What does it cost to grind concrete high spots caused by slab heave in Sydney?

In Sydney, grinding concrete high spots caused by slab heave typically costs between $25 and $80 per square metre (ex GST), depending on the extent of the unevenness, access, job size, and whether it's a localised or more extensive job. Recent industry sources from late 2025 into 2026 point to:

Basic or standard grinding (including high spot removal) often falling in the $25 to $45 per square metre range for Sydney projects. More heavy-duty or complex work (deeper grinding, tough conditions, or small areas with higher setup costs) can reach $35 to $80 per square metre . For smaller residential jobs (under 50 sqm), expect prices towards the higher end due to fixed costs like equipment transport and site setup. This process removes raised sections of a concrete slab before cracks propagate into tiles or finishes. Early intervention reduces structural stress and limits repair costs, particularly in clay soil regions of Western Sydney.

What is slab heave and why does it create high spots?

Slab heave occurs when reactive clay soils beneath a concrete slab absorb moisture and expand. In Western Sydney, seasonal rainfall and irrigation cycles cause uneven ground movement that pushes sections of the slab upward, forming localised humps or ridges.

Reactive clay soils swell when moisture levels increase Uneven moisture distribution creates differential slab movement Raised sections concentrate stress at tile joints and edges Over time, these high points transfer load into brittle finishes such as porcelain tiles, stone, or engineered flooring, often leading to cracking that appears unrelated to installation quality.

How does slab heave impact Sydney property owners or businesses?

For residential owners, slab heave commonly presents as cracked tiles, lifting finishes, or doors that no longer align. In commercial or strata-managed buildings, the issue can escalate into disputes over liability, defect attribution, and compliance responsibility.

Cracked tiles or grout lines above raised slab sections Trip hazards that affect safety obligations Disputes between builders, strata managers, and owners Many companies frequently encounter slab heave during renovation and remediation works where surface finishes fail despite being installed to specification.

Why is this important for NSW projects and compliance?

NSW construction and renovation projects operate within a compliance framework that prioritises safety, durability, and reasonable service life. When slab movement is ignored, resulting damage can compromise these obligations.

Authorities such as NSW Fair Trading and research bodies like CSIRO recognise reactive clay behaviour as a known structural risk in Western Sydney. Addressing high spots early supports compliance with duty of care and reduces downstream liability.

What does grinding high spots typically cost in Sydney?

Here's a general breakdown based on current market data:

Localised concrete grinding: $25 to $80 per sqm – Flatten raised slab sections Moisture and surface assessment: Included or site dependent – Confirm cause and extent Preparation for retiling: Project dependent – Prevent repeat cracking Grinding is typically performed before cracks fully propagate. Once tiles or finishes fracture, costs increase substantially due to demolition, disposal, and reinstatement.

What are the risks or benefits of early intervention?

Grinding high spots is a preventative intervention rather than a cosmetic fix. Its value lies in risk reduction rather than appearance alone.

Reduces stress concentration beneath tiles and stone Extends the service life of surface finishes Limits liability exposure in strata or commercial settings Delaying remediation increases the likelihood of broader slab cracking, insurance disputes, and unplanned downtime for businesses.

Sources & References

Information draws from recent Australian industry sources (2025-2026), including the following:

Tyrolit Australia on concrete grinding price breakdown: https://tyrolit-construction.com.au/predefined/concrete-grinding-price-breakdown/ Tyrolit Australia on what concrete grinding costs: https://tyrolit-construction.com.au/predefined/what-does-concrete-grinding-cost/ Various Sydney concrete specialists and cost guides (e.g., Flooring and Grinding, Concrete Cancer Repairs Sydney) reporting ranges of $10–$90 per square metre for grinding services, with high spot removal commonly in the $25–$80 range CSIRO publication on foundation maintenance and footing performance (discussing reactive clay soils and swell/shrink issues): https://research.csiro.au/infratech/wp-content/uploads/sites/38/2024/12/2979_FoundationMaintenanceandFootingPerformance_WCAG.pdf Geoscience Australia (general soil and ground movement research, though specific reactive clay pages are referenced in broader Australian geotechnical contexts) NSW Government housing and construction guidance (via NSW Fair Trading resources on building standards and tolerances) Prices can vary based on site specifics, so always get multiple quotes for your project. For professional assessment in NSW, consider consulting specialists in concrete grinding and slab remediation.