Description
Atlas Bejca Sealer 03 Walnut is the dark mid-tone in Atlas's 10-shade Bejca palette — a semi-transparent silicone-resin staining impregnant that finishes the Atlas concrete and wood-effect render range with the deepest hardwood read short of ebony. A 4-litre tin covers 26–40 m² per coat at 0.10–0.15 kg/m², dries in around 30 minutes, and resists rain after roughly 24 hours, so a typical elevation can be sealed and colour-finished within one working day.
Where Atlas Bejca Walnut Performs Best on UK Facades
Atlas Bejca 03 Walnut is the colour-and-protection layer for Atlas Cermit WN wood-stamped render, formulated with polymer dispersions and silicone resins that lock a deep walnut grain into cured mineral render at 0.10–0.15 kg/m² per coat. Density sits at 1.02 g/cm³ and hydrophobic performance holds for 5–12 years on UK elevations — with the darker tone, that service life is what protects the dramatic look you paid for from fading prematurely on south- and west-facing walls.
The product earns its place on three project types: full external dark-timber facades over ATLAS ETICS or ROKER EWI build-ups, statement feature panels on porches, plinths, and entrance bays where contrast against pale render is wanted, and interior accent walls in commercial reception areas where a hardwood aesthetic anchors the design. It bonds to cured Cermit WN, standard concrete, smooth and textured mineral renders, gypsum render and putty, and plasterboard, which is what makes the same tin usable inside and out.
Why Trade Specifiers Choose Atlas Bejca Walnut
- Authentic dark-walnut grain depth: Semi-transparent UV-stable pigments build a rich, dark wood read on stamped render — the most dramatic shade in the Bejca range before ebony, suited to elevations where contrast is the design point.
- Hydrophobic silicone film: Rain beads off the cured coating rather than soaking in, which keeps dust and atmospheric soiling from settling into the stamped grooves and preserves the original walnut depth.
- Same-day facade turnaround: Around 30 minutes drying between coats lets a two-coat finish go on inside a single shift, with early rain resistance after roughly 24 hours — useful for UK weather windows.
- Flexible polymer binder: The cured film moves with normal thermal expansion of the render panel, so the colour layer stays intact rather than crazing along stamp lines as temperatures swing.
- Cross-substrate compatibility: One product covers Cermit WN, concrete, mineral renders, gypsum render, and plasterboard, which simplifies ordering on mixed exterior–interior projects.
- Specified system component: Sits within ATLAS ETICS and ATLAS ROKER BBA-certified EWI build-ups, so the dark wood-effect aesthetic does not break the certified render finish path.
Atlas Bejca Walnut — Data Sheet Highlights
| Parameter | Value |
|---|---|
| Colour code | 03 Walnut (semi-transparent dark wood tone) |
| Pack size | 4 litres |
| Density | 1.02 g/cm³ |
| Consumption | 0.10–0.15 kg/m² per coat |
| Coverage per tin | 26–40 m² per coat |
| Drying time between coats | ~30 minutes |
| Early rain resistance | ~24 hours after final coat |
| Binder chemistry | Polymer dispersions + silicone resins |
| Application temperature | +5 °C to +25 °C |
| Application method | Brush, medium-nap roller, or sponge |
| Primary substrate | Cured Atlas Cermit WN render |
| Secondary substrates | Concrete · mineral renders · gypsum render · plasterboard |
| System compatibility | ATLAS ETICS · ATLAS ROKER EWI |
How to Apply Atlas Bejca Walnut — Coats, Coverage, Conditions
Application starts on cured Cermit WN that has hardened for a minimum of 3 days at +20 °C and 50% relative humidity. In typical UK ambient conditions of +8 °C to +15 °C, extend that window to 5–7 days for the most reliable bond. Stir the tin gently before use and at intervals during the job so the dark pigments stay evenly suspended — settling shows up faster on walnut than on lighter shades.
- Coat 1 — thin: Brush at the lower end of the range (around 0.10 kg/m²), working product into the stamp grooves first, then smoothing flat areas with a medium-nap roller. A thin first pass on walnut prevents the dark pigment from pooling and creating uneven patches.
- Coat 2 — standard: After roughly 30 minutes, apply a second coat at 0.12–0.15 kg/m² to deepen the walnut richness and complete the hydrophobic barrier. Two coats is the practical baseline for the canonical dark finish.
- Coat 3 — south/west-facing optional: A third light pass on elevations with high UV load builds in extra pigment depth, compensating for the gradual lightening that all semi-transparent sealers experience in the first 12–18 months.
- Weather window: Stay between +5 °C and +25 °C with no rain forecast for 24 hours after the final coat — the polymer–silicone film needs that cure time to reach full water repellence.
For the full multi-product sealer method across Bejca's colour range — including blended-tone techniques and weathered finishes — read the complete sealers for concrete-effect renders guide. The wider wood-stamp sequence, from primer through render imprint to finished sealer coat, is covered in the concrete-effect render application method.
