Description
The white base is the cleaner route to pure whites and pale tints, and the manufacturer's own two editions disagree on how much you need: 2.2 kg/m² on the English sheet, under 2.5 kg/m² on the Polish. Order against 2.5 kg/m² at 1.5 mm — about 10 m² per 25 kg bucket.
Where the White Base Fits on a UK Facade
Atlas Silicone Render on the white base is a ready-mixed silicone and siloxane finish declared to EN 15824:2017, used as the visible coat of ETICS build-ups over EPS and mineral wool. Renders World lists this bucket at £59.50 (August 2026), and it sits in the silicone render range as the base for the lighter half of the palette.
White is the correct starting pigment for pure whites, creams and pale tints, where a coloured base would pull the finished shade off tone. What the fetched sheet makes clear, and what most listings leave out, is how wide the permitted field of use actually is — this is not an elevation-only product.
- Facade in an EPS insulation system and facade in a mineral wool system — the two ETICS build-ups named on the sheet.
- Single-layer wall facades and even mineral substrates such as concrete and traditional cement or cement-lime plaster.
- Ceiling side of a floor slab, which covers soffits and exposed undercrofts.
- Internal walls, including gypsum substrates and plasterboard, primed first with Atlas Uni-Grunt.
The sheet also flags where it is excluded: horizontal surfaces in permanent contact with water or snow, and any wall drawing moisture up by capillary rise. Resolve rising damp first and the same specification carries the elevation, the reveals and a soffit return.
Why Specifiers Choose This Finish
- 480 shades from one base: the sheet declares 480 colours to the SAH Paints and Plasters range, plus selection of any individual colour through the Atlas colouring system to the customer's instructions.
- Colour fastness confirmed on Xenotests: hybrid inorganic and organic pigments with reflective additives, which is why a pale tint holds tone rather than drifting.
- Hydrophobic and self-cleaning: a high silicone and siloxane resin content stops dust and dirt bonding to the coating so rainfall rinses it, and the sheet separately claims a photocatalytic self-cleaning effect.
- Not susceptible to algae growth: attributed on the sheet to the degree of hydrophobisation, the structural tightness of the coating and a very high content of encapsulated coating-active substances — which is why it is named for shaded city-centre sites and walls near greenery or water.
- V2 vapour permeability: a diffusion resistance of 0.14 ≤ Sd < 1.4 m keeps the finish coat open, so a retrofitted solid wall keeps an outward path for moisture.
- Fibre-reinforced and flexible: cellulose fibres and dedicated polymer resins bridge thermal stress, and with Atlas Stopter K-100 adhesive the render forms a system rated at 140 J impact and 30 m/s hail resistance — a system figure, not a property of the bucket.
- Named for hard-wear locations: the sheet recommends it where resistance to mechanical damage and dirt is high — near playgrounds, gateways, parking zones and industrial pollution.
Declared Performance and the Scope Behind Each Figure
Every value below comes from a document fetched for this page. The scope column is the part that matters on a specification, because three of these belong to a system rather than to a 25 kg bucket.
| Property | Declared value | Scope |
|---|---|---|
| Pack | 25 kg plastic bucket | Product |
| Density | approx. 1.9 g/cm³ | Finished product |
| Texture and grain | Lambskin; max 1.5 mm (N-15) or 2.0 mm (N-20) | Product |
| Colour | 480 SAH shades, plus individual colour to order | Product |
| Water vapour permeability | V2 — high | DoP 145/3/CPR, EN 15824:2017 |
| Diffusion resistance | 0.14 ≤ Sd < 1.4 m | Product |
| Adhesion | 0.35 MPa | DoP 145/3/CPR |
| Water absorption | Average — printed In2 on the English sheet, W2 on the Polish | Same DoP, designation differs by edition |
| Reaction to fire, product | A2-s1, d0 | The render alone, under the DoP |
| Reaction to fire, system | B-s2, d0 | Atlas/Aval EPS system, BBA 13/5018 |
| pH | 8 | Product |
| Application temperature | +5 °C to +30 °C; above 0 °C after adding Atlas Eskimo | Compound, substrate and surroundings |
| Relative humidity | < 80% | During application and setting |
| Drying | approx. 15 min surface, approx. 24 h through | At 20 °C, 60% RH |
| Shelf life | 12 months from date of manufacture | Product |
| System assessments | ETA-06/0081, ETA-06/0173, ETA-16/0933 | ATLAS, ATLAS ROKER and ATLAS GRAWIS systems, of which the render is one component |
Read the water absorption line as a purchasing instruction rather than a curiosity. Two editions of the same manufacturer's sheet, both citing DoP 145/3/CPR, print different letters for the same middle class — so if a specification clause turns on the designation, ask Atlas for the current DoP rather than quoting either sheet.
