Description
For mid-tone and darker SAH tints, Atlas Silicone Render Grey 25 kg builds full colour depth in fewer coats than a white-base equivalent, with 1.5 mm hand coverage from 2.2 kg/m² at roughly 11.4 m² per bucket, tinted on site and dispatched next day. DoP 145/3/CPR confirms compliance to EN 15824:2017 for ETICS finish coats.
Where Atlas Silicone Render Grey Performs Best on UK Facades
Atlas Silicone Render Grey 25 kg is a ready-mixed, fibre-reinforced silicone finish on a grey pigment base, reaching richer colour depth in fewer coats than a white base across mid-tone and dark SAH shades, with A2-s1 d0 reaction to fire, V2 vapour permeability, and 1.5 mm hand coverage from 2.2 kg/m². It sits as the visible finish layer of the wider premium silicone render range, designed for ETICS build-ups over EPS, mineral wool, sound concrete, and traditional cement or cement-lime plasters.
The grey base is the right starting point whenever pigment loading matters: deep architectural greys, terracotta, ochre, charcoal, and any saturated tint from the 480-shade SAH palette. Starting from a grey pigment rather than tinting up from white cuts both material consumption and on-site time, because the colour reaches uniform saturation across the elevation in a single application instead of demanding repeat coats to bury a brighter base. On a contemporary grey facade, that difference shows in both the labour bill and the evenness of the finished wall.
Why Trade Specifiers Choose Atlas Silicone Render Grey
- Deeper saturation in fewer coats: the grey pigment base reaches full colour depth on mid-tone and dark SAH shades faster than a white base, cutting material consumption and on-site labour on contemporary facades that need a rich, even finish.
- Self-cleaning silicone surface: high silicone and siloxane resin content lowers surface tension so rainfall lifts dirt and urban pollutants from the finish, keeping darker shades sharp without manual washing.
- Crack-bridging flexibility: cellulose-fibre reinforcement and dedicated polymer resins absorb thermal movement and minor impacts, reaching 140 J impact resistance within the Atlas Stopter K-100 system assembly.
- 480-shade SAH palette tinted on site: the full standard palette is mixed at the Renders World Southampton warehouse on a dedicated Atlas machine with no remote factory lead time, and bespoke RAL, NCS, or competitor-reference colours are matched to order.
- Year-round application down to 0 °C: the standard +5 °C to +30 °C window extends to 0 °C with Atlas Eskimo setting accelerator, so winter programmes run without compromising cure quality.
- V2 high vapour permeability: an Sd between 0.14 m and 1.4 m lets trapped moisture escape outward through the render, protecting wall fabric from interstitial condensation across UK climate zones.
- UV-stable hybrid pigments: the inorganic-organic pigment system, validated by Xenotest accelerated weathering, keeps darker shades true to spec long after a standard masonry paint would have faded.
Technical Specifications — Atlas Silicone Render Grey Data Sheet Highlights
| Property | Value |
|---|---|
| Pack size | 25 kg plastic bucket |
| Colour base | Grey (Platinum) — tintable to 480 SAH shades + bespoke RAL / NCS |
| Grain size options | 1.5 mm (N-15) · 2.0 mm (N-20) |
| Density | ≈ 1.9 g/cm³ |
| Coverage — 1.5 mm hand | From 2.2 kg/m² (≈ 11.4 m² per bucket) |
| Coverage — 1.5 mm machine | From 1.9 kg/m² (≈ 13.2 m² per bucket) |
| Coverage — 2.0 mm hand | From 2.8 kg/m² (≈ 8.9 m² per bucket) |
| Adhesion to substrate | ≥ 0.35 MPa |
| Water vapour permeability | V2 — high (Sd 0.14–1.4 m) |
| Water absorption | In2 — average |
| Reaction to fire | A2-s1, d0 (EN 13501-1) |
| Application temperature | +5 °C to +30 °C (0 °C with Atlas Eskimo) |
| Relative humidity at application | < 80 % |
| Surface dry time | ≈ 15 min (at 20 °C, 60 % RH) |
| Full cure time | ≈ 24 h (at 20 °C, 60 % RH) |
| Shelf life | 12 months from manufacture date |
| Standard | EN 15824:2017 · DoP 145/3/CPR · ETA-06/0081 · ETA-06/0173 · ETA-16/0933 |
How to Apply Atlas Silicone Render Grey — Mixing, Pot Life, Coverage
The bucket arrives ready for the wall, with no thinning, additions, or proprietary mixing components. Power-stir the mass with a low-speed paddle for 30–60 seconds immediately before each load to even out consistency. A cured reinforced basecoat with embedded alkali-resistant 150 g/m² fibreglass mesh, primed with Cerplast or Ceresit CT 16 from the exterior render primer range, is the foundation that releases the finish coat's full self-cleaning and crack-bridging performance.
