MATERIAL DATA SHEET

I-joist, various depths (Specified by depth and flange size)

I-Joist
composite › Timber-Based Composite › I-Joist
engineered-timberstructuralfloor-systemlvlosbaustralian-madeas1720as4357
ATLAS CODE
COM-TBC-IJT-001
I-joist, various depths (Specified by depth and flange size)
Category composite
Material Family Timber-Based Composite
Regulatory Status Combustible
Density
600 kg/m³
Carbon (A1-A5)
280 kgCO₂e
Fire Class
Combustible
Lifespan
50 yrs
Description

I-joists are engineered wood joists with LVL flanges and an OSB web, forming a lightweight I-shaped section. They offer long spans, dimensional stability, and consistent performance for floors and roofs.

Primary Sectors
[Residential][Commercial]
Typical Uses
  • Residential floor joists
  • Roof rafters and framing
  • Commercial floor systems
  • Cassette floor systems
  • Rim boards and headers
  • Wet area set-downs
Recycled Content 0
Renewable Content 90
Recyclability 95
Embodied Carbon 280 kgCO₂e
Embodied Energy 4500 MJ/kg
EPD Available No
Advantages
Consistent engineered propertiesHigh strength-to-weight ratioMinimal shrinkage and warpingLong spans without intermediate supportsPre-punched service holes availableLighter than steel or concrete alternativesSustainable plantation timber source
Cautions
Requires weather protection during constructionLimited fire resistance without protectionCannot be notched or cut in flangesRequires specific hangers and connectorsHigher initial cost than solid timberSkilled installation required
CLAD MATERIALS ATLAS PAGE 1 OF 4
TECHNICAL DATA: PERFORMANCE PROPERTIES COM-TBC-IJT-001
Density (Dry) 600 kg/m³
Specific Gravity 0.6
Porosity 0.35 %
Water Absorption 18 %
UV Resistance 3
Chemical Resistance 3
pH Tolerance 5-9
Compressive Strength 8 MPa
Tensile Strength 25 MPa
Flexural Strength 38 MPa
Shear Strength 6 MPa
Elastic Modulus 11500 GPa
Impact Resistance 3 J/m
Bearing Capacity 10 kN/m²
Poisson's Ratio 0.35
Creep Resistance 4
Abrasion Resistance 3
Thermal Conductivity 0.13 W/mK
Thermal Resistance 0.9 m²K/W
Specific Heat Capacity 1600 J/kgK
Thermal Expansion 5 μm/m·K
Ignition Temperature 250 °C
Sound Transmission Class (STC) 42
Noise Reduction Coeff. (NRC) 0.15
Optical
Light Transmittance 0 %
Light Reflectance (LRV) 35 %

I-joists were developed in the 1960s as an engineered alternative to solid timber joists. Introduced to Australia in the 1990s, they gained widespread adoption due to declining availability of large-dimension solid timber and superior performance characteristics. Australian manufacturers adapted the technology for local conditions, incorporating termite treatments and designing for cyclonic wind loads.

CLAD MATERIALS ATLAS PAGE 2 OF 4
SAFETY, ECOLOGY & INSTALLATION COM-TBC-IJT-001
Flame Spread Index 75
Smoke Developed Index 150
Combustibility Class Combustible
Ignition Temperature 250 °C
Fire Resistance Rating 30 hours
Heat Release Rate 150 kW/m²
Toxicity of Combustion 2
Embodied Carbon (A1-A3) 280 kgCO₂e/kg
Embodied Energy 4500 MJ/kg
Water Footprint 850 L/kg
EPD Available No
Recycled Content 0%
Renewable Content 90%
LEED Points 2
Circular Economy Score 7 /100
VOC Emissions 0.1 g/L
Skill Level Qualified carpenter
Crew Size 2
Installation Time 0.3 hr/m²
Curing Time 0 hours
Setting Time 0 min
Temperature Range -10 to 40 °C
Humidity Range 0-90 %
Required Tools
Circular sawDrillLevelNail gunMeasuring tape
Certifications Required
Carpentry trade qualification
Weather Limitations
Must be kept dryProtect from rain
CLAD MATERIALS ATLAS PAGE 3 OF 4
COMMERCIAL, LOGISTICS & REGULATORY COM-TBC-IJT-001
Material Cost 80-150
Installation Cost 35-55
Annual Maintenance 0
Lifecycle Cost (50yr) 180
Market Availability Readily available
Lead Time 1-2 weeks standard sizes weeks
Design Life 50 years
Warranty Period 15 years
Maintenance Interval 0 months
Service Temp Range -30 to 60 °C
Freeze/Thaw Resistance 4
Dimensional Stability 5
Certifications Held
AS/NZS 4357 - Structural laminated veneer lumberJAS-ANZ Product CertificationFSC Chain of CustodyPEFC CertifiedE0 Formaldehyde Emission (<0.5mg/L)
Fire Code Compliance
AS 1530.4 - Fire-resistance testsSpecification C1.1 Fire-resisting construction
Standards Compliance
NCC 2022 Volume One and TwoBCA Deemed-to-Satisfy provisionsASTM D5055 - Prefabricated wood I-joistsISO 22389-1 - Timber structures I-beams

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: COM-TBC-IJT-001 Schema: v3.0
CLAD MATERIALS ATLAS PAGE 4 OF 4