MATERIAL DATA SHEET

Earth Brick - Traditional

Earth/Clay
mineral › Clay-Based › Earth/Clay
mineralclay-basedearthadobemud-brickunfiredtraditionalsustainablelow-embodied-energythermal-massfire-resistantbiodegradableowner-builder
ATLAS CODE
MIN-CLY-ETH-001
Earth Brick - Traditional
Category mineral
Material Family Clay-Based
Regulatory Status Non-combustible (by performance)
Density
1500-1900 kg/m3
Carbon (A1-A5)
0.01-0.05 kg CO2-eq/kg
Fire Class
Non-combustible (by performance)
Lifespan
30-100+ years
Description

Unfired clay bricks (adobe/mud bricks) made from a mixture of earth, clay, sand, water, and organic fibres (typically straw or grass), hand-moulded or pressed and sun-dried. Traditional earth bricks are one of humanity's oldest building materials, used for load-bearing and infill walls in residential construction. The ideal soil composition is approximately 15% clay, 10-30% silt, and 55-75% fine sand, with straw or other natural fibres added at 1-4% by volume for tensile reinforcement and crack control. Bricks are typically 300 x 140 x 100 mm or similar dimensions, sun-dried for 2-4 weeks until fully cured. In Australia, mud brick construction is regulated under NCC Volume 2 for Class 1 and 10 buildings, with compliance typically achieved through performance solutions assessed by suitably qualified engineers. The Earth Building Association of Australia (EBAA) promotes earth building standards and practices. Mud brick walls provide excellent thermal mass, fire resistance, and acoustic insulation, but require protection from moisture through deep eaves, renders, and good drainage design.

Primary Sectors
[Residential]
Typical Uses
  • Residential load-bearing walls
  • Thermal mass walls (passive solar design)
  • Infill walls in timber frame
  • Garden and landscape walls
300140mm
Primary Form [300 / X / 140 / X / 100 / Mm / (typical)]
Weight [5-10] kg/brick
Recycled Content 0-100
Renewable Content 1-4
Recyclability 100
Embodied Carbon 0.01-0.05 kg CO2-eq/kg
Embodied Energy 0.5-2.0 MJ/kg
EPD Available No
Advantages
Extremely low embodied energy — materials sourced locally (often from the building site), sun-dried with minimal processing energy.Excellent thermal mass — 300 mm walls provide outstanding diurnal temperature moderation in Australian climates.Fire resistant — unfired earth is non-combustible and provides excellent fire resistance performance.Fully recyclable and biodegradable — earth bricks can be returned to the soil at end of life with zero waste.Healthy indoor environment — earth walls regulate humidity naturally and contain no VOCs, formaldehyde, or synthetic chemicals.
Cautions
Highly vulnerable to moisture damage — driving rain, rising damp, and flooding can cause erosion and structural failure without protective measures.Low insulation value (high thermal mass but low R-value) — additional insulation typically required to meet NCC energy efficiency requirements.NCC compliance is complex — typically requires performance solutions assessed by qualified engineers rather than deemed-to-satisfy provisions.Labour-intensive manufacture and construction — slow build process limits commercial viability without owner-builder participation.Variable material properties — soil composition, mixing quality, and curing conditions create inconsistent brick strength and durability.
TECHNICAL DATA: PERFORMANCE PROPERTIES MIN-CLY-ETH-001
Density (Dry) 1500-1900 kg/m3
Specific Gravity 1.5-1.9
Porosity 20-40 %
Water Absorption 10-25 %
Hardness 1.5-3 Mohs
Surface Roughness 500-5000 um
UV Resistance good
Chemical Resistance poor
pH Tolerance 6-9 pH
Available Colors
Natural earth tones — varies with local soil: ochre, red, brown, cream, greyLime-washed white or tintedRendered and painted — any colourOxide pigments can be mixed into earth for colour variation
Surface Finishes
Unrendered natural earth faceLime render (breathable, traditional finish)Cement render (more durable but less breathable)Lime wash (simple protective coating, reapplied regularly)Earth plaster (clay-based render matching the substrate)Painted render (acrylic or mineral paint over render)
Texture Options
Natural rough (unrendered earth surface)Smooth rendered (cement or lime render)Lime-washedSculptured/carved surface detailsExposed straw fibre texture
Pattern Options
Standard running bondStack bondFlemish bondExposed earth face (natural texture)Rendered (smooth or textured)Sculptural/curved walls (mud brick accommodates organic forms)
Compressive Strength 2-8 MPa
Tensile Strength 0.1-0.5 MPa
Flexural Strength 0.3-1.8 MPa
Shear Strength 0.1-0.5 MPa
Elastic Modulus 0.5-3.0 GPa
Yield Strength Not applicable MPa
Impact Resistance low J/m
Bearing Capacity Not specified kPa
Poisson's Ratio 0.15-0.25
Creep Resistance moderate
Abrasion Resistance Poor
Thermal Conductivity 0.40-0.60 W/mK
Thermal Resistance 0.55 m2K/W
Specific Heat Capacity 900-1000 J/kgK
Thermal Expansion 5-8 x10^-6/degC
Melting Point Not applicable (vitrifies >900) degC
Ignition Temperature Not applicable degC
Sound Transmission Class (STC) 48-55 Rw
Noise Reduction Coeff. (NRC) 0.05-0.15
Optical
Light Transmittance 0 %
Light Reflectance (LRV) 20-50 %
Solar Reflectance (SRI) 15-40

