Atlas Bejca Sealer Walnut 4L — Dark Wood-Tone Impregnant for Decorative Render

Product Overview

Atlas Bejca Sealer 03 Walnut 4L covers approximately 26–40 m² per coat at a consumption rate of 0.10–0.15 kg/m², delivering a rich, dark walnut wood tone to decorative mineral renders. Designed as the finishing component of the Atlas wood-effect facade system within the concrete effect render range, this staining impregnant transforms Atlas Cermit WN render into an authentic hardwood-board finish that protects your walls for years without the maintenance demands of real timber.

Your facade gains long-lasting colour depth and weather protection from a single product — Atlas Bejca's silicone-resin and polymer dispersion formula creates a semi-transparent, hydrophobic coating that actively resists UV degradation and atmospheric soiling. The 4-litre tin needs no mixing or thinning — apply straight from the container, with each coat drying in approximately 30 minutes and the finish reaching early rain resistance after 24 hours, so you can complete a full facade panel in a single working day and trust the finish to hold through overnight weather.

Key Benefits

• Rich Walnut Wood Finish: Semi-transparent pigments replicate the deep, warm grain of natural walnut, giving your facade the appearance of real dark-timber boards without the expense or seasonal upkeep. The pigment blend includes UV-stable inorganic components that maintain colour integrity for years, so the tone you choose at application is the tone you keep.
• Weatherproof Hydrophobic Protection: Silicone resin content significantly reduces surface water absorption, so rain beads off rather than soaking in — keeping dust and dirt from settling into render grooves and preserving the clean, fresh appearance of the finish through every UK season.
• Fast Application, Same-Day Progress: Each coat dries in approximately 30 minutes, allowing you to apply multiple coats in a single session and move on to the next section without delays. A full facade panel can be sealed and colour-finished within one working day, reducing scaffold hire time.
• Flexible, Crack-Resistant Coating: The coating stays flexible after curing, moving with the natural seasonal expansion of your wall (typically ±0.5 mm on a standard panel — an invisible amount, but enough to crack a rigid coating) thanks to a polymer dispersion binder that stays flexible after curing — so the colour coat remains intact season after season.
• Broad Substrate Compatibility: Works on Atlas Cermit WN wood-effect render, standard concrete substrates, all mineral renders (smooth or textured), gypsum render and putty, and plasterboard — making it suitable for both exterior facade projects and interior feature walls.

Technical Specifications

Parameter	Value
Colour	03 Walnut (semi-transparent dark wood tone)
Pack Size	4 litres
Density	1.02 g/cm³
Average Consumption	0.10–0.15 kg/m² per coat
Approximate Coverage (per coat)	26–40 m²
Drying Time	Approx. 30 minutes
Early Rain Resistance	After approx. 24 hours
Binder System	Polymer dispersions + silicone resins
Available Colours in Range	10 shades (rosewood, alder, walnut, oak, teak, mahogany, stone pine, birch, ebony, acacia)
Application Temperature	+5 °C to +25 °C
Application Method	Brush, roller, or sponge (manual)
Compatible Primary Substrate	Atlas Cermit WN decorative render
Additional Compatible Substrates	Concrete, mineral renders, gypsum render, plasterboard
System Compatibility	ATLAS ETICS and ATLAS ROKER EWI systems

Application & Compatibility

A professional walnut-effect finish requires just three layers — primed substrate, stamped Atlas Cermit WN render, and this sealer coat — with the render cured for a minimum of 3 days at +20 °C and 50 % relative humidity before sealing. In typical UK conditions — where ambient temperatures regularly sit between +8 °C and +15 °C — extending the curing window to 5–7 days gives the most reliable bond. Once the render has hardened, Atlas Bejca 03 Walnut is brushed or rolled directly onto the textured surface in thin, even coats, each layer building depth and warmth into the wood-grain pattern.

• Substrate Preparation: A clean, fully cured Cermit WN surface gives you the most uniform sealer bond — remove any dust or loose particles before application so the polymer-silicone film bonds uniformly across the entire panel.
• Coat Application: Apply each coat at 0.10–0.15 kg/m² using a soft brush or medium-nap roller. Work the sealer into the stamped grooves to ensure the wood-grain pattern receives even colour saturation. Allow approximately 30 minutes between coats.
• Number of Coats: Two coats deliver the deepest walnut tone and the strongest hydrophobic barrier. A single coat produces a lighter, more translucent brown — useful for a subtler, sun-aged aesthetic.
• Weather Window: Applying between +5 °C and +25 °C with no rain forecast for 24 hours after the final coat gives the polymer film ideal curing time to reach full hydrophobic performance.

