Ceresit CT 76 Solar Protect Render 25 kg — Silico-Elastomeric UV-Resistant Finish for Dark Facades

Product Overview

Designed for facades where dark or intense colours meet insulated wall systems, Ceresit CT 76 Solar Protect render 25 kg is a silico-elastomeric thin-coat finish that reflects solar infrared radiation to keep surface temperatures significantly lower than standard silicone renders — so you can specify bold anthracite, charcoal, or deep earth tones on south-facing elevations without compromising the durability of the ETICS build-up beneath. This nano-technology hydrophobic render combines Solar Protect infrared-reflective pigments with UV absorbers and free-radical scavengers that intercept polymer degradation at the molecular level, preserving both colour intensity and binder integrity for decades of UK weather exposure. The integrated DoubleDry self-cleaning surface causes rainwater to bead and sheet off the finish, carrying atmospheric dust and biological spores with it — a benefit that is especially visible on dark facades, where even light surface deposits would otherwise stand out. Each 25 kg tub covers approximately 10 m² at the standard 1.5 mm grain size, and the product is approved for use within certified Ceresit Ceretherm ETICS systems on EPS and mineral wool insulation, making it a reliable specification for projects ranging from single-home renovations to multi-unit developer schemes. Browse the full premium silicone render collection to compare CT 76 against standard silicone and silicate-silicone options for lighter-shade projects.

Where standard silicone renders are typically limited to colours with a Heat Brightness Value (HBW) of 25–30 and above, CT 76 extends the safe specification range down to HBW 15 — covering the full spectrum of contemporary dark tones that architects and homeowners increasingly request. The silico-elastomeric binder blends silicone resin flexibility with elastomeric polymer chains (meaning the cured render film stretches and recovers with daily thermal cycling rather than cracking under repeated stress), and the surface self-healing effect repairs micro-cracks before they become visible to the eye. For professionals, this translates to fewer callbacks; for developers, it means a facade that passes inspection years after handover; and for homeowners, it means the dark finish they chose looks exactly as planned, season after season.

Key Benefits

• Safe Dark-Colour Specification Down to HBW 15: Solar Protect infrared-reflective pigments reduce surface temperature on dark facades by reflecting the near-infrared energy that accounts for roughly half of total solar heat gain — so a deep anthracite or charcoal finish stays cool enough to avoid the thermal stress that would crack a standard silicone render on an insulated wall.
• Self-Cleaning Surface That Stays Visibly Clean: The DoubleDry nano-textured hydrophobic finish causes rainwater to bead tightly and run off the wall, lifting atmospheric dust and biological spores as it goes — keeping a dark facade looking sharp between natural rain washes without manual cleaning, because the water absorption rate is classified W3 (Low) per EN 15824.
• Decade-Long Colour Stability: Built-in UV absorbers and free-radical scavengers neutralise the polymer-bond damage that causes chalking and colour fade on exposed elevations, so vibrant dark tones retain their original depth rather than washing out over years of UK sun and rain cycles.
• Crack Resistance Through Thermal Movement: The elastomeric polymer matrix (meaning the cured film flexes with daily temperature swings, keeping the surface smooth and intact year after year) absorbs the expansion and contraction cycles that dark surfaces undergo every sunny day — achieving Category II impact resistance per ETAG 004 for long-term structural integrity.
• High Vapour Permeability for a Healthy Wall: Classified V1 (High) per EN 15824 with an Sd value of ≤ 1.0 m, so the wall breathes freely and moisture vapour escapes outward through the render — keeping your insulation system dry and performing at its full designed thermal efficiency for the life of the building.
• Integrated Bio-Protection Against Algae and Mould: Biocidal agents built into the render formulation create a long-term barrier against algae, mould, and fungi colonisation on the facade surface, which is particularly valuable on dark finishes where green or red biological growth would contrast more visibly against the colour.
• Proven Coverage at 2.1–2.5 kg/m²: Each 25 kg tub delivers approximately 10 m² of finished facade at the 1.5 mm grain size, giving installers and quantity surveyors a reliable figure for ordering — budget 11 tubs per 100 m² to account for reveals, detailing, and standard site waste.

