ARDEX A 826 Ultra-Fine Finishing Plaster

Single coat ultra-fine finishing plaster for smooth, brilliant white surfaces.

ARDEX A 826 is a brilliant white, rapid hardening, ultra-fine plaster designed for the smoothing and finishing of interior walls and ceilings. It delivers a true feather finish and can be painted in as little as one hour — no sanding required. Perfect for creating ultra-smooth finishes on walls and ceilings, ARDEX A 826 is ideal for new builds, refurbishments, and high-end finishing projects where a flawless surface is essential.

Key Features & Benefits

• ✅ Ultra-fine skim coat for a flawless, smooth surface
• ✅ Single coat application – no multiple layering required
• ✅ Paint-ready in as little as 1 hour under normal conditions
• ✅ No sanding required – finish with a damp sponge for perfection
• ✅ Excellent coverage – up to 27m² at 1mm thickness
• ✅ Shrinkage compensated – won’t crack or craze
• ✅ Feather edge to 10mm in a single application
• ✅ Brilliant white finish for high-quality decorative work
• ✅ Conforms to EN 13963:2014 and rated A1 non-combustible (EN 13501-1)

Ideal Applications

ARDEX A 826 provides an exceptional background for paint or wallpaper finishes and is perfect for:

• Plasterboards and construction boards
• Pre-rendered and suitable concrete surfaces
• Aerated concrete and lightweight blockwork
• Filling joints between plasterboards and fine surface finishing
• Areas requiring ultra-smooth finishes, such as those with spotlighting or direct lighting

Mixing & Application

Gradually add 2 parts powder to 1 part clean water (approximately 16L water per 25kg bag) while mixing continuously using a drill and mixing paddle. Allow the mixture to stand for 2–3 minutes, then remix to a smooth, creamy consistency. The working time is approximately 1 hour at 20°C.

Apply ARDEX A 826 using a trowel, blade, or filling knife in a single coat. The unique hardening technology allows entire walls or ceilings to be smoothed in one pass. Finish using a damp sponge — no sanding required. Apply at temperatures above 5°C.

Drying & Finishing

• Surface dry: 1–2 hours
• Ready for paint or wallpaper: Once surface is dry
• Recommended thickness: Feather edge up to 10mm

Drying times may vary depending on layer thickness, substrate porosity, and ambient temperature. At 20°C, skim coats can be ready to paint within 1 hour.

Coverage

Approx. 27m² per 25kg bag at 1mm thickness

Technical Data

Packaging & Storage

Supplied in 25kg paper sacks with polyethylene lining. Store in original, unopened packaging in a cool, dry place, off the ground and protected from moisture. Shelf life: 12 months.

Frequently Asked Questions

What is ARDEX A 826 used for?

ARDEX A 826 is an ultra-fine finishing plaster for smoothing interior walls and ceilings. It creates a flawless, paint-ready surface ideal for premium decorative finishes.

Can ARDEX A 826 be applied directly over plasterboard?

Yes. It can be applied directly onto plasterboard, pre-rendered walls, and suitable concrete surfaces, delivering a smooth, crack-free surface.

Do I need to sand ARDEX A 826 before painting?

No. ARDEX A 826 is designed to be sponge-finished, eliminating the need for sanding. However, it can be lightly sanded if a perfectly smooth surface is desired.

How long before I can paint over ARDEX A 826?

Under typical conditions (20°C, thin coat), paint can be applied in as little as 1 hour after application.

What thickness can I apply ARDEX A 826 at?

It can be applied from a feather edge up to 10mm in a single coat without cracking or crazing.

What is the coverage of ARDEX A 826?

Approximately 27m² per 25kg bag at 1mm thickness, depending on substrate and application method.

Does ARDEX A 826 crack or shrink?

No. The formula is shrinkage-compensated, ensuring a stable, crack-free, and smooth finish even at thin layers.