For a complete guide to the wood-effect facade process — from priming through to final sealer coat — see the sealers for concrete effect renders guide. The full application sequence, including stamp technique and Atlas anti-adhesion release agent usage, is covered in the concrete effect render application guide.

Installation Notes

For the cleanest result, work the sealer into the stamped grooves with a soft-bristle brush before smoothing the flat areas with a roller — rather than rolling the entire surface first and then trying to push product into the recesses. This groove-first technique ensures the deepest parts of the wood-grain pattern receive full colour saturation, giving you a more realistic depth effect with fewer coats. Stir the product gently before use and at regular intervals during application to keep the semi-transparent pigments evenly distributed throughout the tin. Because walnut is a darker shade, even minor pooling in textured recesses becomes more visible than with lighter tones — two thin passes always deliver a more consistent finish than one heavy coat.

Trade Insight: Installer's Note

I always apply the first coat of Bejca Walnut slightly thinner than the manufacturer's maximum — around 0.10 kg/m² — and let it dry fully before judging the colour depth. Walnut is the darkest mid-range tone in the Bejca palette, so it builds richness faster than lighter shades like birch or oak. A light first coat at 0.10 kg/m² followed by a standard second coat gives you the most consistent, natural-looking grain every time — this two-pass approach fills stamp grooves evenly without pooling, keeping the walnut depth uniform across the full panel. On south-facing elevations, adding a third pass compensates for the gradual UV lightening that all semi-transparent sealers experience over the first 12–18 months, so the facade keeps its intended tone for longer.

Is This Product Right for You?

• Yes — if you want a deep, dark timber facade: Atlas Bejca 03 Walnut delivers an authentic dark-wood finish that protects your render with a hydrophobic, UV-stable coating — ideal for feature panels, full facades, or interior accent walls where you want the drama and warmth of natural walnut without the maintenance cost.
• Need a lighter or warmer wood tone? The Atlas Bejca Teak 4L delivers a warmer mid-tone for a classic hardwood appearance, while the Atlas Bejca Birch 4L produces a pale, Scandinavian-inspired finish — both use the same application method and system compatibility.
• Looking for a non-wood decorative finish? Atlas Silkon BA concrete effect silicone render delivers the same weatherproof performance with a smooth, industrial concrete aesthetic — a single-product finish with no multi-step stencilling or sealing required.

Frequently Asked Questions

How much Atlas Bejca Walnut do I need for my project?

Each 4-litre tin covers approximately 26–40 m² per coat, depending on the porosity of the cured Cermit WN surface and your application thickness. For a standard two-coat finish on a moderately absorbent substrate, plan for roughly 13–20 m² of finished facade per tin. Measuring your wall area in advance and ordering one extra tin for a large project ensures you can complete the job without interruption.

Can I mix Atlas Bejca Walnut with other Bejca colours?

Blending two Bejca shades on the same panel creates a layered, multi-tone wood effect — for example, applying a first coat of Walnut followed by a lighter Teak or Birch top coat produces a weathered, sun-faded grain pattern with visible depth. Testing your chosen combination on a sample board of cured Cermit WN first confirms the final colour before committing to the full facade.

How long does the walnut colour last on an exterior facade?

The UV-stable pigment blend and hydrophobic silicone-resin barrier maintain colour fidelity for 5–12 years under normal UK weathering conditions, depending on elevation exposure and orientation. South- and west-facing panels experience higher UV load and may lighten slightly earlier than sheltered elevations. Periodic cleaning with low-pressure water removes atmospheric deposits and keeps the finish looking fresh, with no specialist impregnation required in the way that natural timber demands.

Is Atlas Bejca Walnut suitable for interior feature walls?

Atlas Bejca works on interior substrates including gypsum render, plasterboard, and mineral renders, making it a practical choice for feature walls, reception areas, and commercial interiors where a wood-effect finish adds warmth without the fire risk or moisture concerns of real timber cladding. The low-odour, water-based formula keeps the workspace comfortable during application, and the walnut shade adds a bold, contemporary design accent to any room.

Is Atlas Bejca Walnut environmentally responsible?

Atlas Bejca is a water-based formulation with low volatile organic compound (VOC) content, producing minimal fumes during application and making it safe for both exterior and interior use without specialist ventilation. Each 4-litre tin covers 26–40 m² per coat — significantly less material per square metre than traditional oil-based wood stains or thick-film coatings, which means less packaging waste and lower transport weight per project. The long service life of the sealed finish (5–12 years before recoating) reduces the total number of maintenance cycles over the building's lifetime, lowering the cumulative environmental footprint compared to natural timber cladding that requires annual oiling or staining.