mineral / Cementitious / Concrete
Polished concrete floor, various grit finishes (100mm slab with 1-3mm ground/polished surface)
Polished concrete floors are produced by diamond-grinding a structural concrete slab through progressive grit sequences (30 to 3000 grit) to expose aggregate and create a hardwearing, low-maintenance surface. The finish offers exceptional durability (30–50+ years for the polish, 60–100+ years for the slab), intrinsic thermal mass benefits, zero VOC emissions once cured, and a striking industrial-modern aesthetic suited to a wide range of Australian commercial and residential applications. Silica dust management during the grinding process is the primary WHS concern.
Atlas code
MIN-CEM-CC-006
At-a-glance signals
Polished concrete floors are produced by diamond-grinding a structural concrete slab through progressive grit sequences (30 to 3000 grit) to expose aggregate and create a hardwearing, low-maintenance surface. The finish offers exceptional durability (30–50+ years for the polish, 60–100+ years for the slab), intrinsic thermal mass benefits, zero VOC emissions once cured, and a striking industrial-modern aesthetic suited to a wide range of Australian commercial and residential applications. Silica dust management during the grinding process is the primary WHS concern.
Overview
Executive summary
Polished concrete flooring is produced by mechanically grinding and polishing an existing or newly poured concrete slab using progressively finer diamond-impregnated abrasive pads — typically from 30-grit metal bond tooling through to 400-, 800-, 1500-, and 3000-grit resin-bond pads. The process removes the top surface layer (1–3 mm) to reveal the underlying matrix, which may be cream (minimal grind), salt-and-pepper (fine aggregate exposure), or full aggregate exposure depending on how deep the contractor grinds. A densifier — usually a colloidal silica or lithium silicate hardener — is impregnated mid-way through the grit sequence to react with free calcium hydroxide in the concrete and create additional CSH crystals, significantly increasing surface hardness and abrasion resistance. The final surface is either left as a honed finish (~400 grit) or taken to a high-gloss mirror polish (~1500–3000 grit). A penetrating or topical sealer is commonly applied to protect the surface from staining in commercial and residential settings. Concrete can be integrally coloured, surface-dyed, or left in its natural grey/aggregate tone. The 100 mm structural slab beneath performs as designed under AS 3600, providing thermal mass, fire resistance, and structural continuity. Suitable for residential homes, commercial offices, retail tenancies, café and hospitality fitouts, industrial warehouses, and institutional buildings.
Best when…
- Exceptional longevity: polished surface 30–50+ years with maintenance, underlying 100mm slab 60–100+ years; lowest lifecycle flooring cost over 30+ years
- Zero VOC emissions post-cure: suitable for sensitive occupants and Green Star / WELL certification; no adhesives, underlay, or carpet fibres to off-gas
- High thermal mass (2400–2500 kg/m³, specific heat ~880 J/kg·K): stores solar or hydronic heat, reduces HVAC peak loads by 15–25% in well-designed passive buildings
- Non-combustible (AS 1530.1): does not contribute to fire load; fire resistance level depends on slab thickness — 100mm achieves FRL 60/60/60 per AS 3600 Table 5.3.2
- Abrasion resistance class AR4 (AS 1580): densified and polished surface withstands forklift traffic, retail foot traffic, and wheeled equipment without significant wear
- Slip resistance controllable by grit stopping point: unsealed 400-grit achieves wet pendulum P4 (R11); sealer type and anti-slip additives can achieve P5 (R12) per AS 4586
- Hygienic and allergen-free: no fibres, grout joints, or adhesive reservoirs for bacteria, mould, or dust mites — suitable for food preparation areas and health facilities
- Sustainable use of existing structure: no additional materials required; eliminates embodied carbon of floor covering layer; recycled content achievable via SCM-blended concrete
- Versatile aesthetic: exposure level, dye colour, sealer sheen (matte to mirror), and aggregate selection offer broad design palette suited to residential through to institutional
- Integrates with in-slab hydronic heating and cooling systems without the acoustic/thermal penalty of floating floor finishes; no floor covering layer to degrade heat transfer
Top advantages
- 01 Exceptional longevity: polished surface 30–50+ years with maintenance, underlying 100mm slab 60–100+ years; lowest lifecycle flooring cost over 30+ years
- 02 Zero VOC emissions post-cure: suitable for sensitive occupants and Green Star / WELL certification; no adhesives, underlay, or carpet fibres to off-gas
- 03 High thermal mass (2400–2500 kg/m³, specific heat ~880 J/kg·K): stores solar or hydronic heat, reduces HVAC peak loads by 15–25% in well-designed passive buildings
- 04 Non-combustible (AS 1530.1): does not contribute to fire load; fire resistance level depends on slab thickness — 100mm achieves FRL 60/60/60 per AS 3600 Table 5.3.2
- 05 Abrasion resistance class AR4 (AS 1580): densified and polished surface withstands forklift traffic, retail foot traffic, and wheeled equipment without significant wear
Top limitations
- 01 Hard underfoot: extended standing on polished concrete without anti-fatigue matting causes fatigue — hardness approximately 7 Mohs (densified surface)
- 02 Cold surface temperature in unheated winter conditions (thermal mass absorbs ambient heat); requires in-slab heating for comfort in southern Australia
- 03 Slippery when wet if unsealed or over-polished — AS 4586 wet pendulum P3/R10 compliance requires correct grit stopping point or anti-slip sealer additive
- 04 Silica dust hazard during grinding — RCS classified IARC Group 1 carcinogen; strict WHS controls mandatory (0.05 mg/m³ TWA from 2020)
- 05 Surface cracking: concrete shrinkage cracks will telegraph through polish; control joints must be planned carefully or accepted as part of the aesthetic
Technical
Physical ·9
- Density
- 2400 kg/m3 Normal-weight concrete per AS 3600. Densified polished surface does not significantly change bulk density.
