ATLAS GEMINI RS RENDER WHITE 25kg

Pure whites and pale pastels need a starting base that won't dull them, plus protection against the UV yellowing that ages conventional white renders. Atlas Gemini RS White 25 kg answers both — 10.9 m² hand coverage at 1.5 mm grain (≥ 2.3 kg/m²) under BBA Agrément 13/5018, with Mirror Effect anti-yellowing protection built into every tub.

Where Atlas Gemini RS White Performs Best on UK Facades

Atlas Gemini RS White 25 kg is a fibre-reinforced silicone render with proprietary 4K mineral-aggregate technology and siloxane-enhanced resins, formulated as the brightest possible starting point for pure whites, soft creams, light pastels, and warm neutral SAH tones. The product is part of the premium silicone render range and certified within the Atlas ETICS system under BBA Agrément 13/5018, classified to EN 15824:2017 with V2 vapour permeability, W2 water absorption, and adhesion ≥ 0.35 MPa (DoP 280/CPR).

The white pigment base is the right specification when colour fidelity matters most — residential front elevations, feature walls, schools, and any facade where the client signs off on a chart shade and expects the finished wall to read exactly the same. Three integrated technologies sit beneath that finish: 3D-Flex elasticity bridges thermal stress, Mirror Effect high-reflectance additives shield white pigments and polymer resins from the UV degradation that causes yellowing, and Biosec capsule biocide releases active agents gradually across the coat's full service life — a meaningful advantage on white surfaces where every mark would otherwise show.

Why Trade Specifiers Choose Atlas Gemini RS White

• BBA-certified within Atlas ETICS: BBA Agrément 13/5018 covers the complete Atlas ETICS assembly — adhesive, reinforcing layer, primer, and finish coat assessed together — giving Building Control and warranty providers a single compliance pathway.
• Maximum brightness for pale shades: the white pigment base gives pastels, creams, off-whites, and pure whites their truest colour expression, so the finished facade reads exactly as the SAH chart shows without grey undertone shifting the appearance.
• Mirror Effect anti-yellowing protection: high-reflectance additives lower the surface temperature of the white coat, shielding both white pigments and polymer resins against the UV degradation that causes conventional white renders to yellow and chalk over time.
• 3D-Flex crack-bridging elasticity: high-concentration polymer resins combined with cellulose fibres absorb thermal expansion, freeze-thaw cycles, and minor impacts without micro-cracking, so the facade stays intact through every UK winter.
• Biosec biological defence for white surfaces: encapsulated biocide releases active agents gradually over the coat's service life — particularly valuable on white finishes where algae, mould, and lichen would be immediately visible on shaded or north-facing elevations.
• Self-cleaning siloxane surface: a dense siloxane layer lets rainwater rinse airborne dirt and pollutants away naturally, keeping the white visibly bright between natural washes and dropping maintenance to occasional soft-washing rather than scheduled cleaning.
• Tinted on site with next-day dispatch: every tub is mixed to your chosen shade at our Southampton warehouse on a dedicated Atlas machine, with bespoke RAL, NCS, or other manufacturers' references mixed to order on the same equipment.

Technical Specifications — Atlas Gemini RS White Data Sheet Highlights

Property	Value
Pack size	25 kg plastic bucket
Base material	Siloxane-enhanced resins · 4K mineral aggregates · cellulose fibres
Base colour	White — tintable to full 480 SAH palette + bespoke RAL / NCS
Grain size	1.5 mm (lambskin texture)
Density	≈ 1.9 g/cm³
Coverage — hand	≥ 2.3 kg/m² (≈ 10.9 m² per tub)
Coverage — machine	≥ 1.9 kg/m² (≈ 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 to substrate	≥ 0.35 MPa
Application temperature	+5 °C to +30 °C (0 °C with Atlas Eskimo)
Relative humidity at application	< 80 %
Touch-dry	≈ 15 min (at 20 °C, 50 % RH)
Full cure	≈ 24 h (at 20 °C, 50 % RH)
pH	8
Shelf life	12 months from manufacture date
Standard	EN 15824:2017 (current edition)
DoP	280/CPR · UKCA
BBA system certificate	13/5018 (Atlas ETICS EPS system)

How to Apply Atlas Gemini RS White — Mixing, Pot Life, Coverage

The tub is ready for the wall as supplied — no thinning, no thickening, no proprietary blend additions to the paste. A 30–60 second power-stir with a low-speed paddle mixer immediately before each load smooths consistency and breaks any surface skin. The system beneath the finish carries the rest of the performance: a cured reinforced basecoat embedding the alkali-resistant Atlas reinforcement mesh (150 g/m²), primed with a system-matched quartz primer from the exterior render primer range, is what releases the 4K aggregate's full self-cleaning, crack-bridging, and biocidal behaviour.

