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Secura™ Exterior Flooring

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The Smarter Substrate for Tiled Balconies and Decks

Particle board and plywood are the default substrates on many tiled external deck and balcony projects. They’re cheap, they’re familiar and they’re easy to work with. They’re also moisture-sensitive in a way that creates long-term problems that show up well after the warranty period and cost significantly more to fix than the original substrate was worth.

Scyon® Secura™ Exterior Flooring is the structural flooring substrate designed specifically for external tiled balcony and deck applications; it is lighter than compressed fibre cement, tongue-and-groove jointed, gun-nailable without pre-drilling and sealed on all sides with an advanced polymer coating. Mesh-reinforced on the underside for extra impact resistance. Suitable for use with all standard tile adhesive systems. An alternative to particle board, plywood and CFC that provides genuine moisture defence over the life of the building.

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Technical Specifications

Installation guide

Technology

Scyon® – advanced lightweight cement composite

Thicknesses

19mm · 22mm

Sheet sizes

2700mm × 600mm (primary) · 2400mm × 600mm (22mm only)

Joint system

Tongue-and-groove – engineered joint, no timber trimmers required

Fixing

Gun-nailable – no pre-drilling required

Underside

Mesh-reinforced – extra strength and impact resistance

Sealing

All sides sealed with advanced polymer coating

Moisture protection

Moisture resistant – will not warp, twist or require sanding when exposed to the elements

Site exposure

Weatherable for up to 3 months without replacement or sanding

Tile adhesion

A pre-sealed coating aids adhesive adhesion

Compatible finishes

Ceramic tiles · Natural stone · Pavers – all standard tile adhesive systems

Joist compatibility

Timber or lightweight steel joists – confirm spacing against installation guide

Warranty

25-year product warranty · Australian-made

The Moisture Argument

External balconies and decks are among the highest moisture-exposure building elements in Australian residential and commercial construction. Rain, ponding water, cleaning water, or waterproofing failures – any of these can introduce moisture into the floor substrate. How the substrate responds to that moisture determines whether the tiled surface above it remains stable or begins to fail.

Particle board does not belong here

Standard particle board is not suitable for external applications; it swells, delaminates and loses structural integrity rapidly when wet. Even moisture-resistant particle board grades deteriorate progressively in the ongoing moisture cycling of an external deck or balcony. Tiles over a deteriorating particle board substrate will lift and crack.

Plywood - better, but still moisture-sensitive

Structural plywood performs better than particle board in external applications, but it is still an organic product that swells with moisture absorption, developing surface variation that stresses tile adhesive bonds over time. Delamination is a known failure mode for plywood in high-moisture external floor applications.

Secura™ Exterior - designed for this

Secura™ Exterior is a fibre cement product sealed on all four sides with an advanced polymer coating. It won't swell, won't delaminate and won't lose structural integrity when wet. If moisture gets under the tile system, through a waterproofing failure or at the deck perimeter, the substrate continues to perform while the source of moisture is identified and rectified.

Lighter and faster than compressed CFC

Traditional compressed fibre cement flooring is dense and heavy; handling and installing it on elevated balconies and decks is slow and labour-intensive, requiring pre-drilling and screwing. Secura™ Exterior is lighter (Scyon® technology), gun-nailable, tongue-and-groove jointed and doesn't require timber trimmers under joints and is significantly faster to install.

Waterproofing Note

Secura™ Exterior Flooring is a structural substrate, not a waterproof membrane. A compliant waterproofing membrane must be applied over the substrate in external tiled deck and balcony applications per AS 4654 and the NCC. Secura™ Exterior’s moisture resistance protects the substrate in the event of waterproofing failure but does not replace the membrane requirement.

Application Contexts

Tiled residential balconies

The primary application is a structural substrate for tiled finishes over timber or steel joists on residential balconies. Secura™ Exterior’s moisture resistance and dimensional stability under external conditions make it significantly more appropriate than plywood or particle board for this application, particularly in coastal and high-humidity locations.

External decks with tile finishes

Where the design calls for a tiled deck surface rather than timber boards or composite decking, Secura™ Exterior provides the structural flooring base. Its suitability for gun-nailing and tongue-and-groove jointing makes installation on elevated decks practical without the heavy handling that compressed fibre cement requires.

Covered walkways and verandahs

Partially covered external floor areas that experience regular rain exposure, verandahs, covered walkways and transitional indoor-outdoor spaces. The up-to-3-month weatherability during construction means Secura™ Exterior can be installed ahead of waterproofing and tiling without degrading if construction delays occur.

Featured Projects with Secura™ Exterior Flooring

Bacchus Marsh Grammar Woodlea Project

Mernda Ambulance Station Cladding Project

The Wickham Duplex Residential Project

Frequently Asked Questions

Is Secura™ Exterior Flooring suitable for use over timber joists?
Yes. Secura™ Exterior Flooring is designed for installation over timber or lightweight steel floor joists. The required thickness, 19mm or 22mm, depends on the joist spacing. The installation guide confirms the appropriate thickness for different joist centres and span conditions. Standard residential joist spacings are covered by the 19mm product; wider spacings may require 22mm.
Yes. Secura™ Exterior Flooring is compatible with ceramic tiles, natural stone, slate and pavers using standard or flexible tile adhesive systems. For heavy natural stone (slate, travertine or granite over 15mm thick), confirm the tile adhesive system’s requirements and the joist spacing against the load limits in the installation guide.
Secura™ Exterior Flooring can be exposed to the elements for up to three months without warping, twisting or requiring replacement or sanding. This is significantly better than timber-based alternatives that deteriorate and require replacement or remediation if exposed to prolonged moisture during construction delays.