Loose gravel has been discovered within a concrete platform at a public housing estate in Sha Tin. The floor of an apartment toilet area on the third floor of Shing Chuen House at Shui Chuen O Estate was found to be filled with gravel after it was opened up.

Sha Tin district councillor Yau Man-chun said that “it was so loose that you could use your own hand to dig it out.”

Apple Daily reported that the home owner, surnamed Chung had received complaints from the Housing Authority over the past two months notifying him that there was a need to check his flat as there was water leaking from the ceiling downstairs. The Housing Authority conducted inspections, eventually opening up the floor to find that there was a big hole underneath the tiling.

The waterproof layer at the bottom had cracks, and the steel reinforcing bar as well as the electric wiring and piping could be seen clearly.

Tsim Chai-nam, a building inspector, told the newspaper that the situation was a rare problem in Hong Kong, and said that “if the concrete was 150mm thick, and 50mm became powder, then it would only really be 100mm thick, and the platform may not be able to support [weight].” He added powdering happens because the ratio of water to gravel is not right, or when there are foreign objects added to the mix. He said that the only way to solve the problem was to lay the concrete again.

Shing Chuen House in Shui Chuen O Estate. Photo: Apple Daily.

The Housing Authority told Apple Daily that after preliminary investigations, a worker may have opened up the floor for repairs and did not properly close it up, leading to this incident. It added that the toilet was not a prefabricated part. China State Construction, which built the estate, said in a report that it had used over 60,000 prefabricated parts, including 4,300 prefabricated toilets for construction.

The Authority told HKFP said that this was an “individual case” and there are no safety problems, stating that the case is now closed.

Shui Chuen O Estate has been embroiled in a number of controversies since tenants moved in from April 2015. It was involved in the lead scandal last year, when water at several housing estates was found to contain lead levels over the safety limit. The estate mall was also found to have a leaky roof during heavy rain.

China State Construction told HKFP that it cannot comment without the consent of the Housing Authority.