Earth building is one of the oldest construction techniques known to humanity, with adobe structures dating back over 10,000 years. The earliest known adobe structures are found in the Middle East and North Africa. Notable historical examples include the Great Mosque of Djenne in Mali (rebuilt 1907, original 13th century), the adobe pueblos of the American Southwest (some over 1,000 years old), and numerous ancient structures across Central Asia, South America, and the Mediterranean. In Australia, early European settlers used mud brick extensively from the 1830s onward, particularly in Victoria, South Australia, and New South Wales. Many of these colonial-era mud brick buildings survive today. The 1970s saw a significant revival of mud brick building driven by the alternative living movement and environmental awareness. The Earth Building Association of Australia (EBAA) was formed to promote and standardise earth building practices. Contemporary earth building incorporates modern engineering understanding of soil mechanics, seismic design, and moisture management while retaining the fundamental simplicity and sustainability of traditional techniques.

SAFETY, ECOLOGY & INSTALLATION MIN-CLY-ETH-001
Flame Spread Index 0
Smoke Developed Index 0
Combustibility Class Non-combustible (by performance)
Ignition Temperature Not applicable degC
Fire Resistance Rating 120-240 (estimated, performance solution required) FRL (minutes)
Heat Release Rate 0 kW/m2
Toxicity of Combustion non-toxic
Embodied Carbon (A1-A3) 0.01-0.05 kg CO2-eq/kg
Embodied Energy 0.5-2.0 MJ/kg
Water Footprint 50-100 L/kg
EPD Available No
Recycled Content 100%
Renewable Content 14%
LEED Points 3-6 points
Circular Economy Score 9.5 /10
VOC Emissions 0 ug/m3
Skill Level semi-skilled to skilled
Crew Size 2-4 persons
Installation Time 3-6 m2/day
Curing Time 2-4 weeks
Setting Time 4-24 hours
Temperature Range 10-35 degC
Humidity Range 20-60 %RH
Required Tools
Brick mould (timber or metal, typically 300 x 140 x 100 mm)Mixing pit or mechanical mixer (for soil preparation)Shovel and wheelbarrowSpirit level and string lineTrowel (for mortar application)Water supply (for mixing and curing)Tarp or shade cloth (for drying bricks and protecting walls)
Certifications Required
No specific trade certification exists for mud brick construction in AustraliaStructural engineer assessment required for load-bearing walls (performance solution under NCC)General construction induction (White Card) for commercial sitesBuilding permit required — performance solution typically needed for NCC complianceEBAA training workshops recommended but not mandatory
Weather Limitations
Do not lay bricks or make bricks in rainProtect fresh walls from rain with temporary coversAvoid construction in freezing conditions (mortar freeze damage)Cover completed wall tops each night during constructionDeep eaves must be constructed before removing temporary rain protection
COMMERCIAL, LOGISTICS & REGULATORY MIN-CLY-ETH-001
Material Cost 5-120 AUD/m2
Installation Cost 50-400 AUD/m2
Annual Maintenance 3.00-10.00 AUD/m2/year
Lifecycle Cost (50yr) 200-500 AUD/m2
Market Availability limited
Lead Time 2-6 weeks
Supply & Logistics
Shelf Life Indefinite if kept dry. Bricks will deteriorate rapidly if exposed to rain or standing water. months
Design Life 30-100+ years
Warranty Period Not applicable years
Maintenance Interval 1-5 years
Service Temp Range -5 to 60 degC
Freeze/Thaw Resistance 10-50 cycles
Dimensional Stability 1.0-3.0 mm/m
Fire Code Compliance
Performance solution required — earth walls are not listed in NCC deemed-to-satisfy provisionsEarth walls demonstrate non-combustible performance but require fire engineer assessmentInternational test data supports 2-4 hour fire resistance for 250 mm+ earth walls
Standards Compliance
NCC Volume 2 — Class 1 and 10 buildings (residential)Typically requires performance solution under NCC — not covered by deemed-to-satisfy provisionsEarth Building Association of Australia (EBAA) provides guidance documentsNZ Earth Building Standards (NZS 4297-4299) commonly referenced in Australian performance solutionsMinimum wall thickness 200 mm for NCC compliance (typically 250-350 mm in practice)

DISCLAIMER: This specification document is generated from the CLAD Materials Atlas Database. Information is for general guidance only and does not constitute professional engineering advice. Values are typical and may vary by batch, manufacturer, and production run. Verify suitability for specific project applications independently.

ID: MIN-CLY-ETH-001 Schema: v3.0