Description
Tinted in 480 Atlas SAH shades on a dedicated Atlas mixing machine at our Southampton warehouse, Atlas Silicone-Silicate Render combines an organic siloxane resin with an inorganic silicate binder for V1 vapour permeability at Sd below 0.14 m — the highest breathability class in the range — covering approximately 10 m² per 25 kg tub, certified to EN 15824:2009 under DoP 125/CPR across three Atlas ETICS approvals (ETA 06/0081, ETA 06/0173, AT-15-9090/2014).
Where Atlas Silicone-Silicate Render Performs Best — Heritage and Breathable UK Walls
Listed buildings, conservation-area properties, pre-1919 solid-wall homes, AAC-block construction, and any substrate that depends on outward evaporation to manage moisture demand a thin-coat finish that breathes as freely as the wall behind it — Atlas Silicone-Silicate Render is the hybrid dual-binder formulation built for that brief, certified V1 with Sd below 0.14 m to EN 15824:2009 (DoP 125/CPR), with A2-s1,d0 reaction to fire and ≥ 0.35 MPa adhesion. Part of the premium silicone render range, this 25 kg ready-mixed render covers approximately 10 m² at 1.5 mm grain (2.5 kg/m²) or 7.8 m² at 2.0 mm grain (3.2 kg/m²), with the spotted (baranek) texture available across the full 480-shade Atlas SAH palette and bespoke RAL or NCS matching mixed on the same Southampton equipment.
The chemistry sets this render apart from every other thin-coat in the Renders World range. An organic siloxane resin delivers hydrophobic surface behaviour and crack-resistant flexibility, while an inorganic silicate binder forms a true chemical bond with mineral substrates — natural stone, lime plaster, brick, AAC blockwork — rather than relying solely on a polymer film. Dispersed microfibres reinforce the render through its full thickness, absorbing thermal expansion, settlement shifts, and minor impact stress so the surface flexes with the building rather than developing hairline cracks over a long service life. An acid-alkaline reaction within the binder matrix creates natural conditions that suppress algae and fungi growth without relying on biocide additives that degrade over time.
Why Trade Specifiers Choose Atlas Silicone-Silicate Render
- Walls That Breathe as Freely as Uncoated Masonry: V1-rated vapour permeability with Sd below 0.14 m lets interior moisture escape outward through the render almost without restriction — roughly ten times more permeable than V2-rated pure silicone, so heritage and solid-wall properties stay structurally sound and damp-free from the inside out.
- Chemical Bond to Mineral Substrates: The inorganic silicate binder bonds chemically to natural stone, lime plaster, traditional brick, and AAC blockwork, integrating with the existing wall rather than forming a separate polymer skin — reducing delamination risk on irregular heritage surfaces and meeting the material-compatibility criteria typically referenced by conservation officers.
- Crack-Free Finish on Moving Walls: Dispersed microfibres reinforce the render throughout its full 1.5 mm or 2.0 mm thickness, absorbing thermal expansion, settlement shifts, and minor impact stress so the surface flexes with the building rather than developing hairline cracks across a 25-year service life.
- Natural Bio-Protection Without Biocides: An acid-alkaline reaction within the binder matrix creates conditions that suppress algae and fungi growth naturally, keeping the facade clean on shaded and north-facing elevations without relying on biocide additives — the self-cleaning effect lasts the full service life of the render rather than degrading over time.
- 480 Heritage and Modern Shades Mixed On Site: Every tub is tinted on a dedicated Atlas machine at our Southampton warehouse, with heritage earth tones, muted limestone shades, and bespoke RAL or NCS matching mixed to order — every order arrives ready to apply with next-day UK dispatch.
- Fire Performance for Compliance Documentation: Reaction to fire A2-s1,d0 (limited combustibility) under EN 13501-1, with DoP 125/CPR and three Atlas system ETA approvals (06/0081, 06/0173, AT-15-9090/2014), giving specifiers the documentation that Building Control and warranty providers typically require subject to each project's specific fire strategy assessment.
- Two Grain Sizes for Texture Choice: Specifiers select 1.5 mm (N-15) for a refined spotted texture at 2.5 kg/m² coverage or 2.0 mm (N-20) for a deeper aggregate finish at 3.2 kg/m² — matching the visual scale to the building's architectural context and viewing distance.
