We stabilise and restore affected foundations fast and safely, offering clear solutions and fixed-price quotes to homeowners and property investors. Call 1300 970 930 to speak to Chris or book a site inspection for a free, no-obligation structural assessment.

We are a licensed company of structural preservation specialists with 20+ years’ experience. We deliver resin injection, concrete underpinning and screw piling services that address building movement and related problems.

We prioritise safety, compliance and permanent results. Our team uses targeted resin injection and controlled lift to consolidate soils, re-level slabs and complete most residential jobs within hours with minimal disruption.

We assess your home, explain options simply and coordinate engineering reports and certification so you stay compliant from start to finish. Email photos or call to arrange an inspection and a transparent fixed-price quote.

Key Takeaways

  • Free site assessment and fixed-price quote to start.
  • Licensed specialists with 20+ years’ experience.
  • Resin injection and piled solutions with minimal disruption.
  • We coordinate engineering reports and council compliance.
  • Fast, single-day residential works where suitable.
  • Call 1300 970 930 to speak to Chris or email photos for a quick review.

Trusted chemical underpinning and ground engineering for Sydney homes

We deliver trusted ground engineering services that preserve foundations and reassure homeowners. Our mission is to protect structures with safe, compliant and engineering‑led work across local suburbs.

Non‑invasive resin injection often lets you remain at home during works. Many residential re‑levelling jobs finish within hours or a single day, depending on soil and building conditions.

Advanced monitoring manages controlled lift and keeps outcomes stable. We tailor each plan to local soils, from reactive clay to sandy lenses.

  • Minimal disruption: planned work to reduce time on site.
  • Engineering mindset: certification and safety prioritised.
  • Clear scope and fixed pricing: defined deliverables for clients.
  • Full supervision: staged checks, documentation and council coordination where required.

To discuss your property and book a site inspection, book a site inspection with our company. We bring years of experience so you can make confident decisions about construction and repair.

Chemical underpinning Sydney

Focused polyurethane resin injections strengthen weak ground and lift settled building elements. This method uses small drill points to inject expanding resin beneath footings. The resin flows into fissures and voids, compacts loose soils and cures to form a stable, load-bearing mass.

When resin injection is appropriate

We recommend this solution for localised subsidence, sunken slabs, voids beneath slabs and uneven floors. It suits differential settlement and rocking slabs where a fast, low‑impact fix is needed.

Safety, compliance and certification

We are licensed and insured. An engineering assessment confirms suitability. We monitor lift with live readings and record as‑built data for certification and council needs.

Environmentally responsible resins

Chosen resins are non‑toxic and become inert after cure. Injection depths vary from about 800 mm to 6.5 m to reach the problem horizon. Work is low‑noise and many residential jobs finish within hours, letting you stay in your home.

  • Guided injection densifies soils under footings.
  • Controlled lift re‑levels sunken slabs.
  • Small access points limit landscaping impact.
  • We provide product details, monitoring and certification on completion.

Signs your foundation needs attention and common Sydney causes

Small changes inside your home can point to larger problems in the ground beneath it. Noticing symptoms early makes repair simpler and less costly.

A close-up view of a deteriorating foundation on a Sydney home, focusing on the cracked and uneven ground. In the foreground, show dense patches of grass and soil where the earth has shifted, highlighting signs of subsidence. In the middle ground, include a section of the foundation with visible fissures and peeling paint, showcasing the effects of moisture and age. The background features a tree with roots exposed, indicating potential damage to the foundation from nearby vegetation. The scene is illuminated by warm, natural sunlight casting gentle shadows, creating an atmosphere of urgency and concern. Use a low-angle perspective to emphasize the foundation’s flaws while capturing a clear blue sky above, symbolizing hope for restoration.

Practical symptoms to look for

Settlement often shows as visible cracks in walls near corners or openings.

Jammed windows and doors indicate movement in frames and lintels. Sloping floor planes and gaps at skirtings are signs of uneven support below.

Common causes in our area

Reactive clay cycles between drought and soak and can cause subsidence. Water from leaking pipes or poor drainage softens soil and accelerates movement.

Tree roots draw moisture and reduce bearing capacity near footings. Nearby construction and vibration can create or enlarge voids beneath slabs and other buildings.

Why acting now matters

Early assessment limits progressive damage to slabs, walls and retaining structures. A prompt inspection gives a clear plan tailored to your area and house.

  • Cracks in walls often align with settlement.
  • Jammed windows and doors show frame movement.
  • Local sinks in slabs can signal washout or consolidation.

To learn more about local risks and solutions, see our foundation failure in your area.

Selecting the right underpinning method for your property

The best foundation solution matches site conditions, building loads and access constraints.

Resin injection gives fast stabilisation and re‑levelling with minimal excavation. It suits sunken slabs and localised movement. Works often finish in a few hours and cause little disruption.

Concrete piers add permanent support where heavy masonry or point loads demand deeper intervention. This traditional option suits larger loads and where new piers are required.

Screw piling provides engineered deep support on soft or variable ground. It is ideal for filled sites and where vibration limits other construction methods.

We explain trade‑offs clearly. Cost, access and programme vary between solutions. We tailor designs to your building type, soil profile and target performance.

