1800 18 20 20Engineered Void Filling Solutions for Commercial, Industrial & Infrastructure Assets
Underground voids and sinkholes can develop without warning, compromising the stability of buildings, roads, rail corridors, warehouses, industrial facilities, and critical infrastructure. Left untreated, these hidden cavities can lead to ground subsidence, foundation movement, pavement failure, and significant safety risks.
At Rectify, we provide commercial void filling and sinkhole remediation solutions across Melbourne, Victoria, South Australia, and projects throughout Australia. Using advanced ground engineering techniques, we stabilise underground voids, restore bearing capacity, and strengthen the surrounding ground with minimal disruption to operations wherever practical. Rectify delivers engineered polyurethane injection and lightweight cellular concrete solutions for both localised voids and large underground cavities.
What Causes Underground Voids & Sinkholes?
Underground voids can form gradually over months or years before becoming visible at the surface. Understanding the cause is essential for selecting the right remediation solution.
Soil Erosion
Flowing groundwater, poor drainage, flooding, or leaking underground services can gradually wash fine soil particles away, creating hidden voids beneath foundations, roads, and slabs.
Water Main & Stormwater Leaks
Damaged water pipes, sewer lines, or stormwater systems can soften surrounding soils and transport material away, leaving unsupported cavities beneath structures.
Reactive Soil Movement
Shrink-swell clay soils expand during wet periods and contract during dry conditions. Over time, repeated seasonal movement can contribute to localised void formation and reduced bearing capacity.
Abandoned Services & Excavations
Old utility trenches, decommissioned pipelines, underground tanks, abandoned mine workings, and previous excavations may deteriorate over time, creating unstable underground spaces.
Tunnel Construction & Ground Movement
Excavation associated with tunnels, rail infrastructure, utilities, or adjacent developments can disturb surrounding soils and contribute to the formation of underground voids.
Natural Geological Conditions
In some locations, naturally occurring rock formations such as limestone can dissolve over time, creating underground cavities that may eventually collapse into sinkholes.
Our Void Filling Process
For soil treatment, injecting a range of engineered expanding polyurethane resins that target weak planes within the ground is capable of both filling the cavities and compacting the surrounding soil to re-introduce strength and bearing capacity. Where larger voids are involved, such as sink holes and mine openings, calculations can be made and flowable cellular cementitious fill can be pumped in to create a monolithic mass of light weight concrete that has a design strength and density suited to the application.
Void Filling Options:
Polyurethane injection
Utilising our advanced two-part foam, we utilise foams of differing densities and expansion rates to inject into the void. As the foam expands it rapidly fills the void, and binds to surrounding soils. Once cured it forms a hard, encapsulated soil mass.
Lightweight Cellular Concrete
A specialised polymer solution is hydrated and aerated. This lightweight foam is then mixed with grout or concrete to form lightweight concrete, as light as 300kg/m3. It is poured into voids as engineered bulk fill, and once the LCC is cured, and hardened it forms a permanent replacement to soil and a permanent fill to void. It is self-compacting, with high flowability and minimal creep.
Why Choose Rectify
Engineering-Led Solutions
Every project begins with understanding the cause of the problem, ensuring the right solution is delivered—not just a temporary fix.
Proven Structural Expertise
Trusted to deliver engineered solutions across residential, commercial and infrastructure projects.
Non-Invasive Technology
Our advanced, non-invasive technologies restore structural stability with less excavation, less mess, and minimal interruption.
Long-Term Confidence
We don't just repair today's problem—we strengthen your asset for long-term performance and lasting value.
Restore Ground Support With Engineered Void Filling
Hidden voids beneath slabs, pavements and infrastructure can compromise structural performance and increase long-term maintenance costs. Rectify delivers engineered void filling solutions that stabilise the ground, restore support and minimise operational disruption.
1800 18 20 20
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