Description
Atlas Gemini RS White Silicone Render 25 kg — BBA-Certified Premium Facade Finish
A brilliant white base that gives your chosen pastel, cream, or neutral shade its truest, most vibrant expression on the finished facade — Atlas Gemini RS White 25 kg is a fibre-reinforced silicone render with proprietary 4K aggregate technology and siloxane-enhanced resins, covering approximately 10.9 m² per tub by hand at 1.5 mm grain (≥ 2.3 kg/m²) within the Atlas ETICS system covered by BBA Agrément Certificate 13/5018. Part of the premium silicone render collection, every tub is tinted on a dedicated Atlas mixing machine at our Southampton warehouse from the full 480-shade SAH palette, and our team also mixes bespoke colours to order — matching RAL codes, NCS references, or shades from other manufacturers' palettes — with next-day UK dispatch.
Beneath the surface, three integrated technologies protect your investment for decades: 3D-Flex elasticity bridges thermal stress and absorbs impact without micro-cracking, Mirror Effect high-reflectance additives lower surface temperature to shield both white pigments and polymer resins from UV degradation, and Biosec capsule biocide releases active agents gradually to prevent algae and mould colonisation — especially valuable on a white finish where every mark shows. Classified to EN 15824:2017 with V2 vapour permeability, W2 water absorption, and adhesion ≥ 0.35 MPa (DoP 280/CPR), Gemini RS White delivers specification-ready documentation for Building Control, NHBC inspectors, and warranty providers.
Key Benefits
- Maximum Pigment Brightness: The white base provides the lightest possible starting point for tinting, so pastel, cream, off-white, and light neutral shades achieve their truest colour expression — exactly what homeowners and designers look for on prominent front elevations and feature walls.
- UV-Stable White That Resists Yellowing: Mirror Effect high-reflectance additives protect both white pigments and polymer resins against UV degradation, meaning the surface resists yellowing and chalking far longer than conventional white renders and retains its clean, bright appearance year after year.
- Crack-Free Flexibility: 3D-Flex technology combines high-concentration polymer resins with cellulose fibres to bridge thermal stress, so the facade absorbs freeze-thaw cycles and rapid temperature swings without micro-cracking — the render stays intact through every UK winter without surface repairs.
- Built-In Biological Defence: A white surface shows every mark, which makes Biosec capsule technology especially valuable — it releases active agents gradually over the lifetime of the coat, preventing algae, mould, and lichen colonisation even on shaded or north-facing elevations so the facade stays looking freshly rendered without manual cleaning.
- Low-Maintenance Facades for Years: Rainwater does the cleaning work for you — a dense siloxane layer repels airborne dirt and rinses particles away with every downpour, so your white facade needs nothing more than an occasional soft-wash rather than regular manual scrubbing to maintain its bright, clean appearance.
- 480 Colours Plus Bespoke Matching: Every tub is tinted on a dedicated Atlas mixing machine at our warehouse and dispatched next day. Bespoke colours matched to RAL, NCS, or other manufacturers' references are mixed to order on the same equipment — so every project gets its exact shade without delay.
- Faster Application, Less Waste: On a typical residential front elevation the 4K aggregate formula bonds readily to trowel or machine nozzle, textures quickly, and cuts product waste on site — a two-person crew can finish a full storey in a single pass with a consistent lambskin texture throughout.
Technical Specifications
| Property | Value |
|---|---|
| Pack Size | 25 kg plastic bucket |
| Base Material | Siloxane-enhanced resins with 4K mineral aggregates, cellulose fibres |
| Base Colour | White — tintable across the full SAH palette |
| Grain Size | 1.5 mm (lambskin texture) |
| Density | ≈ 1.9 g/cm³ |
| Coverage (hand) | ≥ 2.3 kg/m² — approx. 10.9 m² per tub |
| Coverage (machine) | ≥ 1.9 kg/m² — approx. 13.2 m² per tub |
| Vapour Diffusion Resistance | 0.14 ≤ Sd < 1.4 m |
| Vapour Permeability Class | V2 (EN 15824) |
| Water Absorption Class | W2 (EN 15824) |
| Adhesion | ≥ 0.35 MPa |
| Application Temperature | +5 °C to +30 °C (0 °C with Atlas Eskimo accelerator) |
| Drying Time (touch-dry) | ≈ 15 min at 20 °C / 50% RH |
| Full Cure | ≈ 24 h at 20 °C / 50% RH |
| Colour Range | 480 SAH shades plus bespoke matching to order |
| pH | 8 |
| Shelf Life | 12 months from date of manufacture |
| Compliance | EN 15824:2017 (current as of early 2026) · DoP 280/CPR · UKCA · BBA System 13/5018 |
Application and Compatibility
Gemini RS White performs best when applied as the decorative finish within a certified ETICS build-up, bonding to a cured quartz primer coat over a properly reinforced basecoat and Atlas 150 g/m² fibreglass mesh. The render adheres to all stable mineral substrates — concrete, traditional cement-lime plasters, and fibre-cement boards — provided the surface is clean, dry, and structurally sound. For plinths and splash zones below the damp-proof course, pair the main-wall Gemini RS finish with a mosaic render at ground level for the heavy-duty impact resistance and washability those conditions require.
- Priming Requirement: Apply a system-matched quartz primer from the exterior render primers range at least 24 hours before rendering to regulate substrate suction and create the mechanical key the siloxane resins need for lasting adhesion.
- Winter Application: When site temperatures drop below +5 °C, adding Atlas Eskimo Setting Accelerator 0.25 kg extends the working window down to 0 °C and up to approximately 80% relative humidity, keeping winter projects on schedule without compromising cure quality.
