Why Mainmark has the best House Underpinning Solutions ?
Mainmark has raised, re-levelled and re-supported thousands of homes and other residential buildings since 1989. Our ground improvement and level correction methods lift subsided slabs and re-level sunken floors.
How much does Underpinning Cost?
Get a FREE house assessment in 3 simple steps:
Step 1:
Submit your enquiry using our online form. Include a brief message about the type of underpinning foundation issues you are experiencing.
Step 2:
Our friendly customer service team will be in touch to schedule a site assessment that suits you to discuss cost of underpinning a house.
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.
The lowest underpinning cost guaranteed
Resin Injection vs Underpinning
What are the benefits of Teretek Resin injection compare to historical Underpinning process?
House Underpinning
Features |
Benefits |
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Excavation | Heavy machinery is required to dig large holes to depths often up to 3 metres. |
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Soil removal | large quantities of dirt and rock are loaded onto dump trucks and transported away from the site. |
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Pouring concrete | filling the holes or “piers” with concrete can be complex and logistically challenging depending on the site. |
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Curing time | concrete can take several days to set. |
House Resin Injection
Features |
Benefits |
|
---|---|---|
Tiny holes | Teretek is applied through keyholes, typically 6mm to 16mm in diameter. |
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Clean and Quiet | The process is clean and quiet, has minimal impact on residents. |
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Pouring concrete | The resin injects into the ground and expands in the ground within minutes. |
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Curing time | One day! You can even use the building during the process. |
How Mainmark's Teretek® Resin Injection Solution Repairs Underpinning?
How we get your home back to level in as little as a day.


Step 1: Our technicians drill small holes around the problem area
Strategically-placed injection holes are barely visible, with work typically carried out like key-hole surgery from the outside of the house through 16mm diameter tubes, reducing to as little as 6mm in diameter if applied from inside the home.


Step 2: Polyurethane resin is injected and lift is monitored
Teretek expanding polyurethane resin mix is injected through very small tubes into the ground of the affected area. Our technicians closely monitor the lift with real time laser level monitoring.


Step 3: Unique two-in-one solution improves ground bearing capacity and fills voids
When Teretek is injected into the ground it’s components mix together and expand by chemical reaction, which strengthens the ground, re-levels the building and fills voids quickly and with minimal disruption.


Step 4: Building is brought back to level, wall cracks close-up and floors are lifted
Benefits of Teretek:
✓ Ground beneath building is strengthened
✓ Soil is compacted
✓ Voids in the ground are addressed
✓ Your home becomes structurally sound, helping secure its future
Unlike many level correction processes, our methods are very resident-friendly.
We use non-invasive techniques, likened to keyhole-surgery, so we don’t tear up floors and excavate ground (the injection holes can be as small as 6mm). |
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We are very quick – many jobs are completed in a day. |
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Residents can usually stay in the home and may not even need to move much furniture. |
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We help strengthen the future of the house – the methods we use strengthen weak ground, so your home generally becomes level, crack-free and more stable. |
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We don’t make mess – there’s no concrete dust, water or anything else to clean up. |
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We don’t cause further damage; in fact cracks generally close up and windows and doors become usable. |
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We provide peace of mind – our resin injection method is backed by an industry leading 50 year product warranty. We are also a licenced builder that provides Home Warranty Insurance/Builders Warranty Insurance where required. |
Teretek® Strengthens Foundation, Raises and Re-levels a Family Home
The homeowner stated that, “the Mainmark team was very friendly and hard working. They have also given us the assurance that the house is now stable. I’m very happy with the work that they did.”
Mainmark’s engineered resin injection solution, Teretek®, was applied beneath the external walls at the back of the home in a U-shape formation, to strengthen the ground beneath the foundations, and re-level and re-support the home.
This successful project was completed in a single day and the fast completion time minimised disruption to the occupants. The solution has also provided the family with peace of mind knowing that their home is now stable and liveable into the future.
JOG Computer-Controlled Grouting and Teretek® Resin Injection Combined to Save House from Demolition
My dealings with Mainmark were nothing but professional. They ensured all aspects of the work, including any queries I had, were thoroughly explained so all parties were aware of the process and that the outcome would be achievable prior to the project commencing. This gave the owner the reassurance and confidence that the home could be stabilised and that there would be no surprise costs or variations to the work.
Mainmark successfully re-levelled the entire length of the three affected side walls, lifting the slab to within +/- 10mm of its target RL without needing soil removal. Mainmark is uniquely positioned to deliver projects of this size and scope utilising two complimentary, proprietary non-invasive solutions. The project took Mainmark a total of only 14 days to complete and was delivered within budget to the client’s complete satisfaction.
We're happy to have helped
“S____ who was leading the Mainmark team onsite is a credit to your company. He talked us through the job, kept us informed of progress and spoke about issues along the way that he resolved in conjunction with your engineer. The team of 3 you sent were probably the most trustworthy, friendly and professional of trades we have come across. They were also respectful of the property and mindful of the need to keep the disruption to a minimum.”
Tim, Caulfield South, VIC. July 2021.
“B____ visited our site and was informative, thorough and helpful. On this particular occasion Mainmark was not able to assist with our problem. This was explained to me and I was directed to the appropriate engineering service. Very professional, would recommend.”
Michelle, Bayswater, Auckland, NZ. July 2021.
“The people we dealt with were polite, timely and kept us informed at all times. All questions we posed were answered without any hesitation They presented as true professionals, completed the work efficiently and left our property in a very tidy state.”
Ken, Boondall, QLD. June 2021
Underpinning FAQ
What is a underpinning approach?
Underpinning is the reinforcing of an existing building foundation. It is required when the original foundation is no longer strong enough to support the house. This is usually a result of a change to the soil structure, whether due to the type of soil or some external influence on the soil.
What are the disadvantages of concrete underpinning?
It involves excavation, which can be messy. If excavation is required under the existing foundation, you may be unable to use parts of your home. It is labour intensive, which can increase costs for larger jobs. The deeper soil is not always stronger.
Why does underpinning devalue a property?
Underpinning can devalue a property by around 20-25%. It can be difficult to find a buyer for a property that has been underpinned, as individuals can be put off by the risk of future subsidence, hence the reduction in value.
Can you sell a house that has been underpinned?
Even though it’s not ideal, the good news is, it is possible to sell your home even if it has subsidence ‒ there are just a few things you might want to do first. Check out our tips below on how to sell your property if you’re experiencing this problem.