Description
Grey-based thin-coat renders earn their place on the elevations nobody treats gently — car parks, school walls, gateways and shaded corners near trees. Atlas builds this one around a four-aggregate formula and declares consumption from 2.3 kg/m² by hand, which is where the specification conversation starts rather than ends.
Where Atlas Gemini RS Grey Fits on a UK Facade
Atlas Gemini RS Render Grey 25kg is a ready-mixed thin-coat silicone render consuming from 2.3 kg/m² by hand at up to 1.5 mm grain, specified where facades meet heavy soiling and mechanical knocks. Renders World stocks it in the premium silicone render range, and the manufacturer's data sheet is unusually specific about the locations it was designed for.
- Urban, industrial and investment zones — the sheet names dust, exploitation factors and industrial pollution as the conditions this render is recommended for.
- Impact-prone ground level — playground surrounds, gateways, drive-through openings and parking bays, where resistance to mechanical damage is the reason for the specification.
- Damp and shaded sites — wetlands, ground near water bodies, close proximity to trees and green areas, and shaded elevations.
Scope matters as much as location. The sheet covers use in ETICS build-ups on EPS boards, on even mineral substrates such as concrete and traditional cement or cement-lime renders, and internally; for a mineral wool build-up it directs the specifier to the ATLAS ROKER system instead, which is a substitution worth settling before the boards are ordered.
Why Specifiers Choose the Grey Base
- Four-aggregate 4K formula: four types of texturing aggregate and filler are credited by Atlas with better hold on the trowel and the wall, faster texturing without repeat passes, and even aggregate distribution across the panel.
- ATLAS 3D-flex elasticity: the fibre-reinforced formulation is described as compensating summer-to-winter thermal movement and sudden surface temperature swings, such as heavy rain landing on a sun-warmed elevation.
- MIRROR EFFECT surface: Atlas attributes a high light reflection coefficient to the finish, lowering the render's surface temperature and shielding the polymer resins and pigments from UV.
- BIOSEC and ATLAS CAPS: biologically active substances are released slowly across the coat's service life, which the sheet ties to protection against algae and mould on the shaded and tree-lined elevations above.
- 406 SAH shades on a tinting base: the grey base is the tinting route trade buyers take for mid-tone and deep shades, and the palette is browsable through the render colour charts and sample books before a tub is committed.
Technical Data Read From the Gemini RS Sheet
| Property | Declared value |
|---|---|
| Pack | 25 kg plastic bucket |
| Density of the ready product | approx. 1.9 g/cm³ |
| Grain and texture | up to 1.5 mm, baranek (lambskin) |
| Colours | 406 SAH shades |
| Diffusion resistance | 0.14 ≤ Sd < 1.4 m |
| Water vapour permeability | V2 (EN 15824) |
| Water absorption | W2 (EN 15824) |
| Adhesion | 0.35 MPa |
| Consumption, hand | from 2.3 kg/m² |
| Consumption, machine | from 1.9 kg/m² |
| Working temperature | +5 °C to +30 °C |
| Relative humidity | < 80 % |
| Surface dry / dry | approx. 15 min / approx. 24 h at 20 °C, 50 % RH |
| Shelf life | 12 months from the production date |
| Standard and DoP | EN 15824:2017 · DoP 280/CPR |
| Named in system assessments | ATLAS GRIP (ICiMB-KOT 2022/0180 issue 1) · ATLAS ETICS (ITB-KOT-2020/1616 issue 3), both Polish national technical assessments |
At the August 2026 fetch the tub is listed at £63.80 per 25 kg bucket and showing as available; the store page displays no VAT label, so none is quoted here. Dividing the pack by the declared hand consumption gives the working arithmetic: 25 kg ÷ 2.3 kg/m² = approximately 10.9 m² per tub, so £63.80 ÷ 10.9 m² ≈ £5.85/m² in material alone, before basecoat, mesh, primer or labour. Renders World dispatches from Southampton, with the site's shipping policy putting parcels up to 25 kg on a next-business-day courier and confirming the method after the order; the render coverage calculator handles the full take-off.
One correction is worth carrying into your ordering: the palette figure previously published on this page did not match the manufacturer's sheet, which states 406 SAH colours. Specify from the SAH fan deck rather than from a headline number, and any bespoke reference gets confirmed against a tinted sample.
How to Apply Gemini RS Grey — Preparation, Stirring, Texturing
- Season and prepare the substrate so it is stable, dry, even and clean; the sheet requires biological growth to be removed with a proprietary biocidal wash before anything else happens.
- Prime with ATLAS CERPLAST, the key coat the sheet names for reinforced layers and mineral substrates — it sits in the exterior render primers range.
- Stir, do not modify. The paste arrives ready to use and must not be combined with other materials, diluted or thickened; a stir immediately before use evens the consistency, and at the top of the temperature range the sheet permits up to 1 % clean water.
- Lay at aggregate thickness with a smooth stainless steel trowel, pulling surplus back into the bucket and re-stirring it.
- Texture with a plastic float in circular motions to raise the baranek grain; machine-applied render is not textured at all.
The reinforced layer beneath does the structural work, and Atlas 150 is the mesh named in the manufacturer's own dark-shade condition — the Atlas 150 g/m² alkali-resistant mesh is therefore the matched roll for that build-up. Method, wet edge and panel planning are covered in depth in the step-by-step thin coat rendering method.
