Description
Renders World stocks this Atlas finish for insulated facades where the specification has to be evidenced as well as installed. Everything below comes from BBA Agrément Certificate 13/5018 and the Atlas thin-coat renders catalogue, both read in full this session, and the figures the manufacturer publishes elsewhere are marked as missing rather than filled in.
Where Acrylic Render Earns Its Place on EPS-Backed Facades
Atlas Acrylic Render White 25kg is named in BBA Agrément Certificate 13/5018 as a finishing coat of the Atlas/Aval EPS system, applied at 2.5 to 5.0 kg/m² over an Atlas Cerplast key coat. That places it in a certified build-up rather than on a wall by itself, which is how it should be quoted and how Building Control will read it. Within the premium silicone render range it is the textured acrylic finish for polystyrene-backed work, and it is a genuine dispersion product, not a hybrid.
- Certified substrates, at system scope: masonry, normal-weight concrete, lightweight concrete, autoclaved concrete and no-fines concrete, on new or existing buildings, with or without existing render.
- Widest grain choice in the Atlas finishing range: 1.5, 2.0 or 3.0 mm particle sizes, against 1.5 to 2.0 mm for every other paste finish in the same certificate.
- Existing walls: the certificate expects no dampness on the inner face other than condensation, so an internal check before ordering keeps the specification sound.
The layer sequence underneath matters more than the topcoat on this kind of job, and the EWI build-up layer guide sets out where each component sits.
Why Trade Buyers Specify a Styrene-Acrylic Finish
The case here is grain range and predictable pricing rather than breathability, and four of the five points below sit on a document you can hand to a specifier.
- Three grain sizes in one product: 1.5, 2.0 and 3.0 mm let the texture scale to the elevation without moving to a different certified finish or a different key coat.
- A key coat that is fixed by the certificate: Atlas Cerplast, also branded Aval KT 16, at 0.25 to 0.35 kg/m², shared with Atlas Cermit Mineral and the acrylic-silicone finish — useful on a facade being finished in more than one material.
- Thirty-year certified system life: under normal service conditions, installed and maintained to the certificate, the system is assessed as remaining effective for at least 30 years.
- A pure styrene-acrylic dispersion: the Atlas catalogue lists this render's binder as styrene-acrylic resin, where the Atlas silicone render is listed as styrene-acrylic and silicone resin — the two are not the clean split the market usually assumes.
- Documented installer route: the system is installed by contractors trained and registered by the certificate holder, which is the evidence trail warranty providers ask for.
Certified Specification — What Certificate 13/5018 States for the Acrylic Render
| Property | Value and scope |
|---|---|
| Product form | Ready-to-use paste |
| Particle sizes | 1.5, 2.0 or 3.0 mm; spotted texture |
| Binder | Styrene-acrylic resin |
| Coverage, certified range | 2.5 to 5.0 kg/m² as a finishing coat of the Atlas/Aval EPS system |
| Consumption by grain | 2.5 kg/m² at 1.5 mm; 3.0 kg/m² at 2.0 mm (2017 Atlas catalogue) |
| Named key coat | Atlas Cerplast / Aval KT 16, at 0.25 to 0.35 kg/m² |
| Basecoat beneath | 2.0 to 5.0 mm, or 4.0 to 6.0 mm with two mesh layers |
| Reinforcing mesh | Atlas 150, 150 g/m², 4.5 by 5.0 mm grid |
| Standard | PN-EN 15824:2010 |
| Height limit, England, Wales, NI | System not for buildings with a storey more than 18 m above ground level |
| Height limit, Scotland | System not for buildings with a storey 11 m or more above ground level, or 1 m or less from a boundary |
| Reaction to fire | Not published — see below |
The certificate's reaction-to-fire table classifies three complete constructions, at B-s1,d0, B-s2,d0 and C-s2,d0. The finishing coats named in those three rows are Atlas Cermit Mineral, Atlas Silicate Render, Atlas Silicone Render and Atlas Acrylic-Silicone Render. This render appears in none of them, so no class is stated for it here and none is borrowed from a neighbouring row. The blanket storey-height limits above still apply; the boundary-proximity allowances attach to the classified constructions, so they should not be claimed for this finish without a fire strategy that covers it.
Atlas publishes a product data sheet and a Declaration of Performance for this render, and neither could be retrieved this session. Water absorption, vapour permeability, adhesion, density, application temperature and the DoP number are therefore absent above rather than approximated. Ask the Renders World team for the current sheet before submitting a specification and those figures reach you on manufacturer paperwork.
How to Apply It: Key Coat, Grain and Coverage
The render is supplied ready to use, so there is no mixing ratio and no pot life to manage — stir each tub to a uniform consistency at low speed and keep the batch sequence consistent across an elevation. The certified figures all sit in the layers beneath it.
- Adhesive and boards: cementitious powder adhesive at 4.0 to 5.0 kg/m² covering at least 40% of each board, with mechanical fixings placed while the adhesive is setting.
- Reinforced basecoat: 2.0 to 5.0 mm with Atlas 150 reinforcing mesh embedded and trowelled flat, rising to 4.0 to 6.0 mm where two mesh layers are specified.
- Key coat: Atlas Cerplast at 0.25 to 0.35 kg/m² on the dry basecoat. Substituting a silicone key coat takes the wall outside the certified build-up, and the wider exterior render primers range covers the consolidating products used first on high-suction substrates.
- Finish: lay on to a coat thickness matching the chosen grain with a stainless float, then texture with a plastic float while the surface is workable.
