1800 623 312
Australia
36 Years In Operation
In-house Engineers
ISO Accredited
50 Year Product Warranty
Strata Units and Underpinning
Understanding the Process and Responsibilities
Strata units are part of a strata-titled property, where individual owners own their lot (apartment, townhouse, or unit) while sharing ownership of common property, such as foundations, roofs, and structural elements. When structural issues arise—especially those related to the building’s foundation, underpinning may be required to stabilise and strengthen the structure.
When is Underpinning Needed in Strata Units?
Subsidence or Foundation Failure
- New buildings or additions often experience slight shifts as they settle into the ground.
- Minor, hairline cracks in the mortar or bricks may appear but usually do not pose a threat.
Poor Initial Construction
If the original foundation was not built to withstand the local soil conditions, underpinning may be needed to correct the issue.
Water Damage & Erosion
Persistent water leaks, poor drainage, or flooding can weaken soil beneath a building, leading to foundation issues.
Tree Roots
Large tree roots near a building can absorb moisture from the soil, causing shrinkage and weakening the foundation.
Nearby Excavation or Construction
When construction occurs near a strata building, vibrations or soil removal can affect the foundation’s integrity.
Additional Load on the Structure
If extensions or renovations add weight to the building, the foundation may require underpinning to handle the extra load.
Mainmark also provide the following in Australia: wall crack repairs, sinking floor repair, Concrete slab repair, sinking foundation repair, underpinning, ground improvement, re-levelling, subsidence repair, void filling and slab lifting
Strata Underpinning
Who is Responsible for Underpinning in a Strata Scheme?
The responsibility for underpinning work in a strata property depends on whether the issue affects common property or an individual lot:
Common Property Responsibility (Owners’ Corporation)
- In most strata schemes, the foundation of the building is considered common property.
- The owners’ corporation (or body corporate) is typically responsible for maintaining and repairing common property, which includes the building’s structural integrity.
- If the underpinning is necessary due to foundation failure affecting the entire building, the costs and arrangements usually fall under the owners’ corporation’s responsibility.
Lot Owner Responsibility
- If the foundation issues only affect a single unit and are due to something within the lot owner’s control (e.g., unauthorised renovations, neglect, or specific damage caused by the owner), they may be responsible for the repairs.
- If underpinning is required due to an extension or alteration made by a unit owner, they might be liable for the costs.
Shared Responsibility
- In some cases, the costs may be shared between the owners’ corporation and individual owners, particularly if the underpinning benefits both common and private property.
Signs of Subsidence
Underpinning in strata units is a complex issue that involves structural engineering, strata governance, and financial considerations. It is crucial for owners and the owners’ corporation to assess the situation carefully, determine responsibilities, and follow proper approval procedures to ensure that the building remains safe and structurally sound.
Consulting with a strata manager, engineer, and legal expert is highly recommended if you’re facing an underpinning issue in a strata property.
Features & Benefits
Mainmark’s Solutions & Technologies
Fast
Our technologies have fast curing times and treated areas can be used immediately or without the delays compared to traditional repair methods.
Environmentally Inert
Our technologies use an inert material that is non-toxic and does not leach into the environment or affect the treated area.
Non-Invasive
Our solutions are of surgical nature compared to traditional methods.
Cost-Effective
Compared to traditional methods, our solutions are more cost-effective, with minimal disruption to the area.
Get a FREE quote
Arrange a site assessment in 3 simple steps:
Step 1
Submit your enquiry using our online form. Include a brief message about the type of foundation issues you are experiencing.
Step 2
Our friendly customer service team will be in touch to schedule a site assessment that suits you.
Step 3
One of the Mainmark experts will visit your home or property, assess the damage, and ascertain the likely cause. They will establish the approach needed, creating a plan specific to the needs of your building and provide you with a detailed quote.
© 2025 The Mainmark group of companies. ‘Mainmark®’, ‘Terefil®’, ‘Terefirm®’ and ‘Teretek®’ are trademarks of the Mainmark group of companies.
Mainmark Ground Engineering Pty Ltd
ABN: 51 606 182 503