- Specific gravity
- 2.4 Per AS 3600 normal-weight concrete assumption.
- Porosity
- 2-5 % Standard concrete 12–18% by volume; densifier treatment reduces surface porosity to 2–5% at the polished face.
- Water absorption
- <1 (sealed) % Polished and sealed surface: <1%. Unsealed honed surface: 3–8% depending on concrete porosity and quality.
- Hardness
- 7-8 Mohs Unpolished concrete approx 6–7 Mohs; densified and polished surface reaches 7–8 Mohs after lithium/colloidal silica treatment.
- UV resistance
- good Concrete matrix is UV-stable; penetrating sealers have UV stability; some topical acrylic sealers may yellow under prolonged UV — specify UV-stable polyurethane or densifier-only finish for sun-exposed areas.
- Chemical resistance
- good (sealed) Good resistance to oils, dilute acids, and alkaline cleaners when sealed with polyurethane or epoxy sealer. Unsealed surface vulnerable to acidic food spills (lemon juice pH 2.2, coffee pH 5) causing etching.
- pH tolerance
- 11-13 pH Alkaline concrete matrix pH 12–13; acid rain or weak acids (pH <4) can etch unsealed surfaces over time.
- Surface roughness
- 0.1-1.5 μm Ra 400-grit honed: Ra ~0.8–1.5 μm; 1500-grit polish: Ra ~0.2–0.5 μm; 3000-grit mirror: Ra <0.1 μm.
Mechanical ·7
- Tensile strength
- 2.2-4.1 MPa Direct tensile strength for normal-weight concrete classes per AS 3600.
- Compressive strength
- 25-50 MPa Typical structural concrete compressive strength classes used in slabs for polished finishing; f'c 32 MPa recommended minimum for quality polished result.
- Flexural strength
- 3.0-5.0 MPa Modulus of rupture per AS 3600 clause 3.1.1.3.
- Shear strength
- 2.5-4.5 MPa Shear strength of concrete slab per AS 3600 design provisions.
- Poisson's ratio
- 0.2 Standard concrete value per AS 3600.
- Impact resistance
- moderate Moderate; polished surface does not provide impact resistance beyond base concrete. Point loads from stiletto heels (concentrated ~5 MPa) can chip densified surface in early cure.
- Creep resistance
- good Creep coefficient 2.0–3.0 at 30 years per AS 3600 Section 3. Polish surface does not affect creep of the slab.
Sustainability & Health
Embodied carbon & energy ·7
- Embodied carbon
- 0.10-0.16 kg CO2-eq/kg Standard concrete (25 MPa, OPC): approx 0.13-0.16 kg CO2e/kg. Blended cement (30% fly ash): approx 0.09-0.11 kg CO2e/kg. Polishing process adds ~0.5-1.5 kg CO2e/m² from equipment. Densifier: negligible (applied at <0.1 L/m²).
- Carbon footprint
- 22-35 kg CO2-eq/m² 100mm concrete slab at 0.13 kg CO2e/kg × 240 kg/m² = ~31 kg CO2e/m². Blended cement reduces this to ~20-25 kg CO2e/m². Polishing process adds ~1-2 kg CO2e/m². Total: ~22-33 kg CO2e/m². Compare: ceramic tile ~15-25 kg CO2e/m² (tile only, no substrate); carpet tile ~8-15 kg CO2e/m² (but replaced every 10 years).
- Embodied energy
- 1.1-1.9 MJ/kg Normal-weight concrete: 1.1-1.9 MJ/kg. Grinding process adds approximately 3-8 MJ/m² depending on number of passes and floor area. Polishing adds minimal additional energy per square metre.
- Water footprint
- 25-40 L/m² Concrete production: approx 200-300 L/m³ water, equating to 20-30 L/m² for 100mm slab. Wet grinding process: 3-8 L/m² slurry water (recycled or disposed per local council requirements for pH and silica content).
- Recycled content
- 0-40 % Concrete with supplementary cementitious materials (SCMs): 20-40% by mass (fly ash, GGBS, silica fume replacing OPC). Recycled aggregate concrete: 20-30% coarse aggregate from recycled concrete (AS 2758.1 compliant, available from Boral Recycling, Repurpose It VIC). Standard OPC concrete with no SCM: 0% recycled content.
