Back to previous projects
Sinking Sydney apartment block underpinned
Our Brief
With cracks growing in its brick walls, the real estate agent of this 1920s apartment block in Sydney’s western suburbs called us for an inspection and repair solution.
Upon our arrival we observed that the apartment block, typical of its era and location, was built upon a brick foundation with brick cavity walls and a triangular shaped pitched roof. The block houses six apartments.
Wall cracks were running throughout both the external and internal walls at the rear of the building. If the cracks had been allowed to progress, the load bearing walls could have become unstable and resulted in the collapse of the roof.
Our Challenge
After a deeper inspection of the apartment block, the brick foundations and the ground on which the entire structure was built, we determined that shifting ground was the cause of the building’s wall cracks.
In fact, the building was sinking. Due to a downpipe that hadn’t been connected to a nearby storm water outlet correctly, liquids running off the pitched roof and down the pipe had been soaking into the ground for years. The soil had eroded significantly due to flooding and was the cause of the subsidence.
Adding further damage was a concrete footpath at the rear of the building that had been funnelling liquids into the base of the building for the longest time.
Our Solution
Left any longer, this apartment block would have been impossibly difficult and prohibitively expensive to repair. Upon the building owner’s request, we quickly created an action plan that wouldn’t disrupt the residents of the building and began work.
To stop the building from sinking further, we reconnected the downpipe coming off the roof to the stormwater outlet. Liquids running off the roof would no longer damage the ground on which the building sat.
We also injected GeoPoly™ into the soil to solidify the ground and stop the apartment block from shifting any further. By inserting our specialist structural steel rods into the walls we stabilised them preventing any further cracking and the risk of a collapsed roof.
The Outcome
The building owner saved a significant amount of money through our repair solutions. The residents of the apartment block are no longer at risk of having walls or a roof collapse on them. Since successfully completing our repairs, the building has remained stable. Both the building owner and the residents feel safe on the premises.

