Description
White is where a pale render starts. This is the base Atlas Silicone Render is tinted from for whites, creams and the light half of the palette, and every bucket is mixed to the shade here in Southampton rather than picked off a shelf. Order the colour reference with the render and it leaves matched.
Atlas Silicone Render on the White Base
Atlas Silicone Render on the white base is a ready-mixed silicone and siloxane thin-coat finish, declared to EN 15824:2017 and used as the visible coat of external wall insulation build-ups over EPS and mineral wool. White is the correct starting pigment wherever the finished shade is a white, a cream or a pale tint, because a coloured base pulls those shades off tone. It sits in the silicone render range alongside the grey base, which carries the darker half of the same palette.
The permitted field of use is wider than most listings admit, and it matters when a job runs past the elevation.
- Facades in an EPS insulation system and in a mineral wool system — the two build-ups Atlas names.
- Single-layer wall facades, and mineral substrates such as concrete and traditional cement or cement-lime plaster.
- The ceiling side of a floor slab, which covers soffits and exposed undercrofts.
- Internal walls, gypsum substrates and plasterboard included, primed first.
Two situations are excluded outright: horizontal surfaces in permanent contact with water or snow, and any wall drawing moisture up by capillary rise. Deal with rising damp first, and the same specification then carries the elevation, the reveals and a soffit return without a second product.
What This Finish Gives a Pale Elevation
- 480 shades from one base. The SAH Paints and Plasters range runs to 480 colours, and any individual colour can be matched through the Atlas colouring system to the customer's own reference.
- Colour fastness is confirmed on Xenotests, using hybrid inorganic and organic pigments with reflective additives — which is why a pale tint holds its tone instead of drifting toward grey.
- A high silicone and siloxane resin content keeps dust and dirt from bonding to the coating, so ordinary rainfall rinses the face. A photocatalytic self-cleaning effect is claimed on top of that.
- Algae resistance has a stated mechanism, not just a claim: the degree of hydrophobisation, the structural tightness of the coating, and a very high content of encapsulated coating-active substances. The conditions this silicone render is named for follow from that mechanism — shaded sites, city centres, and walls near greenery or standing water.
- V2 vapour permeability keeps the finish coat open, so a retrofitted solid wall keeps an outward path for moisture.
- Cellulose fibres and dedicated polymer resins bridge thermal movement, and the silicone render is recommended where resistance to mechanical damage and dirt has to be high — playgrounds, gateways, parking zones and industrial pollution.
Shade references are worth settling against a physical chip rather than a screen; the SAH colour charts and sample books carry the chips the tint is mixed to.
Declared Performance of the Render Itself
Everything in this table describes the 25 kg bucket of Atlas Silicone Render. System figures are a separate matter and sit in the next table, so a specification quotes each class against the scope it actually belongs to.
| Property | Declared value | Scope |
|---|---|---|
| Packaging | 25 kg plastic bucket | Product |
| Density | approx. 1.9 g/cm³ | Finished product |
| Texture and grain | Lambskin; 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 |
| Diffusion resistance | 0.14 ≤ Sd < 1.4 m | Product |
| Adhesion | 0.35 MPa | DoP 145/3/CPR |
| Water absorption | W2 — average | DoP 145/3/CPR |
| Reaction to fire | A2-s1, d0 | The render alone |
| pH value | approximately 8 | Product |
| Application temperature | +5 °C to +30 °C, or above 0 °C with an accelerator | Compound and substrate |
| Relative humidity | below 80% | Application and setting |
| Drying | approx. 15 min surface, approx. 24 h through | At 20 °C, 60% RH |
| Shelf life | 12 months from manufacture | Product |
One line is worth a note. The English-language edition of the manufacturer's data prints the water absorption class as In2, which is not a designation EN 15824 uses; the Polish edition prints W2, and W2 is the class that belongs in a specification.
System Figures, and the Height Limits That Come With Them
A designer works to the assembly, not to the bucket, and the assembly carries the stricter class. These figures belong to build-ups containing this render, never to the render on its own.
| Figure | Value | Whose figure it is |
|---|---|---|
| Reaction to fire, system | B-s2, d0 | One specific Atlas/Aval EPS build-up, BBA 13/5018 |
| Height limit, England, Wales, NI | no storey above 18 m | That same certified build-up |
| Height limit, Scotland | no storey at or above 11 m | That same build-up; also 1 m from a boundary |
| Coverage in the certified system | 2.5 to 3.5 kg/m² | Named for this render, across its grains |
| System assessments | ETA-06/0081, ETA-06/0173, ETA-16/0933 | ATLAS, ATLAS ROKER and ATLAS GRAWIS systems |
The certified construction is a closed list rather than a general permission: named adhesives, EPS to a stated maximum thickness, named basecoats carrying Atlas reinforcing mesh, a key coat, and this render as the finishing coat. Within the height limits above, a B-s2, d0 construction may sit at any proximity to a boundary in England, Wales and Northern Ireland. The certificate asks the designer to confirm the classification against the Building Regulations for the specific project, which is the right sequence on anything above two storeys.
