Column Cracks in Older Buildings: Assessment and Reinforcement

A skyscraper in New York currently being converted into a mixed residential-commercial project recently had one of its structural columns deform. The developer was quick to stress there is no risk of collapse, but the incident has plenty of homeowners here wondering: could a similar structural issue turn up during their own old-building renovation? As a design team that regularly works on old-building renovations in Hong Kong, we want to share an honest look at the site-level structural constraints and the engineering solutions used to address them.

Common Structural Constraints in Hong Kong Old-Building Renovations

Some residential buildings in Hong Kong from the 1960s and 70s show common issues: thin floor slabs, corroded reinforcement bars and columns that have shifted out of position. These problems become especially risky during large-scale renovations, such as knocking down a wall to open up the living room, where a structural wall carries a real chance of affecting the building’s stability.

The Reality of Engineering Solutions: Not Everything Is Permitted

We regularly have to explain clearly to homeowners that structural changes cannot be made at will. Before a structural wall is removed or the structure is altered, for instance, the work should be assessed by an Authorised Person or structural engineer and approved by the Buildings Department, and any new steel column has to land on an existing column or ground beam. It cannot simply be placed on a concrete slab. Site teams use temporary shoring to keep the works safe during construction, much like the approach used on the New York project. Hong Kong’s high building density and tight sites make things harder, but with enough advance planning, most structural issues do have a workable solution.

If you would like to know more about the structural considerations involved in renovating an old building, please contact our team.