composite / Timber-Based Composite / Glue-Laminated Timber
Glulam using Australian Hardwoods (Vic Ash, Tasmanian Oak) (Specified by section size)
High-strength hardwood glulam beams (GL17-GL18) for long spans and high-load structures.
Atlas code
COM-TBC-GLT-002
At-a-glance signals
High-strength hardwood glulam beams (GL17-GL18) for long spans and high-load structures.
Overview
Executive summary
Hardwood glulam (e.g., Vic Ash GL17 or Tasmanian Oak GL18) provides higher strength and stiffness than softwood glulam, enabling longer spans and higher loads in exposed structures.
Best when…
- High strength-to-weight ratio [42]
- Good design flexibility, can be manufactured in a variety of shapes and sizes [34]
- Aesthetically pleasing appearance [34]
- Good fire resistance, chars at a predictable rate [16, 32]
- Utilizes smaller pieces of timber, which can be more sustainable
- Sourced from sustainably managed forests [44]
Top advantages
- 01 High strength-to-weight ratio [42]
- 02 Good design flexibility, can be manufactured in a variety of shapes and sizes [34]
- 03 Aesthetically pleasing appearance [34]
- 04 Good fire resistance, chars at a predictable rate [16, 32]
- 05 Utilizes smaller pieces of timber, which can be more sustainable
Top limitations
- 01 Susceptible to moisture damage if not properly detailed and protected [8, 15]
- 02 Requires preservative treatment for exterior use [9, 21]
- 03 Can be more expensive than other structural materials
- 04 Limited by transport and handling capabilities for very large members [37]
Technical
Physical ·3
- Density
- 650 kg/m3 Lamtim glulam properties (Vic Ash GL17, Tas Oak GL18).
- Specific gravity
- 0.70 (for Victorian Ash) [2]
- Hardness
- Janka hardness of 5.0 - 5.4 kN (for Victorian Ash) [2, 3]
Mechanical ·4
- Tensile strength
- 21-25 MPa Tension strength for GL17-GL18 hardwood glulam.
- Compressive strength
- 35-50 MPa Compression strength for GL17-GL18 hardwood glulam.
- Flexural strength
- 42-50 MPa Bending strength for GL17-GL18 hardwood glulam.
- Shear strength
- 3.7-5.0 MPa Shear strength for GL17-GL18 hardwood glulam.
Sustainability & Health
Embodied carbon & energy ·2
- Recycled content
- Can be manufactured from smaller, otherwise less usable pieces of timber. %
- Renewable content
- 100% (as it is a wood product from managed forests) [26] %
Compliance & Fire
Fire performance ·1
- Fire resistance level
- A one-hour fire resistance rating can be achieved with appropriate design and specification. [32, 35, 36]
Cost & Lifecycle
Capex & lead time ·2
- Material cost (range)
- Prices can vary significantly based on size and grade. For example, a 170x70mm GL18 beam is around $50/linear meter, while a 290x65mm laminated beam is around $60/linear meter. [30, 43, 44]
- Market availability
- Mainly available in Victoria, Tasmania and NSW, with limited availability to other parts of Australia. [33]
Service life & durability ·3
- Expected lifespan
- Can last for well over 50 years with proper design and maintenance. [7, 8, 16]
- Maintenance interval
- Regular inspection is recommended, especially for exterior applications. Recoating of exterior finishes may be needed every 18-24 months. [21]
- Warranty period
- A 25-year warranty is available for H3 treated Vic Ash glulam. [9]
Layer D
Where it's used
Structural beams and columns [9]
Rafters and trusses [9]
Lintels
Floor joists
Architectural features
Bridge components
Furniture [5]