Technical Specifications — Atlas Silicone-Silicate Render Data Sheet
| Property | Value |
|---|---|
| Pack Size | 25 kg plastic bucket |
| Binder Type | Hybrid — organic siloxane + inorganic silicate |
| Aggregate | Marble |
| Density | Approx. 1.9 g/cm³ |
| Grain Size Options | 1.5 mm (N-15) · 2.0 mm (N-20) — spotted (baranek) texture |
| Coverage Rate — 1.5 mm hand | Approx. 2.5 kg/m² — approx. 10 m² per 25 kg tub |
| Coverage Rate — 2.0 mm hand | Approx. 3.2 kg/m² — approx. 7.8 m² per 25 kg tub |
| Vapour Permeability | V1 (high) — Sd < 0.14 m to EN 15824 |
| Water Absorption | W2 (medium) — ≤ 0.5 kg/m²h⁰·⁵ to EN 15824 |
| Adhesion to Substrate | ≥ 0.35 MPa |
| Reaction to Fire | A2-s1,d0 — EN 13501-1 (limited combustibility) |
| Thermal Conductivity | λ₁₀ dry = 0.67 W/(m·K) — EN 1745:2002 |
| Application Temperature | +5 °C to +25 °C (air and substrate); humidity below 80% RH |
| Setting Time | 12–48 hours depending on temperature and humidity |
| Shelf Life | 12 months in sealed packaging at +1 °C to +30 °C |
| Colour Range | 480 Atlas SAH shades plus bespoke RAL/NCS matching |
| Machine Application | 1.5 mm grain — MAI 2 MULTIPUMP / GRACO RTX 1500 (6 mm nozzle, 1 bar) |
| Mandatory Primer | Atlas Silkon ANX priming mass (preceded by consolidation primer on high-suction substrates) |
| System Approvals | ETA 06/0081 (ATLAS) · ETA 06/0173 (ATLAS ROKER) · AT-15-9090/2014 (ATLAS ETICS) |
| Standard Compliance | EN 15824:2009 · DoP 125/CPR |
How to Apply Atlas Silicone-Silicate Render — Heritage Substrates, Priming, EWI Build-Up
This render works best on mineral-based substrates that need unrestricted moisture escape — cellular concrete (AAC blocks), lime-mortared heritage brick, natural stone, traditional lime plasters, and cementitious basecoats over EWI systems using polystyrene, XPS, or mineral wool boards. For high-suction substrates such as aerated block or old lime plaster, apply a consolidation primer first, then follow with Atlas Silkon ANX priming mass — the exterior render primers range includes options matched to every common UK substrate type. Embedding 150 g/m² alkali-resistant fibreglass mesh in a cured reinforced basecoat (three to seven days before priming and topcoat application) creates the stable base this hybrid finish bonds to within the ATLAS, ATLAS ROKER, and ATLAS ETICS systems.
- EWI System Integration: Approved within the ATLAS (ETA 06/0081), ATLAS ROKER (ETA 06/0173), and ATLAS ETICS (AT-15-9090/2014) thermal insulation systems — covering EPS, XPS, and mineral wool board substrates across new-build, retrofit, and over-cladding projects.
- Heritage and Conservation Substrates: V1 vapour permeability and the silicate-based mineral bond meet the breathability and material-compatibility criteria typically referenced in BS 7913 and Historic England guidance, making this the specification conservation officers approve most readily for Grade II listed buildings and conservation-area facades — the silicone-silicate render heritage and conservation guide covers BS 7913 selection criteria, planning documentation, and scenario-matched recommendations for listed buildings in full detail.
- Dark-Colour Guidance: Facades with colours above a 20% diffuse-reflection coefficient perform confidently with this formulation across the full surface area — for very dark shades below that threshold on insulated south-facing walls, a solar-protect formulation provides additional thermal management within the same Ceretherm system family.
- Machine Application: The 1.5 mm grain variant is optimised for MAI 2 MULTIPUMP or GRACO RTX 1500 rendering units with a 6 mm nozzle at 1 bar, delivering faster coverage on large commercial or multi-storey elevations with slightly lower material consumption than hand application.
