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RLA 2 Part: A Technical Overview
RLA 2 Part is a premium two-component cementitious membrane that delivers the ultimate combination of toughness and flexibility. It masterfully blends the durable, high-adhesion characteristics of a cement-based system with the flexible, crack-resistant properties of an advanced acrylic polymer liquid. This versatile formulation is engineered to provide a fully compliant, seamless waterproofing barrier for an exceptionally broad range of applications. From internal wet areas and external balconies to fully immersed swimming pools and AS 4020 certified potable water tanks, RLA 2 Part offers a single-system solution that provides engineered certainty and uncompromising performance.
214%
Elongation (AS 4858). A Class II flexibility rating that accommodates anticipated structural movement and substrate shifts, preventing cracks and ensuring a continuous, durable waterproof barrier.
Core Features & Specifications
- Fully Certified to Australian Standards: Independently tested to AS 4858 (Class II), AS 4654.1 (External), and AS 4020 (Potable Water), providing documented proof of performance for specifiers.
- Suitable for Full Immersion: Engineered for continuous water immersion in swimming pools, ponds, and water features after a 7-day cure, providing a tough and durable barrier.
- Fast Drying & Recoat Time: Ready for recoat in just 2-4 hours and tiling or screeding in 24 hours, significantly accelerating project timelines for follow-on trades.
- High Adhesion Strength: Creates a tenacious bond to correctly primed substrates, ensuring the membrane system acts as a single, monolithic layer that resists delamination.
- UV Stable Formulation: Can be left exposed to UV light during the construction phase without degradation, providing greater flexibility with project scheduling.
The RLA 2 Part Advantage
- Ultimate Project Versatility: Use a single, trusted system for a huge range of applications – from showers and balconies to retaining walls and potable water tanks, simplifying inventory and training.
- Achieve Compliance with Confidence: Extensive third-party testing to key Australian waterproofing standards eliminates compliance risks and provides engineered certainty for your projects.
- Accelerate Project Schedules: The fast-drying formulation allows for subsequent trades (tilers, screeders) to get on-site sooner, improving overall job efficiency and profitability.
- Tough & Durable Finish: The cementitious base provides a robust, durable membrane that resists damage during the construction process and provides a long-service life.
Proactive Troubleshooting
Scenario: Applying to an Unprimed or Incorrectly Primed Substrate
Potential Outcome: Poor adhesion, blistering, or complete delamination of the membrane. Porous substrates can draw water from the mix too quickly, causing pin-holing and a compromised, leaky film.
Adheseal Best Practice: Priming is mandatory. Use RLA Porous Primer on absorbent surfaces like concrete, RLA Non Porous Primer on dense substrates like CFC sheeting, or RLA Moisture Seal on damp substrates per moisture test results.
Scenario: Insufficient Film Thickness (DFT)
Potential Outcome: The membrane fails to meet the performance requirements of a Class II membrane. It will not bridge cracks effectively and is highly susceptible to developing pinholes, leading to inevitable leaks and costly callbacks.
Adheseal Best Practice: Apply a minimum of two coats to achieve a total Dry Film Thickness (DFT) of 1.2mm. Use a wet film thickness gauge during application to ensure the minimum coverage of 1.5 litres/m² is consistently met across the entire area.
Applications in Practice: Trade Scenarios
For Waterproofers — Balcony & External Wet Areas
The Professional's Challenge
Deliver a fully compliant AS 4654.1 system that can withstand external exposure and substrate movement, while ensuring a uniform film build for reliable, long-term performance.
The Adheseal Solution: Engineered Certainty in Practice
The Class II flexibility of RLA 2 Part handles typical balcony movement. Its UV stability and fast cure time make it a reliable choice for external applications. A consistent two-coat application, verified with a WFT gauge, ensures compliance is met.
Best Practice Note
Detail all perimeters, junctions, and outlets with the Elastoproof Joint Band system, fully embedded between the two membrane coats, to create a seamless, monolithic waterproof barrier as required by the standard.
For Pool Builders — Immersed Applications
The Professional's Challenge
Construct a durable, tile-ready waterproof shell that performs under the constant hydrostatic pressure of permanent immersion and is certified safe for use in pools, ponds, and potable water tanks.
The Adheseal Solution: Engineered Certainty in Practice
RLA 2 Part is purpose-built for immersion, providing a tough, durable finish. Its AS 4020 certification provides the compliance needed for potable water applications. The system is ready for tiling after 24 hours and full immersion after a 7-day cure.
Best Practice Note
Ensure concrete substrates have cured for a minimum of 28 days before priming and application. The full 7-day cure time for the membrane is critical and must be observed before filling to ensure maximum durability.
Frequently Asked Questions
Is RLA 2Part suitable for immersion and potable water?
Yes — it is suitable for immersed environments (pools, ponds, water features) and is AS 4020 potable-water approved for tanks and storage facilities.
When can I recoat, tile or immerse?
Typical schedule at 23 °C/50% RH: Recoat 2–4 hours, tile/screed after ~24 hours, and immerse after ~7 days. Cooler/humid conditions extend these times.
What total film build is required?
Apply two coats at ~0.75 mm WFT each (at right angles) to achieve ~1.2 mm DFT minimum and target coverage of ~1.5 L/m².
Which primer should I use?
Porous Primer for absorbent substrates, Non-Porous Primer for dense substrates, and Moisture Seal where residual moisture exceeds thresholds (ASTM F2170/F2659). Follow individual primer TDS for coverage and method.
Can I use bond-breaker tapes in immersed areas?
Use system-approved detailing components; some options are not suitable for immersed applications. Select collars/tapes accordingly and embed per method.
