Ceresit CT76 Solar Protect Render 25kg

Ceresit CT 76 answers UV exposure, not heat. Its sheet claims increased UV absorbers, a self-healing surface effect and high colour stability — and asks for a light reflectance value of HBW 15 or above, with a consultation below it. Renders World lists the 25 kg tub at £65.00, fetched August 2026.

What Ceresit CT 76 Solar Protect Render Is Built to Resist

Ceresit CT76 Solar Protect render 25kg is a silico-elastomeric thin-layer facade render declared to EN 15824, applied at 2.1 to 2.5 kg/m² at 1.5 mm grain, and its distinguishing feature is an increased quantity of UV absorbers rather than anything to do with reflected warmth. It sits in the Renders World silicone render range as the colour-stability specification.

The sheet is worth reading carefully because it is precise about mechanism. UV radiation destroys polymer bonds at the surface, which is what produces chalking and faded tone over years of exposure. CT 76 answers that with a raised absorber content for colour light fastness, plus special additives and fillers that give the surface an ability to self-heal microcracks. Both are surface-durability claims about ultraviolet light.

• Where it belongs: as facade render within Ceresit ETICS over EPS boards and mineral wool, and on concrete, traditional renders and reinforced mortar layers.
• Where high permeability is the driver: the sheet recommends it for partitions requiring high permeability, declared V1 under EN 15824.
• Indoors only: gypsum substrates below 1% moisture, chipboard, gypsum-fibre board, plasterboard and sound paint coats — all interior, all primed CT 17 then CT 16.

The HBW Figure and What It Actually Asks of a Specifier

This is the number that decides whether CT 76 is the right call, and the sheet states it as a recommendation with a direction of travel. For facade durability and to prevent excessive heating of the facade surface, Ceresit recommends using CT 76 with a light reflection value of HBW ≥ 15. Below HBW 15, the sheet asks that the solution be discussed with the Ceresit technical department so that an appropriate insulation system is selected.

Read that as written, it is a floor rather than a licence. The render is not described as a means of making very dark colours safe; the document keeps a reflectance minimum in place and routes anything darker to the manufacturer, and it frames the question as insulation system selection. A scheme sitting near or below that threshold is a conversation with Ceresit before it is an order, and the background to reflectance and orientation is set out in the guide to dark colours on render and solar heat.

• HBW 15 and above: within the recommended range on the sheet.
• Below HBW 15: consult Ceresit technical department, per the document, to select the appropriate system.
• Intense palette availability: the sheet lists the wide Colours of Nature and Intense palettes as a characteristic, which is a colour range statement and separate from the reflectance recommendation above.

Declared Data, With the Scope That Governs Each Figure

Every value below was read from the Ceresit CT 76 data sheet fetched for this page. The EN 15824 rows belong to the render; the ETAG 004 rows and the fire classifications belong to systems containing it.

Property	Declared value	Scope
Base	Water dispersion of silicone and acrylic resins with mineral fillers and pigments	Product
Density	1.7 kg/dm³	Product
Consumption, 1.5 mm grain	2.1 to 2.5 kg/m²	Product, 1.5 mm only
Water vapour permeability	V1 — EN 15824	Product
Water absorption	W3 — EN 15824	Product
Adhesion	0.6 MPa — EN 15824	Product
Thermal conductivity	λ = 0.61 W/(m·K) — EN 15824	Product
Application temperature	+5 °C to +25 °C, humidity below 80%	Product
Drying time	Approx. 15 min	Product
Resistance to rain	24 to 48 hours, depending on temperature	Product
Resistance to mould overgrowth	Total resistance	Product
Storage	Up to 18 months from the production date, dry, frost-free, out of direct sun	Product
Impact resistance	Cat. II — ETAG 004	System
Water vapour permeability	Sd ≤ 1.0 m — ETAG 004	System
Water absorption after 24 h	< 0.5 kg/m² — ETAG 004	System
Inter-layer adhesion after ageing	≥ 0.08 MPa — ETAG 004	System

 

Note what is absent as much as what is present. There is no infrared or heat reflection figure anywhere in the technical data, no surface temperature reduction, and no percentage of solar gain — so any specification written around reflected heat is written around something the manufacturer does not declare. The extended shelf life, at 18 months against the 12 months the CT 74 sheet gives, is a genuine documented advantage for a distributor holding tinted stock.

