Hidden Bomb in our Beloved City

Hong Kong, a well developed international city famous from its dense population and high-rise buildings, is not as prosperous as it looks like. Facing a rapidly aging population and buildings, more and more residential buildings are left deteriorating without maintenance. Multi-ownership of a building also make all the necessary repair and maintenance work difficult to be timely proceed:- Numerous meetings and procedures have to be gone through to reach a consensus for carrying out works among flat owners.

We have been engaged by Client to assess the condition and propose remedial work to an aged building (age over 60 years) in the Jordan District. The subject building is a domestic building of 3-story in height, and is constructed in the 1950s in column-beam-slab structure in reinforced concrete.

From our visual inspection, extensive concrete spalling and cracks were noted at the structural members of the building, while hollowed rendering was evident on the external walls. Waterproofing on roof was obviously malfunctioning. Serious sign of seepage was noted on walls and at window surrounds. Although further random testings suggested the compression strength, chloride ion content, etc. of the reinforced concrete are generally acceptable - The building was in dilapidated condition and a substantial repair work was urgently needed.

Steel props were adopted to temporarily support the building throughout the work to prevent sudden collapse. and the repair work was designed to be conducted in top-down sequence and from load-bearing members to non-loadbearing members in order to make sure no building structure would be further weakened before the existing ones are repaired and/or strengthened.

After a few months of hard-work and intensive site supervision, the building was finally reinstated and suitable for rehabilitation. I believe this kind of buildings are scattering around the city, which would undoubtedly pose grave safety risk to the public. When there is still no plan from the Government for a systematic redevelopment of the district/ city, education to enhance the public's understanding of building repair, maintenance, rehabilitation and retrofitting is necessary. It's time to roll up our sleeves and make our beloved city safe again!