A two-storey brick home situated along the banks of the Woronora River in southern Sydney had been experiencing ongoing settlement due to adverse ground conditions. The home was built approximately 30 years ago on soil comprised of sand, silt and clay associated with the Woronora River. Over time, the poorly compacted ground had caused the property to sink by approximately 200mm.
The northern side passageway of the home had visible deformations throughout with an obvious tilt in the first-floor hallway that sloped down like a ramp. Additionally, a large 6mm wide stepped crack was observed in the home’s western brick wall. The damage was particularly concerning for the owner who had recently undertaken extensive renovations, including laying new tiles and installing underfloor heating. Despite the property’s sought-after riverside location and renovations, the owner was concerned the subsidence would reduce the home’s current and potential market value.
Attempts to re-level the home a few years prior by a 3rd party had proved unsuccessful as they were unable to achieve the degree of lift required to reinstate the home back to its intended levels. The owner engaged Mainmark to deliver a long term solution using its proprietary JOG Computer-Controlled Grouting solution, which was identified as being one of only a few products available in Australia that could provide the guaranteed lift that the client was seeking.
The client required the home to be re-levelled by 200mm, returning it to its original level. The owner was also seeking a permanent, long-term solution that would prevent the home from future settlement.
Prior to commencing the project, the property owner commissioned a geotechnical report to investigate the site’s subsurface conditions and validate the suitability of Mainmark’s JOG Computer-Controlled Grouting to address the pre-existing long term ground settlement and consolidation.
The geotechnical engineers confirmed that the soils subjected to the building’s load configuration had undergone their expected long term settlement and a lifting and re-levelling grouting technology suitable for these soil conditions would be ideal.
Mainmark’s JOG Computer Controlled Grouting is an advanced, award-winning technology that raise sunken foundations and re-levels structures using an extremely precise process that includes multi-point computer-controlled sequenced injections. JOG is predominantly used on large scale commercial and industrial projects, making this one of the few times the solution had been specified for a residential property in Australia (although it has been used extensively in New Zealand to re level earthquake affected homes).
The low-viscosity JOG grout solution was applied through more than 60 injection points which were positioned in a grid pattern across the ground floor of the property. This helped to ensure that the house was re-levelled very gently and evenly, reducing the risk of any possible concentration around individual pressure points. The application process followed the exact engineered specifications to re-level the building.
On completion of the project, the home was returned to its original level without causing any undue stress to the structure. The owner also received the necessary assurance that the home’s foundations were unlikely to experience future movement.
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JOG Computer-Controlled Grouting Re-levels Waterfront Property
JOG Computer Controlled Grouting
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Teretek® Re-levels Home, Closing Cracks in Walls and Preventing Further Subsidence
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