How to Apply It: Consistency, the Cycle and Texturing
The bucket of silicone render arrives ready to use. Nothing is added to it — no water, no thickener, no other material — and a stir before use is all it needs to even out the consistency. There is no pot life to race, because nothing starts a chemical clock when the lid comes off. What governs the day is the technological cycle: the area that can be laid and floated wet-on-wet before the batch skins.
That cycle is established on site, for the substrate and the weather of the day. Plan the breaks in advance — corners, building folds, under downpipes, at colour changes — so that each one lands where the eye expects a line.
- Lay at aggregate thickness with a smooth stainless steel trowel, drawing the excess back into the bucket and stirring it in.
- Texture with a plastic float in circular motions to pull the lambskin effect.
- Sprayed render is left as it lands. Hand and machine textures differ enough that a single object takes one method throughout — the manufacturer states this as a requirement, not a preference.
- Wash tools in clean water straight away; cured residue lifts with a resin remover.
Machine Application and the Grain It Commits You To
Spraying is permitted on the 1.5 mm N-15 grain only, with a Wagner PC 830 on a 6 mm nozzle at minimum feed and around 2.2 bar, or a Graco TexSpray RTX 5500 PX on a 6 mm round nozzle at medium feed. Quoted pressures suit standard hose lengths and are set on site for longer runs. Prime the line with a small charge of key coat before the render goes through, so the hose is wet and clean.
The consequence for a specifier is worth catching early: a spray programme commits the whole building to 1.5 mm, because 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 silicone render against the higher of the two published consumption figures and the delivery covers the wall. Hand-applied at 1.5 mm, the published figures are from 2.2 kg/m² in one edition and an average below 2.5 kg/m² in the other; at 2.0 mm the pair reads from 2.8 kg/m² and an average below 3.0 kg/m². Both assume an even substrate.
- 1.5 mm by hand: plan on 2.5 kg/m², which gives 10 m² per 25 kg bucket. The 2.2 kg/m² minimum would give 11.4 m², and that assumes a basecoat with no tolerance in it at all.
- A 100 m² elevation at 1.5 mm: ten buckets bare, and eleven with a 10% allowance for waste, corners and substrate tolerance.
- 2.0 mm by hand: plan on 3.0 kg/m², about 8.3 m² per bucket, so the same wall takes twelve buckets, or fourteen with the same allowance.
- Sprayed at 1.5 mm the published figure drops to 1.9 kg/m², though no separate bucket count is given for machine work, so the hand figure is the safe basis for the order.
Within the certified EPS system the BBA brackets this render at 2.5 to 3.5 kg/m² across its grain sizes, which confirms 2.5 kg/m² as a sound floor for the finish coat. For a whole build-up rather than the top coat alone, the render coverage calculator runs the arithmetic layer by layer.
Substrate Preparation, and When the Key Coat Comes Off the Quote
A key coat is not universal for Atlas Silicone Render, and it is the item most often over-specified on a render quote. Where the reinforced layer of the build-up is made with an adhesive mortar cleared for the purpose — Stopter K-50 is the one Renders World stocks — no plaster base is required at all. The silicone render goes straight onto the seasoned reinforced layer, and a whole material and a whole day come out of the programme.
Every other route does take one. Reinforced layers built from other adhesive mortars, concrete, and traditional cement or cement-lime plasters all need a quartz-filled key coat first; internal gypsum substrates and boards take Atlas Uni-Grunt first and then the key coat. Both stages sit in the exterior render primers range.
- An ETICS reinforced layer wants a minimum of three days at +20 °C before the finish coat.
- New cement and cement-lime plaster: seven days per centimetre of thickness, to 4% moisture.
- Concrete: twenty-eight days, with structural moisture below 4%.
- Gypsum substrates and boards, internal only, below 2% moisture.
- Treat any biological growth with Atlas Mykos Plus before priming, and make good unevenness with Atlas ZW 330 or a plastering mortar rather than with the finish coat.
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.
How Deep the Shade Can Go on This Base
Deep shades are tied to the mortar in the reinforced layer, expressed as a light reflectance value: below a stated reflectance the manufacturer names particular two-in-one mortars, and the deeper the colour the narrower that choice becomes. Whites, creams and pale tints sit far above the line, which is why the white base is the straightforward half of the palette to specify.
- On this base the reflectance limit does not bite, so the reinforced-layer mortar is chosen on the build-up rather than on the colour.