Reaction to Fire: Two Classes, Two Scopes, and the Height Limits
Specify on the assembly, not the bucket. The product class declared for Atlas Silicone Render is A2-s1, d0 under DoP 145/3/CPR to EN 15824:2017. The certified system class is the stricter B-s2, d0, and that is the figure a designer works to.
BBA Agrément Certificate 13/5018, Product Sheet 1, fourth issue 25 October 2022, awards B-s2, d0 to one specific construction in which this render is named:
- Adhesives — Atlas Stopter K-20, Atlas Hoter S (Aval KT 53) or Atlas Hoter U (Aval KT 55).
- Insulation — EPS of different types, 250 mm maximum thickness; the insulation in isolation is classified E.
- Basecoats — Atlas Stopter K-20 or Atlas Hoter U (Aval KT 55), with Atlas 150 or Atlas 165 mesh.
- Key coats — Atlas Cerplast (Aval KT 16) or Atlas Silkon ANX.
- Finishing coats — Atlas Cermit Mineral or silicone render; paints Atlas Salta E, Salta N or Salta.
Under that certificate the system is not for buildings with a storey more than 18 m above ground level in England, Wales and Northern Ireland, and not for buildings with a storey 11 m or more above ground level, or 1 m or less from a boundary, in Scotland. Within those limits, a B-s2, d0 construction may be used at any proximity to a boundary in England, Wales and Northern Ireland. The certificate asks the designer to confirm the classification against the national Building Regulations for the specific project, which is the right sequence on anything above two storeys.
How to Apply It: Mixing, Pot Life and Texturing
The bucket is supplied ready to use and must not be combined with other materials, diluted or thickened; stir it to even out the consistency immediately before use. There is no pot life to work against, because nothing is being mixed and nothing starts a chemical clock when the lid comes off — the real limit is the technological cycle.
The sheet asks you to establish that cycle experimentally for the substrate and the day's weather: the maximum area you can pull and float wet-on-wet before the laid batch skins. Plan the technological breaks in advance at corners, building folds, under downpipes and at colour changes, because a break anywhere else leaves a visible joint.
- Lay at aggregate thickness with a smooth stainless steel trowel, drawing excess back into the bucket and stirring it in.
- Texture with a plastic float in circular motions to pull the lambskin effect.
- Machine-applied render is not textured at all, and hand and machine textures differ enough to read as a colour difference.
- Never combine the two methods on one object — the sheet states this as impermissible, not as a preference.
- Clean tools in clean water immediately; Atlas Resin Away lifts cured residue.
Machine Application and the Grain It Locks You Into
Spraying is permitted on the 1.5 mm N-15 grain only, using a Wagner PC 830 with a 6 mm nozzle at minimum feed (2/10) and 2.2 bar, or a Graco TexSpray RTX 5500 PX with a 6 mm round nozzle at medium feed (2/6). Quoted pressures are indicative for standard hose lengths and are set on site for longer runs.
Prime the hose with a small charge of Atlas Silkon ANX before the render to wet the line and avoid clogging. The English edition also permits Atlas Cerplast for this; the Polish edition names Silkon ANX alone, so Silkon ANX is the safe instruction. The practical consequence for a specifier is that a spray programme commits the whole building to 1.5 mm, since the 2.0 mm N-20 grain is hand-applied only — the trade-off between the two is set out in the guide to render grain size, texture and coverage.
How Much to Order at 1.5 mm and 2.0 mm
Order Atlas Silicone Render against the higher of the two published consumption figures and the delivery covers the wall. The English sheet gives from 2.2 kg/m² hand-applied at 1.5 mm; the Polish sheet gives an average below 2.5 kg/m² for N-15. Both refer to even substrates under ITB 2020 Technical Conditions.
- 1.5 mm hand, per bucket: 25 kg ÷ 2.5 kg/m² = 10 m². The 2.2 kg/m² minimum would give 11.4 m², which assumes a basecoat with no tolerance in it at all.