  • We recommend resin when speed and low impact matter.
  • Choose concrete for heavy loads and structural piers.
  • Screw piles deliver deep, reliable support in soft ground.
  • Independent engineers review and certify designs for your property and council.

Our expertise and coordination with engineers and councils mean you get a compliant, durable foundations strategy from a trusted company.

Our engineering‑led process for stable, long‑lasting results

Our engineered approach focuses on clear diagnosis, targeted repairs and verified outcomes for lasting stability. We promise honest assessments, no upselling and minimal disruption on every job.

Free no‑obligation assessment and clear diagnosis

We start with a free structural assessment. Our inspection explains the problems plainly and recommends only necessary work.

That means you get an honest plan, not extra work.

Targeted works with small drill points and controlled lift

We prepare by drilling small holes in affected zones. Then we inject polyurethane resin at targeted depths to compact the ground and lift slabs.

This controlled injection addresses local subsidence quickly. Most residential jobs finish within hours, keeping disruption low.

Verification, records and certification

We monitor levels live to manage outcomes and protect your foundation. Holes are sealed with non‑shrink grout on completion.

We supply as‑built records and coordinate certification so your project closes with clear documentation.

  • Free assessment and straightforward diagnosis.
  • Small drill points to protect finishes and landscaping.
  • Controlled injection and live monitoring for safe lift.
  • We select the right product and depth for local ground.
  • We record as‑built data and help with certification on close.
  • Clear communication during the getting job and tidy site handover.
Stage What we do Typical outcome
Inspect Free structural assessment and honest diagnosis Clear scope, no upsell
Prepare Drill small points and set monitoring Low impact to finishes
Act Targeted resin injection and controlled lift Rapid re‑levelling of slabs
Verify Live monitoring, seal holes, as‑built records Certified results and tidy site

Pricing, timelines and disruption

Transparent quotes and efficient scheduling keep disruption low while we restore your slab. We give fixed-price quotes after a free assessment so you know cost and time up front.

A detailed and modern pricing table displayed on a large, sleek screen in a well-lit conference room, with a focus on metallic textures and crisp lines. In the foreground, a stylized calculator and a pen are placed atop a polished wooden table, suggesting a meticulous approach to budgeting. In the middle, the pricing table shows various tiers with icons representing structural integrity services, highlighting timelines with subtle arrows for clarity. In the background, blurred silhouettes of professionals in business attire engage in discussion, adding to the atmosphere of collaboration and planning. Soft natural light filters through large windows, creating a warm, focused mood, while the lens captures the scene from a slight angle to enhance depth.

Clear fixed-price estimates

Many single-day resin projects sit between $5,000 and $15,000. We explain what is included and any allowance for concrete or patching.

That way you see expected results and limits before the job starts. We also outline any product warranties and workmanship guarantees you can expect.

Fast turnarounds with minimal disruption

Most residential projects finish in hours. Work is low-noise and non-invasive, so you can usually stay at home while we work.

  • We protect access, finishes and services during the job.
  • Resin cures quickly, restoring slab and floor use soon after completion.
  • We plan around your schedule to keep interruption to a minimum.
  • Documentation, certification and handover occur when the job is done.
  • We remain available if you have questions after completion.

For a detailed cost guide and to book a free assessment, see our underpinning cost guide. We aim to deliver reliable services and clear outcomes for your house and ground works.

Beyond underpinning: integrated repairs and prevention

We combine foundation stabilisation with practical repairs so problems do not return. Our work protects finishes and reduces future disruption.

Wall crack repairs and re‑pointing

After the foundation is stabilised, we repair cracks and re‑point mortar to restore walls and prevent moisture ingress. This step protects internal and external finishes.

Subfloor ventilation and drainage upgrades

We design ventilation to reduce trapped moisture under homes. Upgraded surface and roof water management keeps water away from foundations and lowers recurrence risk.

Retaining wall support and stabilisation

On sloping sites, we provide engineered support to stabilise retaining structures. This reduces lateral loads and protects adjacent building elements.

Engineering reports and certification

We coordinate structural reports for compliance and insurance. Documentation after works ensures your property meets regulatory and insurer expectations.

  • We sequence repairs after movement is arrested to protect finishes.
  • Our solutions address causes, not just symptoms, for durable outcomes.
  • We advise on maintenance to keep foundations stable over time.
Service What we do Key benefit
Wall repairs Crack stitching, re‑pointing and finish restoration Restores appearance and prevents water ingress
Ventilation & drainage Subfloor vents, French drains and roof runoff control Reduces moisture, limits soil movement
Retaining support Engineered bracing and batter repairs Stabilises slopes and protects foundations
Reports & certification Engineering assessments and compliance documentation Meets council and insurer requirements

Why Underpinning Sydney: assurance built on experience

We pair engineering rigour with a caring approach to protect your home and investment. Our team brings practical local knowledge and clear communication to every job.

20+ years’ experience, fully licensed & insured, Sydney specialists

More than 20 years of experience means we understand local soils and building types. We are fully licensed and insured and operate as trusted specialists in this region.

