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RLA Fairing Coat Mortar: A Technical Overview
RLA Fairing Coat Mortar is a polymer-modified, fine-textured cementitious compound formulated for thin repairs up to 5 mm in a single application. It develops exceptional adhesion to concrete and masonry with negligible shrinkage, curing to a smooth surface that does not reflect through subsequent architectural coatings. Supplied in 20 kg bags, it mixes with 5.9–6.0 L water, yields ~14 L, and has an indicative wet density of ~1800 kg/m³. Apply between 5–35 °C on prepared, SSD substrates for reliable, uniform fairing.
25 min
Typical working time @ 20 °C
Core Features & Specifications
- Thin-build up to 5 mm in one pass; suitable for vertical fairing and feather edges.
- Fast setting with ~25 min working time and ~50 min to no longer workable @ 20 °C.
- Mix-with-water simplicity: 5.9–6.0 L per 20 kg (yield ~14 L).
- Smooth finish that won’t telegraph through architectural coatings.
- Internal and external use; application window 5–35 °C.
- 28-day strengths (typical): Compressive ~20 MPa, Flexural ~7.1 MPa.
- Drying shrinkage (AS 1012.13): <100 µε (7 d), <300 µε (28 d), <450 µε (56 d).
- Shelf life: 12 months (unopened, stored dry). Packaging: 20 kg bags.
The RLA Fairing Coat Mortar Advantage
- Produces a uniform, paint-ready finish with minimal risk of telegraphing.
- Fast turnaround: workable in minutes and coatable from 48 hours (10–35 °C conditions; check coating manufacturer guidance).
- Predictable results using clear water addition, yield, and temperature parameters.
- Strong adhesion and negligible shrinkage help reduce rework and call-backs.
Proactive Troubleshooting
Scenario: Over-watering to extend working time
Potential Outcome: Low strength and extended cure, poor trowelability.
Adheseal Best Practice: Keep to 5.9–6.0 L/20 kg; mix to a smooth, soft mortar and do not re-temper once set begins.
Scenario: Applying in hot, windy conditions without curing
Potential Outcome: Premature drying, poor workability, surface defects.
Adheseal Best Practice: Use chilled water for mixing; apply a compatible curing agent on exposed repairs and those in direct sun or strong winds.
Applications in Practice: Trade Scenarios
For Builders (On-site Applicator): Pre-paint fairing of precast panels
The Professional's Challenge
Eliminate pinholes, bug-holes and minor edge chips quickly so coating crews can proceed without visible telegraphing.
The Adheseal Solution: Engineered Certainty in Practice
Prepare to sound concrete and SSD; trowel apply up to 5 mm in a single pass. Smooth off and allow to cure; coatings can typically proceed after ~48 hours subject to conditions and coating spec.
Best Practice Note
In warm/windy conditions, apply a curing agent after the final trowel to prevent flash drying and retain workability during placement.
For Remedial Contractors: Thin repairs to honeycombing and form tie marks
The Professional's Challenge
Achieve a tight, durable fairing layer that blends with adjacent surfaces without cracking or debonding.
The Adheseal Solution: Engineered Certainty in Practice
Mechanically key the surface, remove laitance and pre-dampen to SSD. Mix with 5.9–6.0 L water per bag; trowel and feather as required.
Best Practice Note
Avoid over-working the surface; protect from rapid drying and implement curing where exposed.
For Asset Maintenance: Stand-alone finish in architectural concrete touch-ups
The Professional's Challenge
Blend repairs seamlessly where no coating is planned, maintaining a durable, uniform appearance.
The Adheseal Solution: Engineered Certainty in Practice
Apply as a thin fairing coat with careful finishing. Product can be left exposed as the final coat where appropriate.
Best Practice Note
Respect the 5–35 °C application window; in cooler weather, use warm mixing water to maintain workability.
Frequently Asked Questions
What thickness can I apply in a single pass?
Apply up to 5 mm per application. You can feather-edge for local patching, but avoid over-working the surface; build in additional passes if greater build is required.
How much water per 20 kg bag?
Use 5.9–6.0 L of clean water. Add powder to liquid while mixing to achieve a smooth, soft mortar. Do not re-temper once setting has commenced.
When can I over-coat?
Under 10–35 °C conditions, finishes can typically be applied after ~48 hours. For <10 °C, allow a further 24 hours. Always follow the coating manufacturer’s requirements.
What are the recommended application temperatures?
Apply between 5–35 °C. Use warm water in cool conditions and chilled water in hot conditions to optimise workability and setting.
Can it be left exposed as the final coat?