- A 100 m² elevation: 100 m² ÷ 10 m² per bucket = 10 buckets, +10% for waste and detailing = 11 buckets.
- 2.0 mm hand: from 2.8 kg/m² on the English sheet, average below 3.0 kg/m² on the Polish — plan on 3.0 kg/m², about 8.3 m² per bucket, so 100 m² needs 12 buckets, or 14 with the same allowance.
- 1.5 mm machine: from 1.9 kg/m². The Polish average of under 2.5 kg/m² is not split by method, so no separate bucket count is published for spraying — the sheet simply notes that mechanical consumption runs lower than manual.
- Material cost: £59.50 ÷ 10 m² = £5.95/m², material only, excluding labour, key coat, basecoat and mesh.
Within the certified Atlas/Aval EPS system the BBA states a coverage of 2.5 to 3.5 kg/m² for this render across its grain sizes, which brackets both sheet figures and confirms 2.5 kg/m² as a sound floor. For a whole build-up rather than the finish coat alone, the render coverage calculator runs the same arithmetic layer by layer.
Substrate Preparation and the Key Coat Question
A key coat is not universal here, and that is worth catching before it goes on a quote. Where the reinforced layer of the ETICS build-up is made from Atlas Stopter K-100, Stopter K-50 or Hoter U2-B, the sheet states plainly that no plaster base is required — the render goes straight onto the seasoned reinforced layer after the minimum three days at +20 °C.
Every other route does need one. Reinforced layers built from other Atlas adhesive mortars, concrete and traditional cement or cement-lime plasters all take Atlas Silkon ANX, with the English edition also permitting Atlas Cerplast; internal gypsum substrates and boards take Atlas Uni-Grunt first and then the key coat. Within the certified system the BBA is narrower still, pairing Silkon ANX specifically with silicone render at 0.25 to 0.35 kg/m² coverage.
- ETICS reinforced layer — minimum 3 days at +20 °C before the finish coat.
- New cement and cement-lime plaster — minimum 7 days per 1 cm of thickness, moisture 4%.
- Concrete — minimum 28 days, structural moisture below 4%.
- Gypsum substrates and boards, internal only — moisture below 2%.
- Biological infestation — remove with Atlas Mykos Plus or Mykos Nr 1 before priming.
Fill unevenness with Atlas ZW 330, Atlas plastering mortar or a reinforcing-layer adhesive, priming with Atlas Uni-Grunt before the repair. Products for the priming stages sit in the exterior render primers range, and the reinforcing layer beneath takes the Atlas 150 g/m² alkali-resistant mesh. For the full sequence from basecoat to final float, the step-by-step thin-coat application method covers it.
Conditions, Drying and Cold-Weather Working
Work between +5 °C and +30 °C with relative humidity below 80%, and protect the surface from direct sun, wind and rain both during application and through the drying period. Drying runs at approximately 15 minutes to surface dry and 24 hours through, measured at 20 °C and 60% RH.
At around +5 °C with raised humidity the setting time lengthens, which means a longer protected period rather than a compromised finish. The sheet's own cold-weather provision is use at reduced temperatures above 0 °C, and at humidity up to about 80%, after the addition of Atlas Eskimo — an Atlas component, not a Ceresit one, and not a licence to work in frost. Seasonal planning for UK programmes is set out in the guide to render application timing across the UK year.
- One manufacture date per surface — the sheet asks for it explicitly, to keep batch shade differences out of the wall.
- Protect the drying render, not just the wet one; the 24-hour window is the vulnerable period.
- Not for horizontal water- or snow-exposed surfaces, or walls affected by rising damp.
Installer Tips That Keep a Pale Finish Even
A white or near-white facade shows what a mid-tone forgives, so the discipline moves back a stage into the substrate and the rhythm of the day rather than the finish coat itself.
- Straight-edge the reinforced layer before the key coat. High spots and shallow dips read clearly under raking light on a pale finish, and they are far cheaper to correct in the basecoat than to disguise afterwards.
- Prove the cycle on the least visible elevation. The sheet requires the maximum one-cycle area to be established experimentally — do that where a learning curve will not be looked at every day.
- Check the reinforced-layer mortar before ordering any tint. The sheet permits shades above HBW 15% over Hoter U2, and above HBW 6% over Stopter K-100, so the mortar underneath decides how far down the palette you can go.