Plan technological breaks at corners, downpipes or colour changes so joints fall where the eye expects them, and the step-by-step thin coat application method covers the trowel work in sequence.
Installation Notes for UK Sites — Timing, Wet Edge and Curing
Working wet-on-wet across a whole elevation is what keeps a spotted texture reading as one surface, so crew size and scaffold lifts are worth planning around the panel rather than the day. Temperature and humidity limits for this render sit on the Atlas product sheet rather than in the certificate, so treat the manufacturer's figures as governing and confirm them before booking shoulder-season work.
- Check the wall, not the forecast: substrate temperature on a shaded elevation lags air temperature by a wide margin first thing, and an infrared thermometer settles it in seconds.
- Tint the key coat towards the topcoat: on white and pale shades this is the most reliable way to keep thin spots reading evenly.
- Confirm one batch across an elevation: pigment differences invisible on a small panel become legible across a full gable, and checking codes at delivery takes minutes.
- Prepare and prime to the substrate: the substrate preparation guide covers suction testing on old render and aerated block, and the UK application weather windows map the calendar.
Acrylic Against the Silicone and Hybrid Finishes in the Same System
All four finishes below are named in the same certificate, at the same stage of the same build-up, which makes this a genuine like-for-like comparison. The key coat column is the practical differentiator, because it changes what else goes on the order.
| Finishing coat | Binder | Certified coverage | Key coat named |
|---|---|---|---|
| Atlas Acrylic Render | Styrene-acrylic resin | 2.5–5.0 kg/m² | Atlas Cerplast |
| Atlas Acrylic-Silicone Render | Styrene-acrylic and silicone resin | 2.5–5.5 kg/m² | Atlas Cerplast |
| Atlas Silicone Render | Styrene-acrylic and silicone resin | 2.5–3.5 kg/m² | Atlas Silkon ANX |
| Atlas Silicone-Silicate Render | Styrene-acrylic and potassium silicate resin | 2.5–3.0 kg/m² | Atlas Silkon ANX |
The acrylic carries the widest coverage band of the four, which is a quantity-risk point rather than a performance one: a rough or heavily textured substrate can pull materially more product than a flat one. Note also that the Atlas silicone render is itself a styrene-acrylic and silicone dispersion, so "silicone versus acrylic" is a difference of degree in this range — the silicone and acrylic binder comparison works through what that means for a specification.
Is This the Right Finish for Your Elevation?
- Choose this render where the build-up is an Atlas EPS system, the storey heights sit inside the certificate's limits, and a 3.0 mm grain or a Cerplast key coat shared with other finishes is useful on the job.
- Look at the silicone or hybrid finishes where coverage predictability matters more than grain choice, or where the wall build-up needs higher vapour openness than an acrylic dispersion offers.
- Settle the colour on a physical swatch — daylight and texture both change how a tinted render reads, and the render colour charts and catalogues let you sign it off before the tinting run.
Renders World lists Atlas Acrylic Render White 25kg at £47.50 per 25 kg tub as displayed in August 2026, in stock at the time of that check. At the certified 2.5 to 5.0 kg/m² one tub covers roughly 5 to 10 m², putting material cost at about £4.75 to £9.50 per m² before labour, access or the layers beneath. To compare it against the rest of the full thin-coat render range or to price a whole elevation, start from the collection page.
FAQ — Quantities, Key Coat, Fire and Ordering
How many tubs does a 100 m² elevation take?
Between eleven and twenty-two, depending on grain and substrate. The working:
- 100 m² × 2.5 kg/m² = 250 kg; 100 m² × 5.0 kg/m² = 500 kg.
- 250 ÷ 25 = 10 tubs; 500 ÷ 25 = 20 tubs.
- Plus 10% for reveals, cut-outs and detailing: 11 to 22 tubs.
On a flat basecoat at 1.5 mm grain the 2017 catalogue's 2.5 kg/m² is the realistic planning figure, giving eleven tubs; order to the upper end where the substrate is irregular. The render coverage calculator runs the same arithmetic across other products.
Which key coat and mesh does the certified build-up need?
Atlas Cerplast, also sold as Aval KT 16, at 0.25 to 0.35 kg/m² directly beneath it, over a reinforced basecoat of 2.0 to 5.0 mm carrying Atlas 150 mesh at 150 g/m². Silkon ANX is the key coat for the silicone and silicone-silicate finishes and is not the one named for this render.
Can it go on mineral wool?
Certificate 13/5018 covers the EPS system, so it does not answer that question, and this page does not extend it to a wool build-up. Mineral wool systems are specified from their own documentation and usually on a different finish, so confirm the intended build-up with the designer and ask us for the Atlas sheet that covers wool substrates.
What fire classification can I quote for it?
None from this certificate. The three classified constructions in 13/5018 name other finishing coats, and no class from those rows transfers to this product. Every construction in the table classifies as B or C rather than A2, which is worth knowing if a project brief calls for A2 performance — that requirement points at a different system entirely, and the project fire strategy should confirm the specification.
How does it differ from the Atlas silicone render?
On the documents, in three ways: binder, coverage band and key coat. This one is a styrene-acrylic dispersion at 2.5 to 5.0 kg/m² over Cerplast; the silicone render is a styrene-acrylic and silicone dispersion at 2.5 to 3.5 kg/m² over Silkon ANX. The vapour and absorption figures that would separate them further sit on the Atlas product sheets, so request both if the comparison has to be evidenced.
Technical Documentation — Certificate and Manufacturer Catalogue