Minimal disruption, council‑compliant methods and workmanship warranties

We use non‑invasive techniques so you can often remain in your home during works. Our methods meet council standards and come with documented workmanship assurance.

We provide a clear warranty and as‑built records to support compliance and future sales or insurance needs.

Clear communication: speak to Chris on 1300 970 930

We keep you informed from first enquiry to final certification. You can call 1300 970 930 to speak to Chris directly.

Send photos for a prompt preliminary assessment and straightforward advice. We value long‑term relationships with our clients and stand behind our services with professional accountability.

  • We bring more than 20 years of local experience to every project.
  • We are fully licensed and insured, and we work to council standards.
  • We focus on minimal disruption and safe delivery at your home.
  • We provide workmanship assurance supported by documentation.
  • We communicate clearly from first enquiry to completion.

Conclusion

A clear, engineered plan turns worrying movement into a manageable repair pathway. We stabilise ground and foundations using resin injection, concrete and screw piling where each suits best.

Many resin jobs finish within hours. Injection depths typically range from 800 mm to 6.5 m. Single‑day projects often sit between $5,000 and $15,000, depending on scope.

We focus on safety, compliance and getting the job done with minimal disruption. We fix slabs, repair walls and address voids and moisture at source so problems do not return.

Call 1300 970 930 to speak to Chris, book a site inspection or email photos. Learn more about our approach at what is underpinning for peace of mind and certified results.

FAQ

What is resin injection and how does it stabilise foundations?

Resin injection is a controlled process where a specialised polyurethane resin is injected into voids and weak soils beneath a slab or footing. The resin expands to fill voids, densifies loose ground and lifts settled concrete. The result is rapid load transfer to improved ground and a durable, inert void‑fill that limits future movement.

When is resin injection the right solution for my home?

Resin works best for subsidence, sunken slabs, localised voids and uneven floors where soils can be consolidated from small access points. It suits most single‑storey and light‑to‑medium load situations. For heavy structural loads or deep unstable layers, we may recommend concrete piers or screw piles after an engineer’s assessment.

How do I recognise foundation problems in my Sydney property?

Look for cracks in walls or render, jammed or sticking doors and windows, sloping floors, gaps to skirtings and cracks above windows. These symptoms often indicate differential movement and should prompt a timely inspection to stop progressive damage to slabs, walls and retaining structures.

What local soil issues cause subsidence around Sydney?

Reactive clay, drought‑soak cycles, leaking water services, poor drainage and tree roots are common causes. Coastal sand pockets and reclaimed fill can also be problematic. We explain the likely cause during our assessment so you get a tailored, long‑term solution.

Are the resins safe for my family and the environment?

Yes. We use industry‑approved polyurethane resins that are non‑toxic after cure and inert in place. Delivery is low‑impact with small drill points and controlled injection volumes, minimising disruption and environmental footprint.

Do you provide engineering reports and council compliance?

We coordinate independent structural engineering reports, provide as‑built documentation and obtain any required approvals. All work is licensed, insured and delivered to meet council requirements and building standards.

How long does a typical resin injection job take and will we need to leave the house?

Many residential resin jobs are completed within hours to a single day. Most work is carried out with the home occupied. We plan works to minimise disruption and explain timing clearly in the fixed‑price quote.

What will the quote include and how much does it cost?

Our quotes are transparent, fixed‑price and based on an on‑site assessment. Typical single‑day residential resin projects commonly range from ,000–,000, depending on access, extent and site conditions. The quote includes materials, labour, monitoring and certification where required.

Will resin injection lift my slab back to level permanently?

Resin frequently restores slab level and supports the structure long‑term by filling voids and stabilising soils. We verify results with live monitoring and provide as‑built records. In some complex cases, a combined approach with piers or drainage works is recommended for permanent stability.

What about concrete underpinning or screw piles — when are they needed?

Concrete piers suit heavier loads and when deep, firm bearing strata are required. Screw piles are ideal where soils are soft or variable but deeper engineered support is needed. We assess and recommend the right technique based on engineering reports and site conditions.

Do you repair cracks and restore finishes after structural work?

Yes. We offer integrated repairs including crack stitching, re‑pointing, render repair and cosmetic reinstatement. We can also upgrade subfloor ventilation and drainage to prevent future moisture‑related movement.

What warranties and guarantees come with your repairs?

We back our workmanship with warranties and provide product warranties where applicable. All work is performed by licensed specialists and documented with warranties and certification to give you peace of mind.

How soon should I act once I notice movement or cracks?

Prompt action prevents progressive damage. Early assessment helps choose the least invasive, most cost‑effective solution. Contact us for a free, no‑obligation structural assessment and honest diagnosis without upselling.

How do you monitor and verify that the repair has worked?

We use live monitoring during injection and record levelling results. Post‑work verification includes as‑built reports and, where needed, ongoing monitoring to confirm stability. These records form part of your certification package.

How can I get a preliminary assessment or quote?

Send photos of cracks, windows, floors and the surrounding ground to our team, or call 1300 970 930 to speak to Chris. We provide an initial view and arrange a free on‑site assessment to prepare a clear, fixed‑price quote.
Scroll to Top