- Order the key coat as a line item only when it is needed. On a Stopter K-100, K-50 or Hoter U2-B reinforced layer the sheet requires no plaster base, which takes a whole material and a whole day out of the programme.
- Keep a spare bucket from the same batch for reveal returns and making good after scaffold strike.
- Confirm the shade against a physical reference, not a screen — the SAH colour charts and sample books carry the chips the tint is mixed to.
White Base or Grey Base: Choosing by Shade
Both buckets are the same silicone and siloxane formula, and the fetched sheet declares one set of performance values without differentiating by base pigment. The choice is therefore about the target shade, not about performance. Renders World lists the two bases on separate product pages, each carrying its own live price.
| Variant | What the sheet declares | Choose it when |
|---|---|---|
| White base — this bucket | V2 · 0.35 MPa · A2-s1, d0 · 480 SAH shades | Pure whites, creams, off-whites and pale tints |
| grey-base Atlas Silicone Render | Same declared figures — the sheet quotes no separate values by base | Mid-tone, dark and saturated shades |
Is the White Base Right for Your Project?
- Specify Atlas Silicone Render on the white base where the finished shade is white, cream or a pale tint, and the build-up sits inside the certificate's height limits for its nation.
- For anything mid-tone or darker, the grey base is the same product with a different starting pigment and reaches saturation with less work.
- For an ageing facade that needs refreshing rather than re-rendering, the sheet names Atlas Salta N as the renovation route — that sits in the silicone masonry paint range, and the intervals are covered in the guide to maintaining a silicone render facade.
- Still comparing brands and binder types? The silicone render buying criteria guide ranks the range on certificate scope, grain and coverage.
When the shade reference and the reinforced-layer mortar are both settled, order the 25 kg bucket from Renders World and send the colour reference with the order so the tint is matched before dispatch.
FAQ: Ordering, Compatibility, Fire and Maintenance
How many 25 kg buckets do I need for 100 m² at 1.5 mm?
Plan on 2.5 kg/m², the higher of the two figures the manufacturer publishes, which gives 10 m² per bucket. That makes 10 buckets for 100 m², or 11 with a 10% allowance for waste, corners and substrate tolerance. At 2.0 mm the basis rises to 3.0 kg/m², so the same wall takes 12 buckets, or 14 with the allowance.
Does this render always need a primer or key coat underneath?
No — and that is the most commonly over-specified item on a quote. Where the reinforced layer is Atlas Stopter K-100, Stopter K-50 or Hoter U2-B, the sheet states that no plaster base is required. Other reinforced layers, concrete and cement or cement-lime plasters take Atlas Silkon ANX, and internal gypsum substrates take Atlas Uni-Grunt first.
When should I switch to the grey base instead?
Shade depth decides it. White gives the cleanest result on whites, creams and pale tints, where a coloured base would dull the pigment; grey gives saturated mid-tones and darks their depth from the same formula. Performance is identical, because the sheet declares one set of values covering both.
Can it be sprayed, and what temperature can I work in?
Spraying is permitted on the 1.5 mm N-15 grain only, with a Wagner PC 830 or a Graco TexSpray RTX 5500 PX on a 6 mm nozzle, and sprayed render is not floated afterwards. The working window is +5 °C to +30 °C at humidity below 80%, extending to above 0 °C once Atlas Eskimo is added.
How dark a colour can this base be tinted to?
The limit is set by the mortar beneath, not by the render. Shades with a light reflectance above HBW 15% are permitted over an Atlas Hoter U2 reinforced layer, and above HBW 6% over Atlas Stopter K-100. HBW is the light reflectance coefficient, so a lower number means a deeper shade — for genuinely deep tones the grey base is the better starting point anyway.
How is the finish maintained, and can it be overpainted?
Routine maintenance is light, because the hydrophobic self-cleaning surface is designed to shed dust and dirt during rainfall. When an ageing facade eventually needs refreshing, the sheet names painting with Atlas Salta N silicone paint as the renovation route, which keeps the vapour-open character of the build-up intact.
What can I quote for fire performance and environmental credentials?
Quote both fire classes with their scopes: A2-s1, d0 for the render under DoP 145/3/CPR, and B-s2, d0 for the Atlas/Aval EPS system containing it under BBA 13/5018, with the 18 m and 11 m height limits attached. On environmental performance, Atlas states that production is covered by a Type III environmental declaration; the sheet names the declaration rather than reproducing its figures, so request the document itself for a sustainability submission.
Technical Documentation