ATLAS BEJCA SEALER RENDERS 08 BIRCH 4L

Atlas Bejca birch is colour 08 in Atlas's range of semi-transparent stains for Cermit WN, the decorative render that imitates natural wood. It comes ready to use in a 4 litre bucket, goes on with a brush, roller or sponge, and covers about 16 to 20 m² a layer. Work on a dry wall, with wall and air between +10 °C and +30 °C and relative humidity under 80 %.

What Atlas Bejca birch is for

Atlas Bejca birch lays a thin, protective coat of colour over Cermit WN, so the pressed planks take on their 08 Birch tone. The maker also names it for use on:

• concrete;
• smooth and textured mineral renders;
• gypsum plasters and fillers;
• plasterboard.

Among the features of Atlas Bejca the maker lists the possibility of an aged-wood effect.

Why it suits Cermit WN

• Atlas Bejca is made for Cermit WN, so render and stain are meant to be used together.
• The silicone resins in Atlas Bejca give strong water repellence and reduce how much dust and dirt sticks, above all in the recesses of the textured render.
• The semi-transparent pigments are selected for high UV resistance, with small additions of inorganic pigment.
• It arrives ready to use, and brushes, rollers and sponges rinse out in clean water straight after the job.

Water and moisture vapour

Over Cermit WN, Atlas Bejca birch takes up 200 g/m² of water or less in 24 hours. Its relative diffusion resistance is 1.0 m or less, and the lower that figure, the more freely vapour can pass out through the coat. The maker rules it out on:

• horizontal surfaces;
• surfaces under permanent direct water or snow;
• walls where damp rises by capillary action.

How far a 4 litre bucket goes

The maker gives 4 to 5 m² per litre for one application, which puts a bucket of Atlas Bejca birch at about 16 to 20 m² a layer. Treat that as the planning figure; a trial patch on the wall you are painting settles the true consumption.

Two practical points when you order:

• One or two layers are permitted, so work the area out per layer.
• When one wall needs several buckets, order them together and check the production date printed on each: Atlas asks for a single production date on any one surface.

The wall and the weather

• The wall must be dry, sound and free of contamination.
• Leave Cermit WN at least 3 days before staining it. New cement renders need at least 14 days and concrete at least 3 months.
• Keep Atlas Bejca birch off strongly sunlit parts of the facade, shield the face from direct sun before the work and for about 24 hours afterwards, and fit protective nets on the scaffold.
• Until the stain has dried through, protect the wall from dust and rain.

One caution concerns the render underneath, not the stain: the maker recommends deep, intense render colours (HBW below 20) for limited areas of a facade only, because they absorb more solar radiation.

Applying it

1. Stir the bucket thoroughly with a slow-speed paint mixer, and again during the work if needed. It is ready to use, so do not combine it with any other material.
2. Brush, roll or sponge it on, following the pressed grain of the plank.
3. Aim for one even, thin layer with no runs and no missed patches, and reach every recess of the grain.
4. If you spray, mask the neighbouring facade, windows and doors carefully first.
5. Drying takes from about 30 minutes to 2 hours, depending on the surface, the temperature and the humidity. Early rain resistance comes after about 24 hours.
6. Wash the tools in clean water straight away.

What to order with it

Staining is the last step of a method that also needs the render, the stamp and the release agent. Renders World lists all of them in its wood-effect render collection.

• Atlas Cermit WN, the render that takes the grain;
• the Atlas silicone wood stamp, which presses the grain in;
• the Atlas release agent, which stops the stamp sticking.

Add a brush, roller or sponge and a slow-speed paint mixer. The Renders World cancellations and returns page sets out the terms before you order.

The colours around 08 Birch

Ten colours are made, and Renders World lists four of them.

All four are the same Atlas Bejca, so the figures and the method here hold for each and only the colour changes. To choose between them, stain a small patch of each on cured Cermit WN and judge it on the wall.

Specification and where it fits

Atlas lists the coating as a component of its ATLAS ETICS, ATLAS ROKER and ATLAS ROKER EPS insulation kits. Their assessments (ITB-KOT-2020/1616, ITB-KOT-2021/1919 and ITB-KOT-2020/1188) are Polish national ones, not UK approvals.

The seasoning times assume setting at +20 °C and 50 % air humidity.

Questions about Atlas Bejca birch

Technical documentation

• Atlas Bejca technical data sheet (English, PDF)
• Atlas Bejca safety data sheet (PDF)
• Atlas Bejca on the Atlas website