Spread the render across each panel with a stainless-steel trowel at aggregate thickness, returning surplus material to the bucket and stirring between loads. Texture immediately afterwards with a plastic float, working steady circular motions until the lambskin grain pulls evenly across the surface. The 4K formula gives extended open time, so a two-person crew can carry the wet edge across a full storey before the leading band begins to set — that wet-edge discipline is decisive on white finishes, where any lap mark or pace-related shade shift reads immediately under afternoon raking light.

• Coverage at 1.5 mm hand: ≥ 2.3 kg/m² — one 25 kg tub covers approximately 10.9 m² on an even basecoat.
• Machine application: 1.5 mm 4K aggregate optimised for professional rendering units with a 6 mm nozzle, ≥ 1.9 kg/m² (≈ 13.2 m² per tub) — preferred for commercial elevations above 50 m².
• Line conditioning: run a charge of system-matched primer through the machine hose before render goes through — the wet interior keeps the first pull clean and uninterrupted.
• Open time and re-stirring: ready-mixed — a second 30-second power-stir handles any tub that has stood more than 10 minutes; never add water, retarder, or proprietary mortars.
• Drying window: approximately 15 min surface dry and 24 h full cure at 20 °C and 50 % RH; protect from rain, wind, and direct sun across that window.

Installation Notes — Conditions, Drying Times, Finishing

White-finish quality is decided at the primer stage: apply a system-matched quartz primer at least 24 hours before rendering to regulate substrate suction and create the mechanical key the siloxane resins need for lasting adhesion. Pick a working day inside +5 °C to +30 °C with relative humidity below 80 %, and shield freshly applied panels from direct intense sunlight during the first 24 hours — temporary shade mesh helps the render cure evenly and prevents the differential surface tension that can mark a bright white coat.

For programmes that push into autumn or early spring, Atlas Eskimo setting accelerator (0.25 kg per 25 kg tub) extends the working range to 0 °C and shortens initial set, so the render is less vulnerable through the longer cold-weather drying window. The full seasonal protocol — temperature thresholds, humidity checks, and 48-hour forecast routine — is covered in the cold-weather rendering timing guide.

Run a single production batch across each elevation so batch-driven shade drift cannot creep in across a white finish where any drift would be visible. Plan technological breaks before scaffolding goes up — corners, downpipes, sill lines, and recess details all conceal a joint, while mid-panel pauses never do. Tools rinse in clean water immediately at break time.

Pro Tips From UK Installers Using Atlas Gemini RS White

White facades reward preparation discipline far more than tinted ones, because the brightest base makes every detail of surface texture visible. The tips below reflect what experienced UK applicators do differently when the spec calls for Gemini RS White on a prominent residential or feature elevation.

• Straight-edge the basecoat before priming: running a 2 m straight edge across the cured reinforcement layer catches the high spots and shallow dips that a dark tint would have absorbed — on white they read clearly in afternoon raking light, and a five-minute fix at basecoat stage saves the entire facade.
• Specify Mirror Effect for south-facing white elevations: the high-reflectance additives lower surface temperature and slow UV degradation of pigments and resins — a meaningful service-life advantage over conventional white renders on the most exposed orientations.
• Shade the wet edge on bright days: intense direct sun during the first 24 hours can cause differential surface tension that marks the cured coat — temporary shade mesh on south-facing elevations is cheap insurance against the kind of patchy finish that can otherwise need a recoat.
• Budget by application method: price at 2.3 kg/m² hand or 1.9 kg/m² machine, add 10 % for reveals and detailing — approximately one extra tub per 100 m² covers waste and corner work without over-ordering.
• Approve bespoke white shades at scale: for off-whites and warm creams matched to a specific RAL or NCS reference, tint a test tub and apply at full thickness on a 1 m² panel under daylight before committing — subtle off-white shades read very differently at scale than on a chip.

Is Atlas Gemini RS White Right for Your Project?