Fire Classification Follows the Ceretherm System

Reaction to fire is declared against named assemblies, so the class comes off the drawing rather than the tub. The less permissive class is listed first.

• B-s1,d0 in Ceresit Ceretherm Popular, Classic, Wool Classic and Universal EPS — Wool Classic included, so a wool build-up does not automatically carry the higher class.
• A2-s1,d0 in Ceresit Ceretherm Universal MW alone.
• Five ETAs are listed with their own certificates and DoP numbers — 08/0309, 09/0014, 09/0026, 13/0535 and 14/0127 — each belonging to a system, not to this render.

Priming Gates, Mixing and Working the Wall

The method matches the rest of the Ceresit thin-coat family, and the priming trigger is a condition rather than a stated number of hours. Get the substrate gates right and the finish behaves predictably.

Substrate Gates and Priming

• External substrates: cement and lime-cement renders over 28 days old, concrete over 3 months old at 4% moisture or below, and reinforced layers of CT 80, CT 85, CT 190, ZU or Thermo Universal over 3 days old — each primed with CT 16.
• Absorbent substrates: CT 17 first, then CT 16 after a minimum of two hours.
• Render when CT 16 is completely dry — that is the gate the sheet names, with no hour figure attached.
• Tint the primer close to the render colour, which the sheet recommends explicitly; take CT 16 from the Renders World exterior render primers range, and reinforce the basecoat with 150 g/m² Atlas mesh beforehand.
• Damaged substrates are smoothed first, with CT 29 filler named for traditional renders and concrete; elastic, lime and adhesive paint coatings are removed rather than overcoated. The full sequence sits in the substrate preparation guide.

Mixing, Floating and the Batch Number

Stir the whole container, adding no more than 1% clean water if needed, and keep rusty tools and containers out of the mix. Apply at grain thickness with a steel long float held at an angle, texture with a plastic float held flat in circular movements, and never sprinkle the surface with water. The sheet also rules out mixing this product with other renders, pigments, resins or binders.

• One batch per surface: mineral fillers cause colour differences between production runs, so the sheet asks for a single batch number, printed on every container, across one elevation. On a saturated shade that check is the difference between one wall and two.
• Staff the scaffold levels so the work stays wet on wet, and plan any stop with self-adhesive tape — render up to it, form the texture, pull the tape with the render on it, restart from that edge.
• Keep it off highly sunny walls and protect against too-fast drying; scaffolding protection is recommended in the document itself, and rain protection runs to the 24–48 hour mark. Timing across the UK year is covered in the render application timing guide, and the trowel method in the step-by-step thin-coat guide.

Ordering CT 76 — Tub Price, Coverage Spread and Quantities

Consumption is declared as a range, and on a full elevation the two ends are about a tub and a half apart. Both are shown so a quantity can be checked against real measurements.

• Tub: £65.00 per 25 kg container, fetched August 2026.
• Coverage: 25 kg ÷ 2.5 kg/m² = 10 m²; 25 kg ÷ 2.1 kg/m² = 11.9 m². One tub covers 10 to 11.9 m².
• Per square metre: £65.00 ÷ 10 m² = £6.50/m²; £65.00 ÷ 11.9 m² = £5.46/m².
• A 100 m² elevation: 100 ÷ 10–11.9 = 8.4 to 10 tubs, plus 10% for reveals and waste = 9 to 11 tubs.

