We stabilise homes and restore foundations across Sydney with engineered, council-compliant methods. If your property shows uneven floors, cracked walls or jammed doors, we provide clear options and a fixed plan within the first inspection.
We are Underpinning Sydney. Our team has over 20 years’ experience delivering structural preservation services.
We assess first, explain the work and recommend only what is necessary. You can get free no‑obligation structural assessments, transparent fixed-price quotes and coordinated engineering reports when required.
Our methods use small access points and fast-curing materials to fill voids and compact ground. Most residential jobs finish in hours, with minimal disruption and areas trafficable quickly.
Fully licensed and insured, we prioritise safety and long-term value. Call 1300 970 930 to speak to Chris, book a site inspection or email photos for a preliminary assessment.
Key Takeaways
- We offer council‑compliant, engineered solutions for foundation issues.
- Get free no‑obligation structural assessments and fixed-price quotes.
- Over 20 years’ experience with a local, licensed team you can trust.
- Minimal disruption: small access points and quick curing work.
- We coordinate engineering reports and certify the foundation repair.
- Call 1300 970 930 to talk to Chris or send photos for a quick review.
Resin injection underpinning for Sydney homes and buildings — safe, compliant and engineered for peace of mind
For calm, certified foundation repair, we deliver fast, engineered solutions for homes and buildings.
Small access points replace large excavations. We use targeted keyholes to place material where the ground needs support. This approach densifies soil, fills voids and can gently re‑level affected areas.
The process is quick. Most jobs finish in one to two days. Treated areas are usable soon after curing, which reduces disruption to your day and garden.
We focus on safety, compliance and long‑term stability. Our services include assessment, site‑specific design, installation and coordination with engineers for certification where required.
- We design a solution that suits your site and foundation and deliver it with precision.
- Works quietly and cleanly to preserve landscaping and internal finishes.
- For buildings affected by subsidence, we restore stability and reduce ongoing problems.
- You receive transparent documentation that meets council and engineering requirements.
We keep the work predictable and communicative. You will know what will happen, when, and how long it will take.
What is resin injection underpinning and how does it stabilise foundations?
This method uses targeted, small‑diameter holes to strengthen soil beneath your home. We place an expanding polyurethane material at controlled depths to compact the ground, seal voids and gently lift settled concrete where safe and practical.
How the expanding process consolidates soil, fills voids and gently re-levels
Small holes, typically 6–16 mm, are drilled through slabs or near footings. The material is injected to depths from roughly 800 mm to 6.5 m, depending on site conditions.
Expansion occurs within minutes. That expansion compacts surrounding soil, fills voids and can produce measured lift. Treated areas are often trafficable soon after curing.
When this method is recommended over traditional concrete underpinning
- Ideal where access is tight or you want to avoid major excavation.
- Faster results and less disruption to landscaping and interiors.
- Suited to many concrete slabs, paths and footings needing ground improvement.
- Our engineers monitor levels in real time to ensure controlled stabilisation and avoid over‑lift.
| Feature | What it does | Typical use |
|---|---|---|
| Small‑diameter holes | Accesses targeted zones beneath slab | Minimal visual impact |
| Expanding material | Compacts soil and fills voids | Re‑levels settled areas |
| Engineering oversight | Controls depth and volume | Ensures compliant outcomes |
We tailor the process to your site and provide clear, engineered reporting so you know the outcome is safe and compliant.
resin injection underpinning sydney — signs you may need an assessment
Early detection prevents bigger problems. Look for small changes around the house and act quickly if you see them.

Cracked walls, jammed windows and doors, gaps at cornices and skirtings
You may notice new or widening cracks in walls or around openings. Doors or windows that stick often show movement.
Gaps at cornices and skirtings are another common sign. These symptoms suggest the structure should be checked.
Uneven or sloping floors, unlevel structures and sudden movement
Uneven or sloping floors point to a need for levelling or ground improvement beneath the slab. Sudden movement or tilt is cause for prompt review.
Sunken foundations, sinking concrete slabs, holes and voids in the ground
Local depressions, visible voids or a sunken footing are red flags for subsidence. Early repairs are usually simpler and more economical.
- New or widening cracks in walls indicate movement.
- Sticking doors and gaps at trims often signal settlement.
- Uneven floors suggest levelling or ground work is needed.
- Localised sinkholes and voids can point to subsidence.
- Sunken footings or a tilted slab require a structural review.
We offer a free, no‑obligation assessment and honest advice on practical solutions that address causes, not just symptoms. If you see any of these issues at your property, book a free assessment with our team.