Hold a stainless-steel trowel at a low angle and lay the render at aggregate thickness across each panel, returning excess to the bucket and re-stirring between loads. Texture immediately with a plastic float in steady circular motions until the lambskin grain pulls through evenly. Plan each elevation as a single continuous wet-edge pass so the leading band never skins before the next is laid; that one discipline is decisive on darker grey tints, where any join reads clearly under afternoon raking light.
- Coverage at 1.5 mm hand: from 2.2 kg/m² — one 25 kg bucket covers approximately 11.4 m² on an even basecoat.
- Machine application: 1.5 mm grain only — Wagner PC 830 with 6 mm nozzle at minimum feed, or Graco RTX 5500 PX with 6 mm round nozzle at medium feed.
- Hose conditioning: run a small charge of Silkon ANX or Cerplast through the line before the first render bucket so the first pull comes through clean.
- Open time and mixing: ready-mixed — re-power-stir if the bucket has stood over 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 60 % RH; protect from rain, wind, and direct sun across that window.
For the full professional method from basecoat preparation through final texturing, the thin-coat render application step-by-step guide covers the complete process for UK walls.
Installation Notes — Conditions, Drying Times, Finishing
Cure quality begins long before the first trowel touches the wall. Allow the primed basecoat at least three days at +20 °C to season fully, with the substrate stable, dust-free, and dry to the touch. Choose a window between +5 °C and +30 °C with relative humidity below 80 %, and shield the fresh surface from direct sun, wind, and rain through the full 24-hour cure.
For programmes pushing into autumn or early spring, Atlas Eskimo at 0.25 kg per bucket extends the working range to 0 °C and shortens initial set, so the render is less exposed through the longer cold-weather drying window. The full seasonal protocol of temperature thresholds, humidity checks, and forecast routine is covered in the cold-weather rendering timing guide.
- Batch alignment: keep all buckets for one elevation on the same manufacture date so batch-driven shade drift cannot creep across the wall.
- Plan breaks at architectural lines: corners, sill lines, downpipes, and recessed details all hide a joint; mid-panel pauses do not.
- Tool care: rinse tools in clean water at break time, and use Atlas Resin Away for any cured residue.
Pro Tips From UK Installers Using Atlas Silicone Render Grey
Dark and mid-tone facades reward different trade habits than bright whites: pigment depth, solar gain, and the way raking light shows joint discipline all shift the priorities. The tips below reflect what experienced UK applicators do differently when the spec calls for a deeper SAH tint on the grey base.
- Check HBW before committing the order: the standard Hoter U2 reinforced basecoat supports tints with a Heat Brightness Value above 15 %; for darker shades down to HBW 6 %, switch the basecoat to Atlas Stopter K-100 to maintain colour stability.
- Mind solar gain on south elevations: very dark shades on south-facing walls absorb significant heat, so for HBW values near the minimum, brief the client on movement margins and confirm warranty conditions before ordering.
- Plan technological breaks at architectural lines: stop at corners, sill lines, or downpipes rather than mid-wall, because dark tints make any pace-related shade difference far more visible than on white.
- Sample bespoke shades at full scale: when a client supplies a RAL or NCS reference outside the SAH book, tint a single bucket and lay it across a 1 m² panel under daylight before committing — saturated tints read very differently on the wall than on a chip.
- Keep batch dates aligned: order all buckets for a facade in one delivery so manufacture dates match, since even minor batch drift is visible on a saturated finish.
