ATLAS GEMINI RS RENDER GREY BASE 25kg

For premium, high-exposure facades that need certified ETICS performance and lifetime self-cleaning, Atlas Gemini RS Grey 25 kg delivers 10.9 m² hand coverage at 1.5 mm grain (≥ 2.3 kg/m²) under BBA Agrément 13/5018, with 3D-Flex elasticity, Mirror Effect UV reflectance, and Biosec capsule biocide built into every tub.

Where Atlas Gemini RS Grey Performs Best on UK Facades

Atlas Gemini RS Grey 25 kg is a fibre-reinforced silicone render with proprietary 4K mineral-aggregate technology and siloxane-enhanced resins, formulated for the elevations that take the heaviest punishment — heavy urban pollution, mechanical impact, shaded greenery, and full UK weather exposure. 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 grey pigment base is the natural starting point whenever the specification calls for mid-tone or dark SAH shades — deep charcoals, rich blues, terracottas, and saturated architectural greys all reach full colour depth from the first coat without the multiple-pass burying that a white base would need. Three integrated technologies sit beneath that finish: 3D-Flex elasticity bridges thermal stress, Mirror Effect high-reflectance additives lower surface temperature to slow UV pigment fade, and Biosec capsule biocide releases active agents gradually across the coat's full service life.

Why Trade Specifiers Choose Atlas Gemini RS Grey

• 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.
• 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.
• Mirror Effect UV reflectance: high-reflectance additives lower the surface temperature of the finished coat, slowing pigment fade and extending colour life on dark and saturated shades that would otherwise be vulnerable to UV stress.
• Biosec biological defence: encapsulated biocide releases active agents gradually over the coat's service life, suppressing algae, mould, and lichen colonisation on shaded elevations near greenery or water without repeat treatments.
• Self-cleaning siloxane surface: a dense siloxane layer creates a tight, hydrophobic surface that lets rainwater rinse airborne dirt and pollutants away naturally — maintenance drops to occasional soft-washing rather than scheduled cleaning.
• Grey-base pigment depth for dark SAH shades: the grey starting point reaches deeper colour saturation in the first coat than a white base, cutting material use and on-site time on contemporary facades that specify mid-tone to dark tints.
• Tinted on site with next-day dispatch: every tub is mixed to your chosen SAH 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 Grey Data Sheet Highlights

Property	Value
Pack size	25 kg plastic bucket
Base material	Siloxane-enhanced resins · 4K mineral aggregates · cellulose fibres
Base colour	Grey — 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 Grey — Mixing, Pot Life, Coverage

Each tub arrives ready for the wall — no dilution, no thickening, no proprietary additions to the paste. A 30–60 second power-stir with a low-speed paddle mixer immediately before each load smooths the consistency. The underlying system carries the rest of the performance: a cured reinforced basecoat embedding the Atlas 150 g/m² alkali-resistant mesh, 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.

Lay 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 what eliminates lap marks on the deeper SAH tints this product is designed for, where any joint would otherwise read in 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

BBA system performance begins with 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 the curing render from direct sun, wind, and rain across the full 24-hour cure.

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. Plan technological breaks before scaffolding goes up — corners, downpipes, sill lines, and recess details all conceal a joint, while mid-panel pauses on a saturated grey-base finish never do. Tools rinse in clean water immediately at break time.

Pro Tips From UK Installers Using Atlas Gemini RS Grey

Premium BBA-certified renders reward disciplined trade habits — the technologies inside the tub do their job only when the surrounding system and site programme give them room to work. The tips below reflect what experienced UK applicators do differently when the spec calls for Gemini RS on a high-exposure commercial elevation.

• Keep the system specification BBA-aligned: Certificate 13/5018 covers the complete Atlas ETICS assembly — substituting a non-system adhesive, primer, or basecoat invalidates the certification, so confirm every layer before ordering.
• 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.
• Order to a single production batch: request all tubs for one facade in the same delivery so manufacture dates match — even minor batch drift is visible on saturated mid-tone and dark SAH shades.
• Approve bespoke RAL or NCS at scale: for non-standard references on the grey base, tint a test tub and apply at full thickness on a 1 m² panel under daylight before committing the full order — dark shades read very differently at scale than on a chip.
• Plan machine runs for elevations above 50 m²: the 4K aggregate is optimised for a 6 mm nozzle and reaches ≈ 13.2 m² per tub by machine — measurably faster and more consistent than hand application on long unbroken commercial elevations.

Is Atlas Gemini RS Grey Right for Your Project?

• Choose this render if: your project needs certified ETICS system compatibility, superior impact resistance, and long-term self-cleaning performance — Gemini RS Grey is the right specification for commercial buildings, schools, multi-unit residential, and any elevation facing heavy pollution, dense greenery, or high foot traffic, with deeper pigment saturation on mid-tone and dark SAH shades.
• For pure whites and the lightest tints: switch to Atlas Gemini RS White 25 kg — same premium 3D-Flex, Mirror Effect, and Biosec technology stack on a white pigment base that preserves brightness on pastels and pure whites where maximum pigment clarity from the first coat is the priority.
• 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 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 — saturated grey-base tints behave very differently in north light versus south, and workshop lighting can mislead at scale.

FAQ — Atlas Gemini RS Grey 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.

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.

How is Gemini RS different from standard Atlas Silicone Render?

Both products share the same silicone-siloxane foundation, V2 vapour permeability, and 1.5 mm lambskin texture, but Gemini RS adds three premium technologies: 3D-Flex elasticity for superior crack bridging, Mirror Effect high-reflectance additives that slow UV pigment fade on darker shades, and Biosec encapsulated biocide that releases active agents gradually over the coat's service life. Gemini RS is also certified within Atlas ETICS BBA system 13/5018, which standard Atlas Silicone Render does not carry — making it the right specification when BBA cover, premium durability, or biological exposure are project priorities.

How dark a tint can I specify on the grey base?

The standard reinforcing system supports tints with a Heat Brightness Value above 15 %; switching the basecoat to a dispersion-adhesive reinforcement extends the range down to HBW 6 %, covering the great majority of the deeper SAH shades. For very dark shades on south-facing elevations, confirm with our technical team that the system specification matches the client's warranty terms and the building's movement-margin expectations — Mirror Effect helps, but every dark facade benefits from a sense check before order.

Can Atlas Gemini RS Grey 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 Grey 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)