Applications & Benefits
| Application / Use Case | Key Benefit | Primary Trades |
|---|---|---|
| Internal/external wet areas & balconies | Class II flexible membrane; fast recoat; tile-ready surface | Waterproofers, tilers, builders |
| Planter boxes & retaining walls | Robust cementitious finish with strong adhesion to mineral substrates | Builders, remedial contractors |
| Pools, ponds, potable water tanks | Immersion-rated; AS 4020 potable-water approved | Waterproofers, asset maintenance |
| Façade walls under tiles/stone | UV-stable membrane compatible with direct fixing of tiles | Tilers, builders |
Applying RLA 2Part: Enhanced Protocols & Best Practices
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Detailing & Bond Breakers
Seal junctions, joints and penetrations before field coating. Embed joint band into a wet coat or use self-adhesive tapes per system method. Use collars for pipes. Note some tapes/sealants are not suitable for immersed areas.
Pro Tip: Press out creases and air pockets when embedding bands/tapes; fully encapsulate with membrane. -
Mixing (Kit Components)
Part A (liquid) 20 L + Part B (powder) 2 × 10 kg. Add powder to liquid while mechanically mixing to a smooth, lump-free paste. Allow 5 min stand, then remix briefly. Do not hand-mix.
Timing: Pot life ~1 hour (shorter in warm conditions). Mix smaller batches as needed. -
Coating & Film Build
Apply the first coat by brush/roller to ~0.75 mm WFT. Once dry, apply the second coat at right angles, again to ~0.75 mm WFT. Verify with a wet film gauge to achieve ~1.2 mm DFT total (coverage target ~1.5 L/m²).
Pro Tip: Maintain even pressure and re-measure build across edges, corners and over detailing tapes. -
Dry Times & Overlays
Recoat 2–4 h, then tile/screed after ~24 h with polymer-modified adhesives. For immersion, allow ~7 days. Cooler temps and high RH extend times.
Pro Tip: For site-mixed screeds/renders over the membrane, dose with a proprietary bonding agent as specified.
How to apply RLA 2 PART Two Component Cementitious Membrane:
- Surface Preparation: Ensure all surfaces are clean, sound, smooth, dry, and free from contaminants. Mechanically remove any unsound layers or contaminants. Fill any defects, voids, or cracks.
- Priming: Apply the appropriate RLA primer based on the substrate's porosity: RLA Porous Primer for porous surfaces (1-2 coats), RLA Non Porous Primer for non-porous surfaces (1 coat), or RLA Moisture Seal for damp surfaces (1-2 coats). Allow primer to dry completely.
- Mixing: Pour half (10 litres) of Part A liquid into a clean 20L bucket. While mechanically stirring, slowly add one 10 kg bag of Part B powder and mix until smooth and lump-free. Allow to stand for 5 minutes and remix before use.
- First Coat Application: Using a brush or medium nap roller, apply an even first coat to the surface, achieving a minimum wet film thickness of 0.75mm (750 micron).
- Drying Time: Allow the first coat to dry completely, typically for 2-4 hours at 23°C and 50% RH. Drying times will vary with temperature and humidity.
- Second Coat Application: Apply a second coat at a right angle to the first coat, again achieving a minimum wet film thickness of 0.75mm (750 micron). This will result in a total minimum dry film thickness of 1.2mm.
- Detailing: Incorporate bond breaker tapes (e.g., Elastoproof Joint Band, BRW PF Tape) at all joints, junctions, and corners as per relevant Australian Standards (AS 3740 & AS 4654.1). Use Elastoproof Collars or BRW PF Tape for pipes and penetrations.
- Curing: Allow the membrane to cure fully before tiling or applying toppings. Polymer-modified adhesives can typically be used after 24 hours. Immersion in water should be delayed for 7 days.
Limitations & Safety
Product Limitations
Apply only when surface/ambient are between 5–35 °C. Do not apply if rain is imminent.
Not a trafficable finish. For pools/spas, not an exposed coating—must be tiled over.
Not suitable for negative hydrostatic pressure areas.
Follow primer selection rules for porous, non-porous and moisture-affected substrates.
Safety & Handling
PPE
Wear gloves, eye protection and a suitable respirator when mixing/applying. Avoid skin and eye contact.
Storage
12-month shelf life in unopened packaging. Store off the ground in a dry area, out of direct sun.
First Aid
Eyes:
Rinse with water for several minutes; seek medical advice.
Skin:
Wash with soap and water; remove contaminated clothing.
Inhaled:
Move to fresh air; seek medical attention if symptoms persist.
Swallowed:
Rinse mouth; do not induce vomiting; seek urgent medical attention.
Refer to the current SDS for full details.
RLA 2Part Waterproofing System Guide
Concrete / Render / Screed
Surface Preparation
Clean, sound, smooth and dry. Remove dust, oil, curing agents, release residues, coatings and laitance. Rectify voids/defects and ensure falls. New concrete: cure 28 days; render/screed: 7 days.
Primer Requirements
Primer required
Porous Primer on absorbent surfaces; Non-Porous Primer on dense/smooth surfaces; Moisture Seal where residual moisture is above thresholds (per ASTM F2170/F2659).
RLA Porous Primer / Non-Porous Primer / Moisture SealMasonry & CFC / Plasterboard
Surface Preparation
Point flush, repair damage and make level. Ensure surfaces are clean, dry and fit for purpose.
Primer Requirements
Primer required
Prime to suit porosity/density as above. Follow building standards and project specs.
RLA Porous / Non-Porous Primer; Moisture Seal if required
- Choosing a selection results in a full page refresh.