Find Out More About Millboard® DuoSpan Beams
Build complex decking structures with confidence using the Millboard® DuoSpan aluminium subframe beam. Engineered for strength and stability, this innovative system allows you to create precise, reliable subframes for ground-level decks, boardwalks, and more.
Manufactured from high-grade 6063 aluminium alloy, DuoSpan beams deliver a lightweight, easy-to-handle solution that offers excellent load-bearing capacity. Their superior straightness and rigidity help simplify installations, while reducing long-term maintenance.
Recommended projects include; residential decking areas, commercial decks, boardwalks and soft ground areas (when used with Plas-Pro posts and joists).
Used alongside Millboard® DuoSpan joists, flexible aluminium brackets, and Plas-Pro posts, the DuoSpan system can enable the construction of decks over soft or uneven ground. Beams are secured using specialist brackets and cathodic barrier-coated fixings, and are designed for high resistance against galvanic corrosion - tested to withstand 1000-hour salt spray exposure.
For residential projects, the beams support spans of up to 1800mm centres (with 400mm joist centres) based on a UDL of 2.5kN/m².
For commercial applications, beams can be supported at 1350mm centres (with 300mm joist centres), designed for heavier loads up to 5kN/m². Refer to DuoSpan loading tables for detailed criteria.
With minimal thermal expansion and maximum durability, the Millboard® DuoSpan beam is the professional choice for long-lasting, structurally sound decking subframes.
Beam specifications
Length: 3.6m
Width: 63mm
Depth: 136mm
Weight: 7.9kg approx
Finish: Mill finish
Technical specifications
Temper: T66
Extrusion standard: EN 755-9
*Residential maximum unsupported span: 1.8m
*Commercial maximum unsupported span: 1.35m
Deflection criteria: UDL 1/360
Thermal expansion: 0.0235 mm/m/°C
Fire and corrosion resistance: Cathodic barrier-coated fixings with 1000-hour salt spray resistance
*Refer to DuoSpan loading tables for detailed load and point load capacities.
Looking for Millboard® fixings?
See our selection of Millboard® fixings
Looking for subframe brackets?
See our DuoSpan flexible bracket set
Or browse our Millboard® decking department for decking boards and more…