For the full step-by-step method covering tools, floating technique, and finishing sequence, the thin-coat render application step-by-step guide walks through every stage in the sequence a professional installer follows on site.
Installation Notes — Mixing, Floating, Curing
The render arrives ready to use — stir with a low-speed mechanical mixer to unify consistency before applying with a stainless-steel float at a coat thickness matching the aggregate grain size (1.5 mm or 2.0 mm). For the cleanest result, work in a wet-on-wet method across the entire elevation rather than allowing one section to dry before starting the next, and plan technological breaks at natural boundaries — corners, downpipes, or colour junctions — so any joints remain invisible on the finished facade.
- Texturing Technique: Texture the freshly applied surface with circular movements using a plastic float while the render is still workable — the silicate-silicone hybrid sets slightly faster than pure silicone in warm conditions, so on elevations above 20 °C, work in panels of roughly 4–5 m² and texture each panel immediately rather than floating a full bay first.
- Curing Protection: Protect the finished surface from direct sunlight, wind, and rain for 12 to 48 hours depending on temperature and humidity — scaffold sheeting on south- and west-facing elevations controls drying speed and prevents flash drying that would compromise binder cross-linking.
- Cold-Weather Pairing: For winter work down to 0 °C, pair the render with Atlas Eskimo setting accelerator to maintain a manageable curing window through the colder months without compromising film formation or finish quality.
- Seasonal Scheduling: The seasonal application timing guide covers the full UK weather-management protocol, including temperature, humidity, and forecast-checking discipline across the calendar year.
Pro Tips From UK Installers Using Atlas Silicone-Silicate Render
Heritage and breathable-wall projects punish the assumption that a forecast temperature applies uniformly across every elevation — and the hybrid binder responds to environmental shifts noticeably faster than pure silicone. These site-tested habits keep silicone-silicate finishes uniform, conservation-compliant, and free of the artefacts that show up only after the scaffold comes down:
- Verify Substrate Temperature With an Infrared Thermometer: A forecast reading of 8 °C does not mean the shaded north elevation is above 5 °C at 07:30. Catching that difference before the render is on the wall keeps the job on programme and the finish flawless across all four elevations.
- Texture Each Panel Immediately Above 20 °C: The open time is noticeably shorter than pure silicone because the mineral binder absorbs moisture from the mix more actively. On warm days, texture each 4–5 m² panel immediately rather than floating a full bay first.
- Confirm the Orange-Lid Identifier on Site: The orange tub lid is the visual identifier for Atlas Silicone-Silicate. If you are expecting silicone-silicate and the lid is not orange, check the label before opening — pure silicone and silicate-silicone are not interchangeable on heritage substrates.
- Calculate Quantities for Both Grain Options Up Front: Use the render coverage calculator to build the full materials list before ordering — coverage shifts from 10 m² to 7.8 m² per tub between 1.5 mm and 2.0 mm grain, so confirm the specification before placing the order.
- Confirm Grain Size With Conservation Officer: On listed and conservation-area projects, the grain size is often part of the consent documentation. Confirm the specified grain against approved drawings before ordering, and submit a physical sample swatch at the specified grain to the conservation officer for sign-off ahead of the main delivery.
Is Atlas Silicone-Silicate Render Right for Your Project?
- Yes — for heritage, lime-mortared, or AAC-block walls: Atlas Silicone-Silicate Render is the right choice when your wall is solid masonry with lime mortar, cellular concrete, natural stone, or any heritage substrate where V1-class breathability is required by conservation officers, building surveyors, or the building's own moisture-management needs — this is the one thin-coat system in the range that lets moisture escape the wall almost as freely as an uncoated surface while delivering hydrophobic rain protection, microfibre crack resistance, and A2-s1,d0 fire performance in a single through-coloured coat.
- Standard new-build or modern masonry? The broader premium silicone render collection includes pure silicone finishes such as Ceresit CT 74 that deliver the same self-cleaning hydrophobic performance at a lower cost point — the additional silicate binder is unnecessary on substrates that do not rely on outward evaporation for moisture control, making pure silicone the more economical specification for modern construction.
- Below the DPC or in a splash zone? For plinth heights, ground-level impact zones, and any area below the damp-proof course, the mosaic render range provides the heavy-duty impact resistance and washability those conditions demand — pair on upper elevations with silicone-silicate for a two-tone heritage-appropriate facade detail.