Technical Specifications

Property	Value
Base Material	Water dispersion of silicone and acrylic resins with mineral fillers and pigments (silico-elastomeric)
Pack Size	25 kg plastic container
Grain Size	1.5 mm (stone texture)
Density	Approx. 1.7 kg/dm³
Coverage (1.5 mm grain)	2.1–2.5 kg/m² (~10 m² per 25 kg tub)
Application Temperature	+5 °C to +25 °C (air and substrate)
Maximum Humidity at Application	Below 80 % RH
Drying Time (surface)	Approx. 15 minutes
Rain Resistance	24–48 hours (temperature-dependent)
Vapour Permeability	V1 (High) per EN 15824:2017; Sd ≤ 1.0 m per ETAG 004
Water Absorption	W3 (Low) per EN 15824:2017; < 0.5 kg/m² after 24 h per ETAG 004
Adhesion	0.6 MPa per EN 15824:2017
Adhesion Between Layers After Ageing	≥ 0.08 MPa per ETAG 004
Impact Resistance	Category II per ETAG 004
Thermal Conductivity	λ = 0.61 W/(m·K) per EN 15824:2017
Fire Classification (EN 13501-1)	B–s1,d0 on EPS systems; A2–s1,d0 on mineral wool systems
Minimum HBW Supported	HBW ≥ 15 (below 15 requires manufacturer consultation)
Bio-Protection	Total resistance to mould overgrowth
Shelf Life	Up to 18 months in original unopened packaging
Compliance	EN 15824:2017; ETAs 08/0309, 09/0014, 09/0026, 13/0535, 14/0127 (current as of March 2026)

Application & Compatibility

CT 76 Solar Protect performs best as the decorative topcoat within a complete Ceresit Ceretherm ETICS, where the full system — insulation boards, adhesive, basecoat, mesh, primer, and render — is designed to work as a certified assembly. The render bonds securely to a cured reinforced basecoat (CT 80, CT 85, CT 190, ZU, or Thermo Universal mortars) that has been primed with Ceresit CT 16 quartz primer to provide the mechanical key and suction control that the thin-coat finish requires. Compatible insulation substrates include graphite EPS boards and mineral wool slabs; on mineral wool systems, the fire classification upgrades to A2–s1,d0 — a specification that satisfies high-rise and Building Safety Act requirements.

• Mandatory Priming: Apply Ceresit CT 16 quartz primer to the fully cured basecoat (minimum 3 days curing) and allow to dry completely before rendering — this step creates the aggregate-loaded grip surface that locks the render permanently to the system and equalises suction across the elevation, delivering an even colour and texture across every square metre.
• Reinforcement Layer: Embed fibreglass mesh at minimum 150 g/m² into the basecoat to distribute thermal and mechanical stress before it reaches the decorative finish — overlapping joints by at least 100 mm ensures continuous reinforcement with no weak points at seams.
• Approved Substrates: CT 76 bonds to concrete (minimum age 3 months, moisture ≤ 4 %), traditional cement renders and lime-cement renders (minimum age 28 days), and gypsum substrates (interior only) — all primed first with CT 16 to achieve consistent adhesion across mixed or uneven masonry surfaces.
• Dark-Colour Guidance: For any colour with an HBW below 25, CT 76 is the correct specification within the Ceresit system. For comprehensive guidance on HBW thresholds, facade orientation assessment, and system pairing for dark shades, read the full dark colours on render solar heat risk guide.
• Renovation and Overcoating: CT 76 can be applied to CT 48 or CT 49 silicone paint surfaces for future colour refreshes — the silicone paint is the manufacturer-approved renovation pathway that extends the facade's life without stripping the original render.

Installation Notes

For the smoothest, most uniform dark finish, complete each elevation in a single continuous wet-on-wet pass using material from the same production batch — this eliminates visible join lines and shade variations that are far more noticeable on dark colours than on whites or pastels. Stir the full tub contents thoroughly with a low-speed mixer before application, adding no more than 1 % clean water if adjustment is needed; apply at grain thickness using a stainless-steel long float held at a slight angle, then texture immediately with circular movements using a clean plastic float to achieve the characteristic stone aggregate pattern. For the cleanest result, plan adequate site labour so that no scaffolding level is left with an exposed edge for more than a few minutes rather than allowing one section to begin skinning before the adjacent pass catches up. Protect the fresh render from rain for at least 24–48 hours and from direct intense sunlight during the initial cure period — scaffolding sheeting on south- and west-facing elevations controls drying speed and prevents flash drying that would compromise the Solar Protect film formation. The seasonal timing guide in the when to apply silicone render in the UK article covers temperature, humidity, and forecast-checking protocols for scheduling around UK weather.