Installation Notes — Drying, Finish Depth, Site Conditions
Two thin coats deliver a more uniform walnut finish than one heavy coat — dark pigment pooling is more visible on a stamped surface than on a flat one, and the grooves catch any excess immediately. Work groove-first with a soft-bristle brush, then move to flat areas with a medium-nap roller, so the deepest pigment lands exactly where the grain is most defined. Sponging is also valid for tighter detail panels.
Allow the full 24-hour rain-resistance window before evening dew falls if you finish late in the day. On large facades, plan section sizes so the wet edge stays live until you reach a stamp line or external corner — dark sealers flash less obviously than light ones, but a visible lap line on walnut is harder to disguise than on birch.
Pro Tips From UK Installers Using Atlas Bejca Walnut
- Sample board first: Stamp a 600 × 400 mm panel of Cermit WN, cure it for 3 days, then trial your two-coat sequence. Walnut reads markedly differently against warm-grey vs cool-grey base render — confirm before scaling up.
- Thin first coat wins: I always pull the first coat back to roughly 0.10 kg/m². Walnut is the darkest mid-range tone in Bejca, so depth builds fast on coat two and a heavy first pass creates dark patches the second coat cannot even out.
- Three coats on south-facing walls: A third light pass on high-UV elevations buys an extra year or two of intended tone before perceptible lightening begins.
- Stir every 15 minutes: Dark pigment settles faster than light pigment. A quick re-stir keeps the bottom-of-tin product matching the top-of-tin.
- Order one extra tin: Coverage varies with stamp depth and render porosity. A spare 4-litre tin avoids stopping mid-facade if absorption runs higher than the 0.15 kg/m² figure.
Is Atlas Bejca Walnut Right for Your Project?
- Right for deep, dramatic hardwood facades: A rich dark-walnut board read on full elevations, plinths, porches, or interior feature walls within ATLAS ETICS / ROKER systems where contrast with pale render is the design intent.
- Warmer mid-tone alternative: The Atlas Bejca Teak 4L delivers a warm classic hardwood look without the visual weight of walnut — useful where lighter rooms or smaller elevations would feel boxed in by a dark facade.
- Lighter Scandi alternative: The Atlas Bejca Birch 4L produces a pale, Scandinavian timber look — useful for north-facing elevations where dark walnut absorbs more daylight than you want.
- Smooth concrete look instead: If the design moves away from wood, Atlas Silkon BA concrete-effect silicone render finishes a facade in a single-product industrial concrete aesthetic with no stamp or sealer required.
FAQ — Atlas Bejca Walnut Coverage, Compatibility, Ordering
How much Atlas Bejca Walnut do I need for my project?
Each 4-litre tin covers 26–40 m² per coat depending on render porosity and stamp depth. For a standard two-coat finish on moderately absorbent Cermit WN, plan for roughly 13–20 m² of completed facade per tin. Measuring elevations in advance and adding one spare tin for projects above 30 m² keeps the wet edge live without an emergency reorder, and budgeting for a third coat on south-facing walls is worth doing at the order stage.
Can I mix Bejca Walnut with other Bejca colours on one facade?
Blending two Bejca shades on the same panel produces layered, weathered grain — a walnut first coat with a lighter teak or birch top coat reads as sun-faded dark hardwood, which suits some heritage and contemporary aesthetics. Trial the chosen combination on a stamped sample board first, since the cured-render shade affects how the two pigments interact and walnut amplifies any inconsistency more than lighter tones.
Is Atlas Bejca Walnut suitable for interior feature walls?
Atlas Bejca works on gypsum render, plasterboard, and interior mineral render, making it usable in reception areas, restaurant interiors, and residential feature walls where a dark hardwood accent is wanted. The low-VOC water-based formula keeps the workspace comfortable during application and avoids the fire and moisture concerns associated with real walnut cladding in interior settings.
How long does the walnut colour hold on a UK exterior facade?
UV-stable pigments and the hydrophobic silicone-resin film maintain colour fidelity for around 5–12 years under typical UK weathering, depending on elevation exposure and orientation. South- and west-facing panels experience higher UV load and may lighten slightly earlier than sheltered elevations — a third light coat at installation, or a refresh coat at year 5–7, restores the intended depth. Low-pressure water cleaning between refreshes removes atmospheric deposits.
What temperature range can I apply Atlas Bejca Walnut in?
Application runs between +5 °C and +25 °C, with no rain forecast for 24 hours after the final coat. Working at the warmer end shortens the recoat interval and tightens the wet-edge window, so plan section sizes accordingly during UK summer afternoons. Outside this band, dispersion of the silicone-resin binder is compromised and full hydrophobic performance is not guaranteed.
Is Atlas Bejca Walnut compatible with ETICS and ROKER EWI systems?
Atlas Bejca Walnut is specified as the finish layer within ATLAS ETICS and ATLAS ROKER external wall insulation systems, both BBA-certified build-ups. Specifying the sealer alongside the certified render and adhesive components keeps the finished dark wood-effect facade inside the manufacturer-certified system rather than as an out-of-system aesthetic add-on.