Those figures are the render coat only — no primer, basecoat, mesh, beads or labour, and no installed rate, since labour is not a figure this store publishes. Build the full materials list with the render coverage calculator. Renders World dispatches parcels next day and pallets next day or on a two-business-day economy service, kerbside, from Southampton.

CT 76 Beside CT 74 and CT 174 — Where the Sheets Separate

All three sheets were read together, and the striking thing is how much is shared: identical V1 classification, W3 absorption, 0.6 MPa adhesion, λ 0.61 W/(m·K), the same 15-minute working time and the same temperature window. The differences worth specifying on are narrower than the marketing suggests.

Render	Consumption at 1.5 mm	What its own sheet claims
CT 76 Solar Protect (this tub)	2.1–2.5 kg/m²	Increased UV absorbers, self-healing surface, HBW ≥ 15 recommendation, 18-month storage
CT 74 Silicone Self Clean	2.1–2.5 kg/m²	Self-cleaning and hydrophobic claims, BioProtect, 12-month storage
CT 174 Silicate-Silicone	Approx. 2.5 kg/m²	Silicate-silicone binder, BioProtect, rain resistance approx. 24 h

 

CT 76 and CT 74 share a declared base — a dispersion of silicone and acrylic resins — at the same price and the same consumption. What you are choosing between is a sheet emphasising UV absorbers and self-healing against one emphasising self-cleaning and dirt resistance. Brand-level differences sit in the Atlas and Ceresit silicone render comparison.

Specifying CT 76 on a UK Facade

• Choose it where colour light fastness over years of sun exposure is the priority — south and west elevations, saturated tones and schemes where the client will notice fade before anything else.
• Check the reflectance value first: at HBW 15 or above you are inside the sheet's recommendation; below it, the documented next step is a conversation with Ceresit about the insulation system.
• Take CT 74 instead where self-cleaning on an urban or shaded wall matters more than UV stability — same price, same coverage, a sheet built around dirt resistance.
• Confirm shades physically before ordering: the sheet names the Colours of Nature and Intense palettes without stating a count, so the render colour charts and sample books are the reliable reference.
• Plan the refresh: the sheet names Ceresit CT 48 and CT 49 silicone paints as the renovation route, keeping the render in service rather than stripping it; upkeep is covered in the silicone render maintenance guide. Renders World holds CT 76 in 25 kg tubs for next-day dispatch.

FAQ — Quantities, Reflectance, Substrates and Renovation

How many tubs cover 100 m²?

Nine to eleven. At 2.1–2.5 kg/m² one 25 kg tub does 10–11.9 m², giving 8.4 to 10 tubs bare, and a 10% allowance for reveals and detailing takes it to 9–11 from a single batch.

Does CT 76 make very dark colours safe on an insulated wall?

Not on its own terms. The sheet recommends CT 76 with a light reflection value of HBW 15 or above and asks for a Ceresit technical consultation below that figure so an appropriate insulation system can be chosen, so a very dark scheme is a manufacturer conversation rather than a straight substitution.

Can it be applied to plasterboard or an old painted wall?

Indoors only. Gypsum below 1% moisture, chipboard, gypsum-fibre board, plasterboard and sound paint coats are all listed as interior substrates; outside, it goes on render, concrete or a reinforced mortar layer, primed with CT 16.

Which fire class applies to a CT 76 facade?

Whichever the assembly carries: B-s1,d0 in Ceretherm Popular, Classic, Wool Classic and Universal EPS, and A2-s1,d0 in Universal MW. The render holds no class independently of the system.

How long can tinted stock be held?

Up to 18 months from the production date in dry, cool conditions in undamaged packaging, protected from frost and direct sunlight — six months longer than the CT 74 sheet allows.

How is an aged CT 76 facade refreshed?

By painting with Ceresit CT 48 or CT 49 silicone paints, the route the sheet names, which restores the surface without removing the existing render.

Technical Documentation — CT 76 Data Sheet

• Technical Data Sheet — Ceresit CT 76 Solar Protect (PDF)