Our engineering-led structural assessment and reporting process
Start your assessment with simple photos and a short description. We use these to form an initial view of site conditions and likely causes.
Get free preliminary reviews by email. Our licensed, insured team gives honest feedback and clear next steps.
What to include when you email photos for a preliminary assessment
- Wide shots of the building and the affected zone.
- Close-ups of cracks, uneven floors, and sticking doors or windows.
- Photos of slab edges, visible voids and any ground depressions.
- Notes on recent drainage changes, leaks or notable weather events.
We attend, test and measure as needed to frame the right foundation repair plan for your property. Our team documents findings, recommends the safest option and provides a transparent, fixed-price quote.
| Step | What we do | What you get |
|---|---|---|
| Preliminary review | Assess photos and description | Initial advice and likely scope |
| Site inspection | Measure, test and confirm conditions | Detailed report and costed plan |
| Certification | Coordinate structural reports | Compliance and documented outcome |
We keep communication simple and supportive. You receive a clear scope, a fixed price and a schedule that suits your family and the required work.
Underpinning Sydney’s resin injection process: precise, fast and non-invasive
We access only the zones that matter, then improve the ground beneath your home with rapid, controlled treatment.
Prepare
We mark target points and drill small holes, typically 6–16 mm. This gives surgical access with minimal impact to gardens and finishes.
Inject
We place a specialised polyurethane material at engineered depths beneath the slab. Depths are set from testing and expected loads.
Expand
The material expands within minutes. It compacts surrounding ground, fills voids and increases load capacity for immediate improvement.
Measure
We monitor levels continuously to control lift. This protects concrete and internal finishes during levelling.
- Result: Stabilisation of foundations and improved floors with precise levelling where achievable.
- Finish: Small holes are sealed neatly and we leave the site tidy.
- Speed & compliance: Many residential jobs finish within hours and treated areas are trafficable soon after. All work is documented and council‑compliant.
| Step | Purpose | Benefit |
|---|---|---|
| Keyhole drilling | Access target zones under slab | Minimal disruption to landscaping |
| Material placement | Controlled depth delivery | Engineered stabilisation and lift control |
| Monitoring & sealing | Level checks and tidy finish | Protects concrete, gives clear certification |
Resin injection vs traditional underpinning: speed, disruption and certainty
For many properties, a targeted ground stabilisation method delivers quicker results with less disturbance than large concrete pours.
Faster outcomes and immediate trafficability of treated areas
Most residential jobs finish in one to two days. Treated surfaces are usable soon after curing, so daily life continues with minimal interruption.
Minimal disruption — no large excavations and reduced noise/dust
There is no need for deep trenches or mass concrete pours. That means less noise, less dust and fewer access constraints around the home.
Clean, tidy and non-invasive with small holes sealed on completion
The process uses small access points. We seal them neatly and leave the site tidy.
- Fast install reduces on-site time and disturbance to family routines.
- Immediate usability minimises impact on work and daily life.
- No large excavations cuts noise and dust at the site.
- Inert materials remain in place to support the structure long term.
- We plan each job to limit risks and avoid unexpected problems.
We provide clear documentation, engineer certification and a written warranty where applicable. This gives you certainty about outcomes and compliance. Together, these factors make it a practical solution for many homeowners who prefer to stay in their property while works proceed.
Where resin injection works best across Sydney properties
From house porches to long warehouse slabs, we deliver engineered ground improvement that fits the site.
We work across many property types. The approach suits small homes, extensions and tight driveways where access is limited.
It is effective beneath concrete slabs, garage floors and paths. The method also treats localised soil washout and voiding beneath footings.
Commercial, strata and civil assets
We service warehouses, logistics buildings and strata common areas needing a fast return to service.
Major infrastructure such as roads, bridges and airport pavements can also benefit where downtime is costly.
- Ideal for residential homes, extensions and house driveways with restricted access.
- Targets slab‑on‑ground buildings, paths and garage floors for localised ground improvement.
- Scales to warehouses, strata sites and transport corridors to reduce interruption to services.
- Addresses soil settlement, washout and voids under footings and slabs.
| Asset | Typical issue | Benefit |
|---|---|---|
| House porch / slab | Local settlement | Fast stabilisation with minimal disturbance |
| Driveways & paths | Sunken concrete slabs | Targeted lift and compaction |
| Warehouses | Floor deflection under heavy loads | Rapid return to service and increased bearing |
| Roads & bridges | Subsurface voids and erosion | Reduced downtime and long‑term support |
Integrated foundation solutions beyond resin
We combine specialist techniques to deliver a complete foundation repair strategy for every property.