Yes. The mortar can be left as a stand-alone finish, or it can be over-coated with suitable protective or decorative systems.
Applications & Benefits
| Application / Use Case | Key Benefit | Primary Trades |
|---|---|---|
| Infill over surface imperfections, bug-holes, tie holes | Thin-build up to 5 mm with smooth, uniform finish | Builders, remedial contractors |
| Vertical fairing of columns, beams, soffits | Fast setting; excellent adhesion and negligible shrinkage | Builders, asset maintenance |
| Over-skimming other RLA mortars for a uniform surface | Consistent texture ready for coatings or stand-alone finish | Remedial contractors, precast installers |
| Stand-alone architectural touch-ups | Smooth finish that won’t telegraph through coatings; can be left exposed | Asset maintenance, builders |
Applying RLA Fairing Coat Mortar: Enhanced Protocols & Best Practices
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Surface Preparation
Mechanically remove laitance and weak material; clean thoroughly. Pre-dampen to SSD and ensure no standing water remains.
Mechanical key
Scabbling, grinding, or high-pressure water-blasting to provide a consistent key.
Moisture conditioning
Pre-soak, then allow surface to return to SSD prior to application.
Timing: New concrete must cure at least 21 days before fairing.Pro Tip: On highly porous substrates, apply Rendergrip A before pre-soaking to reduce flash drying. -
Mixing
Add powder to 5.9–6.0 L of clean water per 20 kg while mixing with a low/medium-speed paddle to a smooth, soft mortar.
Add powder to liquid
Minimises lumps and ensures uniform consistency. Do not re-temper once set begins.
Temperature control
Use warm water in cool weather and chilled water in hot conditions to optimise working time.
Timing: Use only what can be placed within the working time (~25 min @ 20 °C).Pro Tip: Keep mixing gear and buckets clean to maintain finish quality. -
Application & Finishing
Trowel apply to the required finish. Limit single-pass thickness to 5 mm; feather-edge as needed for patching.
Trowelling
Apply with firm pressure to ensure full contact; avoid over-working the surface.
Timing: Product becomes non-workable at roughly ~50 min @ 20 °C.Pro Tip: In hot/windy or direct sun, apply a curing agent immediately after finishing. -
Curing & Over-Coating
Protect from premature drying. Use a compatible curing agent on exposed repairs and in warm or windy conditions. Coatings can generally be applied after ~48 hours at 10–35 °C; allow longer below 10 °C.
Pro Tip: Confirm moisture/condition meets the coating manufacturer’s requirements before over-coating.
Limitations & Safety
Product Limitations
Not for substrates subject to rising damp or wet areas.
Apply only between 5–35 °C; adjust mixing water temperature to suit site conditions.
Do not add excess water; it will reduce strength and can extend cure time.
Maximum single-pass thickness is 5 mm.
Safety & Handling Requirements
Personal Protective Equipment
Wear gloves, eye protection and a suitable dust mask/respirator when handling powder and mixing. Avoid skin contact; wear protective clothing.
Ventilation
Ensure good ventilation during use, particularly indoors or in confined areas.
Storage & Handling
Store sealed in a cool, dry place; keep off cold floors and out of direct sunlight. Shelf life is 12 months in unopened packaging.
Emergency First Aid
Eyes:
Rinse cautiously with water for several minutes. Remove contact lenses if easy. Continue rinsing and seek medical advice.
Skin:
Wash with soap and water; remove contaminated clothing.
Inhaled:
Move to fresh air and rest. Seek medical attention if symptoms persist.
Swallowed:
Rinse mouth; do not induce vomiting. Seek medical attention.
Refer to the latest Safety Data Sheet (SDS) for full health and handling information.
RLA Fairing Coat Mortar Application Guide
Concrete (vertical/horizontal fairing)
Surface Preparation
Remove oil/grease/contaminants; break back to sound substrate. Mechanically key by scabbling, grinding or water-blasting. Pre-dampen to SSD; ensure no free water remains. New concrete must be cured for at least 21 days.
Primer Requirements
Primer optional / SSD required
On highly porous substrates, apply RLA Rendergrip A prior to pre-soaking to reduce flash drying and retain workability. For exposed/warm conditions, also use as a curing aid after finishing.
RLA Rendergrip ACementitious Masonry
Surface Preparation
Remove weak/friable material; clean and pre-dampen to SSD. Create a light mechanical key where necessary.
Primer Requirements
Primer recommended where suction is high
Use RLA Rendergrip A on highly porous surfaces to improve open time and placement quality.
RLA Rendergrip A
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