Block · Sizes pending
Cementitious — indicative fig. M·18
Fire A1 — NCC Group 1 Non-combustibleEmbodied carbon Data pending Per-m² sourceCompressive 10–25 (standard 10–15; structural 15–25)MPa StructuralDesign life 75yr Durable
Solid CMUs in 90, 140, 190, and 290 mm widths; density 2100–2300 kg/m³; f'uc 10–25 MPa; Rw 50–58 for 190 mm solid; FRL up to 240 min structural adequacy; non-combustible (Group 1). Higher mass and cost per unit than hollow CMU but eliminates core-filling and achieves better inherent fire and acoustic ratings.
01 Physical
Density 2100–2300 (dense weight solid); 1800–2100 (lightweight solid)kg/m3
Specific gravity 2.1–2.3
Porosity 12–18%
Water absorption 5–10 (dense); 10–15 (lightweight)% by mass
Hardness 4–6Mohs scale
UV resistance Excellent — no UV degradation
Chemical resistance Good (mild conditions); moderate (sulfate/acid exposure — specify SR cement)
pH tolerance Resistant pH 7–14; avoid sustained pH < 5
Surface roughness 1–3 (standard cast); 3–10 (split face)mm
02 Mechanical
Tensile strength 1.0–2.5 (unit); masonry not designed for tensionMPa
Compressive strength 10–25 (standard 10–15; structural 15–25)MPa
Flexural strength 0.2–0.4 (masonry assemblage, parallel to bed joints)MPa
Shear strength 0.35–1.0 (masonry assemblage)MPa
Poisson's ratio 0.15–0.25
Impact resistance Good (hard surface, high mass)
Creep resistance 1.5–2.5 (long-term creep coefficient)coefficient
03 Thermal
Thermal conductivity 1.3–1.7 (dense); 0.8–1.2 (lightweight)W/mK
Specific heat 840–1000J/kgK
Thermal expansion 10–12x10^-6/C
04 Compliance & Fire First question
Combustibility class Non-combustible — NCC Group 1
Fire resistance level FRL 60/120/120 to FRL 240/240/240 (configuration and thickness dependent)minutes
Flame spread index 0FSI
Smoke dev. index 0SDI
Heat release rate 0 (non-combustible)kW/m2
05 Sustainability & Health
Embodied carbon 45kgCO2e/m2
Carbon footprint 0.137kgCO2e/kg
Embodied energy 1.32MJ/kg
Water footprint 150L/unit
Recyclability 100%
Recycled content 20%
Renewable content 0%
Circular score 7/10
VOC emissions 0g/L
Toxicity rating non-toxic
LEED contribution 3
06 Durability · Cost · Logistics
Expected lifespan 75years
Maintenance interval 10years
Warranty period 10years
Material cost (range) 50 – 120$/m2
Material cost (per unit) 4 – 10$/unit
Lead time 3days
Lifecycle cost 220 – 450$/m2
Annual maintenance 0.5 – 3$/m2/year
Market availability readily available
07 Assessment
Advantages
- Non-combustible — Group 1 material under NCC; no contribution to fire load, no smoke or toxic gas production.
- Superior acoustic performance compared with hollow CMU — solid 190 mm wall achieves Rw 50–52 bare, 54–58 rendered, without core-fill.
- Excellent fire resistance — solid section provides better thermal insulation in fire; FRL up to 240/240/240 achievable.
- High thermal mass (density 2100–2300 kg/m³) reduces peak indoor temperatures and smooths diurnal temperature swings.
- Eliminates core-filling labour and material cost on fire and acoustic walls.
- Standard modular sizing (390 x 190 mm face, 90/140/190/290 mm widths) integrates with standard masonry accessories and ties.
- Durable — 50–100 year design life; resistant to impact, vermin, and weathering.
- Low maintenance — no painting required in many commercial applications; repaintable if desired.
- Recyclable as crushed aggregate at end of life.
Constraints
- Significantly heavier than hollow CMUs — 190 mm solid unit weighs 28–32 kg versus 14–18 kg hollow, requiring mechanical handling for upper courses.
- Higher material cost per unit ($4–10 AUD) and per m² ($50–120 AUD supply only) compared with hollow CMU of equivalent size.
- Greater dead load on foundations and structure compared with hollow or lightweight alternatives.
- Limited thermal insulation in the bare wall — R-value ~0.12 m²K/W for 190 mm; insulation must be added to meet NCC energy efficiency requirements.
- Product data is manufacturer-specific; fire and acoustic ratings must not be applied across brands without independent verification (Island Block manual).
- Fire resistance values are wall-configuration dependent and must be checked per AS 3700 for specific slenderness ratios and load conditions.
- Cutting generates significant dust and noise; wet cutting or appropriate PPE mandatory.
08 Applications
A1 Loadbearing walls in residential and commercial construction Structural loadbearing walls in Class 2–9 buildings where compressive strength, fire rating, and acoustic performance are required simultaneously. 190 mm solid CMU eliminates core-fill for fire compliance.
A2 Fire separation walls and fire compartmentation Fire-rated wall assemblies achieving FRL 120/120/120 to 240/240/240 for NCC fire compartmentation, stair and lift shaft enclosures, and boundary walls without core-filling.
A3 Acoustic party walls and sound separation Party walls in Class 2 and mixed-use buildings. 190 mm solid CMU achieves Rw 50–52 bare (meets NCC Spec C3.4) and Rw 54–58 rendered, without additional treatment.
A4 Retaining walls and basement construction Gravity and cantilever retaining walls where high density (2100–2300 kg/m³) and strength of solid CMU resist hydrostatic and earth pressure loads.
A5 Industrial and warehouse structural walls Heavy-duty structural walls for industrial, warehouse, and cold-storage applications where impact resistance, fire rating, and robustness are paramount.
A6 Educational, healthcare, and correctional facility walls Applications demanding robust, fire-rated, acoustic walls that are resistant to impact, vandalism, and cleaning chemicals — common in schools, hospitals, and secure facilities.
A7 Boundary and site perimeter walls Perimeter walls requiring fire separation from adjacent properties under NCC Section C, and passive security screening through high mass.
A8 Lift and stair shaft enclosures Fire-rated and acoustically isolated enclosures for lift shafts and stair cores where FRL 120–240, Rw 50+, and robustness against construction impacts are required.
09 Sources & Standards
Sources pending — citations for this material are not yet recorded. Verify all figures against manufacturer data and current standards before specifying.