Installation Conditions, Cold Weather and Drying
- Working window: +5 °C to +30 °C with relative humidity below 80 %, for the mix, the substrate and the air, throughout application and setting.
- Shoulder season: the sheet permits work above 0 °C and at humidity to around 80 % after adding Atlas Eskimo setting accelerator, the Atlas-only cold-weather component; the full seasonal routine sits in the guide to render application timing in UK conditions.
- Drying: approximately 15 minutes to surface dry and 24 hours to dry at 20 °C and 50 % RH, extending at around +5 °C or raised humidity — plan the programme around the slower figure and the finish looks after itself.
- Protection: shield the worked and drying surface from direct sun, wind and precipitation.
- Joints and batches: work wet on wet, plan breaks at corners, building returns, under downpipes and at colour changes, and keep one production date across a single surface.
- Not for: horizontal surfaces under permanent water or snow load, or surfaces wetted by rising damp — a detail resolved at design stage with a drip and a plinth finish.
Clean tools in clean water straight after use; hardened residue is removed with the ATLAS SZOP 2000 preparation named on the sheet. That single habit is what keeps a plastic float cutting a clean baranek on the second day of a long elevation.
Grey Base or White Base — How the Two Gemini RS Tubs Differ
| Variant | What differs | When to choose |
|---|---|---|
| Atlas Gemini RS Grey 25 kg | Grey tinting base | Mid-tone and deep SAH shades |
| Atlas Gemini RS Render White 25 kg | White tinting base | Whites, creams and light shades |
Both tubs are covered by one data sheet, which declares a single set of properties for ATLAS GEMINI RS. The honest reading is that the decision is a tinting decision rather than a performance one: pick the base that reaches your chosen shade in the fewest passes, and the declared V2 permeability, W2 absorption and 0.35 MPa adhesion come with either.
How to Specify Gemini RS Grey on a UK Project
BBA Agrément Certificate 13/5018, Product Sheet 1, lists the finishing coats of the Atlas/Aval EPS system as Atlas Cermit Mineral, Atlas Acrylic Render, Atlas Acrylic-Silicone Render, Atlas Silicone Render, Atlas Silicate Render and Atlas Silicone-Silicate Render. Gemini RS is not among them, and its own documented system credentials are the two Polish national technical assessments named on its sheet.
- Where BBA system cover is a project requirement, the simple route is to specify one of the finishing coats the certificate names — those products sit alongside this one in the wider thin-coat render collection, so the switch costs nothing in lead time.
- Where deep shades are the driver, the sheet allows intensive colours with a light reflectance HBW above 15 when the reinforced layer is built with ATLAS STOPTER K-50, STOPTER K-20 or GRAWIS U (the last at minimum 5 mm with a double Atlas 150 mesh). Confirm the basecoat on the specification before the shade is signed off, and read the guidance on dark render shades and solar exposure.
- Below that reflectance threshold, intensive colours may still be used on a maximum of 10 % of the elevation — enough for a feature bay or a recessed entrance treated as an accent.
- Where the choice is still open, the silicone render buying criteria compared set out how Renders World ranks binder, grain and certification against project type.
- To order, take the 25 kg grey base tub for your SAH shade and add roughly one tub per 100 m² for waste; the white base handles the light end of the palette.
FAQ — Coverage, Compatibility and Certification
How many 25 kg tubs cover 100 m²?
Hand application starts at 2.3 kg/m², so 100 m² × 2.3 kg/m² = 230 kg, and 230 kg ÷ 25 kg = 9.2, rounded to 10 tubs. Adding 10 % for reveals and detailing gives 253 kg ÷ 25 kg = 10.1, so 11 tubs is the practical order.
- By machine: 100 m² × 1.9 kg/m² = 190 kg ÷ 25 kg = 7.6, so 8 tubs plus one spare.
- Caveat from the sheet: these consumptions apply to even substrates, and the exact figure comes from a trial patch on the wall being rendered.
What does the sheet require underneath?
ATLAS CERPLAST is the key coat named for reinforced layers and mineral substrates. Seasoning times are specific: minimum one day for a reinforced layer made with ATLAS ETICS mortars, minimum three days for one made with ATLAS GRIP U, minimum seven days per centimetre for new cement renders at 4 % moisture, and minimum 28 days for concrete with structural moisture below 4 %.
Can hand and machine application be combined on one building?
Spraying is supported, with 6 mm nozzles on the units the sheet names, and sprayed render is left untextured. Because the hand and machine textures develop the surface differently and can read as a slight colour difference, the sheet rules out combining the two technologies on a single building — settle the method before the first elevation starts.
Is this render covered by BBA Agrément 13/5018?
The certificate's component list names six other Atlas finishing coats and does not include Gemini RS, so no BBA cover is claimed for it here. Its documented system credentials are the ATLAS GRIP and ATLAS ETICS national technical assessments printed on its data sheet, and where a UK specification asks for BBA cover the certificate's own listed finishes are the direct answer.
How is an aged Gemini RS facade refreshed?
The sheet's renovation route is repainting with a silicone masonry paint from the ATLAS SALTA family — SALTA, SALTA N or SALTA N PLUS. That keeps a tired elevation on a documented pathway rather than an improvised one, and it is a repaint rather than a re-render.
Technical Documentation