SILICONE MASONRY PAINTS

Atlas Salta arrives at Renders World as a single facade paint offered in two tinting bases, and every figure below is copied from the manufacturer data sheet dated May 2024, fetched this session, within the wider rendering materials range.

What the Atlas Salta Data Sheet Declares

Silicone masonry paints from the Atlas Salta range carry a declared water permeability of W3, under 0.1 kg/m²·h⁰·⁵, so wind-driven rain stays on the surface of a sound rendered wall rather than soaking into it.

Vapour movement is where the previously published specification needed correcting. The sheet gives an equivalent air layer thickness Sd of 0.14 m to 1.4 m per coat, which places the film in class V2 — medium permeability rather than the most open class, so a wall that must stay as vapour-open as possible is worth specifying deliberately.

The assessments printed on the sheet — four European Technical Assessments and five ITB national assessments — belong to named Atlas ETICS systems that the paint forms part of, including ATLAS ETA-06/0081 and ATLAS ROKER ETA-06/0173. They describe those assemblies, not the bucket on its own.

Matching Tinting Base to Shade, and What Each Bucket Costs

Both bases share one data sheet, so the declared performance above applies to either; the buying decision is the tinting base your colour code is mixed into, confirmed at order. Where the two differ sharply is price, and that belongs in the estimate before the colour is chosen.

At the sheet's 0.25 l/m² per coat on 1.5 mm mineral thin-coat render, a 10-litre bucket covers 40 m² in one coat and 20 m² in two: £33.17 ÷ 20 m² = £1.66/m² for Base White, and £57.50 ÷ 20 m² = £2.88/m² for Base Grey. The gap of £57.50 − £33.17 = £24.33 makes the grey base roughly 73% dearer per bucket, which is worth carrying into a dark specification early. Both figures are material only, read from the Renders World product endpoints in August 2026; no VAT figure was displayed there and none is stated here.

How to Apply Silicone Masonry Paints on UK Substrates

Both silicone masonry paints in this collection are supplied ready to use and need no separate primer — the sheet has the first coat priming the substrate, which removes a work stage on sound walls. Getting the dilution and the cure interval right is what makes that single-product approach hold up.

• Dilute the first coat by 5%: add 0.5 litres of clean water per 10-litre bucket, keep that ratio across the whole elevation, and apply the final coat undiluted — spray application is undiluted throughout.
• Respect the seasoning times: five days on thin-coat mineral renders, seven on dispersion renders, and two to four weeks on traditional mineral plasters before any paint goes on.
• Work between +5 °C and +30 °C at under 80% humidity, with drying at two to six hours and recoating after about six at 20 °C — an early start puts both coats inside one daylight window.
• Spray settings from the sheet: Wagner HC 950 with a 517 nozzle at 150–170 bar, or an HEA 517 nozzle at 100–120 bar, laid on in a thin even film.
• Plan the breaks: stop at corners, downpipes and colour changes, and use paint of one production date per surface so the finish reads evenly.

Absorbent, chalky or repaired walls are evened out first with one of the exterior render primers stocked here, and biological growth is treated before painting using the render cleaning products range. The Atlas Salta application guide follows the sequence a decorator actually works in.

Check Which Salta Variant the Substrate Calls For

Atlas publishes Salta as a family, and the substrate table on this sheet routes certain surfaces and settings to SALTA S, SALTA N or SALTA E rather than to the paint sold here. That makes the variant check part of specification, not an afterthought.

• Named on the sheet: ATLAS SALTA, plus SALTA S, SALTA N and SALTA E as recommended alternatives against specific rows.
• Not published here: the row-by-row mapping of substrate to variant, because the column alignment in the fetched mirror cannot be resolved to individual rows with certainty.
• Confirmed by the sheet: concrete, cement and cement-lime plasters, thin-coat renders and reinforced layers of the listed Atlas systems all sit within scope.

Where a wall is lime-plastered, gypsum-based, board-faced or already coated, send the substrate description through with the colour code and Renders World will confirm the correct variant against the current Atlas table before anything is tinted. Minor damage is filled and made good first, using a fast-setting levelling mortar of the type the sheet names for the job.

Is a Repaint the Right Call for This Wall?

• Choose paint when the wall is sound: both silicone masonry paints here refresh colour and restore a rain-shedding surface on render or masonry that is structurally intact, with W3 water permeability doing the weather work.
• Choose a full silicone render system instead where the surface is cracked, hollow or beyond cosmetic repair — a thin-coat finish over a reinforced basecoat rebuilds the decorative layer rather than coating it.
• Clean before you coat: algae and mould are treated first so the new film bonds to sound material, which is a step worth getting right on shaded north elevations.
• Weigh the technology honestly: the silicone against acrylic comparison sets out where each binder earns its place by exposure.

FAQ — Coverage, Cold Weather, Compatibility and Base Choice

How much paint does a 100 m² elevation need?

On 1.5 mm mineral thin-coat render the sheet gives 0.25 l/m² per coat: 100 m² × 0.25 l × 2 coats = 50 litres, so five 10-litre buckets, or six with cutting-in and touch-up allowed for. On smooth plaster at 0.15 l/m² per coat the same wall needs 30 litres, three buckets. A trial area remains the accurate way to confirm consumption on textured work.

Can it be applied in cold or humid weather?

Standard application runs from +5 °C to +30 °C at under 80% humidity. Adding ATLAS ESKIMO extends the working window down to 0 °C and up to about 80% humidity, which covers most frost-free winter days. In unfavourable conditions the sheet allows a third coat to even the surface out, so a marginal week still finishes well.

Can it go over an existing painted facade?

Existing paint coatings appear among the substrates on the sheet, and sound, well-bonded film is a workable base once chalking, flaking and growth are dealt with. Some coated substrates are routed to another Salta variant, and that routing could not be read off unambiguously, so confirm the variant with your colour code rather than assuming this base suits every previously painted wall.

Which base should be ordered if the colour is not settled?

Order the colour first and the base follows it: pale and off-white shades are mixed into the white base, deep and saturated shades into the grey. The Atlas SAH colour charts and sample books let a shade be checked against the actual wall in daylight, and Renders World confirms the matching base when the code is placed. For a light scheme already decided, Atlas Salta Base White is the bucket to order.