• Choose this render if: your project specifies pure white, soft pastels, or light neutral tones on a facade that demands certified ETICS system compatibility, anti-yellowing UV protection, and lifetime biological defence — Gemini RS White is the right specification for residential front elevations, feature walls, schools, and any premium project where colour brightness and accuracy are the priority.
• For mid-tone and dark shades: switch to Atlas Gemini RS Grey 25 kg — same premium 3D-Flex, Mirror Effect, and Biosec technology stack on a grey pigment base that delivers deeper colour saturation from the first coat on charcoals, deep blues, and rich terracottas.
• For moderate-exposure residential elevations: the broader premium silicone render collection includes standard silicone finishes that deliver excellent hydrophobic and vapour-permeable performance at a lower price point — a sensible choice when the premium 4K, Mirror Effect, and Biosec technologies are not essential for the project's exposure level.
• For plinth and splash zones: pair the Gemini RS finish above DPC with a hard-wearing decorative finish from the mosaic render range to protect ground-level impact areas without compromising the facade aesthetic.
• Confirm the colour first: review physical chips from the colour charts and sample catalogues against project orientation and lighting before ordering — pale shades behave very differently in north light versus south, and workshop lighting can mislead at scale.

FAQ — Atlas Gemini RS White Coverage, Compatibility, Ordering

How many 25 kg tubs do I need for 100 m² at 1.5 mm grain?

At 1.5 mm hand-applied, consumption starts from 2.3 kg/m², so 100 m² requires a minimum of 230 kg — that is 10 tubs. Adding 10 % for reveals, corner detailing, and uneven substrates brings a practical order to 11 tubs. Machine application is more economical at 1.9 kg/m² (≈ 13.2 m² per tub), so the same area is comfortably covered by 8 tubs plus one spare.

Will the white finish yellow over time?

Mirror Effect technology is specifically engineered to prevent the UV degradation that causes yellowing and chalking on conventional white renders. The high-reflectance additives lower the surface temperature of the white coat and shield the polymer resins and white pigments, so the finish keeps its original brightness for years. Combined with the self-cleaning siloxane surface that rinses away atmospheric deposits in rainfall, a Gemini RS White facade stays visibly brighter for longer than standard white alternatives.

How is Gemini RS White different from standard Atlas Silicone Render White?

The single biggest difference is Mirror Effect anti-yellowing technology — the standard product does not carry it, which means a standard white render relies on pigment stability alone to resist the UV stress that ages every white facade over time. Gemini RS White additionally adds 3D-Flex elasticity for superior crack bridging and Biosec encapsulated biocide that releases active agents gradually over the coat's service life, and the complete system is certified under BBA Agrément 13/5018 which the standard product does not carry. The shared foundation — silicone-siloxane resin matrix, V2 vapour permeability, A2-s1 d0 fire classification — is identical. Choose Gemini RS White when yellowing resistance, premium durability, or BBA cover are project priorities; the standard product is sensible on sheltered residential elevations where those advantages are not essential.

Does the BBA certification cover the whole 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) keeps the certification and any associated warranty valid, giving Building Control a clear compliance pathway for sign-off.

Can Atlas Gemini RS White be applied by machine?

Yes — the 1.5 mm 4K aggregate is optimised for professional rendering units with a 6 mm nozzle, delivering a uniform coat at approximately 13.2 m² per tub (≥ 1.9 kg/m²). Machine application is preferred for commercial elevations above 50 m², where it cuts material use and labour time substantially compared with hand application. Hand and machine textures differ slightly, so the two application methods should never be combined on the same elevation.

Is Gemini RS environmentally certified?

Gemini RS is a water-based formulation with low volatile organic compound (VOC) content, releasing minimal emissions during application and curing. Atlas confirms environmental performance through a Type III Environmental Product Declaration (EPD) — an independently verified lifecycle assessment that architects and developers can reference in BREEAM or other sustainability submissions. Combined with a BBA-expected service life of at least 30 years, each application cycle replaces what would otherwise be multiple repaint or re-render operations.

What colours are available beyond the standard SAH palette?

Beyond the 480 standard SAH shades, our team mixes bespoke colours to order on a dedicated Atlas machine — matching a specific RAL code, an NCS reference, or a shade from another manufacturer's swatch. Our warehouse also mixes the Ceresit Colours of Nature range on separate dedicated equipment, bringing the combined choice across both systems to over 1,000 standard shades plus bespoke matching. Contact our team with your reference code for a bespoke match quote.

Technical Documentation — Atlas Gemini RS White TDS, DoP, BBA

• Atlas Gemini RS — Technical Data Sheet (PDF)
• Atlas Gemini RS — Safety Data Sheet (PDF)
• BBA Agrément Certificate 13/5018 — Atlas ETICS EPS System (PDF)
• Declaration of Performance: 280/CPR · UKCA — EN 15824:2017 (current edition)