Trade Insight — Installer's Note

On dark-colour jobs, coverage sits reliably at 2.3–2.5 kg/m² on a properly primed basecoat, so I always order one extra tub per 100 m² beyond the standard 10 % waste allowance — CT 76 at HBW 15–25 shows every slight inconsistency in application thickness, and having material in reserve means the crew never thins the last bucket to stretch it across a reveal. Tinting the CT 16 primer to a shade close to the final render colour is another step worth getting right: a grey-tinted primer beneath an anthracite topcoat eliminates the white flash that shows through any thin spot, and it gives the entire elevation a consistent backing tone that makes the finished render look deeper and more saturated. For a full walkthrough of quantities, grain-to-coverage ratios, and ordering calculations, the render coverage calculator puts the maths in one place.

Is This Product Right for Your Project?

• Choose CT 76 Solar Protect if you are specifying any dark or intense facade colour with an HBW below 25 on an insulated wall system — the Solar Protect infrared-reflective technology, self-healing binder, and DoubleDry self-cleaning surface combine to deliver a durable, vibrant dark finish that stays crack-free and visually sharp across decades of UK exposure.
• Consider a standard silicone render if your chosen colour has an HBW of 30 or above and the facade is not heavily exposed to prolonged direct sunlight — the full range of silicone and silicate-silicone renders offers the same vapour permeability and self-cleaning benefits at a lower per-tub cost.
• Explore mosaic render for plinth zones if you need a tough, impact-resistant decorative finish at ground level below the main render field — the mosaic render collection pairs with CT 76 on upper elevations to create a professional, two-tone facade detailing scheme that protects the most vulnerable area of the wall.

Frequently Asked Questions

How much CT 76 Solar Protect render do I need for my project?

Each 25 kg tub covers approximately 10 m² at the standard 1.5 mm grain size, based on a consumption rate of 2.1–2.5 kg/m². For a 100 m² facade, order 11 tubs to allow for detailing around window reveals, soffits, and normal site waste. Always source every tub from the same production batch to guarantee consistent colour depth across the entire elevation — dark shades amplify even slight batch-to-batch variation that would be invisible on a white finish.

Can I use CT 76 for a dark anthracite or black facade on an insulated wall?

CT 76 is engineered specifically for this purpose. The Solar Protect pigments reflect near-infrared radiation to keep dark surfaces significantly cooler than a standard silicone render, and the silico-elastomeric binder accommodates the thermal movement that dark colours create on insulated walls. Ceresit approves CT 76 for colours with an HBW of 15 and above; colours below HBW 15 require a manufacturer review of the full system design to confirm suitability, so request the HBW value for your chosen shade from the colour chart before ordering.

What primer and system components does CT 76 require?

CT 76 must be applied over a cured reinforced basecoat primed with Ceresit CT 16 quartz primer — the quartz aggregate creates the mechanical key and suction regulation that the decorative render needs for permanent adhesion. The basecoat itself should embed fibreglass mesh at a minimum density of 150 g/m², with joints overlapped by at least 100 mm. Ordering the full system build-up together — insulation, adhesive, basecoat, mesh, primer, and render — keeps every layer chemically compatible and maintains the certified warranty chain.

Does the self-cleaning surface really keep a dark facade clean?

The DoubleDry nano-textured hydrophobic surface causes water to bead tightly and sheet off the wall, lifting atmospheric dust and biological deposits as it goes. In areas with regular rainfall exposure, this mechanism keeps the facade visibly clean without manual intervention. Sheltered recesses or low-rainfall zones may accumulate light deposits over time, but an annual wash with clean water and a soft brush is usually sufficient to restore the finish — the self-cleaning performance is classified W3 (Low water absorption) per EN 15824:2017, confirming that water runs off rather than soaking into the render surface.

Is CT 76 suitable for projects that need A1 or A2 fire classification?

On mineral wool insulation systems (Ceresit Ceretherm Universal MW), CT 76 achieves a fire classification of A2–s1,d0 per EN 13501-1, meeting the requirements for high-rise residential and commercial facades under the Building Safety Act. On EPS insulation systems, the classification is B–s1,d0. If your project requires the highest fire rating across the entire system, pairing CT 76 with A1-rated mineral wool insulation slabs delivers the compliant specification while preserving the dark-colour capability that Solar Protect technology provides — ask the Renders World team for a full mineral wool system quote alongside your CT 76 order.