FAQ — Atlas Silicone-Silicate Render Coverage, Heritage Use, Specification
How much silicone-silicate render do I need for my project?
A single 25 kg tub covers approximately 10 m² at 1.5 mm grain (2.5 kg/m²) or roughly 7.8 m² at 2.0 mm grain (3.2 kg/m²). For a typical 80 m² heritage cottage facade at 1.5 mm grain, budget eight tubs plus one extra for waste and detailing around window reveals, corners, and pipe cut-outs. Machine application slightly reduces consumption, but always round up to the next full tub so you can maintain the wet-on-wet technique without running short mid-elevation.
Is this render suitable for listed buildings and conservation areas?
V1 vapour permeability (Sd below 0.14 m) makes this the most breathable thin-coat render in the range, and the silicate binder bonds chemically to mineral substrates like lime plaster and natural stone rather than sitting as a polymer film — which is why conservation officers typically approve it more readily than polymer-only finishes for Grade II listed buildings and conservation-area properties where BS 7913 and Historic England guidance recommend materials compatible with traditional building fabric. Each project's planning consent and listed-building consent process determines the final acceptable specification, so confirm with the local conservation officer ahead of ordering.
What makes this render different from pure silicone render?
The practical difference is breathability and substrate bonding. Pure silicone renders typically achieve V2 permeability (Sd 0.14–1.4 m), which works well for modern masonry but restricts moisture movement on solid lime-mortared walls that rely on outward evaporation. This silicone-silicate hybrid achieves V1 (Sd below 0.14 m) — roughly ten times more permeable — and its inorganic silicate component forms a chemical bond with mineral substrates, so the render integrates with heritage masonry rather than forming a separate skin. For standard new-build and modern-masonry projects, pure silicone is the correct and more cost-effective choice; for heritage, AAC, and high-permeability substrates, the silicone-silicate hybrid satisfies both the building's moisture needs and the conservation officer's requirements.
Does Atlas Silicone-Silicate Render meet fire safety requirements?
The render carries an A2-s1,d0 (limited combustibility) reaction to fire classification under EN 13501-1, which typically satisfies the fire performance requirements for residential and commercial facades subject to each project's specific fire strategy assessment. Three Atlas ETICS system approvals (ETA 06/0081, ETA 06/0173, AT-15-9090/2014) document performance across complete build-ups including EPS, XPS, and mineral wool board substrates — pairing the render with mineral wool insulation delivers the highest-rated compliant specification on higher-risk facades where stricter classification is required.
What colours are available and can you match a heritage shade?
The full 480-shade Atlas SAH palette is tinted on a dedicated Atlas mixing machine at our Southampton warehouse and ready for next-day dispatch — including heritage earth tones, muted limestone shades, and soft pastels that complement traditional masonry. For projects that need a shade outside the standard Atlas range, our team mixes bespoke colours to order on the same equipment, matching specific RAL codes, NCS references, or shades from another manufacturer's swatch. Our warehouse also mixes the Ceresit Colours of Nature range on a separate dedicated machine, bringing the combined choice across both systems to over 1,000 standard shades plus bespoke matching. Grain size affects how a colour reads on the wall: a 2.0 mm texture casts deeper micro-shadows that can make the same pigment appear marginally darker than 1.5 mm, so always confirm the shade on a physical swatch at the grain size you plan to specify. Browse the colour sample catalogues to view both palettes on rendered swatches.
Is Atlas Silicone-Silicate Render an environmentally responsible choice?
The formulation is water-based with maximally reduced volatile organic compounds (VOC) and uses only natural marble fillers. The thin application rate of 2.5 kg/m² at 1.5 mm grain generates substantially less material waste per square metre than traditional sand-and-cement renders applied at 15–20 mm thickness, and the 25-year-plus through-coloured service life eliminates the recurring resource consumption of periodic repainting cycles — so the total environmental footprint over the building's life is significantly lower than thicker, shorter-lived alternatives, an important consideration on heritage projects where sustainability and long-term material compatibility are both priorities.
Technical Documentation — Atlas Silicone-Silicate Render TDS and DoP