Filling in basement will take 80 cement trucks
More than 80 trucks loaded with concrete will be required to fill in the illegal basement in the Kowloon Tong home Henry Tang Ying-yen's wife owns. That's enough to fill six double deckers.
A person close to the rectification work ordered by the Buildings Department said the architect Tang employed to carry out the work could submit a plan for approval today.
According to the draft plan, the work does not involve solidifying the house's foundation, as the building has been proven to be structurally safe. The contractor is expected to remove items in the basement, fill it with concrete and seal it.
In order not to overload the existing foundations, the contractor will be asked to use no-fines concrete, which is of a lower density and lighter in weight.
According to the size of the basement - 19 metres long, 11 metres wide and 3.5 metres high - the amount of cement needed to fill it will be over 730 cubic metres. The massive volume will require transportation by more than 80 cement trucks, each holding 9 cubic metres.
The person familiar with the work said workers could make use of the two holes designed in the bottom of the swimming pool above the basement as a vent to pump concrete in. The holes were for windows, designed to allow visitors in the basement to watch people swimming.
The windows will be sealed, according to the demolition plan, to restore the house to its original state as specified in the approved building plan.
A veteran engineer and former president of the Hong Kong Institute of Engineers, Gregory Wong Chak-yan, said the rectification work was a simple task that could normally be completed in three days. But he said it would take as much as two weeks in the case of Tang's house due to constraints at the site.
'The public street outside the house is a bit narrow. It will be difficult to get 30 trucks of concrete to the site every day,' Wong said, adding it would take one truck about 45 minutes to pump out its concrete.
He estimated that the site would allow the operation of five trucks a day, and that the filling work would cost about HK$300,000.
Asked if it was possible for Tang to later take out the concrete and reuse the basement, Wong said it would take two months to dig out such a huge load and it would generate an enormous amount of noise.
'I don't think he will do it, as his house has already become a tourist spot,' he said.
The Buildings Department would not comment on whether it had received the rectification plan or if the house owner was being investigated.
It said last week it was investigating reports that suggested the 2,250 sq ft basement existed before an occupation permit was issued in 2007. Tang said the basement was built after the permit was issued, essentially dismissing reports he had concealed the project from inspectors.
The probe may lead to criminal charges. Tang co-owned the house at No 7 York Road with his wife Lisa Kuo Yu-chin until 2010.
minutes each concrete truck is expected to take to unload its contents - probably via vents in the swimming pool above the basement