Duram Azcothane Reo Waterproofing Membrane

Duram Azcothane Reo is a water-based, polyurethane-fortified acrylic hybrid membrane reinforced with micro-fibres. It is designed for protected waterproofing applications such as balconies, terraces, decks, podiums, showers and wet areas where a flexible liquid-applied membrane is required.

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How it works

Azcothane Reo cures to form a bonded, seamless membrane without joints or laps. Its acrylic hybrid chemistry allows for the direct application of tiles and render. The internal microfibre reinforcement controls tensile forces across the membrane, providing a Class III high-extensibility barrier that accommodates substrate movement. It does not re-emulsify once fully cured, preventing breakdown under standing water, and is completely free of bitumen and tar to ensure grout or tiles will not stain.

Numbers that matter

• Class III elongation (311%): Formulated to meet AS/NZS 4858 and AS 4654.1 standards, absorbing the movement of lightweight composite sheeting, cementitious screeds, and masonry joints without cracking.
• 1.0mm WFT / 0.5mm DFT per coat: Applied at a coverage rate of 1m² per litre per coat. A standard waterproofing application requires a minimum of two coats to achieve a total dry film thickness of 1.0mm.
• 4-day full cure: Reaches full cure in 96 hours (at 25°C and 50% RH). The membrane must be fully cured before installing tiles, screeds, or toppings.
• 1.32 MPa tensile strength: Delivers durable mechanical resistance under protected finishes on concrete and masonry substrates.
• 6.36 g/m²/24 hours water vapour transmission: Restricts moisture passage to protect internal building structures from vapour damage.

Where to use it

Azcothane Reo is suitable for application on clean, sound, and dry water-resistant substrates including:

• Concrete and cementitious screeds
• Masonry
• Lightweight composite sheeting

Limitations

• Do not use as a trafficable waterproof membrane.
• Do not use below grade or in planter boxes.
• Not suitable for application on wet substrates. Cementitious surfaces must be dry: < 75% RH via ASTM F2170 in-situ probe, or < 4.5% via ASTM F2659 non-destructive comparative surface moisture test.
• Do not use in direct contact with high concentrations of chlorine.
• Do not use particleboard sheeting as a substrate for this waterproofing system.
• Do not apply primers, sealants, or membranes to frosty, damp, or wet surfaces, or when the substrate temperature is below 4°C or above 43°C.

Required preparation and priming

To prevent adhesion failure, concrete and cementitious substrates must be cured to a minimum 20MPa compressive strength, free of laitance (removed via shot blasting, grinding, or sandblasting), and free of curing agents, mould, or other contaminants. All voids and indentations greater than 5mm must be filled with a compatible compound prior to application.

Substrates must be primed before membrane application using the following system components:

• Porous substrates: Prime with Duram Primeseal MC (preferred), Duram WB Primer, or Maxiprime. For damp substrates or where a vapour barrier is required, apply two coats of Duram Primeseal MC.
• Metal surfaces: Mechanically abrade to AS 1627.4 Class 2.5 (Near White Metal) and prime with Duram ME Primer.
• Plastic substrates, floor wastes, and puddle flanges: Mechanically abrade to create a profile, wipe clean with isopropyl alcohol using the two-cloth method, and prime with Duram Superprime 711.

Detailing and fillets

• Static cracks < 1.6mm wide: Apply a 150mm wide detail coat of Azcothane Reo over the primed substrate before coating.
• Static cracks > 1.6mm wide and construction joints: Grind out to a minimum width of 6mm. Install a backing rod or bond breaker tape to prevent three-sided adhesion, fill with a compatible sealant to a 1:1 width-to-depth ratio, and apply a 150mm wide detail coat of membrane.
• Internal wet area fillets: Install a 12mm bead of compatible sealant to form a fillet in accordance with AS 3740.
• External above-ground fillets: Install a 15mm x 15mm bead of compatible sealant to form a fillet in accordance with AS 4654.2. All external corners must have chamfered edges to ensure consistent membrane thickness.
• Reinforced detailing: For joints requiring external fabric reinforcement, bed Duram Durascrim polyester fabric into a wet coat of Azcothane Reo, roll flat to remove wrinkles, and apply an additional two coats of Azcothane Reo over the detail area.