We explain how rising water under your slab affects stability and what to do next.
We are Underpinning Melbourne — Structural Preservation Specialists. Our mission is to save homes from foundation failure with a calm, engineering-focused approach. We prioritise safety, structural integrity and VBA-compliant certification.
Melbourne soils vary from clay to sand and basalt. Geotechnical investigation defines soil, rock and water at your site. Reports follow AS 1726 and guide slab and footing design to AS 2870.
Our process covers investigation, repair and certification. We match the design to your building and ground conditions. Methods like screw piling (AS 2159) give stable load transfer with minimal disruption.
Book a free, no‑obligation structural assessment so we can give a clear, fixed‑price plan. Call Chris: 1300 970 930 or Email Chris: chris@underpinning-melbourne.com.au.
Key Takeaways
- We deliver an engineering-first path from investigation to certification.
- Site testing defines soil and water, informing AS-compliant design.
- Proven methods like screw piling limit disruption and protect the ground.
- We handle council requirements, DBI where needed, and traceable reports.
- Free assessments, fixed-price quotes and honest, no‑upsell advice.
Understanding high groundwater Melbourne foundations and why it matters now
A clear geotechnical picture prevents guesswork and keeps your property safe.
Melbourne’s subsurface varies from clay and silt to sand and basalt. Each soil type responds differently to moisture. Clay swells when wet and shrinks when dry. Sandy and silty layers drain quickly. Basalt can be fractured and shallow.
When the water table sits near the slab, bearing capacity drops and footings soften. Seasonal wet‑dry cycles cause differential movement. Over time you may see cracking, jammed doors and uneven floors. Proper site testing removes doubt.
Standards, compliance and our approach
Geotechnical work follows AS 1726. Residential design must meet AS 2870. We prepare permit‑ready documents and certify works to VBA standards.
| Aspect | Why it matters | What we do |
|---|---|---|
| Soil type | Controls movement and bearing capacity | Boreholes, SPT/CPT and lab testing |
| Water level | Affects softness and heave risk | Groundwater checks and tailored design |
| Compliance | Council and VBA expectations | Permit documentation and certification |
We prioritise stability and compliance. We explain risk plainly and recommend only what you need. For an upfront estimate use our cost calculator. Call Chris: 1300 970 930 or Email Chris: chris@underpinning-melbourne.com.au.
How to assess risk and diagnose groundwater-related foundation issues
Begin with facts: detailed checks at the property reveal how water and soil affect stability.
On-site investigation gives clear data for an engineered response. We start with a visual inspection of structures and record visible issues like stepped brick cracks, sticking doors and sloping floors.
On-site geotechnical investigation
We organise boreholes and use SPT and CPT to profile ground layers and measure resistance. Ground water levels are logged during drilling.
Samples go to a lab for moisture, density, plasticity and bearing tests. The report classifies the site under AS 1726 and informs footing design to AS 2870.
Early warning signs at home
- Stepped cracks in brickwork and diagonal wall cracks.
- Doors and windows that bind or gaps that appear.
- Uneven or sloping floors and damp smells in subfloors.
| Check | What it shows | Our action |
|---|---|---|
| Site inspection | Visible damage, service locations | Record, photo, plan safe access |
| Boreholes & tests | Soil profile, water level, strength | Geotechnical report and design input |
| Lab results | Plasticity, density, bearing capacity | Specify footing design and ground work |
| Engineering summary | Risk, requirements and program | Permit-ready docs and fixed-price quote |
We offer free, no‑obligation structural assessments. We coordinate engineering reports, provide transparent fixed-price quotes, and are VBA registered and insured. Call Chris: 1300 970 930 or Email Chris. To act quickly, book a site inspection or email photos for prompt advice.
Choosing the right fix: underpinning, screw piles, restumping and ground improvement
Choosing the right repair starts with matching the method to your site data and risk profile. We balance permanence, disruption and cost so you get the best long‑term outcome.
Concrete underpinning vs resin injection
Concrete underpinning increases depth and bearing area. It suits reactive clay or softened bearing where structural uplift or loss of capacity exists.
Resin injection can fill voids and lift slabs. We only use it where capacity is adequate. It is not a substitute for structural underpinning.
Restumping and reblocking for timber floors
We replace failed timbers with concrete, steel or screw stumps. This restores level floors and long‑term structure performance with minimal fuss.
Screw piling and ground improvement
In water‑logged sites, screw piles use high‑grade shafts and helices to transfer load with little excavation. Installations comply with AS 2159 and include torque and depth logs for traceability.
When soil requires stiffening, we specify soil mixing, stone/sand columns or jet grouting. The chosen type depends on project goals and ground behaviour.
Engineering, permits and cost certainty
Our engineering reports align with AS 1726 and AS 2870. We provide fixed‑price quotes, arrange permits and organise DBI where required. Call Chris: 1300 970 930 or Email Chris. For a comparison of options see restumping vs underpinning.
Conclusion
Our team turns measured site data into clear, compliant repair plans you can trust.
We stabilise the foundation first, then restore finishes. We follow AS 1726 and design to AS 2870. If screw piles are needed we use AS 2159 with torque logs and traceable records.
Water and soil behaviour guide the choice of remedial types. Clay and sandy sites need different approaches. We manage permits, DBI where required and VBA certification so your project stays documented.
Free assessments, fixed-price quotes and clear timelines protect your time and budget. Ready to begin? Underpinning services. Call Chris: 1300 970 930 or Email Chris: chris@underpinning-melbourne.com.au.