composite / Timber-Based Composite / Parallel Strand Lumber
Parallel Strand Lumber (PSL), various sizes (Specified by section size)
High-strength structural composite lumber made from parallel veneer strands; Parallam PSL is commonly specified for long spans and high-load beams and columns.
Atlas code
COM-TBC-PSL-001
At-a-glance signals
High-strength structural composite lumber made from parallel veneer strands; Parallam PSL is commonly specified for long spans and high-load beams and columns.
Overview
Executive summary
Parallel strand lumber (PSL) is a structural composite lumber product made by aligning long veneer strands parallel to the member axis and bonding them with waterproof adhesive under heat and pressure. Weyerhaeuser Parallam PSL is a common product with high stiffness and strength for long-span beams and columns.
Best when…
- Superior bending strength and stiffness
- Excellent dimensional stability
- Consistent and predictable properties
- Long clear spans possible
- Can be preservative treated
- Attractive appearance for exposed applications
- High load-bearing capacity
- Efficient use of wood resources
Top advantages
- 01 Superior bending strength and stiffness
- 02 Excellent dimensional stability
- 03 Consistent and predictable properties
- 04 Long clear spans possible
- 05 Can be preservative treated
Top limitations
- 01 Limited availability in Australia
- 02 Higher cost than conventional timber
- 03 Requires specialised design expertise
- 04 Proprietary product with single manufacturer
- 05 Not covered by Australian Standards
Technical
Physical ·6
- Density
- 721 kg/m3 Converted from 45 lb/ft3 density listed in Weyerhaeuser technical informer.
- Specific gravity
- 0.5 dimensionless
- UV resistance
- Moderate - requires protective coating for exterior use
- Chemical resistance
- Good resistance to mild chemicals, susceptible to strong acids/bases
- pH tolerance
- 3 – 11 pH
- Surface roughness
- Sanded smooth finish as manufactured µm
Mechanical ·5
- Tensile strength
- 15.9 MPa Parallel to grain
- Compressive strength
- 20 MPa Parallel to grain
- Flexural strength
- 20 MPa Fb 2,900 psi (allowable bending stress) from Weyerhaeuser technical informer.
- Shear strength
- 2 MPa Fv 290 psi (allowable shear) from Weyerhaeuser technical informer.
- Creep resistance
- Good - engineered for long-term loading
Sustainability & Health
Embodied carbon & energy ·3
- Embodied carbon
- -0.7 kg CO₂e/kg Estimated - stores biogenic carbon
- Recycled content
- 0 % Made from virgin timber
- Renewable content
- 95 % Wood content with synthetic adhesive
Compliance & Fire
Fire performance ·5
- Combustibility class
- Combustible
- Fire resistance level
- Non-rated without protection - char rate similar to solid timber
- Ignition temp
- 260 °C Typical for wood products
- Flame spread index
- 75 FSI Class B to C (26-200)
- Smoke dev. index
- 150 SDI Typical range 50-250
Cost & Lifecycle
Capex & lead time ·5
- Material cost (range)
- 15 – 45 AUD/linear metre Varies by size
- Material cost (per unit)
- 2500 AUD/m³ Approximate average
- Lead time
- 8 – 16 weeks International shipping required
- Annual maintenance
- 50 AUD/m³ Interior applications
- Market availability
- Limited - special order in Australia
Service life & durability ·3
- Expected lifespan
- 50 years Protected conditions
- Maintenance interval
- 5 years Inspection and coating renewal
- Warranty period
- 1 years Limited manufacturer warranty
Layer D
Where it's used
Long-span beams and headers
Heavy-loaded columns
Architectural exposed beams
Ridge beams and purlins
Post and beam construction
Commercial and industrial structures
Multi-storey construction
Bridge components