- For saturated mid-tones and darks the limit does apply, and those shades belong to the grey base of the same silicone render.
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 during application and through drying. Surface dry runs at about fifteen minutes and through-dry at about twenty-four hours, measured at 20 °C and 60% relative humidity.
At the cold end, with humidity up, the setting time lengthens — which means a longer protected period rather than a compromised finish. Working at reduced temperatures above 0 °C is provided for with Atlas Eskimo added, which extends the silicone render season rather than opening it 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, so the whole wall reads as one colour from the first panel to the last.
- Protect the drying render as well as the wet one; the twenty-four hour window is where that protection earns its keep.
- Not for horizontal surfaces exposed to standing water or snow, or for walls affected by rising damp.
Getting an Even Pale Finish
An even finish is what a pale elevation is for, and most of the work that produces it happens a stage earlier — in the substrate and in the rhythm of the day — not in the finish coat itself.
- Straight-edge the reinforced layer before the key coat. Flatness is cheaper to build into the basecoat than to adjust afterwards, and raking light rewards it on a pale wall.
- Prove the cycle on the least visible elevation. The maximum one-cycle area has to be established on site, and the first bay is where that gets learned.
- Keep a spare bucket from the same batch for reveal returns and for making good after the scaffold comes down.
- Confirm the shade against a physical reference before the order is mixed, because the tint is matched to the chip rather than to a rendering on a screen.
White Base or Grey Base: Choosing by Shade
Both buckets hold the same silicone and siloxane formula and carry the same declared performance. The choice is about the target shade, and it is a matter of how Renders World tints rather than a property of the goods: a white base carries the light end of the palette cleanly, a grey base carries the depth at the other end.
| Variant | Choose it when the finished shade is |
|---|---|
| White base — this bucket | White, cream, off-white or a pale tint |
| Grey base | Mid-tone, dark or saturated |
When an existing facade needs refreshing rather than re-rendering, Atlas names its own silicone masonry paint as the route, which keeps the vapour-open character of the build-up intact; that sits in the silicone masonry paint range, and the intervals are covered in the guide to maintaining a silicone render facade.
Ordering This Render From Renders World
Renders World tints every bucket in house, to order, on a mixer kept for one manufacturer alone — no shared heads, no batch left over from another brand. Send the colour reference with the order and the shade is matched before the silicone render is dispatched.
- Because each bucket is mixed for the job, tinted goods sit outside the fourteen-day change-of-mind return.
- Stock items dispatch the same day. Next-day delivery is available as an option, not as the standard service.
- Delivery is quoted once the order is placed instead of in the basket, and every delivery is kerbside — plan for offloading on site.
- Local delivery runs free in our own van within fifteen miles of Southampton on larger orders, and on a per-mile rate beyond that out to sixty miles.
- Collection from Unit 9A, Central Trading Estate, Southampton SO14 5JP — Monday to Friday 7:00 to 17:00, Saturday 7:00 to 12:00.
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 published figures, which gives 10 m² per bucket. That makes ten buckets for 100 m², or eleven 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 twelve buckets, or fourteen with the allowance.
Does this render always need a primer or key coat underneath?
No, and it is the most commonly over-specified item on a render quote. Where the reinforced layer uses an adhesive mortar cleared for the purpose — Stopter K-50 among them — no plaster base is required. Other reinforced layers, concrete, and cement or cement-lime plasters take a quartz-filled key coat, and internal gypsum substrates take Atlas Uni-Grunt first.
When should I order the grey base instead?
Shade depth decides it. White carries whites, creams and pale tints cleanly, because a coloured base would pull those shades off tone; grey carries mid-tones, darks and saturated colours from the same formula. The declared performance is identical either way.
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 above 0 °C once Atlas Eskimo is added.
How dark a colour can this base be tinted to?
On this base the practical answer is the pale half of the palette, which is what it is pigmented for. The deep-shade limits are set by the light reflectance of the colour and by the mortar in the reinforced layer beneath, and whites, creams and pale tints sit comfortably clear of those limits. For genuinely deep tones, order the grey base.
How is the finish maintained, and can it be overpainted?
Maintenance of a silicone render facade is light, because the hydrophobic self-cleaning surface is designed to shed dust and dirt during rainfall. When an ageing facade eventually wants refreshing, Atlas names painting with its own silicone masonry paint as the route, which keeps the build-up vapour-open.
What can I quote for fire performance and environmental credentials?
Quote both classes with their scopes: A2-s1, d0 for the render under DoP 145/3/CPR, and B-s2, d0 for the certified Atlas/Aval EPS system containing it under BBA 13/5018, with the height limits attached. On environmental performance, Atlas states that production is covered by a Type III environmental declaration and names the declaration rather than reproducing its figures, so request the document itself for a sustainability submission.
Technical Documentation