What is Slab Lifting? Raising and Levelling Sunken Concrete
Slab lifting is a method used to raise and level sunken or uneven concrete surfaces. Over time, concrete slabs can sink due to soil erosion, improper compaction, water infiltration, or other environmental factors. Instead of completely replacing the concrete, slab lifting restores it to its original level by injecting a polyurethane material underneath to provide ground improvement and level correction.
This process is commonly used for factory and warehouse floors, driveways, transport yards, and basement and garage floors. It is a cost-effective, quick, and minimally invasive alternative to full concrete replacement.
Why Do Concrete Slabs Sink?
Soil Erosion
Water can wash away the soil beneath a concrete slab, creating voids that cause it to settle. Poor drainage, leaking pipes, and heavy rainfalls can all accelerate erosion.
Poor Soil Compaction
When concrete is first poured, the soil underneath should be well-compacted to provide a stable base. If not properly compacted, the soil will gradually compress under the slab’s weight, leading to settling and unevenness.
Heavy Loads
Excessive weight from vehicles, heavy furniture, or equipment can cause a slab to sink, especially if the soil underneath is weak or improperly compacted. Driveways and garage floors are particularly susceptible.
Weather conditions
In colder climates, water in the soil can freeze and expand in winter, then thaw and contract in warmer months. This repeated cycle shifts the soil, causing the concrete to heave or sink.
Tree Roots and Organic Matter
Decomposing organic material, such as tree roots or buried debris, can create voids under a slab as it breaks down over time. This leads to uneven surfaces and sinking.
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
Mud Jacking
The traditional method
Made of cement, sand, and limestone-based additives.
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Heavier material, which can help stabilise loose soil.
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Takes longer to cure (usually 24–48 hours).
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Requires larger drill holes (1–2 inches).
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Polyurethane Resin Injection
The modern alternative
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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Resin injection – The resin injects into the ground and expands in the ground within minutes.
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Curing time – 30 minutes. You can even use the building during the process.
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Before and After treatment
Where is Slab Lifting Used?
Slab lifting is commonly used to fix:
✔ Driveways & Sidewalks – Prevents tripping hazards and improves curb appeal
✔ Patios & Pool Decks – Restores a smooth, even surface for outdoor spaces
✔ Garage & Basement Floors – Levels indoor concrete surfaces
✔ Concrete Steps & Porches – Ensures safe entryways
✔ Light Foundation Settling – Can sometimes help with minor foundation issues

Before

After
Features & Benefits
Slab LIfting Solutions
Fast
Correction with Teretek® Resin Injection can be completed within just a few hours rather than days.
Immediately Trafficable
As soon as the repair is completed, the area can be re-opened to traffic and full use.
Non-Invasive
Repairs are performed without the need for excavation, extensive disruption.
Cost-Effective
Compared to traditional methods, our solutions are more cost-effective.

Slab Lifting
Slab lifting is an efficient, cost-effective, and durable solution for sunken concrete.
Whether you choose mudjacking or polyurethane foam injection, lifting your slab can restore safety, appearance, and functionality to your concrete surfaces.
If you’re dealing with uneven concrete, consult a professional to determine the best slab lifting method for your needs.
Mainmark provides underpinning in, Canberra, Hobart, Townsville NSW, QLD, SA, WA, Tasmania, Victoria plus the major cities of Sydney, Melbourne, Perth, Adelaide, Brisbane, Newcastle
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