Concrete underpinning remains the go‑to when heavy loads or complex ground require deep, rigid support. We design concrete piers and pads to suit large structural loads and constrained access.
Deep support with screw piling
Screw piling provides deep bearing where soils are highly reactive or weak near the surface. It gives controlled, adjustable support with minimal excavation.
Wall crack repairs and structural stitching
We stabilise masonry with crack stitching and targeted repairs. This restores structural integrity and prevents further propagation of cracks in walls.
Subfloor ventilation, retaining wall support and reports
Subfloor ventilation and retaining wall reinforcement reduce moisture and lateral pressure risks. We coordinate structural engineering reports and certify work so outcomes meet council requirements.
- We offer concrete solutions for heavy loads or limited access.
- Screw piling provides deep capacity where shallow work will not suffice.
- We complete wall repairs and stitching for lasting durability.
- Our services include ventilation, retaining wall support and full certification.
- Every project integrates assessment, design, installation and one accountable team.
| Service | When used | Benefit |
|---|---|---|
| Concrete piers | Heavy loads, complex footings | Rigid, permanent support |
| Screw piles | Reactive or weak strata | Deep, adjustable bearing |
| Crack stitching | Masonry walls | Durable structural repair |
Our approach blends ground improvement with structural methods where required. You receive a safe, compliant solution focused on long‑term performance.
Costs, quotes and compliance — what Sydney owners should expect
Knowing the likely cost and compliance steps brings calm to any foundation repair decision.
We inspect the site and explain the scope before you commit. We provide clear, fixed-price quotes so you know total cost upfront. You can also get free no‑obligation assessments by phone or on site.
Transparent fixed-price quotes and free no-obligation site inspections
Costs vary with the extent of subsidence, access, foundation type and soil conditions. We list those factors in your quote so there are no surprises.
Many residential jobs finish within hours or over one day. Small holes are sealed on completion and treated areas are often trafficable the same day. This reduces disruption and accommodation concerns for our customers.
Council-compliant methods and certification coordinated with engineers
We coordinate structural reports and certification where required. Documentation supports any warranty and helps with future property transactions.
We schedule work to suit your household or business and explain the conditions that influence scope. For a clear comparison of methods, see our resin injection vs concrete underpinning.

| Cost driver | What we check | Typical impact |
|---|---|---|
| Extent of settlement | Level surveys and visible damage | Increases scope and total cost |
| Access and site constraints | Space around slab and landscaping | Affects labour and time on site |
| Foundation & soil conditions | Type of footing and subsoil tests | Determines method and warranty terms |
Call 1300 970 930 to speak to Chris and book your site inspection today. We give honest advice, a fixed quote and a clear schedule for the job so you can plan with confidence.
Why choose Underpinning Sydney for resin injection underpinning
Experienced technicians, clear advice and tidy execution are at the heart of our service.
20+ years’ experience, fully licensed and insured specialists
We have more than 20 years’ experience delivering foundation work across homes and small commercial sites. Our team is fully licensed and insured, so you get safe, compliant outcomes every time.
Honest assessments, minimal disruption and workmanship you can trust
We give straight advice. You receive a clear assessment and a recommended solution that fits your home and budget.
We do not upsell unnecessary scope. We plan the job to protect finishes, keep disruption low and return areas to use quickly.
We turn up on time, communicate clearly and stay accountable from first visit to certification. Speak to Chris on 1300 970 930 to book an expert assessment today.
- 20+ years’ practical knowledge across systems and structural methods.
- Licensed, insured team focused on safety and compliance.
- Minimal disruption with small sealed access points and fast cure times.
| Benefit | What it means for you | Typical outcome |
|---|---|---|
| Experience | Decades of local job knowledge | Reliable, efficient work done |
| Accountability | One team from assessment to certification | Clear documentation and warranty |
| Low disruption | Small access points and tidy finish | Short on‑site time and quick use of areas |
Conclusion
We bring clear, engineered results that stop movement and restore slab performance. Our process compacts soil, fills voids and can re-level footings using small holes and fast‑curing, inert materials. Work is quick, tidy and designed to limit disruption to your home.
Safety, compliance and documented outcomes guide every job. We match the method to ground conditions and provide engineering oversight and a written quote so you know what to expect.
To book a site inspection, call 1300 970 930 and speak to Chris, or email photos for a preliminary assessment. Learn more about our approach at what is underpinning.