- Renewable content
- 0 % No renewable material content in concrete. Some sealers use bio-based solvents or linseed oil in specific formulations but these are uncommon in Australian market.
- Circular score
- 7 /10 Score: 7/10. Rationale: concrete slab is a permanent in-place asset (high durability); grinding reuses existing structure (no new material); crushed at end-of-life for recycled aggregate; cannot be reclaimed as original product. SCM blends use industrial waste streams. Polishing avoids adhesive-floor-covering waste stream.
Health & emissions ·1
- VOC emissions
- 0 (cured concrete and densifier) μg/m³ Cured concrete: 0 VOC. Silicate densifiers (liquid): 0 VOC (water-based). Water-borne polyurethane sealer: <50 g/L VOC during application; 0 after cure. Solvent-borne acrylic sealer: 400-700 g/L VOC during application — NOT recommended for interior use. Post-cure off-gassing: negligible for all standard sealer systems.
Compliance & Fire
Fire performance ·7
- Combustibility class
- Non-combustible (AS 1530.1 Group 1) Non-combustible per AS 1530.1. Classified as Group 1 non-combustible material under NCC. No contribution to fire load. Complies with NCC Specification C1.1 non-combustible requirements.
- Fire resistance level
- 60/60/60 (100mm slab) FRL (minutes) Per AS 3600 Table 5.3.2 for cover to bottom steel and slab thickness. 100mm slab: FRL 60/60/60 (structural adequacy/integrity/insulation). 120mm: FRL 90/90/90. NCC Group Number 1 — lowest fire hazard group.
- Ignition temp
- N/A °C Concrete does not ignite. Thin sealer coat may flash off above 400°C but does not sustain combustion.
- Flame spread index
- 0 Index value AS 1530.3 Spread of Flame Index: 0 (non-combustible substrate). Topical sealers may have FSI 0–5 depending on formulation.
- Smoke dev. index
- 0 SDI AS 1530.3 Smoke Developed Index: 0 for concrete substrate. Thin sealer layer may contribute SDI 0–3.
- Heat release rate
- 0 kW/m² Concrete is non-combustible — zero heat release rate. Per AS 1530.1 Group 1 (non-combustible material). Sealers may contribute negligible HRR if present in thin coat.
- NCC group number
- Group 1 NCC 2022 Group Number classification for surface finishes. Concrete = Group 1 (lowest risk). Per NCC Volume One C2D2.
Cost & Lifecycle
Capex & lead time ·6
- Material cost (range)
- 180-280 AUD/m³ Slab concrete (32 MPa standard): $180-280/m³ delivered. 100mm slab = $18-28/m² concrete cost. Polishing service cost separate. See installationCostRange.
- Material cost (per unit)
- 65-200 AUD/m² Concrete slab material cost at 100mm depth: $18-28/m². Polishing service and consumables (diamond pads, densifier, sealer): $50-170/m².
- Lead time
- 28 days cure + 3-5 days polishing days Concrete pour to polishing: 28-day cure minimum before grinding commences. Polishing of 200m² floor: 3–5 working days for full grit sequence. Contractor scheduling: 1–4 weeks depending on demand.
- Lifecycle cost
- 120-200 AUD/m² over 30 years Installation ($65-120/m²) + re-seal every 5 years ($8-15/m²) + re-polish once at 15 years ($25-45/m²). Total 30-year LCC approximately $120-200/m². Compare: carpet tile $250-350/m² over 30 years (3 replacements). Excellent long-term value.
- Annual maintenance
- 1-7 AUD/m²/year Annual maintenance: dry mopping daily, wet mop with pH-neutral cleaner weekly = $1-2/m²/year labour in commercial context. Re-seal every 3-5 years: $8-15/m² event. Annualised total: $3-7/m²/year commercial; $1-3/m²/year residential.
- Market availability
- readily available Readily available across all major Australian cities. 50+ specialist polished concrete contractors in Melbourne/Sydney alone. Grinding equipment widely owned or hired. Densifiers and sealers available through Parchem, Sika, Mapei, and specialist concrete coating suppliers nationally.
Service life & durability ·3
- Expected lifespan
- 30-50 (polish); 60-100+ (slab) years Polished/densified surface 30–50+ years with periodic maintenance re-polishing. Structural concrete slab 60–100+ years per AS 3600 design life provisions.
- Maintenance interval
- 2-5 years Light commercial: re-seal or burnish every 2–3 years. Heavy retail/industrial: re-polish every 5–10 years. Residential: clean and re-seal every 3–5 years.
- Warranty period
- 1-2 years Typical contractor warranty for polish quality and densifier penetration. Sealer warranty 2–5 years depending on product.
Layer D
Where it's used
Residential slab-on-ground flooring
Residential renovation / slab reveal
Commercial retail tenancy
Hospitality and food service
Industrial warehouse and logistics
Commercial office fitout
Educational facilities
Health and medical facilities
Passive solar residential design
Heritage industrial building conversion