- Machine Compatibility: The 1.5 mm 4K aggregate is optimised for professional rendering units with a 6 mm nozzle, delivering a uniform coat at lower material consumption (≥ 1.9 kg/m², approximately 13.2 m² per tub) than hand application — ideal for commercial elevations above 50 m².
- White-Base Colour Guidance: The white base achieves the brightest results on light, pastel, and neutral SAH shades — creams, warm greys, soft terracottas, and pure whites render with maximum clarity. For darker or very intense colours where deeper pigment saturation matters, the Gemini RS Grey 25 kg provides richer first-coat depth from the same premium system.
Installation Notes
The 4K formula gives you extended open time and even aggregate distribution, so a two-person crew can plan each elevation as a single continuous wet-edge pass and cover a full storey before the leading edge begins to set — the best route to a flawless white finish. Stir the bucket thoroughly with a low-speed mechanical mixer before use, and keep spare tubs from the same production batch on site to maintain perfect shade consistency across the full facade. White finishes reward careful preparation more than tinted ones, because the lightest base makes every detail of surface texture visible.
- Texturing Technique: Work with a plastic float in consistent circular motions rather than alternating directions, which can create visible pattern breaks on a white surface where uniformity is especially critical.
- Sun Protection During Cure: Protect freshly applied panels from direct intense sunlight during the first 24 hours — temporary shade mesh helps the render cure evenly, preventing differential surface tension that can affect the finished appearance on a bright white coat.
Trade Insight — Installer's Note
The white base is the one to reach for on residential front elevations and feature walls where the client wants a pure white or a very light shade — no grey undertone means the final colour reads exactly as the SAH chart shows, so you deliver exactly the shade the client signed off on without return visits to adjust expectations. On a recent 80 m² residential front, hand application at about 2.3 kg/m² gave a uniform lambskin texture even on a warm day with intermittent sun, and the Mirror Effect technology made a noticeable difference to how evenly the surface dried. For anyone pricing a project, budget at 2.3 kg/m² hand or 1.9 kg/m² machine, add 10% for reveals and detailing (roughly one extra tub per 100 m²), and check a 48-hour weather window before starting — that combination consistently delivers a flawless white surface and accurate material costing.
Is This Product Right for Your Project?
- Yes — for bright, light-coloured premium facades: Gemini RS White is the right render when your design calls for pure white, soft pastels, or light neutral tones on a facade that demands certified ETICS system compatibility, long-term self-cleaning performance, and biological protection — ideal for residential front elevations, feature walls, and any project where colour brightness and accuracy are the priority.
- Need a grey base for darker shades? The Atlas Gemini RS Grey 25 kg in the same premium range uses identical 4K, Mirror Effect, and Biosec technologies with a grey base — choose it when your colour scheme calls for deep blues, charcoals, or intense terracottas where a grey undertone provides richer pigment saturation from the first coat.
- Looking for a cost-effective alternative on sheltered facades? The broader silicone render collection includes standard silicone finishes that deliver excellent hydrophobic and vapour-permeable performance at a lower price point — a smart choice for moderate-exposure residential elevations where the premium 4K, Mirror Effect, and Biosec technologies are not essential.
Frequently Asked Questions
How many tubs of Gemini RS White do I need for my project?
At the standard 1.5 mm grain, hand application uses at least 2.3 kg/m², which means one 25 kg tub covers approximately 10.9 m². For a typical 100 m² elevation, order 10 tubs plus one spare to cover window reveals and detailing. Machine application is more economical — around 1.9 kg/m², giving approximately 13.2 m² per tub — so 8 tubs plus one spare covers the same area comfortably.
Will the white finish yellow over time?
Mirror Effect technology is specifically designed to prevent the UV degradation that causes yellowing and chalking in conventional white renders. The high-reflectance additives lower the surface temperature of the white coat and protect the polymer resins and pigments, so the finish retains its original brightness for years. Combined with the self-cleaning hydrophobic surface that rinses away atmospheric deposits during rainfall, a Gemini RS White facade stays visibly brighter for longer than standard white alternatives.
Is Gemini RS White an environmentally responsible choice?
Gemini RS is a water-based formulation with low volatile organic compound (VOC) content, releasing minimal emissions during application and curing — safer for installers and occupants nearby. Atlas confirms the product's environmental credentials through a Type III Environmental Product Declaration (EPD), independently verified to quantify lifecycle impacts. Combined with a service life measured in decades — the BBA system expects at least 30 years of effective performance — each application cycle replaces what would otherwise be multiple repaint or re-render operations, reducing total material consumption over the life of the building.
What colours are available and can you match a shade from another manufacturer?
The white base accepts tinting across the full 480-shade Atlas SAH palette on a dedicated Atlas mixing machine at our Southampton warehouse, and it achieves its brightest results on light, pastel, and neutral tones. For projects that need a shade outside the standard Atlas range — a specific RAL code, an NCS reference, or a colour matched from another manufacturer's swatch — our team mixes bespoke colours to order on the same equipment. Beyond the Atlas palette, our warehouse also mixes the Ceresit Colours of Nature range on a separate dedicated machine, bringing the combined colour choice across both systems to over 1,000 standard shades plus bespoke matching. Browse the colour sample catalogues to view both palettes on physical rendered swatches, or contact us with your reference code for a bespoke match quote.
Does the BBA certification cover the entire system?
BBA Agrément Certificate 13/5018 covers the complete Atlas ETICS system — adhesive, reinforcing layer, primer, and finish coat are all assessed together as a single certified assembly. Using system-matched components (quartz primer, Atlas mesh, and the correct basecoat mortar) ensures the certification and any associated warranty remain valid, giving Building Control a clear compliance pathway for sign-off on your project.
Technical Documentation