Designed to do more. Engineered to last.

DuoSpan™ combines the strength of aluminium with the design flexibility of recycled plastic. This achieves a system that provides exceptional ease of installation, enormous strength and durability, and the scope to construct stunning decks and structures that would be impossible with conventional subframes.



DuoSpan™ provides the perfect subframe for Millboard decking, as well as a universal support system for other outdoor flooring. Its ingenious design facilitates top-down fixing of decking boards and also makes it an easy installation for all levels of competence.

Flexible connectivity

Multiple bracket types for all types of joints, including Flexible Brackets for non-standard angles.




Slot-and-screw assembly

Screw-locating grooves and self-drilling screws ensure accurate alignment and a fast fix that’s right every time.




Unique curved constructions

The combination of rigid DuoSpan with flexible Plas-Pro enables the construction of stunning curved formations.




Exceptional spans

The DuoSpan 99mm Joist provides an exceptional 1800mm span in residential applications, reducing posts or joist supports required.





Galvanic corrosion between different metals is minimised with our cathodic barrier fixings.




Simple, stable fixing

Decking and cladding can be easily and securely screwed directly into the DuoSpan subframe at almost any angle using Durafix 45mm screws.




DuoSpan has been designed by industry professionals to comply with Eurocode 1: Actions on Structures (BS EN 1991-1-1). The system has been assessed for point loading in relation to both domestic and commercial use, making it suitable for a range of applications.



“I love DuoSpan. It’s so different to everything else out there and reduces stress massively.”

– Ed Phillips, Approved Installer



Where to buy Millboard Decking?

Millboard has a range of distributors and approved installers across the UK – enter your postcode to find one near you. If you need any further help locating a supplier or installer, please get in touch.