Why modern megacity Hong Kong still uses bamboo scaffolding for building

[HONG KONG] Hong Kong plans to phase out its long tradition of using bamboo scaffolding for construction projects, after the city’s deadliest residential fire in more than 60 years.

Investigators are still determining what caused the blaze at the high-rise Wang Fuk Court apartment complex on Wednesday (Nov 26).

As part of their efforts, they are examining whether the materials that were being used in the renovation of the towers, such as the lattice of bamboo wrapped in green plastic mesh, helped the flames spread.

Hong Kong is one of the few places in the world where bamboo scaffolding remains prevalent in construction.

The crisscrossing poles have been a fixture across the financial hub for decades, as new skyscrapers are added to the skyline and existing buildings are revamped. 

But scrutiny of the material has been growing, and the recent tragedy has prompted the government to significantly step up the changes it announced earlier this year to increase the share of metal scaffolding in public works.

Why Hong Kong relies on bamboo for scaffolding

Bamboo scaffolding is a millennia-old practice that originated in mainland China. The craft became prominent in Hong Kong in the 1960s as an economic boom spurred construction growth across the city.

While the mainland has shifted to metal frames to support building and maintenance projects, Hong Kong still relies on thousands of skilled workers who specialise in tying lighter, cheaper and abundant bamboo poles together in an interlocking pattern.

Unlike metal scaffolding that is made up of standardised parts and bolts, bamboo scaffolding is more flexible and can be cut to size more easily to fit limited and irregular spaces.

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This is useful in a densely populated city where buildings are sometimes just inches away from each other.

Risks of bamboo scaffolding

Bamboo scaffolding has been linked to construction accidents in Hong Kong.

Recent scaffold-related incidents include a major collapse at a Kai Tak luxury development last year, that killed two workers and led to manslaughter charges.

Dry bamboo is combustible and can help fuel a blaze’s spread.

In October, the Chinachem Tower covered in bamboo scaffolding caught fire in the central business district, causing four people to be hospitalised.

Bamboo can become increasingly flammable with wear and tear, said Vincent Ho, founder of the Hong Kong Institute of Building Safety, a think tank.

It requires a lot of effort to check and maintain the quality of the material, he added.

However, it is not easy to set fire to bamboo, said Lee Kwong-sing, chairman of Hong Kong Institute of Safety Practitioner, on a Radio Television Hong Kong radio show on Thursday.

The materials used to cover the scaffolds at Wang Fuk Court might not have been flame-retardant, leading to the rapid spread of fire, he added.

While the definitive cause of the blaze has yet to be established, government officials suggested that the sheetings on the exterior of the buildings burned faster than compliant materials, and the highly flammable foam found at the scene also accelerated the fire.

New guidelines around scaffolding

In March, the government announced that at least 50 per cent of new public building works will have to use metal scaffolding.

It pointed to “intrinsic weaknesses” with bamboo frames, including “variation in mechanical properties, deterioration over time and high combustibility”, and said that the metal alternatives are comparatively rigid and durable. 

Aside from safety concerns, the government also flagged a need to align with modern construction practices in mainland China and other advanced economies. 

The regulatory changes drew backlash from industry players, who have long argued that accidents stem from safety protocols not being strictly followed, rather than bamboo scaffolding being structurally unsafe.

There are also concerns that a transition to metal scaffolding will result in a shift in employment from domestic masters in bamboo craft to non-local workers, and a loss of cultural heritage.

Hong Kong’s Labour and Welfare secretary Chris Sun said in July that the government had no intention of banning the use of bamboo scaffolds yet.

But following the fatal Wang Fuk Court fire, Chief Executive John Lee announced on Thursday that the government will move to completely replace bamboo scaffolding in construction projects and ensure workers transition toward using metal ones.

Switching to fire-resistant steel frames would not eliminate the risk of a blaze starting or spreading. Other building materials, such as netting, wooden platforms and protective boards, also need proper fire-proofing, Ho said. BLOOMBERG