, has promised that all housing estates undergoing significant improvements will now be inspected.

“The government has immediately arranged for inspections of all housing estates across the city undergoing major repairs, to examine the safety of scaffolding and building materials,” he wrote on Facebook.