RLA Safe2O

For retaining walls, planter boxes, and under-screed wet areas requiring compliance with AS 4858 and AS 4654.1, Safe2O provides a solvent-free, moisture-curing waterproofing barrier. This single-component membrane is based on Silyl Modified Polymer (SMP) technology, delivering a tough, elastomeric Class III finish without the hazards of traditional solvent-based polyurethane coatings.

How it works

Safe2O cures upon exposure to atmospheric moisture to form a highly flexible, durable barrier. On stable horizontal surfaces, its high-build formulation allows installers to achieve the required film thickness in a single application, eliminating the waiting time between coats. For below-ground applications like planter boxes and retaining walls, the membrane incorporates an in-built root inhibitor to prevent root penetration from compromising the waterproofing layer. It carries Green Star credentials as a Green Tag certified, isocyanate-free alternative for sensitive or confined workspaces.

Numbers that matter

• Class III elongation (>300%): High elasticity tested to AS 4858 and AS 4654.1, absorbing thermal expansion and structural movement in concrete, screeds, and fibre cement sheeting without shearing or cracking.
• 1.2mm minimum dry film thickness (DFT): The required barrier thickness to meet compliance, achieved in 1 coat on horizontal substrates (1.4kg/m²) or 2 coats on vertical surfaces (0.6mm WFT per coat).
• 4-hour drying and recoat time: Rapid initial cure at 23°C and 50% RH, with a strict maximum recoat window of 24 hours to ensure chemical bonding between layers.
• 48-hour screeding window: Safe to accept sand-cement screeds after two days of curing, protecting the membrane during subsequent tiling preparation.
• 72-hour backfilling cure: The minimum curing period required before backfilling soil against treated subterranean retaining walls and planter boxes.

Where to use it

Safe2O bonds to common structural and wet-area substrates, including:

• Concrete (cured minimum 28 days; extremely high MPa concrete requires diamond grinding)
• Render and cement screeds (cured minimum 7 days)
• Masonry pointed flush
• Compressed and fibre cement sheeting
• PAA certified Structural and Marine plywood

Limitations

• Do not apply externally if rain is imminent.
• Do not apply over existing coatings; all paint, grease, curing compounds, and laitance must be mechanically removed.
• Do not apply directly to particle board flooring; a ceramic tile underlay must be installed first.
• Do not use as an external UV-exposed finish or as a trafficable membrane.
• Do not use for permanently immersed applications.
• Do not apply directly under tiles without an intervening screed.
• Do not apply when surface temperatures are below 10°C or above 35°C.
• Do not apply to areas subject to negative hydrostatic pressure or rising damp unless the substrate is first treated with RLA Moisture Seal.

Application and joint preparation

Installation must follow AS 3740 for internal wet areas and AS 4654.2 for external designs.

All static cracks 1mm or wider must be cleaned and filled flush with RLA MAX SMP 25 before membrane application. For floor-to-wall junctions, horizontal and vertical transitions, and around penetrations, drainage outlets, and flanges, install a 12mm x 12mm bond-breaker fillet using RLA MAX SMP 25 sealant.

Apply the membrane using a brush or medium nap roller. Test the depth regularly during application with a wet film thickness gauge to ensure minimum targets are met. Clean tools immediately after use with isopropanol, a suitable cleaning solvent, or a citrus-based cleaner, as the product will begin to cure once exposed to air.