Engineered from the same robust mineral core as Envello Cladding, Millboard Decking resists warping, rotting and algae, ensuring it won't degrade over time. Extensive UV and weathering tests confirm its suitability for New Zealand's environment, while its low-maintenance Lastane® surface offers enduring performance with minimal effort.
Millboard Decking is engineered for performance across New Zealand's demanding conditions, suitable for use in all exposure zones as defined in NZS 3604:2011. Designed for external decking on residential and commercial projects, the system suits both timber framing and the Outdure QwickBuild aluminium subframe system, making it as suitable for ground-level decks as it is for rooftop terraces and balconies. Installation must follow the conditions set out in NZS 3604:2011 to ensure long-term structural performance and compliance.
Key specification points:
Suitable in all exposure zones as defined in NZS 3604:2011 (contact Forté for microclimatic conditions)
Compatible with timber framing or the Outdure QwickBuild aluminium subframe system
Timber framing must have a minimum design load of 2kPa or be subject to specific engineering design
Joist spacing at a maximum of 400mm centres (residential) or 300mm centres (commercial)
Stainless steel Durafix® fixings required throughout (4.5 x 60mm for timber subframe, 4.5 x 45mm for aluminium subframe)
Single board spans up to 3600mm
Full scope, limitations and technical detailing are set out in the Millboard Exterior Decking System Design Guide.
Download the Millboard Decking Design GuideMillboard Decking Specifications
Available in Enhanced Grain and Weathered Oak profiles, Millboard's resin mineral construction delivers consistent Prime grade quality across every board. Finished with a durable Lastane® surface and engineered from a polymer resin core, each profile is built for reliable, long-lasting performance.
Specifications | Enhanced Grain 126 W | Enhanced Grain | Weathered Oak |
|---|---|---|---|
Grade | Prime | Prime | Rustic |
Construction | Resin Mineral Board | Resin Mineral Board | Resin Mineral Board |
Core | Polymer Resin Core | Polymer Resin Core | Polymer Resin Core |
Thickness | 32mm | 32mm | 32mm |
Width | 126mm | 176mm | 200mm |
Length | 3600mm | 3600mm | 3600mm |
Surface Finish | Lastane® Surface | Lastane® Surface | Lastane® Surface |
The Millboard Exterior Decking System Design Guide is the reference point for specifying and detailing Millboard with confidence. It covers the full system — from timber and aluminium subframe requirements through to fixing methods, board setout, pool and spa detailing, ramps, stairs and curved features — giving specifiers the technical grounding needed to design a compliant, long-lasting deck from the ground up.
Detailed technical drawings accompany each junction and condition, providing the dimensional accuracy and construction detail required to translate the guide directly into working drawings.
Compliance is demonstrated under the Millboard Product Assurance Supplier Statement (PASS #19239), addressing NZBC clauses for structure, durability, access routes and hazardous building materials. Every detail in the guide — from subframe setout to pool edges, ramps and stairs — is drawn from tested, documented practice, ensuring the system performs as intended across the full range of design conditions it's built for.
Download the Millboard Decking Design Guide Specify on Masterspec View on Productspec View on Smartspec View on Programma View on EbossCompliance & Testing
NZ Building Code Clause | Compliance Pathway | Demonstrated by |
|---|---|---|
B1 STRUCTURE B1.3.1, B1.3.2, B1.3.3 (a, b, c, e, f, j, m, q) | Alternative Solution | Tested to ASTM D7032-17 for creep-recovery, fastener holding, bending stiffness and bending strength [element, 17/10/22] |
B2 DURABILITY B2.3.1(b) | Alternative Solution | Tested to ASTM D7032-17 for elevated temperature, moisture and freeze-thaw; tested for UV/accelerated ageing [element, 17/10/22; Q-Lab, 11/11/22] |
D1 ACCESS ROUTES D1.3.3(d) | Alternative Solution | Tested to BS 7976-2:2002, cited in AS/NZS 4586:2004. Classified as low slip potential [SATRA Technology Centre] |
F2 HAZARDOUS BUILDING MATERIALS F3.2.1 | Alternative Solution | Manufactured material is inert; use in accordance with supplier's safety information |
Millboard is a low-carbon material that has been rigorously tested to ensure our production has minimal impact on the environment. While most composite decking boards are thermoplastic (melted plastic mixed with wood), the structural core of Millboard is a blend of natural minerals bonded in a polymer resin — such composite materials are designed to provide mechanical strength, chemical resistance and durability.
Every detail, one point of contact. Speak to a Forté specification consultant and get the technical support, documentation, and product knowledge you need to specify Millboard Decking with confidence.