The last roof tile on the venue for the handover might not be put on until just hours before the ceremony. Only a fortnight ago, joint-venture contractors Dragages Travaux Publics and Hip Hing Construction targeted yesterday for the last decorative piece to be fitted to the 40,000-square-metre curvilinear roof. But downpours in the past fortnight wreaked havoc on the schedule, and roofers will have to work round the clock to get the last aluminium tiles in place. Extra lighting and additional safety measures have been employed so that work can continue through the night, a spokesman for Dragages said. 'It should all be finished by the weekend,' she said. 'There are just some decorative tiles that have to go on. The work has been dependent on the weather. 'It has to be done, it will be done.' The construction schedule for the $4.8 billion extension to the Convention and Exhibition Centre has been regarded as tighter than other fast-track schedules, even by Hong Kong standards. But few people predicted it would go so close to the wire, with potentially hours, rather than days, to spare. The building was deemed 'substantially complete' at the beginning of this month when the operators assumed control of the day-to-day running of the facility. However, when the complex was opened to the press on June 14, water could been seen dripping through the ceiling, forming a pool only a short distance from the spot where the British flag will be lowered on June 30. The leak was attributed to blocked drainage that has since been rectified. 'There won't be any leaks on handover night,' said the construction spokesman.