Recoating Wisdom Path pillars will cost double original 'paint'

Department admits its use of a hi-tech material to fight fungus was a mistake

State-of-the-art technology used to protect timber columns on Lantau's Wisdom Path has proved useless against Mother Nature, a senior government official admitted yesterday.

Deputy director of Architectural Services Marigold Lau Lai Siu-wan acknowledged that officials had 'made a mistake' by spending HK$200,000 to use a nanotechnology coating - a material developed at the atomic or molecular level - to protect the wood. Remedial work will cost another HK$410,000.

The nano titanium oxide protective coating contained particles that were too small to stay on the tree bark, she explained. The coating was applied based on the results of a laboratory test.

'No one understands how to protect wood in the outdoors,' Mrs Lau told a conference on the issue at the University of Hong Kong. 'We are learning through mistakes.' The South China Morning Post reported in September that some of the 38 timber columns, which stand between eight and 10 metres and have calligraphy by sinologist scholar Jao Tsung-I on one side, were found to be sprouting fungus and mould. The path, which is an outdoor tourist attraction near Po Lin Monastery, was opened in May last year.

The coating, which is water-soluble, also made it almost impossible to protect the tree bark from the city's humid weather.

The wood would have been easier to preserve had the bark been removed, but it was kept for aesthetic purposes, Mrs Lau said. Because the side inscribed with calligraphy was shaved and peeled, it had suffered minimal damage.