How the Grey Base Compares to the White Variant
The grey and white variants share an identical silicone-siloxane formula and performance ratings; only the base pigment differs, and that single difference decides which one suits your shade. The table below shows where each fits.
| Variant | Key Spec | When to Choose |
|---|---|---|
| Atlas Silicone Render Grey | Grey base · saturates in fewer coats | Mid-tone and dark SAH tints, contemporary greys |
| Atlas Silicone Render White | White base · high solar reflectance | Pure whites and the lightest shades |
Is Atlas Silicone Render Grey Right for Your Project?
- Choose this render if: you want a contemporary grey facade or a rich mid-to-dark tinted finish — the grey base reaches full colour depth in fewer coats than white, the 1.5 mm grain delivers up to 11.4 m² per bucket, and the SAH palette gives you 480 standard shades plus bespoke matches.
- For pure whites and the lightest tints: the Atlas Silicone Render White 25 kg uses the same formula on a white base that preserves brightness on light shades and benefits from high solar reflectance on south-facing elevations.
- For heritage and conservation work: the Atlas silicone-silicate render 25 kg is usually a better fit for older lime-based walls, with a more mineral chemistry offering the maximum vapour permeability historic facades need.
- For plinth and splash zones: pair the grey finish above DPC with a hard-wearing decorative finish from the mosaic render range to protect ground-level impact areas without compromising the facade.
FAQ — Atlas Silicone Render Grey Coverage, Compatibility, Ordering
How many 25 kg buckets do I need for 100 m² at 1.5 mm grain?
At 1.5 mm hand-applied, consumption starts from 2.2 kg/m², so 100 m² needs a minimum of 220 kg, which is nine buckets. Adding 5–10 % for waste, corner detailing, and uneven substrates brings a practical order to 10–11 buckets. At 2.0 mm grain, consumption rises to 2.8 kg/m², requiring at least 12 buckets for the same area.
Is the grey base the same formula as the white variant?
The grey and white variants share an identical silicone-siloxane resin matrix, cellulose-fibre reinforcement, and performance ratings; only the base pigment differs. Both carry DoP 145/3/CPR under EN 15824:2017, A2-s1 d0 reaction to fire, and V2 vapour permeability. The grey base delivers richer saturation for mid-tone and dark finishes, while the white base is optimised for the lightest shades.
How dark a tint can I specify on the grey base?
The standard system with Atlas Hoter U2 reinforced basecoat supports colours with a Heat Brightness Value above 15 %. Switching the basecoat to Atlas Stopter K-100 extends the range down to HBW 6 %, covering the majority of the deeper SAH shades. For very dark shades on south-facing elevations, confirm with the technical team that the specification matches the client's warranty and movement-margin expectations.
Can Atlas Silicone Render Grey be applied by machine?
Yes — the 1.5 mm (N-15) grain is approved for machine application on the Wagner PC 830 with a 6 mm nozzle at minimum feed, and the Graco RTX 5500 PX with a 6 mm round nozzle at medium feed. The 2.0 mm grain is hand-applied only. Hand and machine textures differ slightly, so the two methods should not be combined on the same elevation.
Can I apply this render in winter?
Standard application needs a minimum air and substrate temperature of +5 °C. Adding Atlas Eskimo at 0.25 kg per bucket extends the working range down to 0 °C and shortens initial set, so the render is less vulnerable during the longer cold-weather drying window. Check a 48-hour forecast before each session to confirm the fresh coat has dry time to cure without frost interruption.
Will the grey or tinted finish fade over time?
The pigment runs throughout the full depth of the render using hybrid inorganic-organic pigments validated by Xenotest accelerated weathering, giving UV resistance well above a surface-applied masonry paint. The self-cleaning silicone surface also stops airborne pollutants embedding into the texture, so the chosen shade stays visibly consistent between natural rain washes for the facade's service life.
Is the grey variant environmentally certified?
The render is a water-based, solvent-free formulation, and its environmental performance is independently verified through a Type III Environmental Product Declaration (EPD) that architects and developers can reference in BREEAM or sustainability submissions. The long service life and self-cleaning behaviour further reduce maintenance chemicals and repainting cycles over the building lifetime.
Technical Documentation — Atlas Silicone Render TDS and DoP